Wireless communication device and wireless communication method

Abstract

A communication device (200) according to the present disclosure is provided with a control unit (240). When a resource selected for use in a transmission packet in a sidelink communication is preempted by another wireless communication device (200), the control unit (240) transmits the packet by adjusting transmission parameters.

Description

Technical Field

[0001] This disclosure relates to wireless communication devices and wireless communication methods. Background Technology

[0002] Radio access methods and radio networks used for cellular mobile communications (hereinafter also referred to as "Long Term Evolution (LTE)," "LTE-Advanced (LTE-A)," "LTE-Advanced Pro (LTE-A Pro)," "5G (5th Generation)," "New Radio (NR)," "New Radio Access Technology (NRAT)," "Evolved Universal Terrestrial Radio Access (EUTRA)," or "Further EUTRA (FEUTRA)") are undergoing review by the 3rd Generation Partnership Project (3GPP). Note that in the following description, LTE includes LTE-Advanced, LTE-Advanced Pro, and EUTRA, while NR includes NRAT and FEUTRA. In LTE and NR, base station equipment (base stations) is also referred to as evolved NodeB (eNodeB) in LTE and gNodeB in NR, and terminal equipment (mobile stations, mobile station equipment, and terminals) is also referred to as user equipment (UE). LTE and NR are cellular communication systems in which multiple areas covered by base station equipment are arranged in the form of cells. A single base station equipment can manage multiple cells.

[0003] As the next-generation radio access method for LTE, NR is a different radio access technology (RAT) from LTE. NR is an access technology that can address a variety of use cases, including enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). This study examines NR within the technical framework corresponding to the use cases, request conditions, and deployment scenarios within these use cases.

[0004] In NR, several transmission methods have been studied. For example, transmission methods include licensed transmission (licensed transmission) and unlicensed transmission (unlicensed transmission). The presence or absence of a license corresponds to the presence or absence of a predetermined process for preventing collisions. In the case of licensed communication, transmission is performed after the predetermined process for preventing collisions is executed, while in the case of unlicensed communication, transmission is performed without executing the predetermined process for preventing collisions. Here, the predetermined process for preventing collisions includes base station resource allocation and / or predetermined sensing for preventing collisions. In unlicensed transmission, since the predetermined process for preventing collisions can be omitted, transmission with low latency can be performed compared to licensed transmission. Regarding unlicensed transmission, for example, Patent Document 1 discloses a technique for unlicensed transmission in the uplink.

[0005] On the other hand, in recent years, research has also been actively conducted on technologies related to sidechains, which serve as communication links for direct communication between terminals. In particular, expectations for vehicle-to-everything (V2X) communication have been rising in recent years in order to realize future autonomous driving. V2X communication is an abbreviation for Vehicle-to-X communication, and it is a system in which vehicles and "something" communicate with each other. Examples of "something" include vehicles, infrastructure, networks, pedestrians, etc. (V2V, V2I, V2N, and V2P). As wireless communication for vehicles, Dedicated Short Range Communication (DSRC) based on 802.11p has been the primary technology developed to date, but in recent years, "LTE-based V2X," as an LTE-based vehicle communication, has been standardized. In LTE-based V2X communication, the exchange of basic safety messages, etc., is supported.

[0006] Reference List

[0007] Patent documents

[0008] Patent Document 1: JP2018-191104A Summary of the Invention

[0009] Technical issues

[0010] In addition to the unlicensed transmission in the uplink studied in Patent Document 1, unlicensed transmission in the sidechain is also hypothesized. Unlicensed transmission in the sidechain could, for example, be used to transmit emergency information with low latency and high reliability, such as information indicating sudden braking of an autonomous vehicle or alarms in factory automation.

[0011] However, because the pre-defined procedures for preventing collisions are omitted in unlicensed transmission, unlicensed packets may collide with other packets transmitted and received by other terminals. Considering that communication in a sidechain may not be under centralized control by a base station or similar entity, similar collisions may occur in licensed transmission within the sidechain. Therefore, a mechanism is needed to avoid packet collisions in sidechain communication.

[0012] Therefore, this disclosure provides a mechanism for reducing collisions of packets sent in a sidechain.

[0013] Solution to the problem

[0014] According to this disclosure, a wireless communication device is provided. The wireless communication device includes a control unit. In sidechain communication, if the resources selected for packet transmission are preempted by other wireless communication devices, the control unit adjusts the transmission parameters and transmits the packets. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating an overview of V2X communication.

[0016] Figure 2 This is an illustrative diagram serving as an example of an overall picture for explaining V2X communication.

[0017] Figure 3 This is a diagram illustrating an example of a use case for V2X communication.

[0018] Figure 4 This is a diagram used to illustrate an example of a V2X operation scenario.

[0019] Figure 5 This is a diagram used to illustrate an example of a V2X operation scenario.

[0020] Figure 6 This is a diagram used to illustrate an example of a V2X operation scenario.

[0021] Figure 7 This is a diagram used to illustrate an example of a V2X operation scenario.

[0022] Figure 8 This is a diagram used to illustrate an example of a V2X operation scenario.

[0023] Figure 9 This is a diagram used to illustrate an example of a V2X operation scenario.

[0024] Figure 10 This is a diagram used to describe an extended example of sidechain communication.

[0025] Figure 11 This is a diagram used to describe an extended example of sidechain communication.

[0026] Figure 12 This is a diagram used to describe an extended example of sidechain communication.

[0027] Figure 13 This is a diagram used to describe an extended example of sidechain communication.

[0028] Figure 14 This is a diagram used to illustrate the sidechain resource allocation method.

[0029] Figure 15 This is a diagram illustrating an example of the configuration of resources allocated to sidechain communication.

[0030] Figure 16 This is an illustrative diagram illustrating an example of the operation timeline when a terminal device sends packets based on method B.

[0031] Figure 17 This is an illustrative diagram used to illustrate an example of a sensing operation for selecting resources from a resource pool.

[0032] Figure 18 This is a diagram illustrating an example of a schematic configuration of a system according to an embodiment of the present disclosure.

[0033] Figure 19 This is a sequence diagram used to describe the outline of the wireless communication method according to this embodiment.

[0034] Figure 20 This is a block diagram illustrating an example of the logical configuration of a base station according to an embodiment.

[0035] Figure 21 This is a block diagram illustrating an example of the logical configuration of a first terminal device according to an embodiment.

[0036] Figure 22 This is a block diagram illustrating an example of the logical configuration of a second terminal device according to an embodiment.

[0037] Figure 23 This is a flowchart illustrating the preemption process of the first terminal device according to this embodiment.

[0038] Figure 24 This is a diagram illustrating an example of packet transmission processing of a second terminal device according to this embodiment.

[0039] Figure 25 This is a diagram illustrating another example of packet transmission processing of the second terminal device according to this embodiment.

[0040] Figure 26 This is a diagram illustrating another example of packet transmission processing of the second terminal device according to this embodiment.

[0041] Figure 27 This is a diagram illustrating another example of packet transmission processing of the second terminal device according to this embodiment.

[0042] Figure 28 This is a flowchart illustrating an example of packet transmission processing according to this embodiment.

[0043] Figure 29 This is a diagram illustrating an example of feedback transmission processing of the second terminal device according to this embodiment.

[0044] Figure 30 This is a diagram illustrating another example of feedback transmission processing of the second terminal device according to this embodiment.

[0045] Figure 31 This is a diagram illustrating the preemption of a terminal device according to Variation 2 of this embodiment. Detailed Implementation

[0046] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In each of the following embodiments, the same parts are indicated by the same reference numerals, and redundant descriptions will be omitted.

[0047] This disclosure will be described in the following order of items.

[0048] 1. Introduction

[0049] 1.1.V2X communication

[0050] 1.2. Extended Example of Sidechain Communication

[0051] 1.3. Sidechain Resource Allocation Method

[0052] 2. Summary of the proposed technology

[0053] 2.1 System Configuration Example

[0054] 2.2. Technical Issues

[0055] 2.3. Summary of the proposed technology

[0056] 3. Configuration Example

[0057] 3.1. Configuration example of base station 100

[0058] 3.2. Configuration Example of the First Terminal Device 200P

[0059] 3.3. Configuration Example of Second Terminal Device 200E

[0060] 4. Technical Features

[0061] 4.1. Target of Seizure

[0062] 4.2. Preemption processing of the first terminal device 200P

[0063] 4.3. Packet Transmission Processing of the Second Terminal Equipment 200E

[0064] 5. Variation Example

[0065] 5.1. Variation Example 1

[0066] 5.2. Variation Example 2

[0067] 6. Summary

[0068] <<1. Introduction>>

[0069] <1.1.V2X communication>

[0070] The following is an overview of V2X communication. V2X communication is an abbreviation for Vehicle-to-X communication, and it is a system in which vehicles and "something" communicate with each other. For example, Figure 1 This is a diagram illustrating an overview of V2X communication. Examples of "something" here include... Figure 1 The vehicles, infrastructure, networks, pedestrians, etc. shown are (V2V, V2I, V2N, and V2P).

[0071] (Overall picture of V2X communication)

[0072] Figure 2 This is an illustrative diagram serving as an example to describe the overall picture of V2X communication. Figure 2 In the example shown, the V2X application server (APP server) is maintained as a cloud server, and the application server controls V2X communication on the core network side. The base station, while communicating with the terminal device via a Uu link, also controls direct communication such as V2V or V2P communication. In addition to the base station, roadside units (RSUs) are also deployed as roadside infrastructure. Two types of RSUs can be considered: base station-type RSUs and UE-type RSUs. The RSUs provide support for V2X applications (V2X APPs) and data relay, among other things.

[0073] (Use cases for V2X communication)

[0074] As for wireless communication for automobiles, dedicated short-range communication (DSRC) based on 802.11p has been the primary focus of development to date. However, in recent years, "LTE-based V2X (V2X communication based on LTE)" has been standardized as an LTE-based in-vehicle communication. In LTE-based V2X communication, the exchange of basic security messages is supported. Meanwhile, to further improve V2X communication, NR V2X communication using 5G technology (New Radio (NR)) has been researched in recent years. For example, Figure 3 This is a diagram illustrating an example of a use case for V2X communication.

[0075] In NR V2X communication, new use cases requiring high reliability, low latency, high-speed communication, and high capacity are supported, which is difficult to support in LTE-based V2X. As a concrete example, in... Figure 3 Examples shown may include the provision of dynamic maps, remote driving, etc. In addition, sensor data sharing, where sensor data is exchanged between vehicles and between roads and vehicles, and platooning use cases for platooning, may also be mentioned. Such use cases and requirements for NR V2X communication are defined in 3GPP TR22.886. For reference, an overview of examples of use cases is described below.

[0076] (1) Vehicle platooning

[0077] This is a use case for platooning, where multiple vehicles form a platoon and travel in the same direction, and information is exchanged between the leading vehicle and other vehicles to control the platoon's movement. For example, by exchanging this information, the distance between vehicles during platooning can be further reduced.

[0078] (2) Extended sensor

[0079] This is a use case for exchanging sensor-related information (raw data before processing and processed data) between vehicles, etc. Sensor information is collected through local sensors, real-time video images (e.g., real-time video images between surrounding vehicles, RSUs, and pedestrians), V2X application servers, etc. By exchanging this information, vehicles can obtain information that they cannot obtain through their own sensors and can identify a wider range of environments. In this use case, due to the large amount of information to be exchanged, communication requires a high data rate.

[0080] (3) Advanced driving

[0081] This is a use case for implementing semi-autonomous and fully autonomous driving. In this use case, the RSU shares identification information obtained from its own sensors with surrounding vehicles, allowing each vehicle to adjust its trajectory and operation while synchronizing and coordinating with other vehicles. Each vehicle can share its driving intentions with surrounding vehicles.

[0082] (4) Remote driving

[0083] This is a use case where a remote operator or V2X application performs remote control. Remote control is used in situations where someone else is driving instead of someone with limited driving skills, or operating a vehicle in a hazardous area. For example, cloud-based operations can also be applied to public transportation where routes and roads are somewhat predetermined. In this use case, communication requires high reliability and low transmission latency.

[0084] (Physical layer enhancement)

[0085] To achieve the above requirements, further enhancements to the physical layer of LTE V2X are needed. Examples of target links include Uu links and PC5 links (sidelinks). Uu links are links between infrastructure such as base stations or roadside units (RSUs) and terminal devices. PC5 links (sidelinks) are links between terminal devices. Key enhancements are shown below.

[0086] Examples of enhancements include the following.

[0087] - Channel format

[0088] -Sidechain feedback communication

[0089] -Sidechain resource allocation method

[0090] Vehicle location information estimation technology

[0091] -Inter-terminal relay communication

[0092] -Supports unicast and multicast communication

[0093] Multi-carrier communication, carrier aggregation

[0094] -MIMO (Multiple Input Multiple Output) / Beamforming

[0095] - High frequency support (e.g., 6GHz or higher)

[0096] ...etc.

[0097] Examples of channel formats include flexible numberology, short transmission time interval (TTI), multiple antenna support, and waveforms. Examples of sidechain feedback communication include HARQ and channel state information (CSI).

[0098] (V2X operation scenario)

[0099] The following will describe examples of V2X communication operation scenarios. In V2N communication, only DL / UL communication occurs between the base station and the terminal device, and it is relatively simple. On the other hand, in V2V communication, various communication paths can be considered. In the following text, we will mainly focus on examples of V2V communication to describe each scenario, but similar communication operations can be applied to V2P and V2I. In V2P and V2I, the communication destination is a pedestrian or RSU.

[0100] For example, Figures 4 to 9 This is a diagram used to illustrate an example of a V2X operation scenario. Specifically, Figure 4 This illustrates a scenario where vehicles communicate directly with each other without a base station (E-UTRAN). Figure 5 The illustration shows a scenario where vehicles communicate with each other via a base station. Figure 6 and Figure 7 This illustrates a scenario where vehicles communicate with each other via a terminal device (UE, or RSU in this example) and a base station. Figure 8 and Figure 9 This illustrates a scenario where vehicles communicate with each other via a terminal device (UE, in this example, an RSU or other vehicle).

[0101] exist Figures 4 to 9 In this context, "sidechain" refers to the communication link between terminal devices and is also known as PC5. Specific examples of sidechains include V2V, V2P, and V2I communication links. "Uu interface" corresponds to the wireless interface between a terminal device and a base station. Specific examples of the Uu interface include V2N communication links. "PC5 interface" corresponds to the wireless interface between terminal devices.

[0102] <1.2. Extended Example of Sidechain Communication>

[0103] For sidechain communication, various extended examples can be considered. For instance, the V2X communication described above is one such extended example. In addition, device-to-device (D2D) communication, machine-type communication (MTC), mobile cell communication, and relay communication are also considered extended examples of sidechain communication. The following will refer to... Figures 10 to 13 This is an extended example to describe sidechain communication.

[0104] Figure 10 An example of sidelink communication using a vehicle-mounted base station installed on a vehicle is shown. Figure 10 As shown, the vehicle-mounted base station communicates with surrounding terminal devices (e.g., UEs in the same vehicle) or with other vehicles via sidechain communication. The vehicle-mounted base station can be a UE, RSU, etc.

[0105] Figure 11 An example of using sidechain communication for relay communication to wearable terminals provided by the UE is shown. For example... Figure 11 As shown, the UE communicates with the wearable terminal via a sidechain and relays the communication between the wearable terminal and the base station.

[0106] Figure 12 An example of sidechain communication using a drone base station mounted on a drone is shown. Figure 12 As shown, the drone base station communicates with surrounding UEs via sidechains and relays communication between the UEs and the base station.

[0107] Figure 13 An example of sidelink communication used by a terminal base station installed on the UE is shown. Figure 13 As shown, the terminal base station communicates with surrounding UEs via sidechains and relays communication between the UEs and the base station.

[0108] In addition, factory automation can also be cited as an extended example of sidechain communication. In this case, sidechain communication can be used for communication between robots in a factory. For example, sidechain communication can be used in a use case where an emergency stop signal is broadcast to a group of robots to urgently stop the production line. As an extended example of sidechain communication, there is communication between drones.

[0109] <1.3. Sidechain Resource Allocation Method>

[0110] Next, an overview of the resource allocation methods for sidechains will be described. As methods for allocating sidechain resources, there is method A, where the base station allocates sidechain resources, and method B, where the terminal device senses and selects sidechain resources. Note that method A is also referred to as "Mode 3" in LTE and "Mode 1" in NR, while method B is also referred to as "Mode 4" in LTE and "Mode 2" in NR. When LTE and NR are not distinguished from each other, they will be simply described as method A and method B. The following will refer to... Figure 14 To describe these.

[0111] Figure 14 It is a diagram used to describe how sidechain resources are allocated. Figure 14 The left figure shows an example of Mode A. In Mode A, a resource pool is pre-allocated, and when a transmission packet is generated in the terminal, the base station allocates resources from the resource pool to be used for transmitting the packet. In Mode A, since the base station performs resource allocation every time a transmission packet occurs, packet collisions do not occur, thus avoiding higher signaling overhead. Figure 14 The right figure illustrates an example of Mode B. In Mode B, a resource pool is pre-allocated, and when a packet is generated, the terminal autonomously selects the resources in the pool to use for packet transmission. While the signaling overhead is minimal in Mode B, packet collisions may occur.

[0112] -Resource pool allocation

[0113] When executing either method A or method B, resource pool allocation is performed in advance. Resource pool allocation is performed, for example, by the base station. As another example, resource pools can be allocated through pre-configuration. In method B, the terminal device senses resources for sidechain communication from the allocated resource pool and selects appropriate resources for communication.

[0114] For example, Figure 15 This is a diagram illustrating an example configuration of resources (resource pools) allocated to sidelink communication, and also showing an example of applying Frequency Division Multiplexing (FDM). Figure 15 As shown, the resource pool is divided into a scheduling allocation (SA) area and a data area, and the Physical Sidelink Control Channel (PSCCH) and Physical Sidelink Shared Channel (PSSCH) are transmitted by each area. Note that in the following text, the focus will be on... Figure 15 The application of FDM shown is described, but the application of the techniques according to this disclosure is not necessarily limited. As a specific example, the techniques according to this disclosure described below can also be applied even when Time Division Multiplexing (TDM) is applied. When TDM is applied, the SA area and the data area are orthogonal to each other on the time axis.

[0115] -Method B

[0116] Reference Figure 16 A summary of description method B. Figure 16 This is an illustrative diagram illustrating an example of the operation timeline when a terminal device sends packets based on method B. For example... Figure 16 As shown, the terminal device sending packets first performs sensing to discover resources from the resource pool for packet transmission. Next, the terminal device selects resources from the resource pool based on the sensing results. Then, the terminal device uses the selected resources to send the packets. At this point, the terminal device reserves resources for subsequent packet transmission as needed.

[0117] Here, we will refer to Figure 17 An example describing sensing operations. Figure 17 This is an illustrative diagram used to describe an example of a sensing operation for selecting resources from a resource pool.

[0118] Specifically, the terminal device selects resources in the resource selection window and reserves future resources based on the measurement results of the interference mode in the sensing window and the resource reservation status in the sensing window. As a specific example, in... Figure 17 In the example shown, when a packet D to be sent is generated, the terminal device predicts the future resource usage status based on sensing results, for example, resources that will be used to send other packets A to C in the future. By using the prediction results, the terminal device can select or reserve resources that can be used to send packet D, i.e., resources that are predicted to be unavailable for sending other packets.

[0119] In the following description, unless otherwise stated, it will be assumed that the terminal device sends packets based on method B.

[0120] <<2. Summary of the Proposed Technology>>

[0121] <2.1. System Configuration Example>

[0122] Next, we will refer to Figure 18 An example illustrating the configuration of a system that applies the proposed technology. Figure 18 This is a diagram illustrating an example of a schematic configuration of system 1 according to an embodiment of the present disclosure. As shown in Figure 18, system 1 includes a base station 100, terminal devices 200 (200A to 200D), a core network 20, and a packet data network (PDN) 30.

[0123] Base station 100 is a communication device that operates cell 11 and provides wireless services to one or more terminal devices 200 located within cell 11. Cell 11 can operate according to any wireless communication method such as LTE or NR. Base station 100 is connected to core network 20. Core network 20 is connected to PDN 30.

[0124] Core network 20 may include, for example, a Mobility Management Entity (MME), a Serving Gateway (S-GW), a PDN Gateway (P-GW), a Policy and Charging Rule Function (PCRF), and a Home Subscriber Server (HSS). Alternatively, core network 20 may include an NR entity with similar functions. The MME is a control node that processes control plane signals and manages the mobility state of terminal devices. The S-GW is a control node that processes user plane signals and is a gateway device that switches the transmission path of user data. The P-GW is a control node that processes user plane signals and is a gateway device that serves as a connection point between core network 20 and PDN 30. The PCRF is a control node that performs controls related to policies and charging, such as Quality of Service (QoS) for bearers. The HSS is a control node that processes user data and performs service controls.

[0125] Terminal device 200 is a communication device that wirelessly communicates with other devices. For example, terminal device 200 wirelessly communicates with base station 100 based on the control of base station 100. In this case, terminal device 200 sends uplink signals to base station 100 on the Uu link and receives downlink signals from base station 100. For example, terminal device 200 wirelessly communicates with other terminal devices 200 based on the control of base station 100 or autonomously. In this case, terminal device 200 sends sidelink signals to other terminal devices 200 on the PC5 link and receives sidelink signals from other terminal devices 200. For example, terminal device 200A sends a sidelink signal to terminal device 200B, and terminal device 200C sends a sidelink signal to terminal device 200D. Terminal device 200 may be a so-called user equipment (UE).

[0126] <2.2. Technical Issues>

[0127] In existing sidechain communication, transmission is performed after predetermined processes to prevent collisions, such as resource allocation from the base station in method A or sensing in method B. Therefore, a delay occurs from packet generation to packet transmission. Note that packet collisions indicate that multiple packets are transmitted and received using at least partially overlapping resources (time and frequency resources).

[0128] In use cases such as URLLC, where urgent packets are sent with low latency and high reliability, a mechanism is needed to send packets with high reliability without such latency. Specifically, in sidechain communication, unlike the typical unlicensed transmissions of Uu links where the base station performs overall control, the transmitting entities are multiple terminal devices, thus requiring measures to avoid packet collisions.

[0129] <2.3. Summary of the Proposed Technology>

[0130] Therefore, this disclosure provides a mechanism for avoiding collisions between packets sent in a sidechain. In particular, a mechanism is provided for avoiding collisions between packets sent with low latency and high reliability (hereinafter also referred to as URLLC packets) and other packets in URLLC use cases.

[0131] In this disclosure, the terminal device 200 sending URLLC packets performs a so-called preemption, in which it uses resources selected or reserved by other terminal devices 200 for packet transmission to send the URLLC packets. As a result, the terminal device 200 can omit predetermined processes such as sensing to prevent collisions and can send URLLC packets with low latency and high reliability.

[0132] Note that in the following text, using resources selected or reserved by other terminal devices for packet transmission to send URLLC packets is referred to as preemption or preemption. However, in addition to preemption or preemption, it can also be referred to as, for example, interruption of resource use, resource theft, suspension, etc.

[0133] In the following text, the terminal device 200 that performs preemption to send URLLC packets is referred to as the first terminal device 200P, the preemptor 200P, or UE1. Other terminal devices 200 whose pre-selected or reserved resources are preempted are referred to as the second terminal device 200E, the preemptee 200E, or UE2. Note that unless there is a need to distinguish between the first terminal device 200P and the second terminal device 200E, they are simply referred to as terminal device 200.

[0134] Figure 19 This is a sequence diagram used to describe the outline of the wireless communication method according to this embodiment. Here, it is assumed that the second terminal device 200E reserves resource R1 in advance for data packet transmission, and the first terminal device 200P preempts resource R1 and transmits URLLC packets. To distinguish it from URLLC packets, packets to be transmitted without preemption are also referred to as normal packets.

[0135] Terminal device 200 performs sensing when there are no packets to be transmitted (step S1). Upon detecting a URLLC packet (step S2), the first terminal device 200P selects a resource to preempt based on the sensing result of step S1 (step S3). Specifically, for example, the first terminal device 200P selects or reserves a resource for transmitting a packet with a lower transmission priority than the URLLC packet. Here, the first terminal device 200P makes resource R1, which was reserved by the second terminal device 200E, the resource to be preempted. For example, the packet transmission priority is included in the sidechain control information (SCI) transmitted before transmitting data packets.

[0136] The first terminal device 200P sends an instruction to preempt the resource R1 selected in step S3 to send the URLLC packet information (preemption instruction) (step S4), and sends the URLLC packet in the side chain (step S5).

[0137] Upon detecting a preemption indication (step S6), the second terminal device 200E determines whether resource reselection is possible (step S7). Resource reselection requires processing time for resource reselection, and therefore, depending on the timing of receiving the preemption indication, resource reselection may not be timely.

[0138] Therefore, when it is determined that resources cannot be reselected (step S7; no), the second terminal device 200E adjusts the packet transmission parameters (step S8). Here, the adjustment of transmission parameters includes, for example, reducing the transmission power, switching the modulation and coding scheme (MCS: modulation and coding scheme) to a high-efficiency mode, etc.

[0139] The second terminal device 200E, acting as the preempted party, reduces its transmission power and sends packets to avoid interference (collisions) with the URLLC packet transmission of the first terminal device 200P. Note that performing parameter adjustments to reduce transmission power includes the preempted party ceasing transmission. This is because ceasing transmission reduces the transmission power to zero and also achieves the effect of avoiding interference with the preempted party.

[0140] The second terminal device 200E, acting as the preempted party, adjusts its MCS (Multi-Segment Control) to a high-efficiency mode to reduce the required resources (e.g., the number of resource blocks). As a result, the overlap between the resources of URLLC packets sent by the first terminal device 200P (acting as the preemptor) and the resources of packets sent by the second terminal device 200E (acting as the preempted party) can be reduced. Therefore, the conflict range between the resources of URLLC packets and the resources of packets sent by the second terminal device 200E can be changed from, for example, a complete overlap to a partial overlap, and interference from the second terminal device 200E to the first terminal device 200P can be suppressed (reduced).

[0141] On the other hand, if resources can be reselected (step S7; yes), the second terminal device 200E reselects resources (step S9) and sends data packets in the sidechain (step S10).

[0142] As described above, the first terminal device 200P preempts resources used for sending packets with lower priority than URLLC packets. As a result, the first terminal device 200P can send URLLC packets without hindering the transmission of high-priority packets, thus reducing packet collisions. Since the second terminal device 200E adjusts its transmission parameters and sends data packets, collisions with URLLC packets can be avoided. Consequently, collisions with packets sent in the sidechain can be reduced.

[0143] Note that here, the second terminal device 200E performs a reselection of the preempted resources, but the present invention is not limited to this. For example, if the second terminal device 200E has already reserved future resources including resource R1, it can also reselect the already reserved resources. In this way, the second terminal device 200E can not only reselect the preempted resource R1, but also reselect resources related to resource R1 (resources reserved simultaneously with resource R1 in this example).

[0144] <<3. Configuration Example>>

[0145] The following section will describe configuration examples for each device involved in the proposed technology.

[0146] <3.1. Configuration Example of Base Station 100>

[0147] Figure 20 This is a block diagram illustrating an example of the logical configuration of a base station 100 according to this embodiment. For example... Figure 20 As shown, the base station 100 according to this embodiment includes an antenna unit 110, a wireless communication unit 120, a network communication unit 130, a storage unit 140, and a control unit 150.

[0148] Antenna unit 110 radiates the signal output from wireless communication unit 120 into space as radio waves. Antenna unit 110 converts the radio waves in space into signals and outputs the signals to wireless communication unit 120.

[0149] The wireless communication unit 120 transmits and receives signals. For example, the wireless communication unit 120 receives uplink signals from the terminal device and transmits downlink signals to the terminal device.

[0150] Network communication unit 130 sends and receives information. For example, network communication unit 130 sends information to other nodes and receives information from other nodes. Other nodes include other base stations and core network nodes.

[0151] Storage unit 140 temporarily or permanently stores programs and various data used for the operation of base station 100.

[0152] Control unit 150 provides various functions of base station 100. For example, control unit 150 includes communication control unit 151. Communication control unit 151 has the function of controlling sidechain communication performed by controlled terminal equipment 200, such as allocating resource pools to terminal equipment 200, allocating resources to terminal equipment 200 that generates transmitted packets, and retransmitting conflicting packets. Control unit 150 may also include other components besides communication control unit 151. That is, control unit 150 can also perform operations other than those of communication control unit 151.

[0153] <3.2. Configuration Example of the First Terminal Device 200P>

[0154] Figure 21 This is a block diagram illustrating an example of the logical configuration of the first terminal device 200P according to this embodiment. For example... Figure 21 As shown, the first terminal device 200P according to this embodiment includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a control unit 240P.

[0155] Antenna unit 210 radiates the signal output from wireless communication unit 220 into space as radio waves. Antenna unit 210 converts the radio waves in space into signals and outputs the signals to wireless communication unit 220.

[0156] The wireless communication unit 220 transmits and receives signals. For example, the wireless communication unit 220 receives downlink signals from base station 100 and transmits uplink signals to base station 100. The wireless communication unit 220 transmits to and receives sidechain signals (V2P signals, V2V signals, V2I signals, etc.) from other terminal devices 200.

[0157] Storage unit 230 temporarily or permanently stores programs and various data for the operation of the first terminal device 200P.

[0158] The control unit 240P provides various functions of the first terminal device 200P. For example, the control unit 240P includes a sensing processing unit 241P, a transmission packet detection unit 242P, a resource selection unit 243P, a transmission processing unit 244P, and a reception processing unit 245P.

[0159] The sensing processing unit 241P has the function of sensing resource usage status to select resources for packet transmission. The transmission packet detection unit 242P detects transmission packets, such as URLLC packets, to be sent to other terminal devices 200. The transmission packet is data related to a process generated in the terminal device 200. The data is, for example, data related to a transmission job generated by various programs (e.g., applications or operating systems) executed by the terminal device 200. Note that such data can be divided into multiple data and transmitted in multiple transmission packets.

[0160] For example, the resource selection unit 243P selects resources for transmitting packets detected by the transmission packet detection unit 242P based on the results of sensing resource usage status performed by the sensing processing unit 241P. Suppose the transmission packet detection unit 242P detects, for example, URLLC packets. In this case, the resource selection unit 243P selects resources selected or reserved by other terminal devices 200 for transmitting packets with lower priority than URLLC packets as the resources for transmitting the URLLC packets.

[0161] The transmission processing unit 244P has the function of transmitting transmission packets input from the upper layer. For example, when transmitting URLLC packets using resources selected or reserved by other terminal devices 200, the transmission processing unit 244P notifies that preemption should be performed before transmitting the URLLC packets. Note that the first terminal device 200P can explicitly notify that preemption should be performed, for example, by setting a field indicating preemption in an SCI, or the first terminal device 200P can implicitly notify that resources are used, for example, by using an SCI.

[0162] Note that in the following text, the SCI sent by the transmission processing unit 244P for preemption is also referred to as the Preemption Indication (PI)-SCI, to distinguish it from the SCI sent for normal packets. The PI-SCI can be an SCI sent before the transmission processing unit 244P performs preemption, and is independent of whether there is a field indicating preemption.

[0163] The receiving and processing unit 245P has the function of receiving and decoding packets and outputting the packets to the upper layer. The control unit 240P may also include other components besides these. That is, the control unit 240P can also perform operations other than those of these components.

[0164] <3.3. Configuration Example of Second Terminal Device 200E>

[0165] Figure 22 This is a block diagram illustrating an example of the logical configuration of the second terminal device 200E according to this embodiment. For example... Figure 22As shown, the second terminal device 200E according to this embodiment includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a control unit 240E. Due to the configuration other than the control unit 240E... Figure 21 The configuration of the first terminal device 200P shown is the same, so its description will be omitted.

[0166] The control unit 240E provides various functions of the second terminal device 200E. For example, the control unit 240E includes a sensing processing unit 241E, a preemption detection unit 242E, a parameter adjustment unit 243E, a transmission processing unit 244E, and a reception processing unit 245E.

[0167] The sensing processing unit 241E has the function of sensing resource usage status to select resources for packet transmission. The preemption detection unit 242E detects preemption, for example, by the first terminal device 200P. For example, if the first terminal device 200P sends an SCI with a field indicating preemption, the preemption detection unit 242E detects preemption by detecting the content of the field. Alternatively, suppose the first terminal device 200P implicitly notifies preemption by sending an SCI without setting such a field. In this case, the preemption detection unit 242E detects preemption by the first terminal device 200P based on whether the resources used by the first terminal device 200P overlap with the resources used by the second terminal device 200E.

[0168] If preemption is detected by the preemption detection unit 242E, the parameter adjustment unit 243E adjusts the transmission parameters of the packet that is scheduled to be transmitted using the preempted resource. The parameter adjustment unit 243E adjusts at least one of the transmission power, MCS, or packet size as the transmission parameter.

[0169] For example, parameter adjustment unit 243E adjusts transmission parameters based on sidechain communication quality (e.g., SL-RSRP) information, ensuring that packet transmission by the primary device does not interfere with URLLC packet transmission by the first terminal device 200P. Alternatively, parameter adjustment unit 243E may adjust transmission parameters based on the location of the terminal device 200. Specifically, for example, parameter adjustment unit 243E adjusts transmission parameters according to the locations of the first terminal device 200P and its communication partners, as well as the locations of the second terminal device 200E and its communication partners.

[0170] For example, parameter adjustment unit 243E adjusts the transmission power as a transmission parameter. In the case of V2X communication, packets are transmitted at a specified maximum power, but in the case of resource preemption, for example, parameter adjustment unit 243E adjusts the transmission power of the packets to be transmitted to be less than the specified maximum power.

[0171] Alternatively, by changing the MCS, the parameter adjustment unit 243E adjusts the transmission parameters so that the packet transmission of the main device does not interfere with the transmission of URLLC packets of the first terminal device 200P.

[0172] For example, parameter adjustment unit 243E can adjust the packet size by segmenting packets that are intended to be sent using preempted resources. For instance, if the preempted resources are part of the resources selected for packet transmission, parameter adjustment unit 243E adjusts the packet size to a size that can be transmitted using unpreempted resources. As a result, second terminal device 200E can use resources that do not interfere with first terminal device 200P's transmission of URLLC packets to transmit a portion of the packet.

[0173] As described above, by adjusting the transmission parameters through the parameter adjustment unit 243E, interference with the transmission of URLLC packets by the first terminal device 200P can be reduced, and conflicts between URLLC packets and packets transmitted by the main device can be avoided.

[0174] Here, the transmission parameters adjusted by the parameter adjustment unit 243E are at least one of transmission power, MCS, and packet size, but are not limited to these. The parameter adjustment unit 243E only needs to adjust the transmission parameters so that the packet transmission of the main device does not interfere with the transmission of URLLC packets by the first terminal device 200P, and can adjust parameters other than the aforementioned transmission parameters.

[0175] The parameter adjustment unit 243E reselects resources to be used for packet transmission by the main device. In this case, the parameter adjustment unit 243E selects resources other than those that have been preempted from, for example, the resource pool allocated from the base station 100, based on the sensing results of the sensing processing unit 241E.

[0176] As described above, the parameter adjustment unit 243E reselects resources so that conflicts between URLLC packets sent by the first terminal device 200P and packets sent by the main device can be avoided.

[0177] Note that here, the transmission parameters are adjusted when the parameter adjustment unit 243E does not have processing time to reselect resources, but the invention is not limited to this. For example, if interference occurs in the transmission of URLLC packets of the first terminal device 200P even after the parameter adjustment unit 243E adjusts the transmission parameters, resources can be reselected. Alternatively, the parameter adjustment unit 243E can adjust the transmission parameters when resources cannot be reselected (i.e., there are no available resources in the resource pool).

[0178] If a resource cannot be reselected and interference occurs in the transmission of URLLC packets by the first terminal device 200P even after adjusting the transmission parameters, the parameter adjustment unit 243E may, for example, stop transmitting packets. When packet transmission stops, the parameter adjustment unit 243E may discard packets that were scheduled to be transmitted. In this case, the parameter adjustment unit 243E notifies the upper layer that packet transmission has failed. Alternatively, in the case of packet transmission stopping, for example, the parameter adjustment unit 243E may transmit packets after a certain period of time. In other words, in the case of packet transmission stopping, the parameter adjustment unit 243E delays packet transmission.

[0179] As described above, since the parameter adjustment unit 243E stops sending packets, conflicts between URLLC packets sent by the first terminal device 200P and packets sent by the main device can be avoided.

[0180] Note that here, in the case where resources cannot be reselected and interference occurs in the transmission of URLLC packets by the first terminal device 200P even after adjusting the transmission parameters, the parameter adjustment unit 243E stops transmitting packets; however, the present invention is not limited thereto. For example, the parameter adjustment unit 243E may stop transmitting packets in one of the following situations: where resources cannot be reselected and interference occurs in the transmission of URLLC packets by the first terminal device 200P even after adjusting the transmission parameters. Alternatively, if resources used for packet transmission are preempted, the parameter adjustment unit 243E may stop transmitting packets without reselecting resources or adjusting the transmission parameters.

[0181] The transmission processing unit 244E has the function of transmitting packets input from the upper layer. If the resources selected or reserved for packet transmission are preempted, the transmission processing unit 244E transmits the packets using transmission parameters adjusted by the parameter adjustment unit 243E. Alternatively, the transmission processing unit 244E transmits the packets using resources reselected by the parameter adjustment unit 243E. Note that the transmission processing unit 244E transmits an SCI before packet transmission, which includes information about the transmission parameters adjusted by the parameter adjustment unit 243E or the reselected resources.

[0182] The receiving and processing unit 245E has the function of receiving and decoding packets and outputting packets to the upper layer. The control unit 240E may also include other components besides these components. That is, the control unit 240E can also perform operations other than those of these components.

[0183] <<4. Technical Features>>

[0184] <4.1. Target Acquisition>

[0185] First, before describing the technical features, the resources to be seized by the first terminal device 200P will be described.

[0186] Examples of resources that the first terminal device 200P may preempt include the following.

[0187] -Resources used for initial sending

[0188] -Reserved resources for sending

[0189] - Resources used for sending feedback (PSFCH)

[0190] The resources used for initial transmission are those resources that are not reserved by the terminal device 200 for packet transmission. Before transmitting packets using the selected resources, the terminal device 200 requests radio wave utilization by transmitting an SCI specifying the selected resources. As a result, the terminal device 200 ensures that the selected resources are used for initial transmission.

[0191] Reserved transmission resources are resources that terminal device 200 pre-secures for packet transmission. For example, terminal device 200 sends an SCI (Signal Content Module) to secure resources for the initial transmission by including information related to the reservation of resources for subsequent packet transmission. As a result, terminal device 200 secures resources for future packets as reserved transmission resources.

[0192] Resources used for feedback transmission are, for example, resources secured for blind retransmissions or HARQ feedback transmissions to the sending side.

[0193] <4.2. Preemption Processing of the First Terminal Device 200P>

[0194] First, the preemption process of the first terminal device 200P will be described below. Figure 23 This is a flowchart illustrating the preemption process of the first terminal device 200P according to this embodiment.

[0195] like Figure 23 As shown, the first terminal device 200P performs sensing (step S101) when not performing packet transmission, and obtains information about the resources selected or reserved by other terminal devices 200 for packet transmission.

[0196] Next, the first terminal device 200P determines whether a transmission packet has been detected (step S102). If no transmission packet is detected (step S102; No), the process returns to step S101 to perform sensing. On the other hand, if a transmission packet is detected (step S102; Yes), the first terminal device 200P determines whether the transmission packet is a URLLC packet (step S103).

[0197] When it is determined that the transmitted packet is not a URLLC packet (step S103; no), in other words, when the transmitted packet is a normal packet, the first terminal device 200P selects a resource based on the sensing result and transmits a normal packet (step S104).

[0198] On the other hand, when it is determined that the packet to be sent is a URLLC packet (step S103; Yes), the first terminal device 200P determines whether there are available resources capable of sending URLLC packets based on the sensing results (step S105).

[0199] If available resources exist (step S105; Yes), the first terminal device 200P uses the available resources to send URLLC packets (step S106). On the other hand, if no available resources exist (step S105; No), the first terminal device 200P selects resources that other terminal devices 200 have selected or reserved for sending packets with a lower priority than URLLC packets (step S107).

[0200] Subsequently, the first terminal device 200P uses the selected resource to send an SCI including information about the transmission parameters of the URLLC packet (step S108). Afterward, the first terminal device 200P sends the URLLC packet (step S109).

[0201] In this way, the first terminal device 200P preempts resources according to priority and sends URLLC packets. As a result, the first terminal device 200P can reduce conflicts with packets sent by other terminal devices 200.

[0202] <4.3. Packet Transmission Processing of the Second Terminal Device 200E>

[0203] The packet transmission processing performed by the second terminal device 200E in the event of resource preemption varies depending on the transmission timing of the PI-SCI of the first terminal device 200P. Therefore, the packet transmission processing performed by the second terminal device 200E will be described in the following three modes. In the following text, the first terminal device 200P may be referred to as UE1, and the second terminal device 200E may be referred to as UE2.

[0204] 1) Case where PI-SCI is sent before SCI.

[0205] 2) Case where PI-SCI is sent after SCI.

[0206] 3) Simultaneous sending of PI-SCI and SCI

[0207] (The case where PI-SCI is sent before SCI)

[0208] First, the scenario in which the first terminal device 200P sends a PI-SCI including a preemption instruction to perform preemption before the second terminal device 200E sends an SCI will be described. Figure 24 This is a diagram illustrating an example of packet transmission processing of the second terminal device 200E according to this embodiment.

[0209] Figure 24 (A) shows an example of packet transmission performed by a second terminal device 200E (UE2) when the first terminal device 200P (UE1) has not performed preemption.

[0210] The second terminal device 200E, for example, sends an SCI at time ta before transmitting data packets and performs resource announcement at time tb. The SCI sent at time ta includes, for example, information about time tb and transmission frequency, and the second terminal device 200E can secure (select) resource Rb by sending the SCI at time ta. The SCI sent at time ta includes information about transmission parameters used for transmission in resource Rb, such as transmission power and MCS.

[0211] For example, the second terminal device 200E can use the SCI sent at time ta to reserve resources after time tb. Figure 24 The second terminal device 200E advertises the resource by sending an SCI at time tc before sending data packets on the reserved resource Rd. In this way, the second terminal device 200E sends data packets after sending the SCI.

[0212] Reference Figure 24 (B) describes the preemption situation performed by the first terminal device 200P. Note that the processing until the second terminal device 200E sends a data packet at time tb is the same as... Figure 24 The processing is the same as in (A), so its description is omitted.

[0213] Here, it is assumed that the first terminal device 200P detects the generation of a URLLC packet at time t0. In this case, the first terminal device 200P performs resource preemption of resource Rd by sending a PI-SCI at time tp.

[0214] At this time, if the second terminal device 200E sends data on resource Rd without performing adjustments such as resource reselection, the data packets sent by the first terminal device 200P (URLLC packets in this example) and the data packets sent by the second terminal device 200E will conflict with each other.

[0215] Therefore, when a PI-SCI sent at time tp is detected, the second terminal device 200E performs resource reselection, for example. Figure 24 (C) shows an example of the second terminal device 200E performing resource reselection.

[0216] When resource Rd is preempted, the second terminal device 200E performs resource reselection. Figure 24 In (C), it is assumed that the second terminal device 200E reselects a resource Re different from resource Rd. In this case, the second terminal device 200E, for example, sends an SCI specifying the time and frequency resources for transmitting data packets at time tc, and announces resource Re. Subsequently, the second terminal device 200E transmits data packets at time te. As a result, even if the first terminal device 200P uses resource Rb to transmit URLLC packets, conflicts with data packets from the second terminal device 200E can be avoided.

[0217] Note that here, if resource Rd is preempted, the second terminal device 200E reselects a resource; however, for example, the second terminal device 200E can adjust the transmission parameters of data packets. Alternatively, the second terminal device 200E can stop transmitting data packets.

[0218] (The case where PI-SCI is sent after SCI)

[0219] Next, we will refer to Figure 25 Describe the situation where the first terminal device 200P sends PI-SCI to perform preemption after the second terminal device 200E sends SCI. Figure 25 This is a diagram illustrating another example of packet transmission processing for the second terminal device 200E according to this embodiment.

[0220] Figure 25 (A) shows an example of packet transmission performed by a second terminal device 200E (UE2) when the first terminal device 200P (UE1) has not performed preemption.

[0221] The second terminal device 200E performs resource announcement for resource Rb by sending an SCI at time ta, and sends data packets at time tb. At this time, as... Figure 25 As shown in (b), assume that the first terminal device 200P detects the generation of a URLLC packet at time t0. In this case, the first terminal device 200P performs resource preemption of resource Rd by sending a PI-SCI at time tp.

[0222] At this time, if the second terminal device 200E sends data on resource Rd without performing adjustments such as resource reselection, the data packets sent by the first terminal device 200P (URLLC packets in this example) and the data packets sent by the second terminal device 200E will conflict with each other.

[0223] Therefore, when a PI-SCI sent at time tp is detected, the second terminal device 200E performs resource reselection, for example.

[0224] exist Figure 25 In the example shown, the second terminal device 200E has already made a resource announcement related to resource Rb at time ta. Therefore, if the second terminal device 200E only sends data packets on the reselected resource, the receiving side cannot receive the data packets sent by the second terminal device 200E. This is because the receiving side attempts to receive the data packets sent in resource Rb based on the SCI received at time ta.

[0225] Therefore, in the case of resource reselection, the second terminal device 200E performs resource advertisement for resource Re by resending the SCI at time ta2, such as Figure 25 As shown in (C). As a result, when the second terminal device 200E sends a data packet on the reselected resource Re, the receiving side can receive the data packet.

[0226] exist Figure 25 The previous section described the scenario where the second terminal device 200E performs resource reselection; however, the second terminal device 200E can adjust transmission parameters instead of reselecting resources. (See also...) Figure 26 Describe the situation regarding the adjustment of sending parameters.

[0227] Figure 26 This is a diagram illustrating another example of packet transmission processing for the second terminal device 200E according to this embodiment. Note that... Figure 26 (A) and Figure 26 (B) and Figure 25 (A) and Figure 25 Since (B) is the same, its description is omitted.

[0228] When a PI-SCI is detected being sent at time tp, the second terminal device 200E adjusts, for example, the transmission parameters of the data packets. Figure 26As shown in (C), the second terminal device 200E includes information about the adjusted transmission parameters in the SCI and transmits the SCI at time ta2. Thereafter, the second terminal device 200E transmits data packets using resource Rb at time tb. Note that at time tb, the first terminal device 200P also uses resource Rb to transmit URLLC packets, but because the second terminal device 200E adjusts its transmission parameters, a conflict between the two packets is avoided.

[0229] Note that in Figure 26 In (C), for ease of viewing, the transmission resources of URLLC packets and data packets are shown as shifted, but the transmission resources of URLLC packets and data packets can be completely identical. Alternatively, a portion of the transmission resources of URLLC packets and data packets can overlap.

[0230] The process of the second terminal device 200E performing resource reselection and transmission parameter adjustment has been described here, but the second terminal device 200E can stop sending data packets.

[0231] (Simultaneous submission of PI-SCI and SCI documents)

[0232] For example, the transmission of PI-SCI by the first terminal device 200P and the transmission of SCI by the second terminal device 200E can overlap with each other. (Refer to...) Figure 27 Describe this situation. Figure 27 This is a diagram illustrating another example of packet transmission processing for the second terminal device 200E according to this embodiment.

[0233] like Figure 27 As shown, it is assumed that the time tp for the first terminal device 200P to send the PI-SCI and the time tc for the second terminal device 200E to send the SCI are the same. For example, this can occur when the first terminal device 200P can only perform one of sending or receiving (half-duplex) and cannot receive the message instructing the second terminal device 200E to send the SCI, and the timing of the PI-SCI and SCI transmissions overlaps. In this case, the second terminal device 200E cannot detect the PI-SCI.

[0234] In this scenario, for example, another terminal device 200 (not shown) that receives both PI-SCI and SCI notifies the second terminal device 200E of the preemption by the first terminal device 200P. Examples of other terminal devices 200 include terminal devices 200 that perform sidechain communication with the first terminal device 200P and terminal devices 200 that perform sidechain communication with the second terminal device 200E. Terminal device 200 is a terminal device 200 that sends / receives data to / from the first terminal device 200P or the second terminal device 200E, and sends / receives feedback and auxiliary information to / from the first terminal device 200P or the second terminal device 200E.

[0235] In the alternative location, replacing other terminal devices 200, base station 100 can notify the second terminal device 200E of the preemption. Terminal devices 200, etc., that have some of the functions of base station 100 (e.g., roadside units (RSUs) or primary UEs that allocate resource pools to the first terminal device 200P or the second terminal device 200E) can notify the preemption.

[0236] Note that because SCI and PI-SCI are small in size, the probability of a collision is very low even if they occur simultaneously. Therefore, other terminal devices 200, base station 100, etc., can receive both SCI and PI-SCI transmitted simultaneously.

[0237] Similar to the case of receiving PI-SCI after SCI transmission, the second terminal device 200E, which has received a preemption notification from other devices such as other terminal devices 200, base station 100, or primary UE, transmits packets by performing resource reselection, etc.

[0238] (Processing steps for packet transmission)

[0239] Here, we will refer to Figure 28 To describe reference Figures 24 to 27 The description describes the processing procedure for packet transmission. Figure 28 This is a flowchart used to describe an example of packet transmission processing according to this embodiment.

[0240] First, the second terminal device 200E detects the preemption of the first terminal device 200P by detecting the PI-SCI (step S201). For example, when the timing of the second terminal device 200E sending the SCI is the same as the timing of the first terminal device 200P sending the PI-SCI, the second terminal device 200E cannot detect the PI-SCI. In this case, the second terminal device 200E detects the preemption of the first terminal device 200P by receiving a preemption notification from another device.

[0241] Next, the second terminal device 200E performs resource reselection (step S202). If a new resource can be selected through reselection (step S203; Yes), the second terminal device 200E sends an announcement of the SCI for packet transmission using the new resource (step S204).

[0242] On the other hand, if a new resource cannot be selected (step S203; no), the second terminal device 200E adjusts the transmission parameters (step S205) and sends an SCI to announce the packet transmission using the adjusted transmission parameters (step S206).

[0243] The second terminal device 200E that sent the SCI in step S204 or step S206 sends a data packet according to the SCI announcement (step S207).

[0244] (Used to report situations where the sent resource is preempted)

[0245] In the above example, the situation where resources used for data transmission are preempted has been described; however, the preemption object is not limited to resources used for data transmission. For example, resources used for feedback transmission can also be preempted by the first terminal device 200P. Therefore, the feedback transmission process performed by the second terminal device 200E when the resources used for feedback transmission are preempted by the first terminal device 200P will be described below.

[0246] (For situations where resources are preempted during blind retransmission)

[0247] First, refer to Figure 29 Describes the feedback sending process in the event that the resources used for blind retransmission are preempted. Figure 29 This is a diagram illustrating an example of feedback transmission processing of the second terminal device 200E according to this embodiment.

[0248] Figure 29 (A) illustrates an example of a blind retransmission performed by a second terminal device 200E (UE2) when the first terminal device 200P (UE1) has not performed a preemption.

[0249] For example, the second terminal device 200E sends an SCI at time ta and performs a resource announcement at time tb. Subsequently, the second terminal device 200E sends a data packet at time tb and performs a blind retransmission using resource Rc at time tc. Resource Rc is the resource used for blind retransmission.

[0250] At this time, as Figure 29As shown in (b), assume that the first terminal device 200P detects the generation of a URLLC packet at time t0. In this case, the first terminal device 200P performs resource preemption of resource Rc by sending a PI-SCI at time tp.

[0251] At this time, when the second terminal device 200E sends a blind retransmission on resource Rc, the data packets sent by the first terminal device 200P (URLLC packets in this example) and the blind retransmission sent by the second terminal device 200E conflict with each other.

[0252] Therefore, when a PI-SCI transmitted at time tp is detected, the second terminal device 200E, for example, switches the type (method) of feedback (retransmission). Figure 29 In this process, the second terminal device 200E switches the feedback type from blind retransmission to HARQ-based retransmission. When switching to HARQ feedback, as... Figure 29 As shown in (C), the second terminal device 200E enables HARQ feedback by notifying feedback to be enabled at time ta3.

[0253] As a result, the second terminal device 200E can still perform feedback even when the resources used for sending feedback are preempted.

[0254] (HARQ feedback channel preemption)

[0255] The above example describes the situation where resources for blind retransmission are preempted; however, the resources for feedback transmission that are to be preempted are not limited to those for blind retransmission. For example, if the second terminal device 200E performs HARQ feedback and the resources for the feedback channel are preempted, the second terminal device 200E will be unable to send and receive the PSFCH.

[0256] In this scenario, the second terminal device 200E switches from HARQ feedback to blind retransmission. (Refer to...) Figure 30 Describe this. Figure 30 This is a diagram illustrating another example of the feedback transmission process of the second terminal device 200E according to this embodiment.

[0257] Figure 30 (A) shows an example of PSFCH transmission performed by a second terminal device 200E (UE2) when the first terminal device 200P (UE1) has not performed preemption.

[0258] For example, the second terminal device 200E sends an SCI at time ta and performs a resource announcement at time tb. Subsequently, the second terminal device 200E sends a data packet at time tb and sends a PSFCH using resource Rc at time tc. Resource Rc is the resource of the feedback channel.

[0259] At this time, as Figure 30 As shown in (B), assume that the first terminal device 200P detects the generation of a URLLC packet at time t0. In this case, the first terminal device 200P performs resource preemption of resource Rc by sending a PI-SCI at time tp.

[0260] At this time, when the second terminal device 200E sends PSFCH on resource Rc, the data packets sent by the first terminal device 200P (URLLC packets in this example) and the PSFCH sent by the second terminal device 200E conflict with each other.

[0261] Therefore, when a PI-SCI sent at time tp is detected, the second terminal device 200E, for example, switches the type of feedback (retransmits). Figure 30 In the process, the second terminal device 200E switches the type of feedback from HARQ-based retransmission to blind retransmission.

[0262] When switching the sending type to blind retransmission, such as Figure 30 As shown in (C), the second terminal device 200E disables HARQ feedback by notifying feedback to be disabled at time ta3. The second terminal device 200E then sends a blind retransmission at time td after time ta3.

[0263] As a result, the second terminal device 200E can still perform feedback even when the resources used for sending feedback are preempted.

[0264] Note that here, the feedback type is switched when the feedback channel resources are preempted, but the invention is not limited to this. For example, when HARQ feedback needs to be sent, the second terminal device 200E can send feedback on the PSSCH. As described above, when the PSFCH cannot be sent, the second terminal device 200E can send the information to be sent on the PSFCH on the PSSCH.

[0265] As described above, the wireless communication device (second terminal device 200E) according to this embodiment includes a control unit 240E, which adjusts transmission parameters and transmits packets when, in sidechain communication, the resources selected for use in packet transmission are preempted by other wireless communication devices (first terminal device 200P).

[0266] As a result, collisions of packets sent in the sidechain can be reduced.

[0267] The wireless communication device (first terminal device 200P) according to this embodiment includes a control unit 240P, which preempts resources selected by other wireless communication devices for use in packet transmission and transmits transmission packets in the following situation: in sidechain communication, the priority of the transmission packets is higher than the priority of packets transmitted by other wireless communication devices (second terminal device 200E).

[0268] As a result, collisions of packets sent in the sidechain can be reduced.

[0269] <<5. Variation Example>>

[0270] <5.1. Variation Example 1>

[0271] In the above embodiment, the first terminal device 200P can preempt the resources of the second terminal device 200E to send low-priority packets. Therefore, there is a possibility that the resources for the second terminal device 200E to send low-priority packets will always be preempted, and in this case, the second terminal device 200E cannot send low-priority packets. This addresses the fairness issue in sidechain communication caused by resource preemption.

[0272] Therefore, in Variation 1 of this embodiment, to address such fairness issues, for example, the second terminal device 200E changes its priority based on the number of preemptions. Hereinafter, it is assumed that terminal device 200 uses ProSe per-packet priority (PPPP) to control the priority (QoS) of transmitted packets. Terminal device 200 includes priority information associated with PPPP in its sidechain control information (SCI) when transmitting sidechain packets. This enables priority control between terminals.

[0273] Specifically, when a preemption is detected from the first terminal device 200P, the control unit 240E of the second terminal device 200E counts the number of preemptions.

[0274] When the count of preemption attempts becomes equal to or greater than a predetermined threshold, the second terminal device 200E adjusts the priority of packet transmission. For example, if the count of preemption attempts becomes the predetermined threshold or greater, the control unit 240E of the second terminal device 200E sets PPPP to the highest priority. Alternatively, the second terminal device 200E can set PPPP to one level higher than the current setting.

[0275] For example, in LTE V2X, the PPPP value is set to eight levels, ranging from "0" with the highest priority to "7" with the lowest priority. For example, suppose the PPPP of the second terminal device 200E is set to "5". In this case, when the resources of the second terminal device 200E are preempted k+1 times and become k times or more of a predetermined threshold, the second terminal device 200E will change the PPPP from the previously set "5" to, for example, "0".

[0276] As a result, the second terminal device 200E was not preempted by other terminal devices 200 more than k times, and it was able to send packets even in an environment where resource preemption was being performed.

[0277] Note that when the number of preemption attempts becomes equal to or greater than the predetermined threshold k, the second terminal device 200E can change PPPP from "5" to "4". As described above, the second terminal device 200E sets the priority to high, making it difficult to be preempted a predetermined number of times or more.

[0278] When the second terminal device 200E successfully transmits a packet after changing its priority to high, it reverts the changed priority to the original priority. Alternatively, it sets the priority to a lower priority. For example, as described above, suppose that the second terminal device 200E, which originally had a PPP of "5", has changed its PPP to "0" and successfully transmitted the packet because the resource has been preempted k times or more. In this case, the second terminal device 200E reverts the PPP from "0" to "5". Alternatively, the second terminal device 200E sets the PPP from "0" to "6", which has a lower priority than the original "5".

[0279] As a result, the second terminal device 200E can send packets without maintaining a higher priority than required. Note that if the second terminal device 200E sets PPP to, for example, a "6" which is lower than the original "5", PPP can be returned to the original "5" after a predetermined time period has elapsed or after sending a predetermined number of packets.

[0280] Note that the aforementioned predetermined threshold k can be notified by the base station 100, for example, using RRC or DCI. The predetermined threshold k can be set for each cell, for each resource pool, or for each specific QoS level.

[0281] Note that here, the second terminal device 200E adjusts its priority based on the number of preemptions, but the invention is not limited to this. For example, if the second terminal device 200E is preempted k times or more, preemption by surrounding terminal devices 200 can be prohibited (stopped). The second terminal device 200E, which has been preempted k times or more, notifies the surrounding terminal devices 200 of the prohibition of preemption, thereby preventing the resources from being preempted again. The second terminal device 200E notifies the surrounding terminal devices 200 of the prohibition of preemption, for example, by sending a prohibition of preemption message to the PSCCH, PSSCH, or PSFCH. The first terminal device 200P, which has received the prohibition of preemption notification, does not preempt the resources of the second terminal device 200E that sent the notification, but instead preempts the resources of other second terminal devices 200E.

[0282] In this way, since the second terminal device 200E is prohibited from preemption, the opportunity for the second terminal device 200E to send packets can be guaranteed.

[0283] The first terminal device 200P can control the number of preemption attempts. For example, it can determine whether the first terminal device 200P should perform preemption based on the resource usage status. More specifically, for example, the first terminal device 200P performs preemption when the channel occupancy rate (CR) is less than a predetermined threshold m, and does not perform preemption when the channel occupancy rate is equal to or greater than the predetermined threshold m. Note that CR is a parameter indicating the ratio of resources used or scheduled to be used by the main device within a certain period of time.

[0284] In this way, the first terminal device 200P determines whether to preempt based on the resource usage status, thus making it difficult for the first terminal device 200P to monopolize the resources, and the terminal device 200 can use the resources fairly.

[0285] Note that the aforementioned predetermined threshold m can be notified by the base station 100, for example, using RRC or DCI. The predetermined threshold m can be set for each cell, for each resource pool, or for each specific QoS level.

[0286] When selecting a resource to preempt from among those with low priority, the first terminal device 200P randomly selects the resource to preempt. For example, when the resource with the lowest priority is selected as the preemptible resource, the second terminal device 200E, which has the lowest priority, is more likely to be preempted and unable to send packets. Therefore, the first terminal device 200P randomly selects the resource to preempt. As a result, the second terminal device 200E, which is to be preempted, is less biased.

[0287] Alternatively, the number of times the first terminal device 200P has performed preemption can be counted, and if the first terminal device 200P has performed preemption a predetermined threshold n times or more, preemption can be stopped, for example, for a certain period of time. At this time, the first terminal device 200P can count the number of preemption attempts for each of the preempted second terminal devices 200E, and stop preemption attempts by the second terminal devices 200E whose counts are equal to or greater than the predetermined threshold n.

[0288] In other words, the first terminal device 200P counts the number of times each of the multiple second terminal devices 200Es preempts the resource. The first terminal device 200P selects the resource chosen by the second terminal device 200E whose preemption count is less than a predetermined threshold n as the resource to be preempted.

[0289] Note that the aforementioned predetermined threshold n can be notified by the base station 100, for example, using RRC or DCI. The predetermined threshold n can be set for each cell, for each resource pool, or for each specific QoS level.

[0290] <5.2. Variation Example 2>

[0291] In the above embodiment, method B is adopted, in which both the first terminal device 200P that preempts resources and the second terminal device 200E that is to be preempted are sensing and selecting sidechain resources by the terminal device 200 itself. However, the first terminal device 200P and the second terminal device 200E can adopt resource allocation methods other than method B.

[0292] Examples of resource allocation methods other than Method B include Method A, in which the aforementioned base station 100 allocates sidelink resources. In NR, in addition to Methods A and B, there is also a method (hereinafter referred to as Method C), in which, for example, the main terminal or the like allocates sidelink resources in place of base station 100.

[0293] In the 3GPP discussions to date, terminal device 200, which selects its own sidechain to send resources, performs resource preemption in Mode B (NR Mode 2). Then, terminal device 200 also sends information about resource preemption, such as PI-SCI, on the sidechain channel. However, there are cases where terminal device 200 performing sidechain communication according to Mode A or Mode C as described above is mixed with terminal device 200 performing sidechain communication according to Mode B. How preemption is performed in such a case will be described. Note that the cases of mixed Mode A and Mode B, and mixed Mode B and Mode C, differ in whether the entity performing resource allocation is base station 100 or a third device, but other operations are the same. Therefore, the case of mixed Mode A and Mode B will be described below. In the following description, it is assumed that the first terminal device 200P performing preemption performs resource selection based on Mode B.

[0294] In this scenario, for example, assume that the first terminal device 200P does not preempt the resources of the terminal device 200 in mode A. In other words, the first terminal device 200P preempts the resources of the terminal device 200 in mode B, other than mode A.

[0295] For example, in LTE V2X, the value of the resource reservation field differs between Mode A (LTE Mode 3) and Mode B (LTE Mode 4). For instance, in Mode A, the resource reservation field value is "0". On the other hand, in Mode B, the resource reservation field value corresponds to the reservation interval. Therefore, the first terminal device 200P can determine how it uses resources based on whether the resource reservation field value is "0" or another value, and can prevent the resources of the terminal device 200 in Mode A from being preempted.

[0296] However, if terminal device 200 in method B does not perform resource reservation, the value of the resource reservation field is "0", and therefore it cannot be distinguished from terminal device 200 in method A.

[0297] In this scenario, for example, the first terminal device 200P preempts the resources of a terminal device 200 whose resource reservation field value is not "0". As a result, the resources of terminal device 200 using method B (which does not perform resource reservation) cannot be preempted, but the resources of terminal device 200 using method B (which performs resource reservation) can be preempted. The resources of terminal device 200 using method A are not preempted. In this way, the first terminal device 200P performs resource preemption based on the value of the resource reservation field so that the resources of terminal device 200 using method A can be excluded from the preemption list.

[0298] Alternatively, information about the method can be included in the SCI sent by terminal device 200. As a result, when the first terminal device 200P preempts resources, the resource allocation method of the terminal device 200 to be preempted can be confirmed. In this case, regardless of whether resource reservation has been performed, the first terminal device 200P can preempt the resources of terminal device 200 in method B.

[0299] Note that, as described above, in the case where resource preemption by terminal device 200 in mode A is not performed, the first terminal device 200P confirms the use of the second terminal device 200E for the resource to be preempted when selecting resources. Other processing related to preemption is the same as that described in the above embodiments.

[0300] In the example above, the resources of terminal device 200 in method A are not preempted, but the resources of terminal device 200 in method A can be preempted. (See reference...) Figure 31 Describe this situation. Figure 31 This is a diagram illustrating the preemption of the terminal device 200 according to Variation 2 of this embodiment.

[0301] exist Figure 31 In the sequence diagram shown, the processing from when base station 100 allocates the resource pool to terminal device 200 until the second terminal device 200E (the preempted device) detects the preemption is the same as... Figure 19 The sequence diagram shown is the same. Therefore, it is the same as... Figure 19 The same processing is indicated by the same reference numerals in the accompanying drawings, and their description is omitted.

[0302] like Figure 31 As shown, firstly, base station 100 allocates resources for data packet transmission to second terminal device 200E (step S400). Subsequently, when a preemption indication is detected, second terminal device 200E notifies base station 100 of the preemption (step S401). For example, PUCCH or PUSCH can be used to perform such a notification. For example, such a notification includes information indicating that the resources allocated from base station 100 have been preempted, information about the preempted resources, and information about the preempted second terminal device 200E (such as the ID of the second terminal device 200E), etc.

[0303] Upon receiving the notification, base station 100 reselects resources (step S402) and notifies the second terminal device 200E of the reselected resources (step S403). The second terminal device 200E uses the notified reselected resources to perform sidechain transmission (step S404).

[0304] As a result, regardless of the resource allocation method of the terminal device 200, the first terminal device 200P can perform resource preemption.

[0305] Note that here, the second terminal device 200E is notified to base station 100 that it has been preempted. However, for example, the first terminal device 200P could be notified to base station 100 that it has preempted the resources. In this case, similar to the second terminal device 200E, the first terminal device 200P sends the notification using PUCCH or PUSCH. The notification content is also similar to that of the second terminal device 200E.

[0306] Alternatively, the second terminal device 200E may not notify the base station 100 of the preemption and may adjust its transmission parameters to utilize the preempted resources for sidelink communication. The base station 100 may instruct the second terminal device 200E to adjust its transmission parameters without reselecting resources. The base station 100 may perform resource reselection, transmission parameter adjustment, feedback type switching, and maximum retransmission count adjustment in the same manner as the second terminal device 200E in the above embodiment.

[0307] In resource reselection, for example, reselecting PSSCH or PSFCH transmission resources. Since measurements are required to adjust transmission parameters, when the second terminal device 200E adjusts its transmission parameters, after evaluating the SCI, data, and SL-RSRP of the first terminal device 200P, the transmission parameters, such as transmit power and MCS, are adjusted based on the evaluation results. When the base station 100 adjusts its transmission parameters, the second terminal device 200E notifies the base station 100 of the measurement results. Alternatively, the evaluation results of the measurements can be notified to the base station 10.

[0308] Note that the reselection of resources and the adjustment of transmission parameters can be performed by the second terminal device 200E or the base station 100, or by both.

[0309] The second terminal device 200E can switch the resource allocation method from method A to method B and notify the base station 100 of the switch, instead of notifying preemption in step S401. In this case, the operation of the second terminal device 200E after the method switch is the same as that in the above embodiment, so its description is omitted.

[0310] Note that when the first terminal device 200P performs resource allocation and detects URLLC packets based on method A, the first terminal device 200P selects resources and sends URLLC packets through its host device without waiting for resource allocation from the base station 100. As a result, the first terminal device 200P can send URLLC packets with low latency. Note that the preemption-related processing in this case is the same as that in the above embodiments, and therefore its description is omitted.

[0311] <<6. Summary>>

[0312] As described above, according to this embodiment and its variants, a mechanism is provided that can reduce collisions of packets sent in a sidechain.

[0313] Figure 21 The first terminal device 200P shown can be used as an example of the wireless communication device of this disclosure. The control unit 240P can be used as a control unit of the wireless communication device of this disclosure. Figure 22 The second terminal device 200E shown can be used as an example of the wireless communication device of this disclosure. The control unit 240E can be used as a control unit of the wireless communication device of this disclosure. The terminal device 200 can be a device disposed in a mobile body. The mobile body can be a vehicle.

[0314] Each step in the process performed by each device in this specification does not necessarily need to be processed in a time series according to the order described as a sequence diagram or flowchart. For example, each step in the process performed by each device may be processed in a different order than the order described as a flowchart, or may be processed in parallel.

[0315] Computer programs can also be created to enable the hardware built into each device, such as the CPU, ROM, and RAM, to perform functions equivalent to the configuration of each of the aforementioned devices. Storage media for storing the computer programs can also be provided. By configuring each functional block shown in the hardware block diagram, a series of processes can be implemented in hardware.

[0316] Although preferred embodiments of the invention have been described in detail with reference to the accompanying drawings, the scope of this disclosure is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications will occur within the scope of the technical concept described in the claims, and it is understood that these also fall within the scope of this disclosure.

[0317] The effects described in this specification are merely illustrative or exemplary and not restrictive. That is, other effects that may be apparent to those skilled in the art from the description herein may be demonstrated in conjunction with or in lieu of the effects described above, according to the technology disclosed herein.

[0318] Note that this technology can also have the following configurations.

[0319] (1) A wireless communication device, comprising:

[0320] A control unit configured to: in sidechain communication, adjust transmission parameters and transmit packets if resources used for packet transmission are preempted by other wireless communication devices.

[0321] (2) The wireless communication device according to (1), wherein the adjustment of the transmission parameters includes at least one of the following: reducing the transmission power and switching at least one of the modulation method and coding method to an efficient method.

[0322] (3) The wireless communication device according to (1) or (2), wherein the selected resource is a resource that requests to use radio waves to transmit data packets.

[0323] (4) The wireless communication device according to (1) or (2), wherein the selected resources are resources reserved in advance for transmitting data packets.

[0324] (5) The wireless communication device according to any one of (1) to (4), wherein,

[0325] The control unit is configured to:

[0326] If the selected resource is preempted after sending information about the sending parameters used to send the packet, then adjust the sending parameters; and

[0327] Send information about the adjusted sending parameters.

[0328] (6) The wireless communication device according to (1), wherein the selected resource is a resource selected for transmitting information related to feedback of packet transmission.

[0329] (7) The wireless communication device according to (6), wherein,

[0330] The control unit is configured to:

[0331] If the resource selected for sending information related to feedback is preempted, the feedback method is changed.

[0332] (8) The wireless communication device according to (1), wherein,

[0333] The control unit is configured to:

[0334] If a notification indicating that the selected resource has been preempted is received from a third wireless communication device that is different from the other wireless communication devices, the transmission parameters are adjusted.

[0335] (9) The wireless communication device according to any one of (1) to (8), wherein the control unit adjusts the priority of packets when the number of preemptions is equal to or greater than a predetermined threshold.

[0336] (10) The wireless communication device according to any one of (1) to (8), wherein, when the number of preemption attempts becomes a predetermined threshold or greater, the control unit issues a notification to stop preemption.

[0337] (11) The wireless communication device according to any one of (1) to (9), wherein the control unit adjusts at least one of the transmission power, MCS and packet size as transmission parameters.

[0338] (12) The wireless communication device according to any one of (1) to (11), wherein the control unit adjusts the transmission parameters by reselecting resources for transmitting packets.

[0339] (13) A wireless communication device, comprising:

[0340] A control unit configured to: preempt resources selected by the other wireless communication device for use in packet transmission when the priority of transmitting a packet in sidechain communication is higher than the priority of packets transmitted by other wireless communication devices, and transmit the transmitted packet.

[0341] (14) The wireless communication device according to (13), wherein,

[0342] The control unit is configured to:

[0343] The number of preemptions for each of the other wireless communication devices is counted, and

[0344] The resource to be preempted is selected from the resources chosen by other wireless communication devices whose number of preemptions is less than the predetermined number.

[0345] (15) The wireless communication device according to (13) or (14), wherein,

[0346] The control unit is configured to:

[0347] The resource to be preempted is randomly selected from a plurality of resources selected by at least one of the other wireless communication devices.

[0348] (16) The wireless communication device according to any one of (13) to (15), wherein the transmission packet is a packet transmitted in an ultra-reliable and low-latency communication (URLLC) use case.

[0349] (17) A wireless communication method, comprising:

[0350] In sidechain communication, it is selected to adjust transmission parameters and send packets using the selected resources when the resources used for packet transmission are preempted by other wireless communication devices.

[0351] (18) A wireless communication method, comprising:

[0352] When a packet sent in sidechain communication has a higher priority than a packet to be sent by another wireless communication device, the resources selected by the other wireless communication device for use in sending the packet are preempted to send the packet.

[0353] Reference tag list

[0354] 1 System

[0355] 11 residential communities

[0356] 20-core network

[0357] 30 PDN

[0358] 100 base stations

[0359] 200 terminal devices

[0360] 210 antenna elements

[0361] 220 Wireless Communication Units

[0362] 230 storage units

[0363] 240 Control Unit

Claims

1. A wireless communication device comprising: a control unit configured to, in a case where a resource selected for use in transmission of a packet in sidelink communication is preempted by other wireless communication devices, adjust a transmission parameter, and transmit the packet using the selected resource, wherein the adjustment of the transmission parameter includes switching a modulation scheme to an efficient scheme in order to reduce a resource needed, and wherein the selected resource is a resource selected for transmitting information about feedback of the transmission of the packet; and the control unit is configured to: switch a type of the feedback if the resource selected for transmitting the information about the feedback is preempted.

2. The wireless communication device of claim 1, wherein, the adjustment of the transmission parameter further includes at least one of: reducing a transmission power and switching a coding scheme to an efficient scheme.

3. The wireless communication device of claim 1, wherein, the selected resource is a resource requesting use of radio waves for transmitting a data packet.

4. The wireless communication device of claim 1, wherein, the selected resource is a resource pre-reserved for transmitting a data packet.

5. The wireless communication device according to claim 1, wherein the control unit is configured to: adjust the transmission parameter if the selected resource is preempted after transmitting information about the transmission parameter for transmitting the packet; and transmit information about the adjusted transmission parameter.

6. The wireless communication device according to claim 1, wherein the control unit is configured to: adjust the transmission parameter in a case where a notification indicating that the selected resource is preempted is received from a third wireless communication device different from the other wireless communication devices.

7. The wireless communication device of claim 1, wherein, the control unit adjusts a priority of the packet in a case where a number of preemptions is equal to or greater than a predetermined threshold.

8. The wireless communication device of claim 1, wherein, the control unit issues a notification of stopping preemption in a case where the number of preemptions becomes the predetermined threshold or greater.

9. The wireless communication device of claim 1, wherein, the control unit adjusts at least one of a transmission power, an MCS, and a packet size as the transmission parameter.

10. The wireless communication device of claim 9, wherein, the control unit adjusts the transmission parameter by reselecting a resource for transmitting the packet.

11. A wireless communication device comprising: a control unit configured to, in a case where a priority of a packet transmitted in sidelink communication is higher than a priority of a packet transmitted by other wireless communication devices, preempt a resource selected for use in transmission of the packet by the other wireless communication devices, and transmit the transmitted packet, wherein the other wireless communication devices are configured to, if the resource selected for use in transmission of the packet by the other wireless communication devices is preempted, adjust a transmission parameter, and the adjustment of the transmission parameter includes switching a modulation scheme to an efficient scheme in order to reduce a resource needed, and wherein the selected resource is a resource selected for transmitting information about feedback of the transmission of the packet; and the other wireless communication devices are configured to: switch a type of the feedback if the resource selected for transmitting the information about the feedback is preempted.

12. The wireless communication device according to claim 11, wherein the control unit is configured to: count a number of preemptions for each of the other wireless communication devices, and select a resource selected by the other wireless communication devices whose number of preemptions is less than a predetermined number as a resource to be preempted.

13. The wireless communication device of claim 11, wherein, the control unit is configured to: randomly select the resource to be preempted from a plurality of resources selected by at least one of the other wireless communication devices.

14. The wireless communication device of claim 11, wherein, the transmitted packet is a packet transmitted in an ultra-reliable and low latency communication (URLLC) use case.

15. A wireless communication method comprising: adjusting a transmission parameter and transmitting a packet using a selected resource in case the selected resource is preempted by other wireless communication devices in a sidelink communication for use in transmission of the packet, wherein the adjustment of the transmission parameter comprises switching a modulation scheme to an efficient scheme in order to reduce resources needed, and wherein, the selected resource is a resource selected for transmitting information related to feedback of the packet transmission; and switching a type of feedback if the resource selected for transmitting information related to feedback is preempted.

16. A wireless communication method comprising: preempting a resource selected by other wireless communication devices for use in transmission of a packet by the other wireless communication devices to transmit a transmission packet when a priority of the transmission packet is higher than a priority of a packet to be transmitted by the other wireless communication devices in a sidelink communication, wherein the other wireless communication devices are configured to adjust a transmission parameter if the resource selected for use in transmission of the packet by the other wireless communication devices is preempted, and the adjustment of the transmission parameter comprises switching a modulation scheme to an efficient scheme in order to reduce resources needed, and wherein, the selected resource is a resource selected for transmitting information related to feedback of the packet transmission; and the other wireless communication devices are configured to: switch a type of feedback if the resource selected for transmitting information related to feedback is preempted.

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