Server device, communication control method, terminal device, and base station

Abstract

According to an embodiment of the present invention, a server device is provided that includes a communication unit that communicates with one or more terminal devices operating as clients of a V2X application, and a server processing unit that operates as a server of the V2X application. The server processing unit is capable of accessing a database that indicates an adjacency relation among a plurality of geographical areas, with first and second geographical areas being indicated as adjacent areas. The server processing unit sets each of the one or more terminal devices to receive a warning message relating to on-road safety via a sidelink, receives location information of a first terminal device via the communication unit, determines that the first terminal device is situated within the first geographical area on the basis of the location information, and instructs the first terminal device to relay the warning message received in the first geographical area via the sidelink.

Description

[Technical Field]

[0001] The present invention relates to a server device, a communication control method, a terminal device, and a base station. [Background technology]

[0002] The fourth-generation cellular communication technology, also known as Long Term Evolution (LTE), standardized by the Third Generation Partnership Project (3GPP), is expected to utilize sidelinks, which are direct wireless links between terminals, for Vehicle-to-Everything (V2X) communication (see Section 5.6 of Non-Patent Document 1). Non-Patent Document 2 explains that V2X can include the following four types of concepts: ·V2V: Vehicle to Vehicle · V2I: Vehicle to Infrastructure ·V2N: Vehicle to Network V2P: Vehicle to Pedestrian

[0003] In fifth-generation cellular communication technology, also known as New Radio (NR), the radio access network (RAN) is expected to support both 4G V2X sidelink and 5G NR sidelink (see Section 16.9 of Non-Patent Document 3). For example, a terminal (also referred to as user equipment (UE)) performing sidelink communication establishes a radio link called a PC5 interface with a communicating terminal, and performs V2X communication over communication resources scheduled by the RAN or autonomously selected from a pre-allocated resource pool. While the 4G V2X sidelink only supports broadcast of V2X messages, the 5G NR sidelink supports broadcast, groupcast, and unicast of V2X messages.

[0004] Patent Document 1 discloses a technology in which a terminal device capable of V2X communication mounted on a vehicle evaluates road safety in real time and issues an alert to the user of the vehicle or other users if it determines that there is a threat.

[0005] Non-Patent Document 4 discloses the results of a test conducted on an actual road to verify the communication range of V2V message exchange using a 4G V2X side link. According to the test results, when line of sight was ensured between vehicles, message exchange was possible with good quality at a vehicle interval of up to 1,000 m, whereas when an obstacle was present between the vehicles, message exchange with good quality was possible up to a vehicle interval of 400 m. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] 3GPP TS36.300 v16.7.0, December 23, 2021 [Non-patent document 2] 3GPP TS22.185 v16.0.0, July 16, 2020 [Non-patent document 3] 3GPP TS38.300 v16.8.0, December 23, 2021 [Non-patent document 4] Qualcomm Technologies, Inc.,"Cellular-V2X Technology Overview",[online],2019,80-PE732-63 Rev B,[Retrieved May 9, 2022],Internet,<URL:https: / / www.qualcomm.com / media / documents / files / c-v2x-technology-overview.pdf> [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2020 / 0312142 Summary of the Invention [Problem to be solved by the invention]

[0008] User safety can be improved by V2X devices notifying each other of the existence of safety threats, as in the technology disclosed in Patent Document 1. However, the limited communication range of V2X communication is one of the constraints on improving safety.

[0009] In view of the above, the present disclosure aims to provide a mechanism that can further improve the safety of users in relation to road traffic. [Means for solving the problem]

[0010] According to the present disclosure, a communication unit that communicates with one or more terminal devices that operate as clients of a V2X (Vehicle-to-Everything) application; a server processing unit that operates as a server for the V2X application; Equipped with The server processing unit has access to a database indicating an adjacency relationship between a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The server processing unit configuring each of the one or more terminal devices to receive road safety warning messages sent from other terminal devices via a side link; receiving location information of a first terminal device via the communication unit; determining, based on the location information, that the first terminal device is located within the first geographic area; instructing the first terminal device to relay the warning message received in the first geographic area via the sidelink, thereby enabling a second terminal device located in the second geographic area to receive the relayed warning message; A server device is provided. Corresponding communication control methods, terminal devices, and base stations are also provided. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to further improve the safety of users in relation to road traffic. [Brief explanation of the drawings]

[0012] [Figure 1] Reproduction of Figure 16.9.1-1 from 3GPP TS38.300 v16.8.0. [Figure 2] Reproduction of Figure 6.2-2 from 3GPP TS23.286 v17.3.0. [Figure 3] 1 is a schematic diagram illustrating an example of the configuration of a V2X communication system according to an embodiment. [Figure 4] FIG. 2 is a block diagram showing an example of the configuration of a server device according to an embodiment. [Figure 5] FIG. 1 is an explanatory diagram illustrating an example of a definition of a geographical area according to an embodiment. [Figure 6A] FIG. 10 is an explanatory diagram showing a first example of a message format for relay instruction. [Figure 6B] FIG. 10 is an explanatory diagram showing a second example of a message format for relay instructions. [Figure 6C] FIG. 10 is an explanatory diagram showing a third example of a message format for relay instructions. [Figure 6D] FIG. 10 is an explanatory diagram showing a fourth example of a message format for relay instructions. [Figure 7] FIG. 2 is a block diagram showing an example of the configuration of a UE according to an embodiment. [Figure 8] FIG. 2 is a block diagram showing an example of the configuration of a base station according to an embodiment. [Figure 9] FIG. 3 is a sequence diagram showing an example of a processing flow according to the first embodiment. [Figure 10] FIG. 10 is a sequence diagram showing an example of a processing flow according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0014] <1. Basic system architecture for V2X services> Figure 1, a reproduction of Figure 16.9.1-1 in 3GPP TS38.300 v16.8.0, shows an example of an NG-RAN architecture for a 5G system. A gNB is a 5G base station connected to a 5G core network (not shown). A ng-eNB is a 4G base station connected to a 5G core network. The gNB and ng-eNB are connected to each other via an Xn interface. A user equipment (UE) is a terminal device served by a gNB or ng-eNB. A radio link for transmitting and receiving user data between a UE and a gNB or ng-eNB is called a Uu interface. A PC5 interface is a communication link established between two UEs. Such a direct communication link between UEs that does not pass through a base station is also called a sidelink. Next Generation (NG)-RANs (Radio Access Networks) support such PC5 interfaces. A PC5 interface can be identified by a pair of a Layer 2 ID (Source Layer-2 ID) assigned to the transmitting UE and a Layer 2 ID (Destination Layer-2 ID) assigned to the receiving UE. Resources used for communication are scheduled by the base station (scheduled resource allocation) or autonomously selected by the UE from a pre-configured resource pool (autonomous resource selection). In 5G systems, such PC5 interfaces can be used for V2X services.

[0015] Figure 2, a reproduction of Figure 6.2-2 in 3GPP TS23.286 v17.3.0, shows a layered functional model of a V2X application. In the functional model in Figure 2, a UE acts as a V2X application client (V2X UE). Meanwhile, a V2X application server is typically deployed on an IP (Internet Protocol) network and communicates with one or more V2X UEs via a 3GPP network system consisting of a RAN and a core network. A V2X UE located inside the coverage of the NG-RAN (V2X UE1 in Figure 2) can communicate with a V2X UE located outside the coverage (V2X UE2 in Figure 2) via a sidelink.

[0016] The functional model in FIG. 2 has a hierarchical structure consisting of, from top to bottom in the figure, a V2X application-specific layer, a V2X application enabler (VAE) layer, and a service enabler architecture layer (SEAL).

[0017] SEAL is a layer that provides basic services common to various applications, including V2X and other types of applications. Services related to V2X applications provided in SEAL include, for example, location management, group management, configuration management, identity management, key management, and network resource management. A V2X UE includes a SEAL client, and a V2X application server includes a SEAL server. SEAL-PC5 is the interface between V2X UEs in SEAL. SEAL-UU is the interface between V2X UEs and V2X application servers in SEAL. Details of the functions of the SEAL client and SEAL server are described in 3GPP TS23.434 v17.5.0.

[0018] The VAE layer supports the V2X application-specific layer by interpreting the services provided by the SEAL for V2X application use. The V2X UE includes a VAE client, and the V2X application server includes a VAE server. The VAE client's functions may include, for example, registering the VAE client with the VAE server to receive V2X messages, providing application-level location information to the VAE server, receiving communication configuration information from the VAE server, and supporting dynamic group management. The VAE server's functions may include, for example, accepting VAE client registrations, tracking the application-level location of V2X UEs, providing communication configuration information, and supporting V2X message delivery. The V5-AE is the interface between the V2X UE and the V2X application server in the VAE layer. The V1-AE is the interface between the V2X UE and the V2X application server in the VAE layer.

[0019] The V2X application-specific layer is a layer that provides functionality specific to individual V2X applications with support from the VAE layer. The V2X UE includes a V2X application-specific client, and the V2X application server includes a V2X application-specific server. The V5-APP is an interface between V2X UEs in the V2X application-specific layer. The V1-APP is an interface between V2X UEs and V2X application servers in the V2X application-specific layer.

[0020] The functions of the V2X UE and V2X application server that may have such a hierarchical structure in an embodiment of the technology disclosed herein will be described in detail later.

[0021] As can be seen from Figure 2, at the application level, V2X communication is treated as end-to-end communication between the V2X UE and the V2X application server, and the content of the V2X communication is transparent to the base stations and other network nodes along the communication path.

[0022] Section 7 of 3GPP TS23.286 v17.3.0 describes various deployment models for V2X application-specific servers and VAE servers. The V2X application-specific servers and VAE servers may be physically co-located in a single device or may be located in separate devices. Each of these servers may belong to either the V2X service provider's domain or the network operator's domain.

[0023] 2. Embodiment of V2X Communication System <2-1. System Overview> 3 is a schematic diagram illustrating an example of a configuration of a V2X communication system 1 according to an embodiment. Referring to FIG. 3, the V2X communication system 1 includes a server device 100, UEs 200a, 200b, 200c, and 200d, and base stations 300a and 300b.

[0024] In the following description, when it is not necessary to distinguish between the UEs 200a, 200b, 200c, and 200d, the alphabet at the end of the reference numeral is omitted and they are collectively referred to as the UE 200. The same applies to the base stations 300a and 300b (base station 300) and other components.

[0025] The server device 100 is a V2X application server that provides a V2X service aimed at improving road safety. The server device 100 is connected to a plurality of base stations including base stations 300a and 300b via a network 10. The network 10 may be, for example, a 5G core network or a combination of a 5G core network and an IP network.

[0026] The UE 200 is a terminal device that uses the V2X service provided by the server device 100. In the example of FIG. 3, the UE 200a is an in-vehicle terminal mounted on the vehicle 20a, the UE 200c is an in-vehicle terminal mounted on the vehicle 20c, and the UE 200d is an in-vehicle terminal mounted on the vehicle 20d. The UE 200b is a pedestrian terminal carried by a pedestrian 21b. For example, the UE 200a located in the cell 30a can establish a wireless link with the base station 300a to receive downlink data from the base station 300a and transmit uplink data to the base station 300a. In addition, the UE 200a can communicate with other nearby V2X UEs via a sidelink with the support of the base station 300a (e.g., resource scheduling or pre-allocation of a resource pool). For example, FIG. 3 illustrates a sidelink 40b between the UE 200a and the UE 200b and a sidelink 40c between the UE 200a and the UE 200c. Naturally, UEs 200 other than the UE 200a can also communicate with nearby V2X UEs via sidelink.

[0027] The base station 300 may be, for example, a gNB or an ng-eNB, and relays communication between the UE 200 and the server device 100. In the example of FIG. 3, the base station 300a serves the UE 200 in the cell 30a, and the base station 300b serves the UE 200 in a cell different from the cell 30a. The broadcast of information from the base station 300 to the multiple UEs 200 in the cell is performed on a physical broadcast channel (PBCH). The transmission of downlink data from the base station 300 to a specific UE 200 is performed on a physical downlink shared channel (PDSCH). The transmission of uplink data from a specific UE 200 to the base station 300 is performed on a physical uplink shared channel (PUSCH). Control signaling for controlling these data transmissions (e.g., downlink assignment, scheduling request, uplink grant, retransmission control, etc.) is performed on various control channels including a physical downlink control channel (PDCCH) and a physical uplink control channel (PUCCH).

[0028] In this embodiment, at least some of the UEs 200 are capable of transmitting an alert message on the sidelink when a road safety threat is detected, informing the user of the presence of the threat. The UEs 200 may detect a safety threat using any known method. For example, a UE 200 installed in a vehicle may recognize one or more of the following as a threat: The speed or acceleration of your vehicle or other vehicle exceeds the reference value. - Your vehicle / other vehicles deviating from the correct driving lane - Physiological abnormalities of the driver of the vehicle -Detection of alcohol content in the driver's breath Contact or collision detection - Abnormalities in the driving environment (e.g., presence of fallen objects, drop in road surface temperature) When a UE 200 detects such a security threat, the UE 200 transmits a warning message, for example, on a sidelink shared channel (SL-SCH). The warning message may include type information indicating the type of the detected threat. The server apparatus 100 configures each UE 200 to receive warning messages transmitted from other UEs 200 via the sidelink. When a UE 200 receives the warning message, the UE 200 alerts the user via a user interface, allowing the user to recognize the threat early and take appropriate action to ensure safety.

[0029] However, only UEs 200 located within the communication range of the sidelink can receive the warning message transmitted over the sidelink. According to the results of a verification experiment disclosed in Non-Patent Document 4, the radius of the communication range of the sidelink is a maximum of 1000 m when line-of-sight is ensured and a maximum of 400 m when an obstacle exists between the vehicles. For example, in the situation shown in FIG. 3, assume that UE 200c of vehicle 20c detects that vehicle 20d is traveling at a speed exceeding a reference value and transmits a warning message. UE 200a of vehicle 20a receives the warning message via the sidelink 40c. Meanwhile, UE 200b cannot receive the warning message transmitted by UE 200c due to the long distance between UE 200c and UE 200c or the presence of an obstacle between UE 200c and UE 200c. Therefore, UE 200b does not warn pedestrian 21b, the user, of the threat from vehicle 20d, exposing pedestrian 21b to danger. In this embodiment, in order to eliminate or mitigate such inconveniences, a mechanism is adopted in the V2X communication system 1 that essentially extends the reach of the warning message by having the UE 200 that receives the warning message relay the received message.

[0030] <2-2. Server device configuration example> 4 is a block diagram showing an example of the configuration of the server device 100 according to this embodiment. Referring to FIG. 4, the server device 100 includes a communication interface (I / F) 101, a memory 102, a database 110, and a server processing unit 150.

[0031] The communication I / F 101 is a communication unit that enables the server device 100 to communicate with one or more UEs 200 that operate as clients of a V2X application. The communication I / F 101 is connected to the network 10, and can communicate with the UEs 200 connected to the base station 300 via one or more network nodes in the network 10 and the base station 300.

[0032] The memory 102 may include any combination of a non-volatile storage medium such as a read-only memory (ROM) and a volatile storage medium such as a random access memory (RAM). For example, the ROM stores computer programs for several server modules (described later). The RAM provides a temporary storage area for calculations by the server processing unit 150.

[0033] The database 110 is a database that stores various data required for the server device 100 to provide a V2X application. In this embodiment, the database 110 includes area definition data 120, risk level data 130, and UE location data 140. Note that, although an example in which the server device 100 includes the database 110 will be described here, the database 110 may be implemented in a device (for example, a database server or a cloud server) separate from the server device 100 as long as it is accessible by the server processing unit 150.

[0034] The area definition data 120 is data indicating definitions of multiple geographical areas for V2X applications provided by the server device 100. The area definition data 120 may include, for example, the following four data items for each geographical area: Area ID "Area definition" "Affiliated base stations" "Adjacent areas" "Area ID" is an identifier for uniquely identifying each geographic area. "Area definition" is a set of parameters that define the geographic location and shape of each geographic area. For example, for a polygonal geographic area, the "area definition" indicates a set of coordinate values ​​(e.g., latitude and longitude) of N vertices (N is an integer greater than or equal to 3). For a circular geographic area, the "area definition" indicates the coordinate values ​​of the center point and the radius. "Associated base station" indicates at least one address (or other identification information) for communication with a base station serving each geographic area. "Neighboring area" is data indicating the neighboring relationship between geographic areas. For example, if a first geographic area is adjacent to a second and third geographic area, the "neighboring area" in the record for the first geographic area may indicate a list of area IDs for the second and third geographic areas.

[0035] FIG. 5 is an explanatory diagram illustrating an example of the definition of a geographical area. Referring to FIG. 5, the boundaries of four geographical areas 121-1, 121-2, 121-3, and 121-4 are shown by dashed lines superimposed on a road map of the area where the base station 300a is installed. Here, the geographical areas are approximately rectangular. The geographical areas 121-2, 121-3, and 121-4 are adjacent areas of the geographical area 121-1. Therefore, in this case, the area definition data 120 may include a record associating an "area ID" identifying the geographical area 121-1 with a list of the area IDs of the geographical areas 121-2, 121-3, and 121-4 as "adjacent areas." Two adjacent geographical areas may partially overlap. FIG. 5 also illustrates the boundary of the cell 30a of the base station 300a. Geographical areas are typically defined taking into account the purpose of the V2X application, regardless of cell coverage. For example, in this embodiment, a certain region may be divided into multiple geographical areas based on differences in the characteristics of the wireless communication environment (e.g., density of obstacles such as buildings, noise level, etc.), road characteristics (e.g., speed limit, number of lanes, etc.), or traffic trends (e.g., amount of pedestrians, frequency of traffic congestion, etc.).

[0036] The risk level data 130 is data indicating the risk level determined for each of the multiple geographical areas defined by the area definition data 120. The risk level data 130 may include, for example, the following three data items: "Administration area" "Danger Level" ·"Last updated" The "management area" identifies each geographical area subject to risk management by an "area ID" registered in the area definition data 120. The "risk level" is a parameter indicating the risk level determined for the geographical area identified by the "management area." In this embodiment, the "risk level" is evaluated on a three-level scale, indicating one of the following values: "low," which means the lowest risk level; "medium," which means the medium risk level; and "high," which means the highest risk level. In other embodiments, the "risk level" may be evaluated on a two-level scale or four or more levels. The "last updated" indicates the date and time when the "risk level" value for each geographical area was last updated.

[0037] The UE location data 140 is data for managing the location of a V2X UE that uses a V2X application provided by the server device 100. The UE location data 140 may include, for example, the following four data items: "UE ID" Location "Area to stay" ·“Final report” "UE ID" is an identifier for uniquely identifying each V2X UE. "Location" indicates the location last reported by each V2X UE. "Visit Area" identifies the geographical area corresponding to the location last reported by each V2X UE using the "Area ID" registered in area definition data 120. "Last Report" indicates the date and time when the location was last reported by each V2X UE.

[0038] The configuration of the database 110 is not limited to the configuration described here. The database 110 may store additional data, and some of the data items described above may be omitted. For example, the database 110 may store a user ID and authentication information (e.g., a password or an authentication key) for authenticating a user who uses a V2X application provided by the server device 100.

[0039] The server processing unit 150 is a functional module that operates as a server for a V2X application. The functions of the server processing unit 150 can be realized by one or more processors (for example, a CPU (Central Processing Unit)) executing a computer program stored in the memory 102. As shown in FIG. 4, the server processing unit 150 is composed of three server modules: a V2X application-specific server, a VAE server, and a SEAL server. The division of functions among these server modules may be as described using FIG. 2.

[0040] When UE200, operating as a client of the V2X application, connects to base station 300, server processing unit 150 performs authentication procedures as necessary and then sets up a communication link (V1-APP / V1-AE / SEAL-UU) for V2X communication with UE200.

[0041] The server processing unit 150 also configures each UE 200 to receive road safety warning messages transmitted from other V2X UEs via the sidelink. For example, if the warning message is broadcast over the PC5 interface, the server processing unit 150 configures the UE 200 to monitor the sidelink resources for messages having a destination Layer 2 ID for broadcast reception. If the warning message is groupcast over the PC5 interface, the server processing unit 150 assigns a group ID for receiving the warning message to the UE 200 and configures the UE 200 to monitor the sidelink resources for messages having a destination Layer 2 ID corresponding to the group ID. The group ID may be different for each geographical area, may be common across multiple geographical areas, or may be common across the entire system. The warning message may be transmitted by unicast; however, in terms of rapid transmission of the warning message, broadcast or groupcast is more advantageous than unicast, which requires the establishment of a separate PC5 interface.

[0042] The server processing unit 150 also manages the risk level of each geographical area indicated by the risk level data 130. For example, the initial value of the "risk level" of the risk level data 130 is determined in advance based on static conditions such as the characteristics of the wireless communication environment and the characteristics of the roads in the corresponding geographical area. The server processing unit 150 may update the value of the "risk level" based on temporal conditions, which may include the season or time of day, or sunlight conditions (for example, increasing the risk level by one level in the evening when visibility is poor). Furthermore, in this embodiment, the server processing unit 150 updates the value of the "risk level" of the risk level data 130 based on V2X messages received from one or more terminal devices via the communication I / F 101. Each of the terminal devices here may be the UE 200 described using FIG. 3 or another type of terminal device (for example, a roadside unit having a sensor or a camera). For example, when the server processing unit 150 determines that the following event is occurring in a certain geographical area based on a V2X message received from a terminal device, the server processing unit 150 may temporarily increase the value of the “risk level” for the geographical area until it is determined that the event has been resolved: - The presence of a vehicle that meets the threat detection conditions described above - Vehicles parked on the road ·traffic jam Abnormal driving environment

[0043] The server processing unit 150 also tracks the location of the connected UE 200. Specifically, the server processing unit 150 periodically receives location information of the UE 200 from the connected UE 200 via the communication I / F 101. Then, the server processing unit 150 determines in which geographical area the UE 200 is located based on the received location information, and updates the "Location," "Stay Area," and "Last Report" fields of the corresponding record in the UE location data 140. The location information may indicate, as the location of the UE 200, the position coordinates of a geographical position acquired as a result of positioning in the UE 200. In this case, the server processing unit 150 can determine, based on the "Area Definition" in the area definition data 120, to which geographical area the geographical position indicated by the location information belongs. If the size of the geographical area is equal to or larger than the size of the cell served by the base station 300, the location information may indicate, as the location, the cell ID of the cell to which the UE 200 is connected. In this case, the server processing unit 150 can determine which geographical area the cell to which the UE 200 is connected belongs to based on a known mapping between the cell ID indicated by the location information and the area ID of the corresponding geographical area.

[0044] In this embodiment, when the area definition data 120 indicates that the first and second geographical areas are adjacent areas, the server processing unit 150 instructs the UE 200 located in the first geographical area to relay the received alert message via a sidelink so that the alert message transmitted in the first geographical area can also be received in the second geographical area.

[0045] In the first embodiment, the instruction to relay is performed by transmitting a control message to the UE 200 via the communication I / F 101 in response to a determination that the UE 200 is located within the first geographical area, the control message instructing the UE 200 to relay an alert message received in the first geographical area via the sidelink. That is, in the first embodiment, the instruction to relay is performed at an application level. The server processing unit 150 may transmit the control message to the UE 200 when it is determined that the UE 200 is located within the first geographical area and within or near the second geographical area. When the UE 200 that has received the control message relays the alert message, the range of the alert message is substantially extended, and other UEs 200 located in the second geographical area adjacent to the first geographical area can receive the relayed alert message.

[0046] In the second embodiment, when the first and second geographical areas are adjacent areas, the server processing unit 150 transmits a request message to the base station 300 serving the first geographical area via the communication I / F 101, requesting that the base station 300 broadcast control information indicating that V2X UEs located in the first geographical area and in or near the second geographical area should relay an alert message. That is, in the second embodiment, the relay instruction is performed at the radio link level, not the application level. Upon receiving this request message from the server device 100, the base station 300 broadcasts the control information for instructing the relay of the alert message, for example, by including it in a system information block (SIB) on the PBCH.

[0047] The server processing unit 150 may determine that an alert message received in an adjacent first geographical area should also be receivable in the second geographical area when the level of risk of the second geographical area indicated by the risk level data 130 satisfies a predetermined criterion. The predetermined criterion here may include the level of risk being equal to or greater than a predefined threshold (e.g., being “high,” or being “high” or “medium”). For example, among the three adjacent areas 121-2, 121-3, and 121-4 adjacent to the geographical area 121-1 shown in FIG. 5 , the level of risk of the adjacent area 121-4 is “high” (for example, because there is no separate sidewalk beside the roadway), while the levels of risk of the adjacent areas 121-2 and 121-3 are “low.” In this case, the server processing unit 150 instructs that the alert message be relayed only to the UEs 200 located in or near the adjacent area 121-4 among the UEs 200 located in the geographical area 121-1. Such relay control makes it possible to selectively extend the reach of an alarm message in a particular direction.

[0048] The server processing unit 150 may determine that an alert message received in the first geographical area should also be receivable in the second geographical area when the risk level of the first geographical area as well as the risk level of the second geographical area satisfy the predetermined criterion. For example, among the four geographical areas shown in FIG. 5 , the risk levels of geographical areas 121-1 and 121-4 are assumed to be "high," while the risk levels of geographical areas 121-2 and 121-3 are assumed to be "low." In this case, the server processing unit 150 instructs UEs 200 located near the boundary between the geographical area 121-1 and the geographical area 121-4 to relay the alert message, but does not instruct UEs 200 located near the boundary between the geographical area 121-1 and the geographical area 121-2 or 121-3 to relay the alert message. This relay control makes it possible to selectively extend the reach of only alert messages generated in areas with a relatively high risk level.

[0049] 6A shows a first example of the format of a control message transmitted to UE 200 to instruct relay. In the first example, format 160a includes V2X UE ID 161, visiting area 162, and relay flag 163. V2X UE ID 161 indicates a UE ID that identifies UE 200, the destination of the control message. Visiting area 162 indicates an area ID that identifies a geographical area in which UE 200, identified by V2X UE ID 161, is determined to be located. Relay flag 163 is a control parameter that indicates whether UE 200, identified by V2X UE ID 161, should relay the alert message. For example, a value of "0" for relay flag 163 indicates that UE 200, which has received this control message, should not relay the alert message, and a value of "1" for relay flag 163 indicates that UE 200, which has received this control message, should relay the alert message.

[0050] 6B shows a second example of the format of a control message to instruct relaying to the UE 200. In the second example, the format 160b includes the V2X UE ID 161 and the relay flag 163.

[0051] 6C shows a third example of the format of a control message transmitted to UE 200 to instruct relaying. In the third example, format 160c includes V2X UE ID 161, a stay area 162, and a neighboring area 164. Neighboring area 164 indicates one or more geographical areas that are adjacent to the geographical area identified by stay area 162 and are in the vicinity of the location of UE 200 identified by V2X UE ID 161. Format 160c does not indicate whether UE 200 receiving this control message should relay the alert message, and therefore may be used in combination with format 160d, which will be described next.

[0052] 6D shows a fourth example of the format of a control message transmitted to UE 200 for instructing relay. In the fourth example, format 160d includes area number 165 and K pairs of area ID 166-k and relay area list 167-k (k=1, 2, ..., K). Area number 165 indicates the number K of pairs of area ID and relay area list included in the control message. Area ID 166-k indicates an area ID that identifies the kth geographical area. Relay area list 167-k indicates a list of area IDs that identify geographical areas to which an alert message from the kth geographical area should be relayed. When a UE 200 receives control messages in both formats 160c and 160d, it looks up the area ID indicated by the stay area 162 of the former control message in the K area IDs 166-k of the latter control message, and if the relay area list 167-k paired with the discovered area ID 166-k includes the area ID indicated by the adjacent area 164 of the former control message, it can recognize that relaying of an alert message has been instructed.

[0053] In the first embodiment described above, the control message that the server processing unit 150 may send to the UE 200 may be one of the following options: Message A (Format 160a) Message B (format 160b) Message C (format 160c) and Message D (format 160d) Message A, message B, or message C may be transmitted whenever the location of UE 200 changes. On the other hand, message D, once transmitted to UE 200, may not be transmitted again to the same UE 200 unless the risk level of one or more geographical areas changes. Of course, each message may include additional control parameters not shown. If UE 200 can autonomously determine the geographical area in which it is currently located and its adjacent areas based on its own location (e.g., by referring to a pre-downloaded area definition), only message D (format 160d) may be transmitted to UE 200.

[0054] In the second embodiment described above, the control information that the UE 200 may receive may be one of the following options: System information broadcast from the base station (format 160d) and message C received from the server device 100 (format 160c) System information broadcast from the base station (format 160d) The second option may be adopted when the UE 200 is able to autonomously determine the geographical area in which it is currently located and its adjacent areas based on its location. Broadcasting of the system information from the base station may be performed, for example, by including the system information in a system information block provided for controlling V2X communications.

[0055] In the first embodiment, when a plurality of UEs 200 are present near the boundary between the first and second geographical areas, the server processing unit 150 may instruct only some of the plurality of UEs 200 to relay the warning message. The server processing unit 150 may determine which UEs 200 should relay the warning message by taking into consideration one or more of the capability, location, processing performance, and remaining power of each UE 200. For example, by instructing only the UE 200 with the highest processing performance among the UEs 200 located close to each other to relay the warning message, it is possible to effectively extend the reach of the warning message while avoiding message collisions caused by the plurality of UEs 200 relaying the warning message.

[0056] <2-3. Example of terminal device configuration> 7 is a block diagram showing an example of the configuration of the UE 200 according to this embodiment. Referring to FIG. 7, the UE 200 includes a wireless I / F 201, a memory 202, a storage 203, a sensor group 204, a camera 205, a positioning module 206, an input device 207, an output device 208, a power source 209, and a control unit 210.

[0057] The wireless I / F 201 is a wireless communication unit for performing wireless communication by the UE 200. In this embodiment, the wireless I / F 201 is capable of communication via a wireless link established with the base station 300, and is also capable of communication with other V2X UEs via a side link.

[0058] The memory 202 may include any combination of a non-volatile storage medium such as a ROM and a volatile storage medium such as a RAM. For example, the ROM pre-stores computer programs for several client modules that run on the control unit 210. The RAM provides a temporary storage area for calculations by the control unit 210.

[0059] The storage 203 is a storage device for storing large amounts of data, and may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0060] The sensor group 204 is a collection of various sensors mounted on the UE 200. If the UE 200 is a pedestrian terminal, the sensor group 204 may include an acceleration sensor, a gyro sensor, and a direction sensor. If the UE 200 is an in-vehicle terminal, the sensor group 204 may include, in addition to the above-mentioned sensors, further sensors such as a ranging sensor (e.g., LiDAR or millimeter-wave radar) and a biometric sensor.

[0061] The camera 205 is an imaging module capable of capturing images of the surroundings of the UE 200. The sensors 204 and the camera 205 may be used to detect threats related to road safety in accordance with the threat detection conditions described above.

[0062] The positioning module 206 is a module for measuring the position of the UE 200. The positioning module 206 may be capable of acquiring the latitude, longitude, and altitude of the current position of the UE 200 using, for example, a Global Navigation Satellite System (GNSS) such as a Global Positioning System (GPS). Alternatively or additionally, the positioning module 206 may be capable of estimating the current position of the UE 200 based on the known absolute position of a base station to which the UE 200 is connected and a relative position from the base station.

[0063] The input device 207 is a device that allows the UE 200 to receive instructions and information input from a user. The input device 207 includes, for example, one or more of a touch sensor, a button, a switch, a keypad, and a microphone.

[0064] The output device 208 is a device for the UE 200 to output information or signals to a user, and includes, for example, one or more of a display, a speaker, a light, and a vibrator.

[0065] The power supply 209 is a rechargeable battery for supplying power to each unit of the UE 200 via a power line partially shown in the figure. The supply of power from the power supply 209 is controlled by the control unit 210.

[0066] The control unit 210 includes one or more processors and controls the overall functions of the UE 200 by executing computer programs stored in the memory 202. For example, the control unit 210 functions as a client processing unit 220 that operates as a client of a V2X application. The client processing unit 220 is composed of three client modules: a V2X application-specific client, a VAE client, and a SEAL client. The functional division among these client modules may be as described with reference to FIG. 2. The control unit 210 may also have various other functions that a general pedestrian terminal or an in-vehicle terminal has, but here, for simplicity of explanation, the functions of the client processing unit 220 will be mainly described.

[0067] The client processing unit 220 connects to a server device operating as a V2X application server via a wireless link between the wireless I / F 201 and the base station 300. The client processing unit 220 sets up the wireless I / F 201 to receive road safety warning messages from other V2X UEs via the sidelink according to settings signaled by the server processing unit 150 of the server device 100. For example, the wireless I / F 201 monitors sidelink resources for messages with a destination Layer 2 ID for warning messages and receives such messages when they are transmitted from nearby V2X UEs. When a warning message is received via the sidelink, the client processing unit 220 alerts the user via the user interface of the UE 200 so that the user can take appropriate action to ensure safety. For example, the alert may be generated by displaying warning text or an icon on the display of the output device 208, outputting a warning sound or audio from the speaker, or vibrating the device.

[0068] The client processing unit 220 may be capable of detecting a security threat based on sensor data input from the sensor group 204 or video data input from the camera 205, in accordance with one or more of the above-described threat detection conditions. When the client processing unit 220 detects a security threat, it issues an alert to the user and causes the wireless I / F 201 to transmit an alert message over the sidelink communication resources. As described above, the alert message may be transmitted by broadcast, groupcast, or unicast. Note that the client processing unit 220 of all UEs 200 does not necessarily have the function of transmitting an alert message.

[0069] The client processing unit 220 periodically reports location information indicating the latest location of the UE 200, acquired by the positioning module 206, to the server device 100. A V2X message for reporting the location information is transmitted to the server device 100 via the wireless I / F 201 and the connected base station 300. As described above, the server processing unit 150 of the server device 100 determines in which geographical area the UE 200 is located, based on the reported location information. The V2X message transmitted to the server device 100 may include information for updating the risk level for each geographical area managed by the server processing unit 150. For example, the client processing unit 220 may transmit sensor data input from the sensor group 204 to the server device 100. The client processing unit 220 may also notify the server device 100 that a safety threat has been detected according to any threat detection condition. The client processing unit 220 may also perform more advanced processing, such as determining whether a vehicle is stopped, whether there is a traffic jam, or whether there is an abnormality in the driving environment, and notify the server device 100 of the determination result.

[0070] In this embodiment, the client processing unit 220 receives instructions regarding relaying of alert messages received from other V2X UEs via sidelinks directly from the server device 100 at the application level or indirectly at the radio link level.

[0071] For example, assume that the location information of the UE 200 reported to the server device 100 indicates a location within a first geographical area and within or near an adjacent second geographical area. In this case, the client processing unit 220 may receive an instruction to relay an alert message received from another V2X UE via a sidelink. Alternatively, such an instruction may be received when the risk data 130 indicates that the risk level of the second geographical area (or the risk levels of both the first and second geographical areas) is high. When the client processing unit 220 receives the instruction to relay the alert message, it causes the radio I / F 201 to relay the alert message received in the first geographical area from another V2X UE via a sidelink. This allows a V2X UE located in a second geographical area adjacent to the first geographical area to receive the relayed alert message.

[0072] In the first embodiment, an instruction regarding relaying of the alert message is included in a control message received from the server device 100 via the wireless link of the wireless I / F 201 as a response to the transmission of the location information. For example, when it is determined that the UE 200 is located in a location where relaying of the alert message is required, the control message includes a control parameter (for example, the relay flag 163 indicating the value "1") instructing to relay the alert message. On the other hand, when it is determined that the UE 200 is located in a location where relaying of the alert message is not required, the control parameter includes a control parameter (for example, the relay flag 163 indicating the value "0") indicating that the alert message does not need to be relayed.

[0073] In the second embodiment, an instruction regarding relaying the warning message is included in control information broadcast from the base station 300 serving the geographical area in which the UE 200 is located and received by the wireless I / F 201. For example, if relaying of the warning message is required near the boundary between a first geographical area and a second geographical area, the control information broadcast from the base station 300 includes an association between the area IDs of the first and second geographical areas (e.g., a combination of the area ID 166-k and the relay area list 167-k). The client processing unit 220 may, for example, monitor a system information block (e.g., SIB13 or SIB14) for controlling V2X communication periodically broadcast from the base station 300 to obtain the control information including the instruction regarding relaying the warning message. The client processing unit 220 may receive a control message including the area ID of the geographical area in which the UE 200 is located from the server device 100, or may autonomously determine which geographical area the UE 200 is located in.

[0074] In the first and second embodiments, the control message or control information that the UE 200 may receive may have the format described above with reference to FIGS. 6A to 6D.

[0075] In this embodiment, the warning message transmitted and received via the sidelink may include a control parameter for distinguishing between an original warning message transmitted by a V2X UE that detected a threat and a warning message that has been relayed at least once. The control parameter may be, for example, a flag indicating different values ​​for the original warning message and the relayed warning message, or a counter indicating the number of times the message has been relayed. The client processing unit 220 may then refrain from relaying a warning message for which the control parameter indicates that the message has been relayed at least once, regardless of an instruction from the server device 100. This can prevent message congestion or excessive range extension due to relaying the warning message over multiple hops.

[0076] <2-4. Example of base station configuration> 8 is a block diagram showing an example of the configuration of a base station 300 according to this embodiment. Referring to FIG. 8, the base station 300 includes a wireless I / F 301, a network I / F 302, a memory 303, a storage 304, and a communication control unit 310.

[0077] The wireless I / F 301 is a wireless communication unit that enables the base station 300 to provide wireless access to one or more UEs 200 within the cell 30. For example, if the coverage of the cell 30 of the base station 300 includes a first geographical area, the base station 300 can wirelessly communicate with at least the UEs 200 located within the first geographical area via the wireless I / F 301.

[0078] The network I / F 302 is a network communication unit that enables the base station 300 to communicate with network nodes within the network 10 and other devices connected to the network 10. The base station 300 can communicate with the server device 100, for example, via the network I / F 302.

[0079] The memory 303 may include any combination of a non-volatile storage medium such as a ROM and a volatile storage medium such as a RAM. For example, the ROM stores in advance a computer program to be executed by the communication control unit 310. The RAM provides a temporary storage area for calculations by the communication control unit 310. The storage 304 is a storage device for storing large amounts of data. The storage 304 may be, for example, an HDD or an SSD.

[0080] The communication control unit 310 includes one or more processors and executes computer programs stored in the memory 303 to control wireless communication performed by the wireless I / F 301 and network communication performed by the network I / F 302. For example, when a connection request from the UE 200 is received by the wireless I / F 301, the communication control unit 310 establishes a wireless link between the UE 200 and the wireless I / F 301. Furthermore, when the UE 200 uses a V2X application provided by the server apparatus 100, the communication control unit 310 mediates application-level communication between the UE 200 and the server apparatus 100. Furthermore, the communication control unit 310 schedules sidelink resources or allocates a resource pool for the sidelink for the UE 200, which is a V2X UE. This enables the UE 200 to communicate wirelessly with the base station 300 via a wireless link and with other V2X UEs via a sidelink.

[0081] In one embodiment, the communication control unit 310 is involved in controlling relay of the warning message by the UE 200. For example, when the server device 100 determines that the first geographical area and the second geographical area are adjacent areas and that the risk level of the second geographical area (or both the risk levels of the first and second geographical areas) satisfies a predetermined criterion, the server device 100 transmits to the base station 300 a request message requesting broadcast of control information indicating that the UE 200 located near the boundary between these two geographical areas should relay, via a sidelink, a warning message received from another V2X UE. When the server device 100 receives this request message via the network I / F 302, the communication control unit 310 causes the radio I / F 301 to broadcast the control information indicating that the UE 200 located near the boundary should relay the warning message via a sidelink. The format of the broadcasted control information may be the format described above in relation to the second embodiment. The radio I / F 301 may broadcast the control information by including it in a system information block for controlling V2X communication. In this case, terminal devices not involved in V2X communication can ignore the system information block.

[0082] <3. Processing flow> In this section, an example of a process flow that can be executed in the above-described V2X communication system 1 will be described using the sequence diagrams of Figures 9 and 10. In the following description, a processing step will be abbreviated as S (step).

[0083] <3-1. First Example> 9 is a sequence diagram showing an example of a processing flow according to the first embodiment. The processing shown in the figure mainly involves the server device 100, the UE 200a, the UE 200b, the UE 200c, and the base station 300. However, a plurality of V2X UEs other than the UEs 200a to 200c also exchange V2X messages with the server device 100.

[0084] First, in S11, server device 100 receives V2X messages from multiple V2X UEs. Each received V2X message may include any information, such as the speed or acceleration of a traveling vehicle, its position on a road, physiological parameters of the driver, or the state of the traveling environment. In S13, server processing unit 150 of server device 100 updates the risk level of each geographical area indicated by risk level data 130 based on the received V2X messages. Such updates may be performed periodically or intermittently while server device 100 is operating.

[0085] Next, when the UE 200a enters the coverage of the cell 30 served by the base station 300, a radio link is established between the UE 200a and the base station 300 in S15. Next, in S17, the communication control unit 310 of the base station 300 schedules sidelink resources or allocates a resource pool for the sidelink for the UE 200a, which is a V2X UE.

[0086] Next, in S21, the client processing unit 220 of the UE 200a accesses the server device 100 using, for example, the URL of the server device 100 stored in advance in the memory 202, and participates in the V2X service provided by the server device 100. In S23, the server processing unit 150 of the server device 100 registers the UE 200a as a connected client (if authentication of the UE 200a is successful). Then, in S25, the server processing unit 150 sets up a communication link with the UE 200a. For example, the client processing unit 220 of the UE 200a sets up the wireless I / F 201 in accordance with the setting from the server processing unit 150 so as to receive alert messages transmitted from other V2X UEs via a side link.

[0087] Next, in S31, the client processing unit 220 of the UE 200a transmits location information indicating the latest location of the UE 200a to the server device 100. The server processing unit 150 of the server device 100, which has received the location information, determines in S33 whether the UE 200a is located in a location where a warning message on the sidelink should be relayed. Here, it is assumed that the UE 200a is located near the boundary between the first and second geographical areas, which are indicated as having a high risk by the risk level data 130, and therefore is determined to be located in a location where a warning message should be relayed. In S35, when the server processing unit 150 receives a warning message via the sidelink, it transmits a control message to the UE 200a indicating that the warning message should be relayed via the sidelink. The client processing unit 220 of the UE 200a receives this control message via the wireless I / F 201.

[0088] Subsequently, in S41, UE 200c, which is participating in the same V2X service, detects a threat to road safety. In S43, the client processing unit 220 of UE 200c transmits (e.g., broadcasts or groups) a warning message on the sidelink communication resources. The radio I / F 201 of UE 200a continuously monitors the resources for sidelink broadcasts or groups, and receives the warning message transmitted from UE 200c. Meanwhile, UE 200b also continuously monitors the resources for sidelink broadcasts or groups, but does not receive the warning message because UE 200b is located outside the reachable range of the warning message from UE 200c. In response to receiving the warning message, the client processing unit 220 of UE 200a alerts the user via a user interface so that the user can take appropriate action to ensure safety.

[0089] Having received the instruction to relay the warning message in S35, the client processing unit 220 of the UE 200a relays the warning message received from the UE 200c over the sidelink communication resources in S47. The wireless I / F 201 of the UE 200b then receives the warning message transmitted (relayed) from the UE 200a. Then, in S49, in response to receiving the relayed warning message, the client processing unit 220 of the UE 200b issues a warning to the user via the user interface so that the user can take appropriate action to ensure their safety.

[0090] <3-2. Second Example> 10 is a sequence diagram showing an example of a processing flow according to the second embodiment. The processing shown in the figure mainly involves the server device 100, the UE 200a, the UE 200b, the UE 200c, and the base station 300. However, a plurality of V2X UEs other than the UEs 200a to 200c also exchange V2X messages with the server device 100.

[0091] The processing steps S11 to S33 may be the same as the corresponding processing steps in the first embodiment described with reference to Fig. 9. Therefore, the description of these processing steps will be omitted here.

[0092] In S34, the server processing unit 150 of the server device 100, which has determined the location of the UE 200a in S33, transmits to the UE 200a a control message including an area ID that identifies the geographical area in which the UE 200a is located and its adjacent areas. Note that if the UE 200a can autonomously determine the area, the area notification in S34 may be omitted. Here, it is assumed that the UE 200a is located near the boundary between the first and second geographical areas, which are indicated to have a high level of risk by the risk level data 130, and therefore is determined to be located at a location where a warning message should be relayed. Next, in S36, the server processing unit 150 requests the base station 300 serving the first geographical area in which the UE 200a is located to broadcast control information for instructing V2X UEs in the first geographical area to relay the warning message. Upon receiving the broadcast request, the communication control unit 310 of the base station 300 causes the wireless I / F 301 to broadcast control information indicating that V2X UEs located within the first geographical area and within or near the second geographical area should relay the warning message via the sidelink at S38. The client processing unit 220 of the UE 200a receives the control information via the wireless I / F 201.

[0093] The subsequent processing steps S41 to S49 may be the same as the corresponding processing steps in the first embodiment described with reference to Fig. 9. Therefore, a description of these processing steps will be omitted here.

[0094] <4. Summary of embodiments> The above embodiment discloses at least the following server device, communication control method, terminal device, and base station.

[0095] 1. The server device (100) of the above embodiment is A communication unit (101) that communicates with one or more terminal devices (200) that operate as clients of a V2X (Vehicle-to-Everything) application; A server processing unit (150) that operates as a server for the V2X application; Equipped with The server processing unit is capable of accessing a database (110) indicating an adjacency relationship (120) between a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The server processing unit Configure each of the one or more terminal devices to receive road safety warning messages sent from other terminal devices via a side link (S25); receiving location information of the first terminal device via the communication unit (S31); determining, based on the location information, that the first terminal device is located within the first geographic area (S33); By instructing the first terminal device to relay the warning message received in the first geographical area via the sidelink (S35, S36), a second terminal device located in the second geographical area is enabled to receive the relayed warning message. According to this embodiment, the reachable range of a warning message notifying the presence of a threat can be extended by relaying the message using the sidelink of the terminal device. The relayed warning message is transmitted from the first geographical area to the second geographical area without passing through a base station, so the latency involved in relaying is small. Therefore, V2X UE users over a wide area can be notified of the presence of a threat in a timely manner, further improving user safety in road traffic.

[0096] 2. In the above embodiment, Instructing the first terminal device to relay the alert message includes: transmitting a control message to the first terminal device via the communication unit instructing the first terminal device to relay the alert message in response to determining that the first terminal device is located within the first geographical area and within or near the second geographical area (S35); Includes: According to this embodiment, communication for controlling the relay operation of the terminal device is performed at the application level between the V2X application server and client. That is, the content of the communication is transparent to base stations located along the communication path. Therefore, it is possible to define multiple geographical areas based on road traffic conditions and control the relay operation on a geographical area basis, regardless of the location of base stations.

[0097] 3. In the above embodiment, Instructing the first terminal device to relay the alert message includes: requesting a base station serving the first geographical area to broadcast control information indicating that a terminal device operating as a client of the V2X application, the terminal device being located within the first geographical area and located within or near the second geographical area, should relay the warning message (S36); Includes: According to this embodiment, one or more terminal devices that receive control information broadcast from the base station relay the warning message, thereby enabling the range that the warning message can reach to be expanded more widely and efficiently.

[0098] 4. In the above embodiment, the database further indicates a risk level (130) for each of the plurality of geographic areas; The server processing unit determines that the warning message received in the first geographical area should also be received in the second geographical area if the risk level of the second geographical area indicated by the database meets a predetermined criterion. According to this embodiment, the reachable range of the warning message can be adaptively extended toward areas where user safety is likely to be threatened, such as areas with many obstacles blocking the line of sight or areas with many pedestrians, etc. Therefore, sufficient safety can be achieved while avoiding excessive consumption of communication resources due to relaying the warning message.

[0099] 5. In the above embodiment, The server processing unit determines that the warning message received in the first geographical area should also be received in the second geographical area when both the risk level of the first geographical area and the risk level of the second geographical area indicated by the database meet the predetermined criteria. According to this embodiment, for an alarm message generated in an area of ​​relatively high risk, the reachable range can be adaptively extended toward areas that are also relatively high risk and therefore more likely to threaten the user's safety.

[0100] 6. The communication control method of the above embodiment is A communication control method performed by a server device (100) operating as a server of a V2X (Vehicle-to-Everything) application to control V2X communication by a terminal device (200) operating as a client of the V2X application, comprising: The server device has access to a database (110) that indicates an adjacency relationship (120) between a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) that are predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: Configuring each of the one or more terminal devices to receive road safety warning messages from other terminal devices via a side link (S25); Receiving location information of a first terminal device (S31); determining (S33) that the first terminal device is located within the first geographic area based on the location information; instructing the first terminal device to relay the warning message received in the first geographical area via the sidelink (S35, S36), thereby enabling a second terminal device located in the second geographical area to receive the relayed warning message; Includes: According to this embodiment, the reachable range of a warning message notifying the presence of a threat can be extended by relaying the message using the sidelink of the terminal device. The relayed warning message is transmitted from the first geographical area to the second geographical area without passing through a base station, so the latency involved in relaying is small. Therefore, V2X UE users over a wide area can be notified of the presence of a threat in a timely manner, further improving user safety in road traffic.

[0101] 7. The terminal device (200) of the above embodiment is a wireless communication unit (201) that performs wireless communication via a wireless link between the terminal device and a base station (300) and a side link between the terminal device and another terminal device (200); a client processing unit (220) that operates as a client of a V2X (Vehicle-to-Everything) application and connects to a server device (100) that operates as a server of the V2X application via the wireless link of the wireless communication unit; Equipped with The server device has access to a database (110) that indicates an adjacency relationship (120) between a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) that are predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The client processing unit setting up the wireless communication unit to receive a road safety warning message transmitted from the other terminal device via the side link (S25); Transmitting location information of the terminal device to the server device (S31); receiving an instruction to relay the alert message via the sidelink when the server device determines that the terminal device is located within the first geographic area based on the location information (S35, S38); The warning message received in the first geographical area is relayed via the side link of the wireless communication unit (S47), thereby enabling a terminal device located in the second geographical area to receive the relayed warning message. According to this embodiment, when the terminal device is located in a first geographical area adjacent to a second geographical area, the terminal device relays a warning message notifying the presence of a threat via a sidelink under control of the server device. This extends the reachable range of the warning message to a range spanning the first and second geographical areas. Because the warning message is relayed without going through a base station, the latency associated with relaying is small. Therefore, it is possible to notify V2X UE users over a wide area of ​​the presence of a threat in a timely manner, further improving user safety in road traffic.

[0102] 8. In the above embodiment, The client processing unit receives, in response to the transmission of the location information, a control message from the server device via the wireless link of the wireless communication unit, instructing it to relay the warning message (S35). According to this embodiment, a control message for controlling relay operation of a terminal device is received from a server device through communication at the application level, which allows control of relay operation on a geographical area basis, independent of the location of base stations.

[0103] 9. In the above embodiment, The client processing unit receives the control message from the server device when the server device determines that the terminal device is located within the first geographical area and within or near the second geographical area. According to this embodiment, the reachable range of the warning message can be adaptively extended toward areas where user safety is likely to be threatened, thereby achieving sufficient safety while avoiding excessive consumption of communication resources due to relaying the warning message.

[0104] 10. In the above embodiment, the wireless communication unit receives control information broadcast by a base station serving the first geographic area in response to a request from the server device (S38); The control information indicates that a terminal device operating as a client of the V2X application, the terminal device being located within the first geographical area and within or near the second geographical area, should relay the warning message. According to this embodiment, there is no need for the server device to send individual control messages to each terminal device in order to extend the range within which the warning message can be received, so range extension can be achieved efficiently.

[0105] 11. The communication control method of the above embodiment is A communication control method performed by a terminal device (200) operating as a client of a V2X (Vehicle-to-Everything) application to control V2X communication by the terminal device, The terminal device includes a wireless communication unit (201) that performs wireless communication via a wireless link between the terminal device and a base station (300) and a side link between the terminal device and another terminal device (200), The wireless communication unit connects to a server device (100) that operates as a server of the V2X application via the wireless link of the wireless communication unit; The server device has access to a database (110) that indicates an adjacency relationship (120) between a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) that are predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: setting up the wireless communication unit to receive road safety warning messages transmitted from the other terminal device via the side link (S25); Transmitting location information of the terminal device to the server device (S31); receiving an instruction to relay the alert message via the sidelink when the server device determines that the terminal device is located within the first geographic area based on the location information (S35, S38); relaying (S47) the warning message received in the first geographical area via the side link of the wireless communication unit, thereby enabling a terminal device located in the second geographical area to receive the relayed warning message; Includes: According to this embodiment, when the terminal device is located in a first geographical area adjacent to a second geographical area, the terminal device relays a warning message notifying the presence of a threat via a sidelink under control of the server device. This extends the reachable range of the warning message to a range spanning the first and second geographical areas. Because the warning message is relayed without going through a base station, the latency associated with relaying is small. Therefore, it is possible to notify V2X UE users over a wide area of ​​the presence of a threat in a timely manner, further improving user safety in road traffic.

[0106] 12. The base station (300) of the above embodiment is a wireless communication unit (301) that performs wireless communication in at least a first geographical area among a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) that are predefined for a V2X (Vehicle-to-Everything) application; A network communication unit (302) that communicates with a server device (100) that operates as a server of the V2X application; a control unit (310) that controls communications performed by the wireless communication unit and the network communication unit; Equipped with The server device has access to a database (110) that indicates neighboring relationships (120) between geographical areas for a plurality of geographical areas that are predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; In response to a request from the server device, the control unit causes the wireless communication unit to broadcast control information indicating that when a terminal device (200) operating as a client of the V2X application, which is located within the first geographical area and within or near the second geographical area, receives a road safety warning message transmitted from another terminal device via a side link, the warning message should be relayed via the side link (S38). According to this embodiment, through the broadcasting of control information from the base station, one or more terminal devices located near the boundary between the first and second geographical areas can be configured to relay a warning message notifying the presence of a threat. This can extend the reachable range of the warning message to a wider range spanning the two geographical areas. Therefore, V2X UE users over a wide area can be notified of the presence of a threat in a timely manner, further improving user safety in road traffic.

[0107] 13. In the above embodiment, The control unit causes the wireless communication unit to include the control information in a system information block for controlling V2X communication and broadcast the system information block. According to this embodiment, terminal devices that are not involved in V2X communication can ignore the system information blocks carrying the control information, so that the addition of control information broadcast from the base station does not increase the processing load of terminal devices that do not benefit from the warning messages.

[0108] 14. The communication control method of the above embodiment is A communication control method performed by a base station (300) for controlling V2X (Vehicle-to-Everything) communication by a terminal device (200) operating as a client of a V2X application, The base station includes a wireless communication unit (301) that performs wireless communication in at least a first geographical area among a plurality of geographical areas (121-1, 121-2, 121-3, 121-4) that are predefined for the V2X application, and a network communication unit (302) that communicates with a server device (100) that operates as a server for the V2X application, the server device has access to a database (110) that indicates adjacency relationships (120) between the geographic areas; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: receiving a request message from the server device via the network communication unit (S36); In response to receiving the request message, causing the wireless communication unit to broadcast control information indicating that a terminal device located within the first geographical area and within or near the second geographical area should relay a road safety warning message received from another terminal device via a side link (S38). Includes: According to this embodiment, through the broadcasting of control information from the base station, one or more terminal devices located near the boundary between the first and second geographical areas can be configured to relay a warning message notifying the presence of a threat. This can extend the reachable range of the warning message to a wider range spanning the two geographical areas. Therefore, V2X UE users over a wide area can be notified of the presence of a threat in a timely manner, further improving user safety in road traffic.

[0109] Although the embodiments of the invention have been described above, the invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0110] 1 V2X communication system, 100 server device, 101 communication unit, 110 database, 120 area definition data, 121-1, 121-2, 121-3, 121-4 geographical area, 130 risk level data, 140 UE location data, 150 server processing unit, 200 UE (terminal device), 201 wireless communication unit, 220 client processing unit, 300 base station, 301 wireless communication unit, 302 network communication unit, 310 communication control unit

Claims

1. a communication unit that communicates with one or more terminal devices that operate as clients of a V2X (Vehicle-to-Everything) application; A server processing unit that operates as a server of the V2X application; Equipped with The server processing unit has access to a database indicating an adjacency relationship between geographical areas for a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The server processing unit configuring each of the one or more terminal devices to receive road safety warning messages originating from other terminal devices via a side link; receiving location information of a first terminal device via the communication unit; determining, based on the location information, that the first terminal device is located within the first geographic area; instructing the first terminal device to relay the warning message received in the first geographic area via the sidelink, thereby enabling a second terminal device located in the second geographic area to receive the relayed warning message; Server device.

2. Instructing the first terminal device to relay the alert message includes: In response to determining that the first terminal device is located within the first geographic area and within or near the second geographic area, transmitting a control message to the first terminal device via the communication unit, the control message instructing the first terminal device to relay the alert message; The server device according to claim 1 , comprising:

3. Instructing the first terminal device to relay the alert message includes: requesting a base station serving the first geographical area to broadcast control information indicating that a terminal device acting as a client of the V2X application, the terminal device being located in the first geographical area and in or near the second geographical area, should relay the alert message; The server device according to claim 1 , comprising:

4. the database further indicates a risk level for each of the plurality of geographic areas; the server processing unit determines that the warning message received in the first geographic area should also be received in the second geographic area if the risk level of the second geographic area indicated by the database satisfies a predetermined criterion; The server device according to any one of claims 1 to 3.

5. 5. The server device of claim 4, wherein the server processing unit determines that the warning message received in the first geographical area should also be received in the second geographical area when both the risk level of the first geographical area and the risk level of the second geographical area indicated by the database satisfy the predetermined criteria.

6. A communication control method performed by a server device operating as a server of a V2X (Vehicle-to-Everything) application for controlling V2X communication by a terminal device operating as a client of the V2X application, the server device has access to a database indicating an adjacency relationship between geographical areas for a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: configuring each of one or more terminal devices to receive road safety warning messages originating from other terminal devices via a side link; receiving location information of a first terminal device; determining, based on the location information, that the first terminal device is located within the first geographic area; instructing the first terminal device to relay the warning message received in the first geographic area via the sidelink, thereby enabling a second terminal device located in the second geographic area to receive the relayed warning message; A communication control method comprising:

7. A terminal device, a wireless communication unit that performs wireless communication via a wireless link between the terminal device and a base station and a side link between the terminal device and another terminal device; a client processing unit that operates as a client of a V2X (Vehicle-to-Everything) application and connects to a server device that operates as a server of the V2X application via the wireless link of the wireless communication unit; Equipped with the server device has access to a database indicating an adjacency relationship between geographical areas for a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The client processing unit setting up the wireless communication unit to receive a road safety warning message transmitted from the other terminal device via the side link; transmitting location information of the terminal device to the server device; receiving an instruction to relay the alert message over the sidelink when the server device determines that the terminal device is located within the first geographic area based on the location information; relaying the warning message received in the first geographic area via the side link of the wireless communication unit, thereby enabling a terminal device located in the second geographic area to receive the relayed warning message. Terminal device.

8. The terminal device according to claim 7, wherein the client processing unit receives a control message from the server device via the wireless link of the wireless communication unit instructing it to relay the alert message in response to the transmission of the location information.

9. 9. The terminal device according to claim 8, wherein the client processing unit receives the control message from the server device when the server device determines that the terminal device is located within the first geographical area and within or near the second geographical area.

10. the wireless communication unit receives control information broadcast by a base station serving the first geographic area in response to a request from the server device; the control information indicates that a terminal device operating as a client of the V2X application, the terminal device being located within the first geographical area and within or near the second geographical area, should relay the alert message. The terminal device according to claim 7.

11. A communication control method performed by a terminal device operating as a client of a V2X (Vehicle-to-Everything) application to control V2X communication by the terminal device, the terminal device includes a wireless communication unit that wirelessly communicates via a wireless link between the terminal device and a base station and a side link between the terminal device and another terminal device; The wireless communication unit connects to a server device operating as a server of the V2X application via the wireless link of the wireless communication unit, the server device has access to a database indicating an adjacency relationship between geographical areas for a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: setting up the wireless communication unit to receive road safety warning messages transmitted from the other terminal device via the side link; transmitting location information of the terminal device to the server device; receiving an instruction to relay the alert message over the sidelink when the server device determines that the terminal device is located within the first geographic area based on the location information; relaying the warning message received in the first geographic area via the side link of the wireless communication unit, thereby enabling a terminal device located in the second geographic area to receive the relayed warning message; A communication control method comprising:

12. a wireless communication unit configured to perform wireless communication in at least a first geographical area among a plurality of geographical areas predefined for a vehicle-to-everything (V2X) application; A network communication unit that communicates with a server device that operates as a server of the V2X application; a control unit that controls communications performed by the wireless communication unit and the network communication unit; Equipped with the server device has access to a database indicating an adjacency relationship between geographical areas for a plurality of geographical areas predefined for the V2X application; the first geographic area and the second geographic area are designated by the database as adjacent areas; In response to a request from the server device, the control unit causes the wireless communication unit to broadcast control information indicating that, when a terminal device operating as a client of the V2X application, the terminal device being located within the first geographical area and within or near the second geographical area, receives a warning message related to road safety transmitted from another terminal device via a side link, the warning message should be relayed via the side link. Base station.

13. The base station according to claim 12, wherein the control unit causes the radio communication unit to include the control information in a system information block for controlling V2X communication and broadcast the system information block.

14. A communication control method performed by a base station for controlling V2X (Vehicle-to-Everything) communication by a terminal device operating as a client of a V2X application, the base station comprises: a wireless communication unit that performs wireless communication in at least a first geographical area among a plurality of geographical areas predefined for the V2X application; and a network communication unit that communicates with a server device that operates as a server for the V2X application; the server device has access to a database indicating adjacency relationships between the geographical areas; the first geographic area and the second geographic area are designated by the database as adjacent areas; The communication control method includes: receiving a request message from the server device via the network communication unit; In response to receiving the request message, causing the wireless communication unit to broadcast control information indicating that terminal devices located within the first geographical area and within or near the second geographical area should relay road safety warning messages received from other terminal devices via a side link. A communication control method comprising:

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