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

Abstract

According to one embodiment, the present invention provides a server device comprising a communication unit that communicates with one or more terminal devices each operating as a client of a V2X application and a server processing unit that operates as a server of the V2X application. The server processing unit can access a database that indicates a risk level for each of a plurality of geographical areas defined in advance for the V2X application. The server processing unit receives location information for a first terminal device via the communication unit, uses the location information to determine that the first terminal device is positioned in a first geographical area among the plurality of geographical areas, and if the database indicates that the risk level for the first geographical area is high, notifies the first terminal device that operation in a discontinuous reception mode is not permitted.

Description

Technical Field

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

Background Art

[0002] In the fourth-generation cellular communication technology, also called Long-Term Evolution (LTE) standardized by the 3rd Generation Partnership Project (3GPP), it is assumed that a sidelink, which is a direct wireless link between terminals, is used for Vehicle-to-Everything (V2X) communication (see Section 5.6 of Non-Patent Document 1). Non-Patent Document 2 explains that V2X may 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 the fifth-generation cellular communication technology, also called New Radio (NR), the radio access network (RAN) is supposed to support both the 4G V2X sidelink and the 5G NR sidelink (see Section 16.9 of Non-Patent Document 3). For example, a terminal (also called a user equipment (UE)) that performs sidelink communication establishes a wireless link called a PC5 interface with a communication partner terminal, and performs V2X communication on a communication resource scheduled by the RAN or a communication resource autonomously selected from a pre-allocated resource pool. In the 4G V2X sidelink, only the broadcast of V2X messages is supported, whereas in the 5G NR sidelink, the broadcast, groupcast, and unicast of V2X messages are supported.

[0004] Patent Document 1 discloses a technique in which a V2X communication-capable terminal device mounted on a vehicle evaluates the safety on the road in real time and issues an alarm to the user of the vehicle or other users when it is determined that there is some threat.

[0005] Non-patent document 4, a technical report published by 3GPP, raises concerns that in V2X communication scenarios where road safety messages are sent and received, discontinuous reception (DRX) operation, intended to reduce power consumption at terminals, could lead to the loss of safety-critical messages. [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] 3GPP TR23.776 v17.0.0, March 31, 2021 [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0312142 [Overview of the project] [Problems that the invention aims to solve]

[0008] Non-patent document 4 proposes several solutions to the trade-off between reducing power consumption in terminals participating in V2X communication and ensuring the reliable transmission of safety messages. One of these solutions involves the V2X application running on the terminal determining whether to transition to DRX mode based on the latest road conditions. However, since the information that terminals can collect is limited, leaving the decision of whether to transition to DRX mode to the terminal may result in a situation where user safety cannot be adequately guaranteed.

[0009] In light of the points mentioned above, this disclosure aims to provide a mechanism that can further improve the safety of users involved in road traffic. [Means for solving the problem]

[0010] According to this disclosure, A communication unit that communicates with one or more terminal devices acting as clients for a V2X (Vehicle-to-Everything) application, A server processing unit that operates as a server for the aforementioned V2X application, Equipped with, The server processing unit can access a database indicating the risk level for each of the multiple geographic areas predefined for the V2X application, The server processing unit, The location information of the first terminal device is received via the communication unit. Based on the location information, it is determined that the first terminal device is located within the first geographic area among the plurality of geographic areas. If the database indicates that the risk level of the first geographic area is high, the first terminal device is notified that it is not permitted to operate in discontinuous reception mode. Server equipment will be provided. Corresponding communication control methods, terminal devices, and base stations are also provided. [Effects of the Invention]

[0011] According to the present disclosure, the safety of users related to road traffic can be further improved.

Brief Description of the Drawings

[0012] [Figure 1] Copy of Figure 16.9.1-1 in 3GPP TS38.300 v16.8.0. [Figure 2] Copy of Figure 6.2-2 in 3GPP TS23.286 v17.3.0. [Figure 3] Schematic diagram showing an example of the configuration of a V2X communication system according to an embodiment. [Figure 4] Block diagram showing an example of the configuration of a server device according to an embodiment. [Figure 5] Explanatory diagram for explaining an example of the definition of a geographical area according to an embodiment. [Figure 6A] Explanatory diagram showing a first example of a message format for operation mode control. [Figure 6B] Explanatory diagram showing a second example of a message format for operation mode control. [Figure 6C] Explanatory diagram showing a third example of a message format for operation mode control. [Figure 6D] Explanatory diagram showing a fourth example of a message format for operation mode control. [Figure 6E] Explanatory diagram showing a fifth example of a message format for operation mode control. [Figure 7] Block diagram showing an example of the configuration of a UE according to an embodiment. [Figure 8] Block diagram showing an example of the configuration of a base station according to an embodiment. [Figure 9] Sequence diagram showing an example of the processing flow according to the first embodiment. [Figure 10] Sequence diagram showing an example of the processing flow according to the second embodiment.

Modes for Carrying Out the Invention

[0013] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features from the multiple features described in the embodiments may be combined arbitrarily. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0014] <1. Basic System Architecture for V2X Services> Figure 1 is a reproduction of Figure 16.9.1-1 from 3GPP TS38.300 v16.8.0 and shows an example of the NG-RAN architecture of a 5G system. A gNB is a 5G base station connected to the 5G core network (not shown). An ng-eNB is a 4G base station connected to the 5G core network. The gNB and ng-eNB are connected to each other via the Xn interface. User equipment (UE) is terminal equipment serviced by the gNB or ng-eNB. The radio link for sending and receiving user data between the UE and the gNB or ng-eNB is called the Uu interface. The PC5 interface is a communication link established between two UEs. Such direct communication links between UEs that do not pass through a base station are also called sidelinks. NG (Next Generation)-RAN (Radio Access Network) supports these PC5 interfaces. A PC5 interface can be identified by a pair of Layer 2 IDs: a Source Layer-2 ID assigned to the transmitting UE and a Destination Layer-2 ID assigned to the receiving UE. Resources used for communication are either 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 utilized for V2X services.

[0015] Figure 2 is a replica of Figure 6.2-2 from 3GPP TS23.286 v17.3.0 and shows a layered functional model of a V2X application. In the functional model of Figure 2, the UE acts as a client (V2X UE) of the V2X application. On the other hand, the server of the V2X application 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 NG-RAN coverage (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 Figure 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. Detailed information on the functions of SEAL clients and SEAL servers is described in 3GPP TS23.434 v17.5.0.

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

[0019] The V2X application-specific layer is a layer that, with support from the VAE layer, provides functionality specific to individual V2X applications. The V2X UE includes V2X application-specific clients, and the V2X application server includes V2X application-specific servers. The V5-APP is the interface between V2X UEs in the V2X application-specific layer. The V1-APP is the interface between the V2X UE and the V2X application server 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 the embodiments of the technology described herein will be described in detail later.

[0021] As can be seen from Figure 2, V2X communication is treated at the application level as end-to-end communication between the V2X UE and the V2X application server, and the contents of the V2X communication are transparent to 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 co-located in a single physical device or they 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. Embodiments of V2X Communication Systems> <2-1. System Overview> Figure 3 is a schematic diagram showing an example of the configuration of a V2X communication system 1 according to one embodiment. Referring to Figure 3, the V2X communication system 1 includes a server device 100, UEs 200a, 200b, 200c, 200d, and base stations 300a, 300b.

[0024] In the following explanation, when it is not necessary to distinguish between UE200a, 200b, 200c, and 200d, the alphabet at the end of the code will be omitted, and they will be collectively referred to as UE200. The same applies to base stations 300a, 300b (base station 300), and other components.

[0025] The server device 100 is a V2X application server that provides V2X services aimed at improving safety on roads. The server device 100 is connected to multiple base stations, including base stations 300a and 300b, via the 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] UE200 is a terminal device that utilizes the V2X service provided by the server device 100. In the example in Figure 3, UE200a and UE200b are pedestrian terminals, and UE200c and UE200d are in-vehicle terminals. For example, UE200a located within cell 30a can establish a wireless link with base station 300a to receive downlink data from base station 300a and transmit uplink data to base station 300a. In addition, with the support of base station 300a (e.g., resource scheduling or pre-allocation of resource pools), UE200a can communicate via sidelinks with other nearby V2X UEs. For example, Figure 3 shows sidelink 40b between UE200a and UE200b, and sidelink 40c between UE200a and UE200c. Naturally, UE200s other than UE200a can also communicate via sidelinks with nearby V2X UEs.

[0027] The base station 300 may be, for example, a gNB or an ng-eNB, and relays communication between the UE200 and the server device 100. In the example in Figure 3, base station 300a serves the UE200 in cell 30a, and base station 300b serves the UE200 in a different cell from cell 30a. Broadcasting of information from base station 300 to multiple UE200s in a cell takes place over the physical broadcast channel (PBCH). Transmission of downlink data from base station 300 to a specific UE200 takes place over the physical downlink shared channel (PDSCH). Transmission of uplink data from a specific UE200 to base station 300 takes place over the physical uplink shared channel (PUSCH). Control signaling to control these data transmissions (e.g., downlink allocation, scheduling requests, uplink permission, and retransmission control) takes place over various control channels, including the physical downlink control channel (PDCCH) and the physical uplink control channel (PUCCH).

[0028] In this embodiment, the UE200 can operate in one of several operating modes, including Continuous Reception mode and Discontinuous Reception (DRX) mode. The operating mode may be a mode relating to all downlink, uplink, and sidelink, or a mode relating only to sidelink. For example, when operating in Continuous Reception mode, the UE200 monitors all candidate resources on the sidelink and receives broadcast, groupcast, or unicast V2X messages addressed to the device. On the other hand, when operating in DRX mode, the UE200 monitors only candidate resources included in ON intervals that arrive periodically according to the DRX cycle and receives V2X messages transmitted over those candidate resources. By operating in DRX mode, the UE200 can reduce power consumption and extend battery life.

[0029] Furthermore, in this embodiment, at least some UE200s are capable of transmitting a warning message on the sidelink to indicate the presence of a road safety threat when such a threat is detected. The UE200s may detect safety threats using any known method. For example, a UE200 mounted on a vehicle may recognize one or more of the following as threats: • The speed or acceleration of your vehicle or another vehicle exceeds the standard value. • Deviation of one's own vehicle / other vehicles from the correct lane • Physiological abnormalities of the driver of the vehicle • Detection of alcohol components from the driver's breath • Detection of contact or collision • Abnormal driving conditions (e.g., presence of fallen objects, decrease in road surface temperature) When a UE200 detects such a security threat, it sends an alarm message, for example, over a sidelink shared channel (SL-SCH). The alarm message may include type information indicating the type of threat detected. The server device 100 configures each UE200 to receive alarm messages sent from other UE200s via sidelinks. When a UE200 receives an alarm message, it alerts the user via the user interface, allowing the user to recognize the threat early and take appropriate action to ensure security.

[0030] However, if a UE200 is operating in DRX mode to reduce power consumption, that UE200 cannot receive warning messages transmitted from other UE200s in a timely manner during the off-period of the DRX cycle. Non-patent document 4 proposes that UEs autonomously determine whether to transition to DRX mode based on the latest road conditions, but since UEs cannot always recognize potential threats, autonomous determination does not adequately guarantee user safety. On the other hand, if operation in DRX mode is uniformly prohibited, power consumption of UEs will not be reduced even in low-risk situations, and the battery may be depleted prematurely. Therefore, as will be explained in detail in the following sections, the V2X communication system 1 incorporates a mechanism to manage data indicating the level of risk for each predefined geographic area and to control UE200s so that they do not operate in DRX mode in high-risk geographic areas.

[0031] <2-2. Example of Server Device Configuration> Figure 4 is a block diagram showing an example of the configuration of the server device 100 according to this embodiment. Referring to Figure 4, the server device 100 includes a communication interface (I / F) 101, memory 102, database 110, and server processing unit 150.

[0032] The communication interface 101 is a communication unit for the server device 100 to communicate with one or more UE200s that act as clients of a V2X application. The communication interface 101 is connected to the network 10 and can communicate with UE200s connected to the base station 300 via one or more network nodes and base stations 300 within the network 10.

[0033] Memory 102 may include any combination of non-volatile storage media such as ROM (Read Only Memory) and volatile storage media such as RAM (Random Access Memory). For example, ROM pre-stores computer programs for several server modules, which will be described later. RAM provides a temporary storage area for calculations performed by the server processing unit 150.

[0034] Database 110 is a database that stores various data required for the server device 100 to provide V2X applications. In this embodiment, database 110 includes area definition data 120, risk level data 130, and UE location data 140. Although this example describes a server device 100 that includes database 110, database 110 may be implemented on a separate device (e.g., a database server or cloud server) from the server device 100, as long as it is accessible by the server processing unit 150.

[0035] Area definition data 120 is data that indicates the definition of multiple geographic areas for a V2X application provided by the server device 100. For example, area definition data 120 may include the following three data items for each geographic area: • "Area ID" • "Area Definition" • "Related base stations" The "Area ID" is an identifier that uniquely identifies each geographic area. The "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) for N vertices (where N is an integer greater than or equal to 3). For a circular geographic area, the "Area Definition" indicates the coordinate value of the center point and the radius. The "Associated Base Station" indicates at least one address (or other identifying information) for communication with the base station serving each geographic area.

[0036] Figure 5 is an explanatory diagram illustrating an example of the definition of a geographic area. Referring to Figure 5, the boundaries of four geographic areas 121-1, 121-2, 121-3, and 121-4 are shown as dashed lines superimposed on a road map of the area where the base station 300a is installed. Here, the shape of these geographic areas is roughly rectangular. Geographic areas 121-2, 121-3, and 121-4 are adjacent areas to geographic area 121-1. Figure 5 also shows the boundaries of cell 30a of base station 300a. Geographic areas are typically defined considering the purpose of the V2X application, independently of cell coverage. For example, in this embodiment, a region may be divided into multiple geographic areas based on differences in road characteristics (e.g., speed limits, number of lanes, etc.) and traffic trends (e.g., pedestrian volume, frequency of congestion, etc.).

[0037] Risk data 130 is data indicating the risk level determined for each of the multiple geographic areas defined by area definition data 120. Risk data 130 may include, for example, the following three data items: • "Management Area" • "Danger level" ·"Last updated" The "Management Area" identifies each geographic area subject to risk management using the "Area ID" registered in the area definition data 120. The "Risk Level" is a parameter indicating the risk level determined for the geographic area identified by the "Management Area". In this embodiment, the "Risk Level" is evaluated in three stages, representing one of the following values: "Low" (meaning the lowest risk), "Medium" (meaning a moderate risk), or "High" (meaning the highest risk). In other embodiments, the "Risk Level" may be evaluated in two or four or more stages. The "Last Updated" indicates the date and time when the "Risk Level" value for each geographic area was last updated.

[0038] UE location data 140 is data for managing the location of V2X UEs that utilize V2X applications provided by the server device 100. UE location data 140 may include, for example, the following four data items: • "UE ID" • "Location" • "Area of ​​Stay" ·“Final report” "UE ID" is an identifier that uniquely identifies each V2X UE. "Location" indicates the last location reported by each V2X UE. "Area of ​​Stay" identifies the geographic area corresponding to the last location reported by each V2X UE using the "Area ID" registered in the area definition data 120. "Last Report" indicates the date and time when the location was last reported by each V2X UE.

[0039] Note that the configuration of database 110 is not limited to the configuration described herein. Database 110 may store additional data, and some of the data items mentioned above may be omitted. For example, database 110 may store user IDs and authentication information (e.g., passwords or authentication keys) for authenticating users who use the V2X application provided by server device 100.

[0040] 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 (e.g., a CPU (Central Processing Unit)) executing a computer program stored in memory 102. As shown in Figure 4, the server processing unit 150 consists 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 explained using Figure 2.

[0041] When the UE200, which acts as a client for the V2X application, connects to the base station 300, the 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 the UE200.

[0042] Furthermore, the server processing unit 150 configures the UE200 to receive alarm messages sent from other V2X UEs via the sidelink. For example, if an alarm message is broadcast on the PC5 interface, the server processing unit 150 configures the UE200 to monitor the sidelink resource for messages with a destination Layer 2 ID for broadcast reception. If an alarm message is groupcast on the PC5 interface, the server processing unit 150 assigns the UE200 a group ID for receiving alarm messages and configures the UE200 to monitor the sidelink resource for messages with a destination Layer 2 ID corresponding to that group ID. Alarm messages may be sent by unicast, but from the standpoint of rapid transmission of alarm messages, broadcast or groupcast is more advantageous than unicast, which requires the establishment of individual PC5 interfaces.

[0043] Furthermore, the server processing unit 150 manages the hazard level of each geographic area indicated by the hazard data 130. For example, the initial value of the "hazard level" in the hazard data 130 is predetermined based on static road characteristics in the corresponding geographic area, such as speed limits, number of lanes, curvature, separation of roadways and sidewalks, and the presence of steps. The server processing unit 150 may update the "hazard level" value based on temporal conditions, which may include seasons or time of day, or sunlight conditions (for example, increasing the hazard level by one level during the evening hours when visibility deteriorates). In addition, in this embodiment, the server processing unit 150 updates the "hazard level" value of the hazard 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 UE200 described with reference to Figure 3, or other types of terminal devices (for example, roadside units with sensors or cameras). For example, if the server processing unit 150 determines, based on a V2X message received from a terminal device, that the following event is occurring in a certain geographic area, it may temporarily increase the "risk level" value of that geographic area until it is determined that the event has been resolved: • Presence of a vehicle that meets the threat detection conditions described above. • Stopping vehicles on the road ·traffic jam • Abnormal driving conditions

[0044] The server processing unit 150 also tracks the location of the connected UE200. Specifically, the server processing unit 150 periodically receives location information of the connected UE200 via the communication I / F 101. Based on the received location information, the server processing unit 150 determines which geographic area the UE200 is located in and updates the "Location," "Area of ​​Stay," and "Last Report" in the corresponding record of the UE location data 140. The location information may also indicate the geographic coordinates obtained as a result of positioning in the UE200 as the location of the UE200. In this case, the server processing unit 150 can determine which geographic area the geographic location indicated by the location information belongs to based on the "Area Definition" in the area definition data 120. If the size of the geographic area is equal to or greater than the size of the cell serviced by the base station 300, the location information may indicate the cell ID of the cell to which the UE200 is connected as the location. In this case, the server processing unit 150 can determine which geographic area the cell to which the UE200 is connected belongs, based on a known mapping between the cell ID indicated by the location information and the area ID of the corresponding geographic area. If, as a result of this location tracking, it is determined that a UE200 is located in a geographic area where the risk data 130 indicates a high risk level, then in this embodiment, that UE200 is not permitted to operate in DRX mode.

[0045] For example, if the risk data 130 indicates that the risk level of a first geographic area is high, the server processing unit 150 notifies the UE200 located within that first geographic area that it is not permitted to operate in DRX mode. In the first embodiment, this notification is made by sending a control message to the UE200 via the communication I / F 101, indicating that it is not permitted to operate in DRX mode, in response to the determination that the UE200 is located within the first geographic area. In other words, in the first embodiment, the control of the operating mode of the UE200 is performed at the application level.

[0046] In the second embodiment, if the risk data 130 indicates that the risk level of the first geographic area is high, the server processing unit 150 sends a request message to the base station 300 serving the first geographic area via the communication I / F 101, requesting that control information be broadcast indicating that V2X UEs located within the first geographic area are not permitted to operate in DRX mode. In other words, in the second embodiment, the control of the operating mode of the UE 200 is performed at the radio link level, not at the application level. Upon receiving this request message from the server device 100, the base station 300 broadcasts control information for controlling the operating mode of the UE 200, for example, by including it in a system information block (SIB) on the PBCH. The broadcasted control information includes at least control parameters indicating whether or not the UE 200 that receives the control information is permitted to operate in DRX mode.

[0047] Figure 6A shows a first example of the format of a control message sent to the UE200 for controlling the operating mode. In the first example, format 160a includes a V2X UE ID 161, a dwelling area 162, and a DRX prohibition flag 163. The V2X UE ID 161 is the UE ID that identifies the UE200 to which the control message is addressed. The dwelling area 162 is the area ID that identifies the geographical area where the UE200 identified by the V2X UE ID 161 is determined to be located. The DRX prohibition flag 163 is a control parameter that indicates whether operation in DRX mode is permitted in the geographical area identified by the dwelling area 162. For example, a value of "0" for the DRX prohibition flag 163 indicates that operation in DRX mode is permitted, and a value of "1" for the DRX prohibition flag 163 indicates that operation in DRX mode is prohibited. Note that the name "prohibition flag" here is merely an example, and other names such as "permission flag" may be used for the above control parameter.

[0048] Figure 6B shows a second example of the format of a control message sent to the UE200 for controlling the operating mode. In the second example, format 160b includes the V2X UE ID 161 and the DRX prohibition flag 163.

[0049] Figure 6C shows a third example of the format of a control message sent to the UE200 for controlling the operating mode. In the third example, format 160c includes the V2X UE ID 161 and the dwell area 162. Since format 160c alone does not indicate whether operation in DRX mode is permitted, it can be used in combination with format 160d, which is described below.

[0050] Figure 6D shows a fourth example of the format of a control message sent to the UE200 for controlling the operating mode. In the fourth example, format 160d includes area number 164 and K pairs of area IDs 165-k and prohibition flags 166-k (k=1,2,...,K). Area number 164 indicates the number K of area ID-prohibition flag pairs included in the control message. Area IDs 165-k indicate area IDs that identify the k-th geographical area. Prohibition flags 166-k are control parameters that indicate whether operation in DRX mode is permitted in the k-th geographical area. Upon receiving control messages of both formats 160c and 160d, the UE200 can identify the corresponding prohibition flag by looking up the area ID indicated by the dwelling area 162 in the former control message in the latter control message, and thus determine whether operation in DRX mode is permitted in the geographical area where it is located.

[0051] In the first embodiment described above, the control message that the server processing unit 150 can send to the UE200 may be one of the following options: Message A (Format 160a) Message B (Format 160b) • Message C (format 160c) and Message D (format 160d) Messages A, B, or C may be sent each time the UE200's location changes. Message D, on the other hand, does not need to be sent again to the same UE200 once it has been sent, unless the risk level of one or more geographic areas changes. Each message may, of course, include additional control parameters not shown. If the UE200 can autonomously determine its current geographic area based on its location (for example, by referring to a pre-downloaded area definition), only message D (format 160d) may be sent to the UE200.

[0052] Figure 6E shows an example of the format of a control message broadcast for controlling the operating mode. In this example, format 160e includes M control parameters, including a DRX prohibition flag 167. The DRX prohibition flag 167 is a control parameter that indicates whether the V2X UE that receives the control message is permitted to operate in DRX mode. For example, a value of "0" for the DRX prohibition flag 167 indicates that operation in DRX mode is permitted, and a value of "1" for the DRX prohibition flag 167 indicates that operation in DRX mode is prohibited. Format 160e may be used, for example, in a system information block provided for side link control, or in a system information block provided for V2X communication control.

[0053] In the second embodiment described above, the control information that the UE200 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) • System information broadcast from the base station (format 160e) The second option may be adopted if the UE200 can autonomously determine the geographic area in which it is currently located based on its own location. The third option may be adopted if operation in DRX mode is uniformly permitted or prohibited within a single cell.

[0054] In both the first and second embodiments, the notification that operation in DRX mode is not permitted may be applied to communication over the sidelink. In this case, UE200 can reduce power consumption by providing periodic off-periods on the radio link with base station 300, while operating the sidelink in continuous receive mode to receive alarm messages from other V2X UEs in a timely manner. Alternatively, the notification that operation in DRX mode is not permitted may be applied to the radio link with base station 300 in addition to the sidelink. In this case, when there are V2X messages transmitted over base station 300, the possibility of user safety being compromised due to delays in receiving such V2X messages can be reduced.

[0055] <2-3. Example of terminal device configuration> Figure 7 is a block diagram showing an example of the configuration of the UE200 according to this embodiment. Referring to Figure 7, the UE200 includes a wireless I / F 201, memory 202, storage 203, sensor group 204, camera 205, positioning module 206, input device 207, output device 208, power supply 209, and control unit 210.

[0056] The wireless interface 201 is the wireless communication unit for the UE 200 to perform wireless communication. In this embodiment, the wireless interface 201 can communicate via a wireless link established with the base station 300, and can also communicate with other V2X UEs via a side link. Furthermore, the wireless interface 201 can operate in one of several operating modes, including continuous reception mode and discontinuous reception (DRX) mode.

[0057] Memory 202 may include any combination of non-volatile storage media such as ROM and volatile storage media such as RAM. For example, ROM pre-stores computer programs for several client modules that operate in the control unit 210. RAM provides a temporary storage area for calculations performed by the control unit 210.

[0058] Storage 203 is a storage device for storing large amounts of data. Storage 203 may be, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0059] Sensor group 204 is a collection of various sensors mounted on the UE200. If the UE200 is a pedestrian terminal, sensor group 204 may include an accelerometer, a gyroscope, and a compass sensor. If the UE200 is an in-vehicle terminal, sensor group 204 may include, in addition to the sensors mentioned above, further sensors such as a distance measuring sensor (e.g., LiDAR or millimeter-wave radar) and a biometric information sensor.

[0060] Camera 205 is an imaging module capable of capturing images of the surroundings of UE200. Sensor group 204 and camera 205 may be used to detect road safety threats in accordance with the threat detection conditions described above.

[0061] The positioning module 206 is a module for measuring the position of the UE200. The positioning module 206 may be capable of obtaining the latitude, longitude, and altitude of the UE200's current position using a GNSS (Global Navigation Satellite System), such as GPS (Global Positioning System). Alternatively or additionally, the positioning module 206 may be capable of estimating the UE200's current position based on the known absolute position of the connected base station and its relative position from said base station.

[0062] The input device 207 is a device for the UE200 to receive instructions and information input from the user. The input device 207 includes, for example, one or more of the following: a touch sensor, a button, a switch, a keypad, and a microphone.

[0063] Output device 208 is a device for the UE200 to output information or signals to the user. Output device 208 includes, for example, one or more of the following: a display, a speaker, a light, and a vibrator.

[0064] Power supply 209 is a rechargeable battery that supplies power to various parts of the UE200 via power lines partially shown in the diagram. The power supply from power supply 209 is controlled by the control unit 210. For example, when the wireless interface 201 is operating in DRX mode, the power supplied from power supply 209 to the wireless interface 201 is reduced during periodically occurring off-periods.

[0065] The control unit 210 includes one or more processors and controls the overall functions of the UE200 by executing computer programs stored in memory 202. For example, the control unit 210 functions as a client processing unit 220 that acts as a client for a V2X application. The client processing unit 220 consists of three client modules: a V2X application-specific client, a VAE client, and a SEAL client. The division of functions among these client modules may be as explained using Figure 2. The control unit 210 may also have various other functions that a typical pedestrian terminal or in-vehicle terminal has, but for the sake of simplicity, the functions of the client processing unit 220 will be described here.

[0066] The client processing unit 220 is configured by the server processing unit 150 of the server device 100 to receive road safety warning messages transmitted from other V2X UEs via the side link. When the client processing unit 220 receives a warning message via the side link, it alerts the user via the user interface of the UE 200 so that the user can take appropriate action to ensure their safety. For example, the alert may be displayed as warning text or an icon on the display of the output device 208, output as a warning sound or voice from the speaker, or sounded by a vibrator.

[0067] The client processing unit 220 may detect security threats 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 threat detection conditions described above. 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 resource. As described above, the alert message may be transmitted by broadcast, groupcast, or unicast. Not all UE200 client processing units 220s necessarily have the function to transmit alert messages.

[0068] The client processing unit 220 periodically reports location information to the server device 100, indicating the latest location of the UE 200 acquired by the positioning module 206. A V2X message for reporting 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 which geographic area the UE 200 is located in in response to this location information report. The V2X message transmitted to the server device 100 may also include information for updating the risk level for each geographic 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 of the threat detection conditions. Furthermore, the client processing unit 220 may perform more advanced processing, such as determining whether a parked vehicle is present, whether there is congestion, or whether there is an abnormality in the driving environment, and notify the server device 100 of the determination results.

[0069] In this embodiment, the client processing unit 220 receives a control message from the server device 100 via the wireless interface 201 as a response to the transmission of location information. This control message may include an area ID that identifies the geographic area where the UE200 is determined to be located, from among a plurality of geographic areas predefined for the V2X application. The client processing unit 220 then controls the wireless interface 201 to prevent the UE200 from operating in DRX mode if it is not permitted to operate in DRX mode in the geographic area where the UE200 is located.

[0070] In the first embodiment, the control message received as a response to the transmission of location information may include a control parameter indicating whether or not the UE200 is permitted to operate in DRX mode. For example, if it is determined that the UE200 is located in a first geographic area where the risk level data 130 indicates a high risk level, the control parameter will indicate a value that means operation in DRX mode is not permitted (prohibited). In this case, the client processing unit 220 controls the wireless I / F 201 to operate in continuous receive mode, at least for sidelink communication (i.e., DRX mode is not applied to sidelinks). On the other hand, if it is determined that the UE200 is located in a second geographic area where the risk level data 130 indicates a low risk level, the control parameter will indicate a value that means operation in DRX mode is permitted. In this case, the client processing unit 220 may decide whether or not to operate the wireless I / F 201 in DRX mode by considering other factors, such as the battery level.

[0071] In the second embodiment, the client processing unit 220 receives control information broadcast from the base station 300 serving the geographic area where the UE200 is located, via the radio I / F 201. This control information includes at least a control parameter indicating whether the UE200 is permitted to operate in DRX mode. Similar to the first embodiment, the client processing unit 220 may control the operating mode of the radio I / F 201 according to the value of this control parameter.

[0072] In the first and second embodiments, the control messages or control information that the UE200 can receive may have the format described above using Figures 6A to 6E.

[0073] When control information having format 160d, as explained using Figure 6D, is provided, the client processing unit 220 can determine whether it is permitted to operate in DRX mode in the new geographic area as soon as it obtains the area ID of the new geographic area after moving across the boundary of a geographic area. If the area definition of each geographic area is known to the UE200, the client processing unit 220 can also obtain the area ID of the new geographic area without requiring communication with the server device 100. In scenarios where the UE200 may temporarily move outside the coverage of the V2X communication system 1, the ability to make such autonomous determinations of permitting / denying DRX mode is beneficial.

[0074] As described above, in both the first and second embodiments, the control of the operating mode of the wireless I / F 201 according to the control parameters may be applied only to sidelink communication, or it may be applied to both sidelink communication and communication with the base station 300.

[0075] <2-4. Example of base station configuration> Figure 8 is a block diagram showing an example of the configuration of a base station 300 according to this embodiment. Referring to Figure 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.

[0076] The radio interface 301 is a radio communication unit for the base station 300 to provide radio access to one or more UEs 200 within cell 30. For example, if the coverage of cell 30 of the base station 300 includes a first geographic area, the base station 300 can radio communicate with at least one UE 200 located within the first geographic area via the radio interface 301.

[0077] The network interface 302 is a network communication unit for the base station 300 to communicate with network nodes in the network 10 and other devices connected to the network 10. For example, the base station 300 can communicate with the server device 100 via the network interface 302.

[0078] Memory 303 may include any combination of non-volatile storage media such as ROM and volatile storage media such as RAM. For example, ROM pre-stores computer programs executed by the communication control unit 310. RAM provides a temporary storage area for calculations performed by the communication control unit 310. Storage 304 is a storage device for storing large amounts of data. Storage 304 may be, for example, an HDD or an SSD.

[0079] The communication control unit 310 includes one or more processors and controls wireless communication via the wireless interface 301 and network communication via the network interface 302 by executing computer programs stored in the memory 303. For example, when the communication control unit 310 receives a connection request from the UE200 via the wireless interface 301, it establishes a wireless link between the UE200 and the wireless interface 301. The communication control unit 310 also mediates application-level communication between the UE200 and the server device 100 when the UE200 uses a V2X application provided by the server device 100. Furthermore, the communication control unit 310 schedules sidelink resources or allocates a resource pool for sidelinks for the UE200, which is a V2X UE. This enables the UE200 to communicate wirelessly via the wireless link to the base station 300 and sidelinks to other V2X UEs.

[0080] In one embodiment, the communication control unit 310 is involved in controlling the operating mode of the UE200. For example, if the server device 100 determines that a first geographic area is at high risk, it sends a request message to the base station 300 requesting the broadcast of control information to prevent V2X UEs located within the first geographic area from operating in DRX mode. When the communication control unit 310 receives this request message via the network interface 302, it causes the wireless interface 301 to broadcast control information indicating that V2X UEs located within the first geographic area are not permitted to operate in DRX mode. The format of the broadcasted control information may be the format described above in relation to the second embodiment.

[0081] As an example, the wireless I / F 301 may broadcast the control information in a system information block for sidelink control (e.g., SIB 12). In this case, the operating mode of terminal devices that use the sidelink for purposes other than V2X communication can also be commonly controlled by the control information. As another example, the wireless I / F 301 may broadcast the control information in a system information block for V2X communication control (e.g., SIB 13 or SIB 14). In this case, terminal devices that are not involved in V2X communication can ignore the system information block, and the operating mode of such terminal devices will not be affected by the control information.

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

[0083] <3-1. First Example> Figure 9 is a sequence diagram showing an example of the processing flow according to the first embodiment. The illustrated processing mainly involves the server device 100, UE200a, UE200c, and base station 300. However, several V2X UEs other than UE200a and UE200c also perform V2X communication with the server device 100.

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

[0085] Next, when the UE200a enters coverage of cell 30 served by the base station 300, a radio link is established between the UE200a and the base station 300 in S15. Then, in S17, the communication control unit 310 of the base station 300 schedules sidelink resources or allocates a resource pool for sidelinks for the UE200a, which is a V2X UE.

[0086] Next, in S21, the UE200a's client processing unit 220 accesses the server device 100 using, for example, the URL of the server device 100 that is pre-stored in 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 UE200a as a connected client (if authentication of the UE200a is successful). Then, in S25, the server processing unit 150 sets up a communication link with the UE200a. At this time, the server processing unit 150 configures the UE200a to receive alarm messages sent from other V2X UEs via the side link.

[0087] Next, in S31, the client processing unit 220 of the UE200a transmits location information indicating the latest location of the UE200a to the server device 100. Upon receiving the location information, the server processing unit 150 of the server device 100 determines in S33 which geographic area the UE200a is located in. Here, it is determined that the UE200a is located in a first geographic area that is indicated as having a high risk level by the risk level data 130 (for example, the "risk level" value is "high"). In S35, the server processing unit 150 transmits a control message to the UE200a indicating that it is not permitted to operate in DRX mode. Upon receiving this control message, the client processing unit 220 of the UE200a controls the wireless I / F 201 so that it does not operate in DRX mode (or, if it is already operating in DRX mode, to transition to continuous reception mode).

[0088] Subsequently, in S41, the UE200c, an in-vehicle terminal participating in the same V2X service, detects a road safety threat. In S43, the UE200c's client processing unit 220 transmits an alarm message (e.g., broadcast or groupcast) over the sidelink communication resources. The UE200a's wireless I / F 201 continuously monitors the sidelink broadcast or groupcast resources without operating in DRX mode and receives the alarm message transmitted from the UE200c in a timely manner. In S45, the UE200a's client processing unit 220 alerts the user via the user interface so that the user can take appropriate action to ensure safety in response to the receipt of the alarm message.

[0089] <3-2. Second Example> Figure 10 is a sequence diagram showing an example of the processing flow according to the second embodiment. The illustrated processing mainly involves the server device 100, UE200a, UE200c, and base station 300. However, several V2X UEs other than UE200a and UE200c also perform V2X communication with the server device 100.

[0090] The processing steps S11 to S33 may be the same as the corresponding processing steps in the first embodiment described with reference to Figure 9. Therefore, the explanation of those processing steps will be omitted here.

[0091] In S33, the server processing unit 150 of the server device 100, which has determined the geographical area where UE200a is located, sends a control message to UE200a in S34 that includes an area ID identifying the determined geographical area. Note that if the geographical area where UE200a is located can be determined autonomously, the area notification in S34 may be omitted. Here, it is assumed that UE200a is determined to be located in a first geographical area that is indicated to have a high risk level by the risk level data 130. Next, in S36, the server processing unit 150 requests the base station 300 serving the first geographical area to broadcast control information indicating that V2X UEs in the first geographical area are not permitted to operate in DRX mode. Upon receiving this 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 in the first geographical area are not permitted to operate in DRX mode in S38. Upon receiving control information broadcast from base station 300, the client processing unit 220 of UE200a controls the wireless I / F 201 to prevent it from operating in DRX mode (or, if it is already operating in DRX mode, to transition to continuous reception mode).

[0092] The subsequent processing steps S41 to S45 may be the same as the corresponding processing steps in the first embodiment described with reference to Figure 9. Therefore, the explanation of those processing steps will be omitted here.

[0093] <4. Summary of Embodiments> The above embodiment discloses at least the following server device, communication control method, terminal device, and base station.

[0094] 1. The server device (100) of the above embodiment is A communication unit (101) that communicates with one or more terminal devices (200) that act as clients for a V2X (Vehicle-to-Everything) application, A server processing unit (150) that operates as a server for the aforementioned V2X application, Equipped with, The server processing unit can access a database (130) that indicates the risk level for each of the multiple geographic areas (121-1, 121-2, 121-3, 121-4) predefined for the V2X application. The server processing unit, The location information of the first terminal device is received via the communication unit (S31), Based on the location information, it is determined that the first terminal device is located within the first geographic area among the plurality of geographic areas (S33), If the database indicates that the risk level of the first geographic area is high, the first terminal device is notified that it is not permitted to operate in discontinuous reception mode (S35, S36). According to this embodiment, it is possible to prevent situations where a terminal device operates in a discontinuous reception mode based on autonomous control even when it is located in a high-risk geographical area. As a result, the terminal device can receive safety-related messages in a timely manner, further improving the safety of users related to road traffic. When located in a geographical area that is not high-risk, the terminal device is permitted to operate in a discontinuous reception mode, thus providing an opportunity to reduce power consumption by utilizing the discontinuous reception mode.

[0095] 2. In the above embodiment, Notifying the first terminal device that operation in the aforementioned discontinuous reception mode is not permitted is: In response to the determination that the first terminal device is located within the first geographical area, a control message indicating that operation in the discontinuous reception mode is not permitted is transmitted to the first terminal device via the communication unit (S35). Includes. According to this embodiment, communication for controlling the operating mode of a terminal device is performed at the application level between the server and client of the V2X application. In other words, the content of the communication is transparent to base stations located along the communication path. Therefore, regardless of the placement of base stations, it is possible to define multiple geographic areas based on road traffic conditions and realize control of the operating mode on a unit basis for each geographic area.

[0096] 3. In the above embodiment, Notifying the first terminal device that operation in the aforementioned discontinuous reception mode is not permitted is: Requesting a base station (300) serving the first geographic area to broadcast control information indicating that a terminal device located within the first geographic area and operating as a client of the V2X application is not permitted to operate in the discontinuous reception mode (S36), Includes. According to this embodiment, communication for controlling the operating mode of the terminal device is performed at the radio link level mediated by the base station. In this case, the terminal device can immediately reflect the instructed control content in the lower-layer radio interface without transmitting the received control information to the application layer.

[0097] 4. In the above embodiment, The control information includes, for each of the first geographic area and at least one second geographic area within the same cell as the first geographic area, an identifier (165) that identifies the geographic area and a parameter (166) that indicates whether or not operation in the discontinuous reception mode is permitted in the geographic area. According to this embodiment, when a terminal device moves across the boundary of a geographical area, it can determine whether it is permitted to operate in a discontinuous reception mode in the new geographical area, based on an identifier that identifies the new geographical area and the control information it has received.

[0098] 5. In the above embodiment, The server processing unit updates the risk level indicated by the database based on V2X messages received via the communication unit from one or more second terminal devices (S13). According to this embodiment, the condition of roads over a wide area, which changes over time, can be dynamically reflected in the risk level indicated by the database. Therefore, in geographical areas where there are potential risks that are difficult to recognize with a single terminal device, the operating mode of the terminal device can be appropriately controlled to prevent it from transitioning to a discontinuous reception mode.

[0099] 6. In the above embodiment, The server processing unit configures the first terminal device to receive road safety warning messages transmitted from other terminal devices via the side link (S25). According to this embodiment, in geographical areas where potential hazards exist, the terminal device can be made to monitor warning messages on the sidelink while preventing the terminal device from transitioning to a discontinuous reception mode. In this way, the possibility of the terminal device missing warning messages indicating road safety threats is minimized, thereby achieving a high level of safety related to road traffic.

[0100] 7. In the above embodiment, The aforementioned notices (163, 166, 167) that prohibit operation in the discontinuous reception mode apply to communications over the sidelink. According to this embodiment, the terminal device can reduce power consumption by operating the sidelink in continuous reception mode to receive alarm messages in a timely manner, while operating the wireless link to the base station in discontinuous reception mode.

[0101] 8. The communication control method of the above embodiment is: A communication control method performed by a server device (100) acting as a server for a V2X (Vehicle-to-Everything) application, for controlling V2X communication by a terminal device (200) acting as a client for the V2X (Vehicle-to-Everything) application, wherein the server device (100) acting as a server for the V2X application controls V2X communication by the terminal device (200) acting as a client for the V2X (Vehicle-to-Everything) application, The server device has access to a database (130) that indicates the risk level for each of the multiple geographic areas (121-1, 121-2, 121-3, 121-4) that are predefined for the V2X application. The aforementioned communication control method is: Receiving location information of the first terminal device (S31), Based on the location information, it is determined that the first terminal device is located within the first geographic area among the plurality of geographic areas (S33), If the database indicates that the risk level of the first geographic area is high, the first terminal device is notified that it is not permitted to operate in discontinuous reception mode (S35, S36), Includes. According to this embodiment, it is possible to prevent situations where a terminal device operates in a discontinuous reception mode based on autonomous control even when it is located in a high-risk geographical area. As a result, the terminal device can receive safety-related messages in a timely manner, further improving the safety of users related to road traffic. When located in a geographical area that is not high-risk, the terminal device is permitted to operate in a discontinuous reception mode, thus providing an opportunity to reduce power consumption by utilizing the discontinuous reception mode.

[0102] 9. The terminal device (200) of the above embodiment is A wireless communication unit (201) that wirelessly communicates via a wireless link between the terminal device and a base station (300) and a side link between the terminal device and other terminal devices (200), A client processing unit (220) that operates as a client for a V2X (Vehicle-to-Everything) application and receives road safety warning messages transmitted from the other terminal device via the side link, Equipped with, The wireless communication unit can operate in one of several operating modes, including a continuous reception mode and a discontinuous reception mode. The aforementioned client processing unit, The location information of the terminal device is transmitted via the wireless communication unit to the server device operating as the server for the V2X application (S31). If a notification is received that operation in the discontinuous reception mode is not permitted in the first geographic area where the terminal device is located, among a plurality of geographic areas predefined for the V2X application (S35, S38), the wireless communication unit is controlled so as not to operate in the discontinuous reception mode. According to this embodiment, when the terminal device is located in a high-risk geographical area, it refrains from operating in discontinuous reception mode based on notifications from the server device, rather than through autonomous control. Therefore, in situations where there are potential hazards that are difficult for the terminal device to recognize, the possibility of missing warning messages regarding road safety threats due to operation in discontinuous reception mode can be minimized. When located in a low-risk geographical area, the terminal device is permitted to operate in discontinuous reception mode, thus providing an opportunity to reduce power consumption by utilizing discontinuous reception mode.

[0103] 10. In the above embodiment, The client processing unit receives a control message from the server device via the wireless communication unit indicating whether or not it is permitted to operate in the discontinuous reception mode as a response to the transmission of the location information (S35). According to this embodiment, control messages for controlling the operating mode of the terminal device are received from the server device via application-level communication. Therefore, it is possible to control the operating mode on a geographical area basis, regardless of the placement of base stations.

[0104] 11. In the above embodiment, The wireless communication unit receives control information broadcast from a base station serving the first geographic area (S38), The control information indicates whether a terminal device located within the first geographical area and acting as a client of the V2X application is permitted to operate in the discontinuous reception mode. According to this embodiment, the terminal device can immediately reflect the instructed control content in the lower-layer wireless interface without transmitting the control information broadcast from the base station to the application layer.

[0105] 12. In the above embodiment, The control information includes, for each of the first geographic area and at least one second geographic area within the same cell as the first geographic area, an identifier (165) that identifies the geographic area and a parameter (166) that indicates whether or not operation in the discontinuous reception mode is permitted in the geographic area. According to this embodiment, when a terminal device moves across the boundary of a geographical area, it can determine whether it is permitted to operate in a discontinuous reception mode in the new geographical area, based on an identifier that identifies the new geographical area and the control information it has received.

[0106] 13. In the above embodiment, When the client processing unit receives the alarm message via the side link (S43), it issues an alarm to the user via the user interface of the terminal device (S45). According to this embodiment, in geographical areas where potential hazards exist, the terminal device reliably receives warning messages on the sidelink and alerts the user, thereby enabling the user of the terminal device to take timely action to ensure safety in response to threats to road safety.

[0107] 14. In the above embodiment, If operation in the discontinuous reception mode is not permitted, the client processing unit does not apply the discontinuous reception mode to the side link. According to this embodiment, the terminal device can reduce power consumption by operating the sidelink in continuous reception mode to receive alarm messages in a timely manner, while operating the wireless link to the base station in discontinuous reception mode.

[0108] 15. The communication control method of the above embodiment is: A communication control method performed by a terminal device (200) that operates as a client for a V2X (Vehicle-to-Everything) application, for controlling V2X communication by the terminal device, The terminal device includes a wireless communication unit (201) that wirelessly communicates via a wireless link between the terminal device and a base station (300) and a side link between the terminal device and other terminal devices (200). The wireless communication unit can operate in one of several operating modes, including a continuous reception mode and a discontinuous reception mode. The aforementioned communication control method is: The location information of the terminal device is transmitted via the wireless communication unit to a server device that operates as a server for the V2X application (S31), Receiving via the wireless communication unit a notification that operation in the discontinuous reception mode is not permitted in the first geographic area where the terminal device is located, among a plurality of geographic areas predefined for the V2X application (S35, S38), In response to receiving the aforementioned notification, the wireless communication unit is controlled so as not to operate in the discontinuous reception mode. Receiving a road safety warning message transmitted from the other terminal device using the side link via the wireless communication unit (S43), Includes. According to this embodiment, when the terminal device is located in a high-risk geographical area, it refrains from operating in discontinuous reception mode based on notifications from the server device, rather than through autonomous control. Therefore, in situations where there are potential hazards that are difficult for the terminal device to recognize, the possibility of missing warning messages regarding road safety threats due to operation in discontinuous reception mode can be minimized. When located in a low-risk geographical area, the terminal device is permitted to operate in discontinuous reception mode, thus providing an opportunity to reduce power consumption by utilizing discontinuous reception mode.

[0109] 16. The base station (300) of the above embodiment is A wireless communication unit (301) that performs wireless communication in at least one of several predefined geographic areas (121-1, 121-2, 121-3, 121-4) for V2X (Vehicle-to-Everything) applications, A network communication unit (302) that communicates with a server device (100) that operates as a server for the V2X application, A control unit (310) that controls the communication performed by the wireless communication unit and the network communication unit, Equipped with, In response to a request message received via the network communication unit (S36) from the server device which has determined that it is not permitted for one or more terminal devices (200) located within the first geographical area and operating as clients of the V2X application to operate in discontinuous reception mode, the control unit causes the wireless communication unit to broadcast control information indicating that the one or more terminal devices are not permitted to operate in discontinuous reception mode (S38). According to this embodiment, it is possible to prevent situations where terminal devices operate in discontinuous reception mode even though they are located in a high-risk geographical area. Furthermore, it is possible to ensure that terminal devices located in a low-risk geographical area have the opportunity to reduce power consumption by utilizing discontinuous reception mode.

[0110] 17. In the above embodiment, The control unit causes the wireless communication unit to broadcast the control information, including it in a system information block (160e) for side link control. According to this embodiment, the control information broadcast in a system information block having a common format can be used to uniformly control the operating modes of terminal devices that utilize side links for various purposes.

[0111] 18. In the above embodiment, The control unit causes the wireless communication unit to broadcast the control information, including it in a system information block (160e) for controlling V2X communication. According to this embodiment, terminal devices not involved in V2X communication can ignore the system information block that carries the control information. Therefore, such terminal devices can reduce power consumption by using a discontinuous reception mode regardless of the control information.

[0112] 19. The communication control method of the above embodiment is: A communication control method performed by a base station (300) for controlling V2X communication by a terminal device (200) acting as a client of a V2X (Vehicle-to-Everything) application, The base station comprises a wireless communication unit (301) that performs wireless communication in at least a first geographic area among a plurality of geographic areas (121-1, 121-2, 121-3, 121-4) 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 aforementioned communication control method is: The server device, which has determined that it does not permit one or more terminal devices located within the first geographical area and operating as clients of the V2X application to operate in discontinuous reception mode, receives a request message via the network communication unit (S36), In response to receiving the request message, the wireless communication unit broadcasts control information indicating that one or more terminal devices are not permitted to operate in the discontinuous reception mode (S38). Includes. According to this embodiment, it is possible to prevent situations where terminal devices operate in discontinuous reception mode even though they are located in a high-risk geographical area. Furthermore, it is possible to ensure that terminal devices located in a low-risk geographical area have the opportunity to reduce power consumption by utilizing discontinuous reception mode.

[0113] Although embodiments of the invention have been described above, the invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the gist of the invention. [Explanation of Symbols]

[0114] 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 acting as clients for a V2X (Vehicle-to-Everything) application, A server processing unit that operates as a server for the aforementioned V2X application, Equipped with, The server processing unit can access a database indicating the risk level for each of the multiple geographic areas predefined for the V2X application, The server processing unit, The location information of the first terminal device is received via the communication unit. Based on the location information, it is determined that the first terminal device is located within the first geographic area among the plurality of geographic areas. If the database indicates that the risk level of the first geographic area is high, the first terminal device is notified that it is not permitted to operate in discontinuous reception mode. Server device.

2. Notifying the first terminal device that operation in the aforementioned discontinuous reception mode is not permitted is: In response to the determination that the first terminal device is located within the first geographical area, a control message indicating that operation in the discontinuous reception mode is not permitted is transmitted to the first terminal device via the communication unit. The server device according to claim 1, including the following:

3. Notifying the first terminal device that operation in the aforementioned discontinuous reception mode is not permitted is: Requesting a base station serving the first geographic area to broadcast control information indicating that a terminal device located within the first geographic area and operating as a client of the V2X application is not permitted to operate in the discontinuous reception mode, The server device according to claim 1, including the following:

4. The server device according to claim 3, wherein the control information includes, for each of the first geographic area and at least one second geographic area in the same cell as the first geographic area, an identifier that identifies the geographic area and a parameter that indicates whether or not operation in the discontinuous reception mode is permitted in the geographic area.

5. The server device according to any one of claims 1 to 4, wherein the server processing unit updates the risk level indicated by the database based on V2X messages received from one or more second terminal devices via the communication unit.

6. The server processing unit is configured to receive the first terminal device via a side link a warning message regarding road safety transmitted from other terminal devices, according to any one of claims 1 to 4.

7. The server device according to claim 6, wherein the notification that operation in the discontinuous reception mode is not permitted applies to communication via the sidelink.

8. A communication control method performed by a server device acting as a server for a V2X (Vehicle-to-Everything) application, for controlling V2X communication by a terminal device acting as a client for the V2X (Vehicle-to-Everything) application, The server device is capable of accessing a database indicating the risk level for each of a plurality of geographic areas predefined for the V2X application. The aforementioned communication control method is: Receiving location information of the first terminal device, Based on the location information, it is determined that the first terminal device is located within the first geographic area among the plurality of geographic areas, When the database indicates that the risk level of the first geographic area is high, the first terminal device is notified that it is not permitted to operate in discontinuous reception mode, A communication control method, including a communication control method.

9. A terminal device, A wireless communication unit that wirelessly communicates via a wireless link between the terminal device and the base station and a side link between the terminal device and other terminal devices, A client processing unit that operates as a client for a V2X (Vehicle-to-Everything) application and receives road safety warning messages transmitted from the other terminal device via the side link, Equipped with, The wireless communication unit can operate in one of several operating modes, including a continuous reception mode and a discontinuous reception mode. The aforementioned client processing unit, The location information of the terminal device is transmitted via the wireless communication unit to the server device operating as the server for the V2X application. If a notification is received that operation in the discontinuous reception mode is not permitted in the first geographic area where the terminal device is located, among a plurality of geographic areas predefined for the V2X application, the wireless communication unit is controlled to prevent operation in the discontinuous reception mode. Terminal device.

10. The terminal device according to claim 9, wherein the client processing unit receives a control message from the server device via the wireless communication unit indicating whether or not it is permitted to operate in the discontinuous reception mode as a response to the transmission of the location information.

11. The wireless communication unit receives control information broadcast from a base station providing service in the first geographic area. The control information indicates whether a terminal device located within the first geographical area and acting as a client of the V2X application is permitted to operate in the discontinuous reception mode. The terminal device according to claim 9.

12. The terminal device according to claim 11, wherein the control information includes, for each of the first geographic area and at least one second geographic area in the same cell as the first geographic area, an identifier for identifying the geographic area and a parameter indicating whether or not operation in the discontinuous reception mode is permitted in the geographic area.

13. The terminal device according to any one of claims 9 to 12, wherein the client processing unit, when it receives the alarm message via the side link, issues an alarm to the user via the user interface of the terminal device.

14. The terminal device according to any one of claims 9 to 12, wherein if operation in the discontinuous reception mode is not permitted, the client processing unit does not apply the discontinuous reception mode to the side link.

15. A communication control method performed by a terminal device for controlling V2X communication by a terminal device acting as a client for a V2X (Vehicle-to-Everything) application, The terminal device comprises 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 other terminal devices. The wireless communication unit can operate in one of several operating modes, including a continuous reception mode and a discontinuous reception mode. The aforementioned communication control method is: The location information of the terminal device is transmitted via the wireless communication unit to a server device that operates as a server for the V2X application. Receiving via the wireless communication unit a notification that operation in the discontinuous reception mode is not permitted in the first geographic area where the terminal device is located, among a plurality of geographic areas predefined for the V2X application, In response to receiving the aforementioned notification, the wireless communication unit is controlled so as not to operate in the discontinuous reception mode. The wireless communication unit receives road safety warning messages transmitted from the aforementioned other terminal device using the side link, A communication control method, including a communication control method.

16. A wireless communication unit that performs wireless communication in at least one of several geographic areas predefined for a V2X (Vehicle-to-Everything) application, A network communication unit that communicates with a server device that operates as a server for the aforementioned V2X application, A control unit that controls the communication performed by the wireless communication unit and the network communication unit, Equipped with, The control unit, in response to a request message received via the network communication unit from the server device which has determined that it does not permit one or more terminal devices located within the first geographical area and operating as clients of the V2X application to operate in discontinuous reception mode, causes the wireless communication unit to broadcast control information indicating that one or more terminal devices are not permitted to operate in discontinuous reception mode. Base station.

17. The base station according to claim 16, wherein the control unit causes the wireless communication unit to broadcast the control information in a system information block for side link control.

18. The base station according to claim 16, wherein the control unit causes the wireless communication unit to broadcast the control information in a system information block for controlling V2X communication.

19. A communication control method performed by a base station for controlling V2X communication by a terminal device acting as a client for a V2X (Vehicle-to-Everything) application, The base station comprises a wireless communication unit that performs wireless communication in at least a first geographic area among a plurality of geographic 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 aforementioned communication control method is: The server device, which has determined that it does not permit one or more terminal devices located within the first geographical area and operating as clients of the V2X application to operate in discontinuous reception mode, receives a request message via the network communication unit from the server device, In response to receiving the aforementioned request message, the wireless communication unit is instructed to broadcast control information indicating that one or more terminal devices are not permitted to operate in the discontinuous reception mode. A communication control method, including a communication control method.

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