Terminal and communication method

Abstract

The terminal includes: a control unit, which is connected to other terminals in the RRC (Radio Resource Control) layer; and a sending unit, which sends data to the other terminals. When the other terminals or the terminal performs at least one of sending, receiving or sensing at a specific timing, the control unit controls the actions related to the connection in the RRC layer according to the specific timing.

Description

Technical Field

[0001] The present invention relates to a terminal and a communication method in a wireless communication system. Background Art

[0002] In LTE (Long Term Evolution) and its successor systems (e.g., LTE-A (LTE Advanced), NR (New Radio) (also known as 5G)), D2D (Device to Device) technology, which allows direct communication between terminals without going through a base station, is being studied (e.g., non-patent document 1).

[0003] D2D reduces the traffic between terminals and base stations, enabling inter-terminal communication even when base stations are unable to communicate, such as during disasters. While 3GPP (3rd Generation Partnership Project) refers to D2D as "sidelink," this specification uses the more general term D2D. However, in the following descriptions of the embodiments, sidelink may also be used as needed.

[0004] D2D communication is broadly divided into D2D discovery (also called D2D discovery) for discovering other terminals with which communication can be performed, and D2D communication (also called D2D direct communication, D2D communication, direct communication between terminals, etc.) for direct communication between terminals. Hereinafter, when no special distinction is made between D2D communication (D2D communication), D2D discovery (D2D discovery), etc., they are referred to as D2D for short. In addition, signals sent and received via D2D are referred to as D2D signals. Various use cases for services related to V2X (Vehicle to Everything) in NR are being studied (e.g., Non-Patent Document 2).

[0005] Prior art literature

[0006] Non-patent literature

[0007] Non-Patent Document 1: 3GPP TS 38.211 V16.2.0 (2020-06)

[0008] Non-Patent Document 2: 3GPP TR 22886 V15.1.0 (2017-03) Summary of the Invention

[0009] Problems to be solved by the invention

[0010] As an enhancement of the NR side link, power saving is being studied. It is assumed that the terminal performing power saving action (Power savingUE) transmits and receives data only at a specific timing. On the other hand, for unicast communication supported in the NR side link, an RRC (Radio resource control) connection is established in the interface PC5 specified between the terminals, and communication is performed while maintaining the connection. Therefore, it is assumed that when a terminal performing power saving action performs unicast communication, the PC5-RRC connection is frequently disconnected, causing obstacles to communication.

[0011] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to realize unicast communication suitable for power saving operation in inter-terminal direct communication.

[0012] Means for solving problems

[0013] According to the disclosed technology, a terminal is provided, which includes: a control unit, which is connected to other terminals in the RRC (Radio Resource Control) layer; and a sending unit, which sends data to the other terminals, and when the other terminals or the current terminal perform at least one of sending, receiving or sensing at a specific timing, the control unit controls actions related to the connection in the RRC layer according to the specific timing.

[0014] Effects of the Invention

[0015] According to the disclosed technology, unicast communication suitable for power saving operation can be realized in inter-terminal direct communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram used to explain V2X.

[0017] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode.

[0018] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode.

[0019] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode.

[0020] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode.

[0021] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode.

[0022] Figure 7 This is a diagram for explaining example (1) of the V2X communication type.

[0023] Figure 8 This is a diagram for explaining example (2) of the V2X communication type.

[0024] Figure 9 This is a diagram for explaining example (3) of the V2X communication type.

[0025] Figure 10 This is a timing diagram showing an operation example (1) of V2X.

[0026] Figure 11 This is a timing diagram showing an operation example (2) of V2X.

[0027] Figure 12 This is a timing diagram showing an operation example (3) of V2X.

[0028] Figure 13 This is a timing diagram showing an operation example (4) of V2X.

[0029] Figure 14 is a diagram showing an example of a sensing operation.

[0030] Figure 15 3 is a diagram showing an example of a partial sensing operation.

[0031] Figure 16 This is a sequence diagram showing an example of information notification in the embodiment of the present invention.

[0032] Figure 17 This is a diagram showing example (1) of the transmission and reception operation in the embodiment of the present invention.

[0033] Figure 18 This is a diagram showing example (2) of the sending and receiving operation in the embodiment of the present invention.

[0034] Figure 19 This is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention.

[0035] Figure 20 This is a diagram showing an example of the functional configuration of the terminal 20 in the embodiment of the present invention.

[0036] Figure 21 This is a diagram showing an example of the hardware configuration of the base station 10 or the terminal 20 in the embodiment of the present invention. DETAILED DESCRIPTION

[0037] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0038] When operating the wireless communication system according to the embodiments of the present invention, existing technologies are appropriately used. However, this existing technology is, for example, existing LTE, but is not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning that includes LTE-Advanced and post-LTE-Advanced systems (for example, NR) or wireless LANs (Local Area Networks).

[0039] Furthermore, in the embodiment of the present invention, the duplexing method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, flexible duplex, etc.).

[0040] Furthermore, in the embodiment of the present invention, “configuring” wireless parameters and the like may be pre-configuring predetermined values, or may be configuring wireless parameters notified from the base station 10 or the terminal 20 .

[0041] Figure 1 This is a diagram for explaining V2X. 3GPP is researching technologies to implement V2X (Vehicle to Everything) or eV2X (enhanced V2X) by extending D2D functionality and is promoting standardization. Figure 1 As shown, V2X is a part of ITS (Intelligent Transport Systems), and is a general term for V2V (Vehicle to Vehicle) which represents the communication between vehicles, V2I (Vehicle to Infrastructure) which represents the communication between vehicles and roadside equipment (RSU: Road-Side Unit) installed next to the road, V2N (Vehicle to Network) which represents the communication between vehicles and ITS servers, and V2P (Vehicle to Pedestrian) which represents the communication between vehicles and mobile terminals held by pedestrians.

[0042] Furthermore, 3GPP is researching V2X, which utilizes cellular communications and inter-device communications using LTE or NR. V2X using cellular communications is also referred to as cellular V2X. Research is progressing on achieving high capacity, low latency, high reliability, and QoS (Quality of Service) control in NR-based V2X.

[0043] Regarding LTE and NR V2X, research is envisioned to continue beyond 3GPP specifications. For example, research is envisioned to ensure interoperability, reduce costs associated with high-level installation, integrate and switch between multiple RATs (Radio Access Technologies), support regulations in various countries, and acquire, publish, manage, and utilize data from LTE and NR V2X platforms.

[0044] While the embodiments of the present invention primarily envision the communication device being mounted on a vehicle, the embodiments of the present invention are not limited to this configuration. For example, the communication device may be a terminal held by a person, a device mounted on a drone or aircraft, or a base station, RSU, relay node, or terminal with scheduling capabilities.

[0045] In addition, SL (Sidelink) can also be distinguished by UL (Uplink) or DL ​​(Downlink) and any one or a combination of the following 1) to 4). In addition, SL can also be other names.

[0046] 1) Time Domain Resource Allocation

[0047] 2) Frequency Domain Resource Allocation

[0048] 3) Reference synchronization signal (including SLSS (Sidelink Synchronization Signal))

[0049] 4) Reference signal used for path loss measurement for transmit power control

[0050] In addition, for OFDM (Orthogonal Frequency Division Multiplexing) of SL or UL, any one of CP-OFDM (Cyclic-Prefix OFDM), DFT-S-OFDM (Discrete Fourier Transform-Spread-OFDM), OFDM without transform precoding, or OFDM with transform precoding can also be used.

[0051] LTE's SL specifies Mode 3 and Mode 4 for SL resource allocation to terminal 20. In Mode 3, transmission resources are dynamically allocated using DCI (Downlink Control Information) sent from base station 10 to terminal 20. Mode 3 also supports Semi-Persistent Scheduling (SPS). In Mode 4, terminal 20 autonomously selects transmission resources from a resource pool.

[0052] In addition, the time slot in the embodiments of the present invention may be replaced by a symbol, a mini-slot, a subframe, a radio frame, or a TTI (Transmission Time Interval). Furthermore, the cell in the embodiments of the present invention may be replaced by a cell group, a carrier component, a BWP, a resource pool, a resource, a RAT (Radio Access Technology), a system (including a wireless LAN), or the like.

[0053] Furthermore, in the embodiments of the present invention, the terminal 20 is not limited to a V2X terminal, but may be any type of terminal that performs D2D communication. For example, the terminal 20 may be a user-held terminal such as a smartphone, or an IoT (Internet of Things) device such as a smart meter.

[0054] Figure 2 This is a diagram for explaining example (1) of the V2X transmission mode. Figure 2In the transmission mode of the sidelink communication shown in FIG, in step 1, the base station 10 sends the sidelink scheduling information to the terminal 20A. Then, the terminal 20A sends the PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) to the terminal 20B based on the received scheduling information (step 2). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 3 in LTE. In sidelink transmission mode 3 in LTE, sidelink scheduling based on Uu is performed. Uu refers to the radio interface between UTRAN (Universal Terrestrial Radio Access Network) and UE (User Equipment). Figure 2 The transmission mode of the sidelink communication shown is called sidelink transmission mode 1 in NR.

[0055] Figure 3 This is a diagram for explaining example (2) of the V2X transmission mode. Figure 3 In the transmission mode of the side link communication shown in FIG, in step 1, the terminal 20A transmits the PSCCH and PSSCH to the terminal 20B using the resources selected autonomously. Figure 3 The transmission mode of the sidelink communication shown is called sidelink transmission mode 4 in LTE. In sidelink transmission mode 4 in LTE, the UE itself performs resource selection.

[0056] Figure 4 This is a diagram for explaining example (3) of the V2X transmission mode. Figure 4 In the transmission mode of the sidelink communication shown in FIG, in step 1, the terminal 20A uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20B. Similarly, the terminal 20B uses the resources selected autonomously to transmit the PSCCH and PSSCH to the terminal 20A (step 1). Figure 4 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2a in NR. In sidelink transmission mode 2 in NR, the terminal 20 performs resource selection itself.

[0057] Figure 5 This is a diagram for explaining example (4) of the V2X transmission mode. Figure 5In the transmission mode of the sidelink communication shown in FIG, in step 0, the base station 10 sets a grant for transmitting the sidelink to the terminal 20A via RRC (Radio Resource Control). Then, the terminal 20A transmits the PSSCH to the terminal 20B according to the received resource mode (step 1). Figure 5 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2c in NR.

[0058] Figure 6 This is a diagram for explaining example (5) of the V2X transmission mode. Figure 6 In the transmission mode of the side link communication shown in FIG, in step 1, terminal 20A transmits the scheduling information of the side link to terminal 20B via PSCCH. Then, terminal 20B transmits PSSCH to terminal 20A based on the received scheduling information (step 2). Figure 6 The transmission mode of the sidelink communication shown is called sidelink transmission mode 2d in NR.

[0059] Figure 7 This is a diagram for explaining example (1) of the V2X communication type. Figure 7 The communication type of the side link shown is unicast. Terminal 20A sends PSCCH and PSSCH to terminal 20. Figure 7 In the example shown, the terminal 20A performs unicast to the terminal 20B, and also performs unicast to the terminal 20C.

[0060] Figure 8 This is a diagram for explaining example (2) of the V2X communication type. Figure 8 The communication type of the side link shown is multicast. Terminal 20A transmits PSCCH and PSSCH to the group to which one or more terminals 20 belong. Figure 8 In the example shown, the group includes the terminal 20B and the terminal 20C, and the terminal 20A performs multicast for the group.

[0061] Figure 9 This is a diagram for explaining example (3) of the V2X communication type. Figure 9 The communication type of the side link shown is broadcast. Terminal 20A sends PSCCH and PSSCH to one or more terminals 20. Figure 9 In the example shown, terminal 20A broadcasts to terminal 20B, terminal 20C, and terminal 20D. Figures 7 to 9 The terminal 20A shown is referred to as a head UE (header-UE).

[0062] Furthermore, NR-V2X envisions supporting HARQ (Hybrid Automatic Repeat Request) in both unicast and multicast on the sidelink. Furthermore, NR-V2X defines SFCI (Sidelink Feedback Control Information) that includes HARQ responses. Furthermore, research is underway to transmit SFCI via the Physical Sidelink Feedback Channel (PSFCH).

[0063] In the following description, it is assumed that the PSFCH is used for transmission of HARQ-ACK on the sidelink. However, this is only an example. For example, HARQ-ACK on the sidelink may be transmitted using the PSCCH, the PSSCH, or other channels.

[0064] For convenience, all information reported by terminal 20 in HARQ will be referred to below as HARQ-ACK. This HARQ-ACK may also be referred to as HARQ-ACK information. Furthermore, more specifically, the codebook used for HARQ-ACK information reported from terminal 20 to base station 10, etc., is referred to as the HARQ-ACK codebook. The HARQ-ACK codebook defines the bit string of the HARQ-ACK information. Furthermore, HARQ-ACK allows NACKs to be transmitted in addition to ACKs.

[0065] Figure 10 This is a timing diagram showing an example of V2X operation (1). Figure 10 As shown, the wireless communication system according to the embodiment of the present invention may include a terminal 20A and a terminal 20B. In addition, there are actually multiple user devices, but Figure 10 The terminal 20A and the terminal 20B are shown as examples.

[0066] Hereinafter, when the terminals 20A and 20B are not particularly distinguished, they are simply referred to as "terminal 20" or "user device". Figure 10 In the embodiment, the case where both the terminal 20A and the terminal 20B are within the coverage of the cell is shown as an example, but the operation in the embodiment of the present invention can also be applied to the case where the terminal 20B is outside the coverage.

[0067] As described above, in this embodiment, the terminal 20 is a device mounted on a vehicle, such as an automobile, and has cellular communication functions and sidelink functions as a UE in LTE or NR. The terminal 20 may also be a general portable terminal (such as a smartphone). Furthermore, the terminal 20 may also be an RSU. This RSU may be a UE-type RSU (UE type RSU) that has UE functions, or a gNB-type RSU (gNB type RSU) that has base station functions.

[0068] Furthermore, the terminal 20 does not need to be a device having a single housing. For example, even when various sensors are dispersedly arranged in a vehicle, the terminal 20 may be a device including these various sensors.

[0069] Furthermore, the processing of sidelink transmit data by terminal 20 is essentially the same as that of UL transmission in LTE or NR. For example, terminal 20 scrambles the codewords of transmit data, modulates them, and generates complex-valued symbols. These complex-valued symbols (transmit signals) are mapped to layer 1 or layer 2 and precoded. The precoded complex-valued symbols are then mapped to resource elements to generate a transmit signal (e.g., a complex-valued time-domain SC-FDMA signal), which is then transmitted from each antenna port.

[0070] The base station 10 also has cellular communication functions as a base station in LTE or NR, as well as functions for enabling communication with the terminal 20 in this embodiment (e.g., resource pool configuration, resource allocation, etc.). Furthermore, the base station 10 may also be an RSU (gNB-type RSU).

[0071] In addition, in the wireless communication system according to the embodiment of the present invention, the signal waveform used by the terminal 20 in the SL or UL may be OFDMA, SC-FDMA, or other signal waveforms.

[0072] In step S101 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0073] In steps S102 and S103, terminal 20A uses the resources autonomously selected in step S101 to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

[0074] Terminal 20B receives the SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The received SCI may include information about the PSFCH resources used by terminal 20B to transmit HARQ-ACK for the received data. Terminal 20A may include information about the autonomously selected resources in the SCI and transmit it.

[0075] In step S104 , the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the PSFCH resources determined by the received SCI.

[0076] If the HARQ-ACK received in step S104 is a NACK (negative acknowledgement) indicating a retransmission request, terminal 20A retransmits PSCCH and PSSCH to terminal 20B in step S105. Terminal 20A can retransmit PSCCH and PSSCH using autonomously selected resources.

[0077] In addition, when HARQ control is not performed, step S104 and step S105 may not be performed.

[0078] Figure 11 This is a timing diagram showing an example of V2X operation (2). Blind retransmissions may be performed independently of HARQ control for improving the transmission success rate or the reach distance.

[0079] In step S201 , the terminal 20A autonomously selects resources to be used for the PSCCH and PSSCH from a resource selection window having a predetermined duration. The resource selection window may be set by the base station 10 for the terminal 20 .

[0080] In steps S202 and S203, terminal 20A uses the resources autonomously selected in step S201 to transmit SCI using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. For example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

[0081] In step S204, the terminal 20A retransmits the SCI based on the PSCCH and / or PSSCH and the SL data based on the PSSCH to the terminal 20B using the resources autonomously selected in step S201. The retransmission in step S204 may be performed multiple times.

[0082] In addition, when blind retransmission is not performed, step S204 may not be performed.

[0083] Figure 12 This is a sequence diagram illustrating an example of V2X operation (3). The base station 10 can perform sidelink scheduling. Specifically, the base station 10 can determine the sidelink resources used by the terminal 20 and transmit information indicating the resources to the terminal 20. Furthermore, when HARQ control is applied, the base station 10 can transmit information indicating PSFCH resources to the terminal 20.

[0084] In step S301, the base station 10 transmits DCI (Downlink Control Information) to the terminal 20A using the PDCCH, thereby performing SL scheduling. Hereinafter, for convenience of explanation, the DCI for SL scheduling is referred to as SL scheduling DCI.

[0085] Furthermore, the following scenario is envisioned: in step S301, the base station 10 also transmits DCI for DL ​​scheduling (also referred to as DL allocation) to the terminal 20A using the PDCCH. Hereinafter, for convenience, the DCI for DL ​​scheduling is referred to as DL scheduling DCI. Upon receiving the DL scheduling DCI, the terminal 20A receives DL data using the PDSCH using the resources specified by the DL scheduling DCI.

[0086] In steps S302 and S303, terminal 20A uses the resources specified by the SL scheduling DCI to transmit SCI (Sidelink Control Information) using the PSCCH and / or PSSCH, and transmits SL data using the PSSCH. Alternatively, the SL scheduling DCI may specify only PSSCH resources. In this case, for example, terminal 20A may transmit the PSCCH using frequency resources adjacent to the frequency resources of the PSSCH, within the same time resources as at least a portion of the time resources of the PSSCH.

[0087] Terminal 20B receives SCI (PSCCH and / or PSSCH) and SL data (PSSCH) transmitted from terminal 20A. The SCI received using PSCCH and / or PSSCH includes information on the resource of the PSFCH used by terminal 20B to transmit HARQ-ACK for receiving the data.

[0088] The resource information is included in the DL scheduling DCI or SL scheduling DCI transmitted from the base station 10 in step S301. The terminal 20A obtains the resource information from the DL scheduling DCI or SL scheduling DCI and includes it in the SCI. Alternatively, if the DCI transmitted from the base station 10 does not include the resource information, the terminal 20A autonomously includes the resource information in the SCI and transmits it.

[0089] In step S304 , the terminal 20B transmits HARQ-ACK for the received data to the terminal 20A using the PSFCH resources determined by the received SCI.

[0090] In step S305, the terminal 20A, for example, sends a HARQ-ACK using the PUCCH (Physical uplink control channel) resources specified by the DL scheduling DCI (or the SL scheduling DCI) at the timing (e.g., timing in time slots) specified by the DL scheduling DCI (or the SL scheduling DCI), and the base station 10 receives the HARQ-ACK. The HARQ-ACK codebook may include an ARQ-ACK generated based on the HARQ-ACK received from the terminal 20B or based on the unreceived PSFCH, and a HARQ-ACK for DL ​​data. However, in the case where there is no allocation of DL data, the HARQ-ACK for DL ​​data is not included. In Rel.16 of NR, the HARQ-ACK codebook does not include a HARQ-ACK for DL ​​data.

[0091] In addition, when HARQ control is not performed, step S304 and step S305 may not be performed.

[0092] Figure 13 This is a timing diagram showing an example of V2X operation (4). As described above, the side link of NR supports the case of sending HARQ responses through PSFCH. In addition, the format of PSFCH can use the same format as PUCCH (Physical Uplink Control Channel) format 0 (PUCCH format 0), for example. That is, regarding the format of PSFCH, it can be a sequence-based format in which the PRB (Physical Resource Block) size is 1 and ACK and NACK are identified based on the difference in timing and / or cyclic shift. The format of PSFCH is not limited to this. The resources of PSFCH can be configured as the codeword at the end of the time slot or multiple codewords at the end. In addition, a period N is set or predefined for the PSFCH resources. The period N can be set or predefined in units of time slots.

[0093] exist Figure 13 In the figure, the vertical axis corresponds to the frequency domain and the horizontal axis corresponds to the time domain. PSCCH can be configured in one symbol at the beginning of the time slot, or in multiple symbols starting from the beginning, or in multiple symbols starting from symbols other than the beginning. PSFCH can be configured in one symbol at the end of the time slot, or in multiple symbols at the end of the time slot. Figure 13 In the example shown, three subchannels are configured in the resource pool, and two PSFCHs are allocated three slots after the slot in which the PSSCH is allocated. The arrow from the PSSCH to the PSFCH shows an example of the PSFCH associated with the PSSCH.

[0094] When the HARQ response in NR-V2X multicast is multicast option 2 of sending ACK or NACK, it is necessary to determine the resources used for PSFCH transmission and reception. Figure 13 As shown, in step S401, terminal 20A as the transmitting terminal 20 performs multicast via SL-SCH to terminal 20B, terminal 20C and terminal 20D as the receiving terminal 20. In the next step S402, terminal 20B uses PSFCH#B to send a HARQ response to terminal 20A, terminal 20C uses PSFCH#C to send a HARQ response to terminal 20A, and terminal 20D uses PSFCH#D to send a HARQ response to terminal 20A. Figure 13As shown in the example, when the number of available PSFCH resources is less than the number of receiving terminals 20 belonging to the group, it is necessary to determine how to allocate the PSFCH resources. Furthermore, the transmitting terminal 20 can understand the number of receiving terminals 20 in the multicast. Furthermore, in multicast option 1, only NACK is transmitted as the HARQ response, and ACK is not transmitted.

[0095] Figure 14 1 is a diagram showing an example of sensing operation. Figure 14 As shown, the terminal 20 selects resources to send. Figure 14 As shown, terminal 20 performs sensing within a sensing window within the resource pool. Through sensing, terminal 20 receives the resource reservation field contained in the SCI sent from other terminals 20 and, based on this field, identifies available resource candidates within the resource selection window within the resource pool. Terminal 20 then randomly selects a resource from the available resource candidates. Sensing resources within the entire sensing window is referred to as full sensing.

[0096] In addition, if Figure 14 As shown, the resource pool setting may have a period, for example, the period may be a period of 10240 milliseconds. Figure 14 is subframe t0 SL To subframe t Tmax SL The resource pool area within the period can be set by, for example, a bitmap.

[0097] In addition, if Figure 14 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX The terminal 20 can detect that in subframe t n-10×Pstep SL To subframe t n-1 SL In the sensing window, for example, other terminals 20 are performing priority p RX When SCI is detected in the sensing window and RSRP is greater than the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the sensing window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold can also be, for example, based on the priority p TX and priority p RX The threshold Th is set or defined according to each resource in the sensing window. pTX，pRX .

[0098] In addition, if Figure 14 The subframe t shown Z SL In this way, resources within the resource selection window are excluded as candidates for resource reservation information corresponding to resources within the sensing window that are not monitored, for example, for transmission.

[0099] like Figure 14 As shown, in the resource selection window from subframe n+T1 to subframe n+T2, the resources occupied by other UEs are identified, and the resources after the resources are excluded become the available resource candidates. A When S A If the threshold value Th is less than 20% of the resources in the resource selection window, the threshold value Th set for each resource in the sensing window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3dB. pTX，pRX The resource identification is performed again to increase the resources that are not excluded because the RSRP is less than the threshold. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to the set S B You can also repeat the S A The resource with the minimum RSSI is added to S B The actions in the above table are continued until the set of resource candidates S is obtained. B Become more than 20% of the resource selection window.

[0100] The lower layer of terminal 20 can B Report to the upper layer. The upper layer of terminal 20 can report to S B The terminal 20 may use the determined resources to perform sidelink transmission. In addition, the terminal 20 may not use the predetermined number of times (e.g., C) after temporarily securing the resources. resel times) to perform sensing and periodically use resources.

[0101] Figure 15 FIG is a diagram showing an example of partial sensing operation. When partial sensing is set by a higher layer in the LTE side link, as shown in FIG. Figure 15 As shown, the terminal 20 selects resources to send. Figure 15 As shown, terminal 20 performs partial sensing on a portion of the sensing window within the resource pool. Through partial sensing, terminal 20 receives the resource reservation field contained in the SCI sent from other terminals 20 and, based on this field, identifies available resource candidates within the resource selection window within the resource pool. Terminal 20 then randomly selects a resource from the available resource candidates.

[0102] In addition, if Figure 15 As shown, the resource pool setting may have a period, for example, the period may be a period of 10240 milliseconds. Figure 15 is subframe t0 SL To subframe t Tmax SL The resource pool area within the period can be set by, for example, a bitmap.

[0103] like Figure 15 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX .like Figure 15 As shown, in subframe n+T1 to subframe n+T2, subframe t Y SL To subframe t y+Y SL The Y subframe can be set as the resource selection window. Figure 15 As shown, assuming that the transmission trigger in terminal 20 occurs in subframe n, the priority of the transmission is p TX .

[0104] The terminal 20 can detect that in the subframe t which is the length of Y subframes y-k×Pstep SL To subframe t y+Y-k×Pstep SL In one or more sensing windows, for example, other terminals 20 are performing priority p RX k can be a 10-bit bitmap, for example. Figure 15 , an example is shown in which the 3rd and 6th bits of the bitmap k are set to "1" indicating that partial sensing is performed. Figure 15 In subframe t y-6×Pstep SL To subframe t y+Y-6×Pstep SL and subframe t y-3×Pstep SL To subframe t y+Y-3×Pstep SL As described above, the i-th bit of the bitmap k may correspond to the subframe t y-i×Pstep SL To subframe t y+Y-i×Pstep SL sensing window.

[0105] When SCI is detected in one or more sensing windows and RSRP is greater than the threshold, the resources in the resource selection window corresponding to the SCI are excluded. In addition, when SCI is detected in the sensing window and RSRP is less than the threshold, the resources in the resource selection window corresponding to the SCI are not excluded. The threshold can also be, for example, based on the priority pTX and priority p RX The threshold Th is set or defined according to each resource in the sensing window. pTX，pRX .

[0106] In the resource selection window set with Y subframes, the terminal 20 identifies the resources occupied by other UEs, and the resources after the resources are excluded become the available resource candidates. A When S A If the threshold value Th is less than 20% of the resources in the resource selection window, the threshold value Th set for each resource in the sensing window can be set to pTX，pRX The resource identification is performed again by increasing the threshold Th by 3dB. pTX , pRX The resource identification is performed again to increase the number of resources that are not excluded because the RSRP is less than the threshold. A The RSSI of each resource is calculated, and the resource with the smallest RSSI is added to the set S B You can also repeat the S A The resource with the minimum RSSI is added to S B The actions in the above table are continued until the set of resource candidates S is obtained. B Become more than 20% of the resource selection window.

[0107] The lower layer of terminal 20 can B Report to the upper layer. The upper layer of terminal 20 can report to S B The terminal 20 may use the determined resources to perform sidelink transmission. In addition, the terminal 20 may not use the predetermined number of times (e.g., C) after temporarily securing the resources. resel times) to perform sensing and periodically use resources.

[0108] In the above Figure 14 and Figure 15 In the description, the operation of the transmitting terminal 20 is described, but the receiving terminal 20 may detect data transmission from another terminal 20 based on the result of sensing or partial sensing, and receive data from the other terminal 20.

[0109] In the NR Release 17 sidelink, power saving based on the aforementioned random resource selection and partial sensing is being studied. For example, for power saving, the random resource selection and partial sensing of the LTE Release 14 sidelink can be applied to the resource allocation mode 2 of the NR Release 16 sidelink. Terminals 20 that are applying partial sensing perform reception and sensing only in specific time slots within the sensing window.

[0110] Furthermore, in the sidelink of NR Release 17, research is underway on enhanced Ultra Reliable Low Latency Communication (eURLLC), using inter-UE coordination as a baseline. For example, terminal 20A and terminal 20B share information indicating resource sets, and terminal 20B considers this information when selecting resources for transmission.

[0111] On the other hand, NR Release 16 adopts unicast communication. A PC5-RRC connection is established between terminals, and unicast communication is performed while maintaining the RRC connection. For example, the following rules define the actions related to the sidelink RRC connection.

[0112] 1) Sidelink RRC reconfiguration

[0113] The PC5-RRC connection is established / changed by sending or receiving the "RRCReconfigurationSidelink" message or receiving or receiving the "RRCReconfigurationCompleteSidelink" message.

[0114] 2) Sidelink UE capability transfer

[0115] The UE capability related to the sidelink is notified by sending or receiving "UECapabilityEnquirySidelink" and receiving or sending "UECapabilityInformationSidelink".

[0116] 3) Actions in the event of a sidelink radio link failure

[0117] For example, if the maximum number of retransmissions has been reached, the timer (T400) has expired, the number of consecutive HARQ-DTXs has reached the maximum, or the sidelink PDCP entity integrity check fails, it is determined that a PC5-RRC connection failure has been detected. Timer T400 starts when "RRCReconfigurationSidelink" is sent and stops when "RRCReconfigurationFailureSidelink" or "RRCReconfigurationCompleteSidelink" is received. In addition, for example, when timer T400 expires, the sidelink RRC reconfiguration failure procedure is executed.

[0118] 4) Sidelink measurement

[0119] The terminal 20 can set the NR sidelink measurement and reporting via the corresponding PC5-RRC connection for the other terminal 20 through the "RRCReconfigurationSidelink" message.

[0120] Here, a terminal 20 performing power-saving operations (power-saving UE) may only receive and / or transmit data for a limited period. Therefore, it is conceivable that the PC5-RRC connection cannot be maintained and is severed, hindering unicast communication. To enable unicast communication for terminals 20 performing power-saving operations, the PC5-RRC connection mechanism needs to be modified.

[0121] Therefore, for example, when terminal 20A and terminal 20B are connected via the RRC layer in a sidelink, and either terminal 20A or terminal 20B performs at least one of transmission, reception, or sensing at a specific timing, actions related to the RRC layer connection can be set as actions based on the specific timing. In addition, timing can refer to, for example, one or more periodic time slots or symbols, or any interval based on other time domain units. Furthermore, specific timing can refer to one or more non-periodic time slots or symbols. Furthermore, specific timing can also refer to timing in which an offset is applied to one or more periodic time slots or symbols.

[0122] For example, when at least one of the following conditions 1) to 5) is satisfied, the above-mentioned operation based on specific timing can be applied.

[0123] 1) A case where both the terminal 20A and the terminal 20B perform at least one of transmission, reception, or sensing operations only at specific timings.

[0124] 2) A case where either the terminal 20A or the terminal 20B performs at least one of transmission, reception, or sensing operations only at a specific timing.

[0125] 3) When either terminal 20A or terminal 20B performs at least one of transmission, reception, or sensing at a specific timing, and the other terminal can perform the aforementioned actions based on the specific timing, it does not matter whether the other terminal 20 is notified of the UE capability that can be implemented.

[0126] 4) When one of the terminal 20A and the terminal 20B instructs the other to perform the above-mentioned operation at a specific timing.

[0127] 5) Either the terminal 20A or the terminal 20B notifies the other that the aforementioned specific timing operation can be performed. This notification may be "UECapabilityEnquirySidelink" or may be a notification based on another message.

[0128] Furthermore, for example, the above-described operation based on specific timing may be applied to any one of the following 1) to 3).

[0129] 1) Both the terminal 20A and the terminal 20B.

[0130] 2) Of the terminals 20A and 20B, the terminal 20 that can perform the above-mentioned specific timing operation.

[0131] 3) Of the terminals 20A and 20B, the terminal 20 that instructs the operation at the specific timing described above.

[0132] Figure 16 This is a sequence diagram illustrating an example of information notification in an embodiment of the present invention. Information related to power saving operations can be shared between terminals 20 that have established a PC5-RRC connection. The information related to power saving operations can be, for example, any one or a combination of the following 1)-4).

[0133] Can include

[0134] 1) Information indicating that “at least one of transmission, reception, and sensing operations is performed only at a specific timing”.

[0135] 2) Information indicating whether power saving action is being performed.

[0136] 3) Information indicating the operation of the object performing the power saving operation.

[0137] 4) Information indicating “which time resource the specific timing is”, that is, information indicating a period during which a power saving operation is performed (or not performed).

[0138] exist Figure 16 In step S1, terminal 20A sends an "RRCReconfigurationSidelink" message containing information related to power-saving actions to terminal 20B. The "RRCReconfigurationSidelink" message can be replaced with other PC5-RRC signaling. For example, "RRCReconfigurationSidelink" can be replaced with "UECapabilityInformationSidelink." Subsequently, terminal 20B sends an "RRCReconfigurationCompleteSidelink" message to terminal 20A.

[0139] Furthermore, the information on the power saving operation can be notified from terminal 20A to terminal 20B via at least one of the aforementioned PC5-RRC signaling, MAC-CE, SCI, layer 1 ID, and layer 2 ID. The layer 1 ID and layer 2 ID can be pre-associated with the information on the power saving operation.

[0140] By notifying the counterpart terminal 20 of the information related to the power saving information as described above, it is possible to perform operations related to maintaining the PC5-RRC connection by referring to the mutual information.

[0141] In the case where terminal 20A and terminal 20B are connected through the RRC layer in the side link, and either terminal 20A or terminal 20B performs at least one of sending, receiving or sensing actions only at a specific timing, the action related to the connection of the RRC layer based on the specific timing may be at least one of the following A)-L).

[0142] A) Regarding the maximum number of retransmissions N1, which is one of the RLF (Radio link failure) determinations, the number of retransmissions may be counted only for transmission or reception at a specific timing. Figure 17 This is a diagram showing example (1) of the transmission and reception operation in the embodiment of the present invention. Figure 17 The specific timing is an example of a timing that can be received by the terminal 20B. Since transmission #1 and transmission #2 are included in the specific timing, they are counted, and since transmission #3 is not included in the specific timing, it is not counted.

[0143] B) The maximum number of retransmissions N1, which is one of the RLF determinations, can be set using a parameter different from the maximum number of retransmissions N2 for operations outside of the specified timing interval (e.g., operations of terminal 20 not performing power-saving operations). For example, N1 can be greater than N2 (N1>N2), or N1 can be greater than N2 (N1>=N2). Furthermore, for example, assuming R is the ratio of receivable timing to total timing (receivable timing / total timing), N1 can be determined based on R, or N1 = N2 / R. The definition of R is not limited to this.

[0144] As shown in A) and B) above, transmission at a timing that is assumed to be unreceivable can be excluded from the operation related to maintaining the PC5-RRC connection.

[0145] C) The timer (T400_1) used as one of the RLF determinations may be valid only at this specific timing. Figure 18 This is a diagram showing example (2) of the sending and receiving operation in the embodiment of the present invention. Figure 18 The specific timing is an example of a timing that can be received by the terminal 20B. The specific timing can be set as a section where the timer runs, and sections other than the specific timing can be set as sections where the timer does not run or stops.

[0146] D) The timer (T400_1), one of the RLF determinations, can be set so that the time until expiration differs from timer T400 used for actions outside of the specified timing interval (e.g., actions of the terminal 20 not performing power-saving actions). For example, T400_1 can be greater than T400 (T400_1>T400), or T400_1 can be greater than T400 (T400_1>=T400). Furthermore, for example, assuming R is the ratio of receivable timing to total timing (receivable timing / total timing), T400_1 can be determined based on R, or T400_1 = T400 / R. The definition of R is not limited to this.

[0147] As shown in C) and D) above, the timer operation that is assumed to have a timing at which reception is impossible can be excluded from the operation related to maintaining the PC5-RRC connection.

[0148] E) Regarding the number of consecutive HARQ-DTX times, which is one of the RLF determinations, the number may be counted only for the transmission or reception of the PSFCH corresponding to the transmission or reception of data at the specific timing. In other words, regarding the number of consecutive HARQ-DTX times, the number of PSFCH transmissions or receptions corresponding to the transmission or reception of data in intervals other than the specific timing may not be counted.

[0149] F) Regarding the number of consecutive HARQ-DTXs, which is one of the RLF determinations, it is possible to count only the HARQ feedback at a specific timing, i.e., the transmission or reception of the PSFCH. In other words, regarding the number of consecutive HARQ-DTXs, it is also possible not to count the transmission or reception of HARQ feedback in intervals other than the specific timing.

[0150] G) Regarding the maximum value M of the number of consecutive HARQ-DTX times as one of the RLF judgments 1， It can be set by a parameter different from the maximum value M2 of the number of consecutive HARQ-DTX times in the operation outside the specific timing interval (for example, the operation of the terminal 20 that does not perform power saving operation). For example, M1 can be greater than M2 (M1>M2), or M1 can be greater than M2 (M1>=M2). In addition, for example, R is set as the ratio of the timing that can be received to the total timing (timing that can be received / total timing), M1 can be determined based on R, or it can be M1=M2 / R. In addition, the definition of R is not limited to this.

[0151] H) Regarding the number of consecutive HARQ-DTXs, which is one of the RLF determinations, in the case of the HARQ-ACK mode in which only NACKs are fed back, this number may not be counted. However, in the case of the HARQ feedback mode in which both ACKs and NACKs are fed back, this number may be counted. Whether the HARQ feedback mode is in which only NACKs are fed back may be notified to the receiving terminal 20 or the receiving terminal 20 via the SCI.

[0152] 1) Regarding the number of consecutive HARQ-DTXs, which is one of the RLF determinations, the number can be counted only within a specific interval in the time domain. For example, the specific interval can be a period that specifies the upper limit of the number of HARQ feedbacks for a certain PSCCH / PSSCH.

[0153] As shown in E)-I) above, HARK feedback at a timing that is assumed to be unreceivable can be excluded from the operation related to maintaining the PC5-RRC connection.

[0154] J) At least one of the criteria for determining RLF for a terminal 20 not related to the specific timing (e.g., a terminal 20 not performing power saving) may not be applied to the terminal 20 performing this embodiment. Specifically, at least one of the criteria for determining RLF in intervals other than the specific timing: reaching the maximum number of retransmissions, expiration of the timer (T400), reaching the maximum number of consecutive HARQ-DTXs, and failure of the sidelink PDCP entity integrity check may be applied to the RLF determination.

[0155] K) can be added to the RLF determination in a terminal 20 not related to the specific timing (for example, a terminal 20 that does not perform power saving operations) and / or at least one of the above-mentioned A)-I), or instead of at least one, at least one of the following 1)-5) can be specified as an action for RLF determination.

[0156] 1) When a signal transmitted from the counterpart terminal 20 is not received within a certain fixed time, it can be determined as RLF. For example, the fixed time can be measured only at the specific timing.

[0157] 2) If the number of consecutive HARQ-DTXs reaches the maximum, it can be determined as RLF. However, if a HARQ-ACK is received from the counterpart terminal 20 to the other terminal 20, it can be determined not to be HARQ-DTX and the number of consecutive HARQ-DTXs can be cleared.

[0158] 3) A signal transmission at a specific period is specified, set, or notified. If the signal transmission is not received a specific number of times, it can be determined as RLF.

[0159] 4) A signal transmission with a specific period is specified, set, or notified. If HARQ feedback related to the signal transmission is not received within a specific number of times, it can be determined as RLF.

[0160] 5) For specific data transmission, if the transmission is not completed within the packet delay budget, it can be determined as RLF. For example, if an ACK is not received within the packet delay budget, it can be determined as RLF.

[0161] L) The transmission and reception (at least the initial transmission) shown in 1) to 3) below can be performed at this specific timing.

[0162] 1)RRCReconfigurationSidelink message.

[0163] 2)RRCReconfigurationFailureSidelink message.

[0164] 3)RRCReconfigurationCompleteSidelink message.

[0165] For example, all of 1)-3) above can be sent and received at the specific timing. For example, 1) above can be sent and received at any time, while 2) and 3) can be sent and received at the specific timing. For example, the message in 1) can include information related to the specific timing. For example, this can be information indicating "in which time resources at least one of transmission, reception, and sensing is possible."

[0166] As shown in J) to L) above, the RLF determination or RRC message processing can be set as an operation suitable for the terminal 20 performing the power saving operation, and the PC5-RRC connection can be appropriately maintained.

[0167] Furthermore, the above-described embodiments can be applied to terminals 20 that have settings related to power saving configured. Terminals 20 that have settings related to power saving configured may refer to terminals 20 that perform partial sensing or terminals 20 that are (pre-)configured to perform partial sensing. Alternatively, they may refer to terminals 20 that perform a sensing method different from the full sensing specified in Release 16, terminals 20 that do not perform sensing, or terminals 20 that perform reception only for a limited time (e.g., DRX).

[0168] In addition, full sensing may refer to sensing all resources within a sensing window. The sensing window may be composed of a time slot interval [n-T0, nT proc，0 ] is used to specify that n can be the time slot corresponding to the packet arrival timing.

[0169] In the above-described embodiment, “at least one of a transmission operation, a reception operation, and a sensing operation is performed at a specific timing” may be replaced with “settings related to power saving are performed”.

[0170] In the above embodiment, the receiving-side terminal 20 may refer to multiple terminals 20 , and may also belong to the same group.

[0171] In the above-described embodiment, both the receiving terminal 20 and the transmitting terminal 20 may be terminals 20 that perform a power saving operation.

[0172] The above embodiments are not limited to V2X terminals, but can also be applied to terminals performing D2D communication.

[0173] The transmitting terminal 20 can also know the timing at which the receiving terminal 20 can receive and / or send. This can be done by determining the timing in the specification or in advance, or by receiving a notification from the receiving terminal 20.

[0174] In addition, in the above embodiments, timing, i.e., time resources, can be replaced by frequency resources. For example, this can be applied to the following situation: at least one of transmission / reception / sensing is performed in a portion of frequency resources (eg, a portion of sub-channels).

[0175] Furthermore, in the above-mentioned embodiment, the connection with other terminals in the RRC layer is not limited to the RRC layer. For example, the connection with other terminals can also be made in the MAC layer.

[0176] According to the above-described embodiment, the terminal 20 can realize unicast communication suitable for the PC5-RRC connection by performing RLF determination and HARQ feedback in consideration of the power saving operation of the receiving-side terminal 20 .

[0177] That is, in inter-terminal direct communication, unicast communication suitable for power saving operation can be realized.

[0178] (Device Structure)

[0179] Next, the functional configuration examples of the base station 10 and terminal 20 that perform the above-described processing and operations are described. The base station 10 and terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and terminal 20 may each include only a portion of the functions described in the embodiments.

[0180] <Base Station 10>

[0181] Figure 19 1 is a diagram showing an example of the functional configuration of the base station 10. Figure 19 As shown, the base station 10 includes a transmitting unit 110 , a receiving unit 120 , a setting unit 130 , and a control unit 140 . Figure 19 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0182] The transmitter 110 includes a function of generating a signal to be transmitted to the terminal 20 and wirelessly transmitting the signal. The receiver 120 includes a function of receiving various signals transmitted from the terminal 20 and obtaining, for example, higher-layer information from the received signals. Furthermore, the transmitter 110 includes a function of transmitting the NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL reference signals, and the like to the terminal 20.

[0183] The setting unit 130 stores pre-set setting information and various setting information to be sent to the terminal 20 in a storage device, and reads the setting information from the storage device as needed. The content of the setting information is, for example, information related to the setting of D2D communication.

[0184] As described in the embodiments, the control unit 140 performs processing related to the configuration for the terminal 20 to perform D2D communication. Furthermore, the control unit 140 transmits scheduling information for D2D communication and DL communication to the terminal 20 via the transmission unit 110. Furthermore, the control unit 140 receives information related to HARQ responses for D2D communication and DL communication from the terminal 20 via the reception unit 120. Functional units related to signal transmission within the control unit 140 may be included in the transmission unit 110, while functional units related to signal reception within the control unit 140 may be included in the reception unit 120.

[0185] <Terminal 20>

[0186] Figure 20 2 is a diagram showing an example of the functional structure of the terminal 20. Figure 20 As shown, the terminal 20 includes a transmitting unit 210 , a receiving unit 220 , a setting unit 230 , and a control unit 240 . Figure 20 The functional configuration shown is merely an example, and any functional divisions and names of functional units may be used as long as the operations according to the embodiments of the present invention can be executed.

[0187] The transmitting unit 210 generates a transmission signal based on the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly and obtains higher-layer signals from the received physical layer signals. In addition, the receiving unit 220 has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals or reference signals transmitted from the base station 10. In addition, for example, as D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0188] The configuration unit 230 stores various configuration information received by the receiving unit 220 from the base station 10 or the terminal 20 in a storage device and reads it from the storage device as needed. Furthermore, the configuration unit 230 also stores pre-set configuration information. This configuration information may include, for example, information related to D2D communication configuration.

[0189] As described in the embodiment, the control unit 240 controls D2D communication for establishing an RRC connection with another terminal 20. Furthermore, the control unit 240 performs processing related to power conservation. Furthermore, the control unit 240 performs processing related to HARQ for D2D communication and DL communication. Furthermore, the control unit 240 transmits information related to HARQ responses for D2D communication and DL communication scheduled by the base station 10 to the base station 10. Furthermore, the control unit 240 may also schedule D2D communication for the other terminal 20. Furthermore, the control unit 240 may autonomously select resources to be used for D2D communication from a resource selection window based on monitoring results. Furthermore, the control unit 240 performs processing related to power conservation in D2D communication transmission and reception. The functional units of the control unit 240 related to signal transmission may be included in the transmitter 210, while the functional units of the control unit 240 related to signal reception may be included in the receiver 220.

[0190] (Hardware Structure)

[0191] The block diagram used in the description of the above embodiment ( Figure 19 and Figure 20 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or it can be implemented by connecting two or more physically or logically separated devices directly or indirectly (for example, using wired or wireless connections) and using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0192] Functionally, these include, but are not limited to, judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning. For example, a functional block (structural unit) that enables the transmission function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0193] For example, the base station 10 , the terminal 20 , and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 21 This figure shows an example of the hardware configuration of a base station 10 and a terminal 20 according to one embodiment of the present disclosure. The base station 10 and the terminal 20 described above can also be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0194] In the following description, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and the terminal 20 may include one or more of the devices shown in the figures, or may exclude some of the devices.

[0195] The various functions in the base station 10 and the terminal 20 are implemented by reading predetermined software (programs) into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs calculations and controls the communication of the communication device 1004 or controls at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0196] Processor 1001 controls the entire computer by, for example, running an operating system. Processor 1001 may also be comprised of a central processing unit (CPU) that includes interfaces with peripheral devices, a control device, a computing device, registers, and the like. For example, control unit 140 and control unit 240 described above may also be implemented by processor 1001.

[0197] In addition, the processor 1001 reads a program (program code), a software module, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and performs various processes based on the program. As a program, a program that causes the computer to execute at least a part of the actions described in the above embodiment is used. For example, Figure 19 The control unit 140 of the base station 10 shown may also be implemented by a control program stored in the storage device 1002 and executed in the processor 1001. Figure 20The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and executed by the processor 1001. Regarding the various processes described above, although they are described as being executed by a single processor 1001, they can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be implemented on one or more chips. Furthermore, the program can be transmitted from a network via a telecommunications line.

[0198] The storage device 1002 is a computer-readable recording medium and may be composed of, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and RAM (Random Access Memory). The storage device 1002 may also be referred to as a register, cache, or main memory (main storage device). The storage device 1002 can store executable programs (program code), software modules, and the like for implementing the communication method according to one embodiment of the present disclosure.

[0199] The auxiliary storage device 1003 is a computer-readable recording medium, and can be composed of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic stripe, etc. The above-mentioned storage medium can be, for example, a database, a server, or other appropriate medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0200] Communication device 1004 is hardware (a transceiver) used to communicate between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network card, or communication module. Communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, communication device 1004 may also implement a transceiver antenna, an amplifier, a transceiver, a transmission path interface, and the like. The transceiver may also be physically or logically separated from the transmitter and receiver.

[0201] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to the outside (e.g., a display, speaker, LED light, etc.). Alternatively, the input device 1005 and the output device 1006 may be integrally formed (e.g., a touch panel).

[0202] Furthermore, the processor 1001, the storage device 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured as a single bus or may be configured as different buses between devices.

[0203] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array), and may implement some or all of the functional blocks using this hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0204] (Summary of Implementation Methods)

[0205] As described above, according to an embodiment of the present invention, a terminal is provided, comprising: a control unit connected to other terminals in an RRC (Radio Resource Control) layer; and a sending unit sending data to the other terminals, wherein the control unit controls actions related to the connection in the RRC layer according to the specific timing when the other terminal or the present terminal performs at least one of sending, receiving or sensing at a specific timing.

[0206] With the above configuration, the terminal 20 can implement unicast communication suitable for PC5-RRC connection by performing RLF determination and HARQ feedback assuming power saving operation of the receiving terminal 20. In other words, unicast communication suitable for power saving operation can be implemented in inter-terminal direct communication.

[0207] The terminal may further include a receiving unit that receives information indicating that the other terminal is performing at least one of transmission, reception, or sensing at the specific timing, or information indicating the specific timing, from the other terminal. This configuration enables RLF determination and HARQ feedback that take into account power conservation by the receiving terminal 20.

[0208] The receiving unit may also receive HARQ (Hybrid Automatic Repeat Request) feedback regarding the data from the other terminal, and the control unit may determine link failure at the RRC layer based only on the HARQ feedback related to the specific timing. This configuration enables RLF determination and HARQ feedback to be performed with consideration given to power saving operations by the receiving terminal 20.

[0209] The control unit may determine the link failure of the RRC layer based on a timer related to the specific timing. According to this configuration, it is possible to perform RLF determination assuming a power saving operation of the receiving terminal 20.

[0210] The transmitting unit may transmit the message in the RRC layer only at the specific timing. According to this configuration, it is possible to reliably notify the RRC message in anticipation of the power saving operation of the receiving terminal 20.

[0211] As described above, according to an embodiment of the present invention, a communication method is provided, wherein the terminal performs the following steps: a control step of connecting with other terminals in the RRC (Radio Resource Control) layer; and a sending step of sending data to the other terminals, and the control step includes the following steps: when the other terminal or the current terminal performs at least one of sending, receiving or sensing at a specific timing, controlling the actions related to the connection in the RRC layer according to the specific timing.

[0212] With the above configuration, the terminal 20 can implement unicast communication suitable for PC5-RRC connection by performing RLF determination and HARQ feedback assuming power saving operation of the receiving terminal 20. In other words, unicast communication suitable for power saving operation can be implemented in inter-terminal direct communication.

[0213] (Supplementary Implementation Methods)

[0214] The above describes the embodiments of the present invention, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, substitutions, and replacements. Specific numerical examples are used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate value may be used. The distinction between the items in the above description is not essential to the present invention. Matters recorded in two or more items may be combined and used as needed, and matters recorded in one item may be applied to matters recorded in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. The actions of multiple functional units may be performed by one physical component, or the actions of one functional unit may be performed by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing may be reversed if there is no contradiction. For the convenience of explaining the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices may also be implemented using hardware, software, or a combination thereof. The software that operates by the processor of the base station 10 according to the embodiment of the present invention and the software that operates by the processor of the terminal 20 according to the embodiment of the present invention can also be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and any other appropriate storage medium.

[0215] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information can be implemented through physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), high-layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals or a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, it may also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0216] Each form / embodiment described in this disclosure may also be applied to at least one of LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems derived therefrom. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G) may also be applied.

[0217] The processing procedures, timings, and flows of each form / implementation described in this specification may be performed in a different order unless there is a conflict. For example, the methods described in this disclosure use an illustrative order to present the elements of various steps, but are not limited to the specific order presented.

[0218] In this specification, specific operations performed by base station 10 may also be performed by its upper node depending on the situation. In a network consisting of one or more network nodes including base station 10, various operations performed to communicate with terminal 20 can be performed by at least one of base station 10 and other network nodes other than base station 10 (e.g., MME or S-GW, but not limited to these). While the above example illustrates a single other network node other than base station 10, the other network node may also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0219] The information or signals described in this disclosure can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), and can also be input or output via multiple network nodes.

[0220] Input or output information can be stored in a specific location (e.g., memory) or managed using a management table. Input or output information can be overwritten, updated, or appended. Output information can also be deleted. Input information can also be sent to other devices.

[0221] The determination in the present disclosure may be performed using a value represented by one bit (0 or 1), a Boolean value (Boolean: true or false), or a comparison of numerical values ​​(for example, comparison with a predetermined value).

[0222] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to instructions, sets of instructions, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0223] Furthermore, software, commands, information, and the like may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of a wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0224] The information, signals, etc. described in this disclosure may also be represented using any of a variety of different technologies. For example, data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be referred to in the entire description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0225] In addition, the terms used in this disclosure and those necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0226] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0227] In addition, the information, parameters, etc. described in this disclosure may be represented by absolute values, relative values ​​relative to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0228] The names used for the above parameters are not limiting in any way. Furthermore, the formulas and the like using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way.

[0229] In this disclosure, terms such as "base station (BS)," "wireless base station," "base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" are used interchangeably. Base stations are sometimes also referred to as macrocells, small cells, femtocells, and picocells.

[0230] A base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the base station's overall coverage area can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (for example, a small base station for indoor use (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a portion or the entire coverage area of ​​at least one of the base station and base station subsystem that provide communication services within the coverage area.

[0231] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0232] For mobile stations, those skilled in the art sometimes also use the following terms to refer to them: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client or some other appropriate terms.

[0233] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a means of transportation (e.g., a car, an airplane, etc.), a mobile body that moves unmanned (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0234] In addition, the base station in the present disclosure can also be replaced by a user terminal. For example, regarding a structure in which the communication between the base station and the user terminal is replaced by the communication between multiple terminals 20 (for example, it can also be called D2D (Device-to-Device: device to device), V2X (Vehicle-to-Everything: vehicle to everything system), etc.), the various forms / implementations of the present disclosure can also be applied. In this case, it can also be set as a structure in which the terminal 20 has the functions of the above-mentioned base station 10. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (such as "side"). For example, uplink channels, downlink channels, etc. can also be replaced by side channels.

[0235] Likewise, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station may also have the functions of the user terminal described above.

[0236] As used in this disclosure, terms such as “determining” and “determining” sometimes also include a variety of actions. “Determining” and “judging” may, for example, include considering matters such as judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (for example, searching in a table, database or other data structure), and ascertaining as matters that have been “determined” or “determined”. In addition, “determining” and “receiving” (for example, receiving information), transmitting (for example, sending information), inputting, outputting, accessing (for example, accessing data in a memory) as matters that have been “determined” or “determined”. In addition, “determining” and “resolving” may include matters such as selecting, choosing, establishing, and comparing as matters that have been “determined” or “determined”. That is, "judgment" and "decision" can include matters that are considered to have "judged" or "decided" any action. In addition, "judgment (decision)" can also be replaced by "assuming (assuming)", "expecting (expecting)", "considering (considering)", etc.

[0237] The terms "connected", "coupled" or any variation of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include situations where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used instead of "connection". As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region and optical (visible and invisible) region may be used to "connect" or "couple" to each other.

[0238] The reference signal may be referred to as RS (Reference Signal) for short, or may be called a pilot signal depending on the applied standard.

[0239] The phrase "according to" used in this disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to."

[0240] Any reference to an element using the terms "first," "second," etc., as used in this disclosure, does not necessarily limit the number or order of these elements. These terms can be used as a convenient way to distinguish between two or more elements in this disclosure. Therefore, a reference to a first element and a second element does not imply that only two elements can be used or that the first element must precede the second element in any manner.

[0241] The “unit” in the configuration of each of the above-mentioned devices may be replaced with a “section,” “circuit,” “device,” or the like.

[0242] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," are intended to be inclusive. Furthermore, the term "or" used in this disclosure does not mean an exclusive or.

[0243] A radio frame can be composed of one or more frames in the time domain. In the time domain, one or more frames can be called a subframe. A subframe can be further composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) that is independent of the numerology.

[0244] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a signal or channel. For example, the parameter set may represent at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by the transceiver in the frequency domain, specific windowing performed by the transceiver in the time domain, and the like.

[0245] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0246] A time slot may contain multiple mini-slots. Each mini-slot may consist of one or more symbols in the time domain. Furthermore, a mini-slot may also be referred to as a sub-slot. A mini-slot may consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in time units larger than a mini-slot may be referred to as PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as PDSCH (or PUSCH) mapping type B.

[0247] Radio frame, subframe, time slot, mini-time slot, and symbol all represent time units for signal transmission. Radio frame, subframe, time slot, mini-time slot, and symbol may be referred to by other corresponding names.

[0248] For example, a subframe can also be called a Transmission Time Interval (TTI), multiple consecutive subframes can also be called a TTI, and a slot or a mini-slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. Furthermore, the unit representing a TTI may be called a slot, a mini-slot, or the like, rather than a subframe.

[0249] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communications. For example, in the LTE system, a base station schedules each terminal 20 by allocating wireless resources (such as the frequency bandwidth and transmit power available to each terminal 20) in units of TTI. The definition of TTI is not limited to this.

[0250] The TTI can be the time unit for transmitting data packets (transport blocks), code blocks, code words, etc. after channel coding, and can also be the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the time interval (for example, the number of symbols) to which the transport blocks, code blocks, code words, etc. are actually mapped can be shorter than the TTI.

[0251] In addition, when one time slot or one mini-time slot is referred to as a TTI, one or more TTIs (i.e., one or more time slots or one or more mini-time slots) can constitute the minimum time unit for scheduling. In addition, the number of time slots (the number of mini-time slots) constituting the minimum time unit for scheduling can be controlled.

[0252] A TTI with a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a time slot, etc.

[0253] In addition, for long TTI (for example, normal TTI, subframe, etc.), it can be replaced with a TTI with a time length of more than 1ms, and for short TTI (for example, shortened TTI, etc.), it can be replaced with a TTI length that is smaller than long TTI (longTTI) and has a TTI length of more than 1ms.

[0254] A resource block (RB) is a unit of resource allocation in the time and frequency domains. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers contained in an RB can also be determined by the parameter set.

[0255] In addition, the time domain of an RB may include one or more symbols and may be the length of one slot, one mini-slot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0256] In addition, one or more RBs may be referred to as a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like.

[0257] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0258] A bandwidth part (BWP) (also known as a fractional bandwidth) can represent a subset of contiguous common resource blocks (RBs) used for a parameter set within a carrier. Common RBs can be identified by their index relative to the common reference point of the carrier. PRBs can be defined within a BWP and numbered within that BWP.

[0259] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for the terminal 20 within one carrier.

[0260] At least one of the set BWPs may be active, and it is not assumed that the terminal 20 transmits or receives predetermined signals / channels outside the active BWP. In addition, "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

[0261] The above-described structures of radio frames, subframes, slots, mini-slots, and symbols are merely examples. For example, various modifications may be made to the structures, such as the number of subframes in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots in a slot, the number of symbols and RBs in a slot or mini-slot, the number of subcarriers in an RB, the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP) length.

[0262] In the present disclosure, when an article is added by translation, such as a, an, and the in English, the present disclosure may also include cases where the noun following the article is in a plural form.

[0263] In this disclosure, the phrase "A is different from B" may also mean "A and B are different from each other." Alternatively, the phrase may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

[0264] Each form / implementation described in this disclosure may be used individually or in combination, and may be switched between them depending on the execution. Furthermore, notification of scheduled information is not limited to being performed explicitly (e.g., a notification of "yes X") but may also be performed implicitly (e.g., not notifying the scheduled information).

[0265] In addition, in the present disclosure, PSCCH / PSSCH is an example of data.

[0266] While the present disclosure has been described in detail above, it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in various modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes only and does not have any limiting meaning on the present disclosure.

[0267] Label Description

[0268] 10: base station;

[0269] 110: Sending department;

[0270] 120: receiving unit;

[0271] 130: Setting department;

[0272] 140: Control Department;

[0273] 20: terminal;

[0274] 210: Sending department;

[0275] 220: receiving unit;

[0276] 230: Setting department;

[0277] 240: Control Department;

[0278] 1001: processor;

[0279] 1002: storage device;

[0280] 1003: auxiliary storage device;

[0281] 1004: Communication devices;

[0282] 1005: input device;

[0283] 1006: Output device.

Claims

1. A terminal comprising: a transmitting unit that transmits information indicating an intermittent reception operation of another terminal to another terminal that performs intermittent reception; and a control unit that controls an action related to maintaining a connection in the RRC layer with the other terminal via an interface between terminals according to a specific timing, wherein the other terminal performs at least one of reception and sensing, The specific timing is a timing at which a timer related to a section in which the other terminal performs at least one of reception and sensing advances.

2. The terminal according to claim 1, wherein: The control unit autonomously determines resources for maintaining the connection in the RRC layer.

3. The terminal according to claim 1, wherein: The terminal further includes a receiving unit configured to receive a sidelink UE capability notification including information indicating whether the other terminal performs an operation related to discontinuous reception.

4. A communication method, wherein: Perform the following steps from the terminal: a sending step of sending information indicating the intermittent reception operation of the other terminal to the other terminal performing the intermittent reception; as well as a control step of controlling an action related to maintaining a connection in the RRC layer with the other terminal via an interface between the terminals according to a specific timing, wherein the other terminal performs at least one of reception and sensing at the specific timing; The specific timing is a timing at which a timer related to a section in which the other terminal performs at least one of reception and sensing advances.

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