Terminal device, network device, server, communication system, communication control method, and program

Abstract

A terminal device according to the present invention comprises a communication unit that performs wireless communication and a communication control unit that controls the wireless communication performed by the communication unit. When the communication unit has received notification information that includes information that indicates a specific area from an access network device, the communication control unit causes the communication unit to perform intermittent communication. A network device according to the present invention comprises a reception control unit that receives information that indicates the risk in the surroundings of a terminal device, a determination unit that determines a time interval at which the terminal device is to transmit location information for the terminal device on the basis of the risk in the surroundings of the terminal device, and a transmission control unit that performs control for transmitting information that indicates the time interval to an access network device.

Description

Terminal device, network device, server, communication system, communication control method, and program

[0001] The present invention relates to a terminal device, a network device, a server, a communication system, a communication control method, and a program.

[0002] Patent Documents 1 to 7 describe techniques related to discontinuous reception (DRX) in wireless communication. [Prior art documents] [Patent documents] Patent Document 1: JP 2017-139659 A Patent Document 2: JP 2019-165328 A Patent Document 3: JP 2013-201508 A Patent Document 4: WO 2020 / 80285 Patent Document 5: JP 2018-191353 A Patent Document 6: JP 2010-50969 A Patent Document 7: JP 2023-536419 A Problem to be solved

[0003] However, when a terminal device performs wireless communication to improve traffic safety, etc., there is a problem that the period during which the terminal device performs wireless communication becomes longer, and the amount of power consumed by the terminal device for wireless communication increases. In order to solve the above problem, the present application aims to improve safety, etc. while suppressing the amount of power consumed by the terminal device for wireless communication. This can ultimately further improve traffic safety and contribute to the development of sustainable transportation systems. General disclosure

[0004] In a first aspect of the present invention, there is provided a terminal device. The terminal device includes a communication unit that performs wireless communication. The terminal device includes a communication control unit that controls wireless communication by the communication unit. The communication control unit causes the communication unit to perform intermittent communication when the communication unit receives broadcast information including information indicating a specific area from an access network device.

[0005] In the above-mentioned terminal device, when the communication unit is performing intermittent communication and the communication unit receives interval information indicating the communication interval in the intermittent communication, the communication control unit may change the communication interval in the intermittent communication by the communication unit based on the interval information.

[0006] In any of the above terminal devices, the specific area may be an area to which information regarding the location of the terminal device is provided, and the communication control unit may, when the communication unit receives the notification information, cause the communication unit to intermittently transmit the location information of the terminal device.

[0007] In any of the above terminal devices, the specific area may be an area in which information regarding risks in the vicinity of the terminal device is provided.

[0008] In any of the above terminal devices, when intermittent communication is being performed by the communication unit, the communication control unit may change the communication interval in the intermittent communication by the communication unit depending on the level of risk in the surrounding area of ​​the terminal device.

[0009] In any of the above terminal devices, when intermittent communication is being performed by the communication unit, the communication control unit may change the communication interval in the intermittent communication by the communication unit to a shorter interval, the higher the risk in the vicinity of the terminal device.

[0010] In any of the above terminal devices, the communication control unit may cause the communication unit to start non-intermittent communication when the risk around the terminal device exceeds a predetermined height while intermittent communication is being performed by the communication unit.

[0011] In any of the above terminal devices, the terminal device may be movable together with traffic participants, and the specific area may be an area for which information on traffic risks around the terminal device is provided.

[0012] Any of the above terminal devices may be equipped with a warning control unit that performs control to output warning information to the traffic participants when the communication unit receives information indicating that a traffic risk exists around the terminal device.

[0013] In a second aspect of the present invention, there is provided a program that causes a computer to function as any one of the terminal devices described above.

[0014] In a third aspect of the present invention, there is provided a network device. The network device includes a reception control unit that controls reception of information indicating a risk in the vicinity of a terminal device. The network device includes a determination unit that determines a time interval at which the terminal device should transmit location information of the terminal device based on the risk in the vicinity of the terminal device. The network device includes a transmission control unit that controls transmission of the information indicating the time interval to an access network device.

[0015] In a fourth aspect of the present invention, there is provided a program that causes a computer to function as the network device described above.

[0016] In a fifth aspect of the present invention, there is provided a server. The server includes a reception control unit that controls reception of location information transmitted from a terminal device. The server includes a determination unit that determines a risk in the vicinity of the terminal device based on the location information received from the terminal device. The server includes a transmission control unit that controls transmission of information to a network device that is responsible for wireless communication with the terminal device, the information causing the terminal device to shorten the transmission interval of the location information in accordance with the risk determined by the determination unit.

[0017] In the server, the determination unit may determine a traffic risk around the terminal device based on the location information of the terminal device, and may determine a transmission interval at which the terminal device should transmit the location information of the terminal device based on the determined risk. The transmission control unit may perform control to transmit information indicating the transmission interval determined by the determination unit to the network device.

[0018] In a sixth aspect of the present invention, there is provided a program that causes a computer to function as any one of the above-described servers.

[0019] In a seventh aspect of the present invention, there is provided a communication system. The communication system includes a server and any of the terminal devices described above. The server includes a reception control unit that controls reception of location information transmitted from the terminal device. The server includes a determination unit that determines a risk around the terminal device based on the location information received from the terminal device. The server includes a transmission control unit that controls transmission of information for shortening the transmission interval of the location information from the terminal device in accordance with the risk determined by the determination unit to a network device that is responsible for wireless communication with the terminal device.

[0020] In an eighth aspect of the present invention, there is provided a communication control method, the communication control method comprising: receiving broadcast information from an access network device; and, when the broadcast information includes information indicating a specific area, causing a communication unit that performs wireless communication to perform intermittent communication.

[0021] In a ninth aspect of the present invention, there is provided a communication control method. The communication control method includes a step of performing control to receive information indicating a risk in the vicinity of a terminal device. The communication control method includes a step of determining a time interval at which the terminal device should transmit location information of the terminal device based on the risk in the vicinity of the terminal device. The communication control method includes a step of performing control to transmit information indicating the time interval to an access network device.

[0022] In a tenth aspect of the present invention, there is provided a communication control method. The communication control method includes a step of performing control for receiving location information transmitted from a terminal device. The communication control method includes a step of determining a risk around the terminal device based on the location information received from the terminal device. The communication control method includes a step of performing control for transmitting information to a network device responsible for wireless communication with the terminal device, the information causing the terminal device to shorten an interval between transmissions of the location information in accordance with the risk determined in the risk determining step.

[0023] In an eleventh aspect of the present invention, there is provided a communication control method. The communication control method includes a step of, in an access network device, performing control to transmit broadcast information including information indicating a specific area. The communication control method includes a step of, in a terminal device, starting intermittent communication that performs wireless communication at predetermined time intervals when the broadcast information is received. The communication control method includes a step of, in a server, transmitting, to a network device responsible for wireless communication with the terminal device, information for changing the time intervals in accordance with risks around the terminal device, based on location information transmitted from the terminal device.

[0024] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0025] 1 shows an overall configuration of a communication system 10 according to an embodiment; FIG. 2 shows an example of the system configuration of a terminal device 82; FIG. 3 shows an example of the system configuration of a network device 130; FIG. 4 shows an example of the system configuration of a server 140; FIG. 5 shows an execution sequence of processes executed in the communication system 10; FIG. 6 shows an execution sequence of processes executed in the communication system 10; FIG. 7 shows an execution sequence of processes executed in the communication system 10; FIG. 8 shows an example of a computer 2000;

[0026] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0027] 1 is a schematic diagram illustrating a configuration of a communication system 10 according to an embodiment. The communication system 10 includes an access network device 120, a core network 132, a terminal device 82, a mobile unit 20a, a mobile unit 20b, and a mobile unit 20c, a server 140, and an imaging device 70.

[0028] In this embodiment, the mobile units 20a and 20b may be collectively referred to as "mobile units 20" with the suffixes of their reference numerals omitted. The mobile unit 20a includes an information processing device 40a, the mobile unit 20b includes an information processing device 40b, and the mobile unit 20c includes an information processing device 40c. In this embodiment, the information processing devices 40a, 40b, and 40c may be collectively referred to as "information processing devices 40."

[0029] The access network device 120 is, for example, a radio base station. For example, the access network device 120 is a mobile communication base station that supports one or more mobile communication methods. The terminal device 82 is a mobile station that supports one or more mobile communication methods. The terminal device 82 may be called a user equipment (UE). In this embodiment, the mobile communication methods supported by the access network device 120 and the terminal device 82 may be, for example, mobile communication methods used in mobile communication systems such as a fourth-generation mobile communication system (4G) or a fifth-generation mobile communication system (5G).

[0030] The access network device 120 is a base station fixed at a specific location. The access network device 120 forms a cell and performs wireless communication with the terminal device 82 by forming the cell. The terminal device 82 can access the core network 132 via the access network device 120 and communicate with the server 140.

[0031] The core network 132 includes a network device 130. The network device 130 is a core network device. The network device 130 may be, for example, an AccessSS and Mobility Management Function (AMF). The server 140 is included in a data network 142. The data network 142 includes, for example, a communication network such as the Internet.

[0032] The mobile body 20 is a mobile device. The mobile body 20 is, for example, a vehicle such as an automobile or a train. A vehicle is an example of a transportation device. In this embodiment, the mobile body 20 is an automobile. Specifically, the mobile body 20 is an automobile that travels on a road 90. However, the mobile body 20 may include not only a vehicle but also various aircraft including unmanned aerial vehicles. In other embodiments, the mobile body 20 may include an artificial satellite, a ship, etc. The mobile body 20 is an example of a traffic participant.

[0033] The mobile object 20 is configured to include various sensors such as a position sensor including a Global Navigation Satellite System (GNSS) receiver, a vehicle speed sensor, an imaging device, and a radar. The information processing device 40 has a function of processing information acquired by the various sensors included in the mobile object 20. The information processing device 40 has a function of communicating with the server 140 through the access network device 120. When the information processing device 40 is located within the cell of the access network device 120, it can periodically transmit current position information of the mobile object 20 detected by the position sensor including the GNSS receiver to the server 140 through the access network device 120.

[0034] The terminal device 82 is a terminal carried by the person 80. In this embodiment, the person 80 is a pedestrian. The person 80 is an example of a traffic participant. The terminal device 82 is, for example, a mobile terminal such as a smartphone. When the terminal device 82 is within the range of the cell of the access network device 120, the terminal device 82 may periodically transmit current location information of the terminal device 82 detected by a location sensor including a GNSS receiver to the server 140 via the access network device 120.

[0035] The imaging device 70 is an imaging device installed on a transportation infrastructure. The imaging device 70 acquires the positions of the moving objects 20 and the people 80 present within the imaging range of the imaging device 70 by analyzing the captured images, and transmits the acquired position information indicating the current positions of the moving objects 20 and the people 80 to the server 140. The imaging device 70 may transmit the position information of the moving objects 20 and the people 80 to the server 140 via the access network device 120. The imaging device 70 may transmit the position information of the moving objects 20 and the people 80 to the server 140 via a communication path other than the communication path via the access network device 120.

[0036] The server 140 identifies the current and / or future positions of the person 80 and the mobile object 20 based on the position information transmitted from the information processing device 40, the terminal device 82, and the imaging device 70. However, the server 140 considers the position of the terminal device 82 to be the position of the person 80. Based on the identified positions of the person 80 and the mobile object 20, the server 140 determines the risk that the person 80 and the mobile object 20 will approach each other within a predetermined distance in the future. The server 140 causes the terminal device 82 and the mobile object 20 to output warning information based on the level of risk that the person 80 and the mobile object 20 will approach each other within the predetermined distance. The risk that the person 80 and the mobile object 20 will approach each other within the predetermined distance is an example of a traffic risk.

[0037] 1 , for example, if the risk that the person 80 and the moving body 20a will approach within a predetermined distance in the future exceeds a predetermined height, the server 140 transmits warning information to the terminal device 82 and the information processing device 40a via the access network device 120. When the terminal device 82 receives the warning information, it outputs a warning to the person 80. For example, the terminal device 82 outputs the warning to the person 80 by sound, vibration, and / or display. When the information processing device 40a receives the warning information, it outputs a warning to the passengers of the moving body 20a. For example, the information processing device 40a outputs the warning to the passengers of the moving body 20a by sound, vibration, and / or display.

[0038] In this way, the communication system 10 can provide information about traffic risks within the coverage area of ​​the cell of the access network device 120. The access network device 120 broadcasts notification information including information indicating the area where information about traffic risks is provided. The notification information is, for example, a system information block (SIB). By receiving the notification information from the access network device 120, the terminal device 82 and the information processing device 40 recognize that they have entered the area where information about traffic risks is provided, and start transmitting location information to the server 140.

[0039] Here, we will take the case where terminal device 82 moves from outside the cell coverage area of ​​access network device 120 to within the cell coverage area of ​​access network device 120 and explain the process by which terminal device 82 sends location information to server 140 via access network device 120.

[0040] When the terminal device 82 receives the notification information from the access network device 120, it autonomously performs a call origination process to the access network device 120. When the access network device 120 performs a procedure related to the call origination process in response to a request from the terminal device 82, it transitions the wireless communication state of the terminal device 82 to a state in which discontinuous reception (DRX) is performed at a relatively long period. For example, the access network device 120 transitions the terminal device 82 to a state in which discontinuous reception is performed at a five-second period. This enables the access network device 120 to transmit the location information of the terminal device 82 to the server 140 at a five-second period (or at a period that is an integral multiple of five seconds).

[0041] As described above, the server 140 determines the risk that the person 80 and the mobile body 20 will approach within a predetermined distance in the future based on the location information transmitted from the information processing device 40, the terminal device 82, and the imaging device 70. When the risk that the person 80 and the mobile body 20 will approach within the predetermined distance becomes high, the server 140 transitions the wireless communication state of the terminal device 82 to a state in which discontinuous reception is performed at a relatively short period. For example, the access network device 120 transitions the wireless communication state of the terminal device 82 to a state in which discontinuous reception is performed at a period of 100 milliseconds. This enables the access network device 120 to transmit the location information of the terminal device 82 to the server 140 at a period of 100 milliseconds (or a period that is an integer multiple of 100 milliseconds).

[0042] When the risk of the person 80 and the moving object 20 approaching within a predetermined distance exceeds a predetermined height, the server 140 transitions the wireless communication state of the terminal device 82 to a non-discontinuous reception (non-DRX) state, which enables the server 140 to quickly transmit warning information to the terminal device 82.

[0043] Thus, according to the communication system 10, when the terminal device 82 enters the range of the cell of the access network device 120, it enters a state of discontinuous reception with a relatively long cycle and transmits location information at a relatively long cycle. Then, when the traffic risk around the terminal device 82 increases, it enters a state of discontinuous reception with a shorter cycle or a state of non-discontinuous reception. This makes it possible to reduce the amount of power consumed by the terminal device 82 to transmit location information to the server 140 via wireless communication. Then, when the traffic risk increases, the server 140 can determine the traffic risk with higher accuracy and quickly transmit warning information to the terminal device 82. Ultimately, this can improve safety in the transportation system.

[0044] 2 shows an example of the system configuration of the terminal device 82. The terminal device 82 includes a control unit 200, a storage unit 210, a communication unit 280, and an output unit 290.

[0045] The control unit 200 performs overall control of the terminal device 82. The communication unit 280 is responsible for wireless communication. The control unit 200 is realized by an arithmetic processing unit including a processor. The memory unit 210 is realized by including a non-volatile memory medium. The control unit 200 performs processing using information stored in the memory unit 210. The control unit 200 may be realized by a microcomputer including a CPU, ROM, RAM, I / O, buses, etc. The terminal device 82 may be realized by one or more computers. At least some of the functions of the terminal device 82 may be realized by a virtual system realized using virtualization technology.

[0046] The control unit 200 includes a warning control unit 220 and a communication control unit 230. The communication control unit 230 controls wireless communication by the communication unit 280. When the communication unit 280 receives notification information including information indicating a specific area from an access network device, the communication control unit 230 causes the communication unit 280 to perform intermittent communication.

[0047] When the communication unit 280 is performing intermittent communication and the communication unit 280 receives interval information indicating the communication interval in the intermittent communication, the communication control unit 230 changes the communication interval in the intermittent communication by the communication unit 280 based on the interval information.

[0048] The specific area is, for example, an area in which information about the location of the terminal device 82 is provided. When the communication unit 280 receives notification information, the communication control unit 230 causes the communication unit 280 to intermittently transmit the location information of the terminal device 82.

[0049] The specific area is, for example, an area for which information regarding risk in the vicinity of the terminal device 82 is provided. When intermittent communication is being performed by the communication unit 280, the communication control unit 230 changes the communication interval of the intermittent communication by the communication unit 280 in accordance with the level of risk in the vicinity of the terminal device 82. When intermittent communication is being performed by the communication unit 280, the communication control unit 230 changes the communication interval of the intermittent communication by the communication unit 280 to a shorter interval as the risk in the vicinity of the terminal device 82 increases. When intermittent communication is being performed by the communication unit 280 and the risk in the vicinity of the terminal device 82 exceeds a predetermined level, the communication control unit 230 causes the communication unit 280 to start non-intermittent communication.

[0050] The terminal device 82 may be movable together with the traffic participants. The specific area may be an area in which information regarding traffic risks around the terminal device 82 is provided. When the communication unit 280 receives information indicating that a traffic risk exists around the terminal device 82, the warning control unit 220 performs control to output warning information to the traffic participants.

[0051] 3 shows an example of the system configuration of the network device 130. The network device 130 includes a control unit 300, a storage unit 310, and a communication unit 380.

[0052] The control unit 200 performs overall control of the network device 130. The communication unit 380 is responsible for communication in the core network 132. The control unit 300 is realized by an arithmetic processing unit including a processor. The memory unit 310 is realized by including a non-volatile memory medium. The control unit 300 performs processing using information stored in the memory unit 310. The control unit 300 may be realized by a microcomputer including a CPU, ROM, RAM, I / O, buses, etc. The network device 130 may be realized by one or more computers. At least a portion of the functions of the network device 130 may be realized by a virtual system realized using virtualization technology.

[0053] The control unit 300 includes a determination unit 320, a reception control unit 332, and a transmission control unit 334. The reception control unit 332 performs control for receiving information indicating risks in the vicinity of the terminal device 82. The determination unit 320 determines the time interval at which the terminal device 82 should transmit location information of the terminal device 82, based on the risks in the vicinity of the terminal device 82. The transmission control unit 334 performs control for transmitting information indicating the time interval to the access network device.

[0054] 4 shows an example of the system configuration of the server 140. The server 140 includes a control unit 400, a storage unit 410, and a communication unit 480.

[0055] The control unit 400 performs overall control of the server 140. The communication unit 480 is responsible for communication with at least the core network 132. The communication unit 480 is responsible for communication with at least computer networks other than the core network. The control unit 400 is realized by an arithmetic processing unit including a processor. The memory unit 410 is realized by including a non-volatile memory medium. The control unit 400 performs processing using information stored in the memory unit 410. The control unit 400 may be realized by a microcomputer including a CPU, ROM, RAM, I / O, buses, etc. The server 140 may be realized by one or more computers. At least a portion of the functions of the server 140 may be realized by a virtual system realized using virtualization technology.

[0056] The control unit 400 includes a determination unit 420, a reception control unit 432, and a transmission control unit 434. The reception control unit 432 performs control for receiving location information transmitted from the terminal device 82. The determination unit 420 determines a risk in the vicinity of the terminal device 82 based on the location information received from the terminal device 82. The transmission control unit 434 performs control for transmitting information for shortening the transmission interval of location information from the terminal device 82 to a network device responsible for wireless communication with the terminal device 82 in accordance with the risk determined by the determination unit 420. The "information for shortening the transmission interval of location information from the terminal device 82" is, for example, "period information" and "risk information" described below.

[0057] The determination unit 420 determines a traffic risk around the terminal device 82 based on the location information of the terminal device 82, and based on the determined risk, determines a transmission interval at which the terminal device 82 should transmit the location information of the terminal device 82. The transmission control unit 434 performs control to transmit information indicating the transmission interval determined by the determination unit 420 to the network device 130.

[0058] 5 shows an execution sequence of processing executed in the communication system 10. It is assumed that the terminal device 82 is in an idle state when this sequence starts. In this sequence, the network device 130 may be an AMF (Access and Mobility Management Function).

[0059] In S502, the communication unit 280 of the terminal device 82 receives the SIB transmitted from the access network device 120. The SIB includes information indicating an area for which information on traffic risks is provided.

[0060] When the communication unit 280 receives the SIB indicating the area where information on traffic risks is provided, the communication control unit 230 starts the registration process and causes the communication unit 280 to transmit an RRC setup request (RRC) message to the access network device 120 (S504). At S506, the communication unit 280 of the terminal device 82 receives the RRC setup (RRC) message from the access network device 120.

[0061] When the communication unit 280 receives the RRC setup message, the communication control unit 230 causes the communication unit 280 to transmit an RRC Setup Complete (RRC) message to the access network device 120 (S508). The RRC Setup Complete message includes a NAS Registration Request message, which is a NAS message.

[0062] The access network device 120 extracts the registration request message included in the RRC setup complete message and sends it together with an initial UE message to the network device 130 (S510). The initial UE message is, for example, an NGAP message, NGAP: Initial UE Message.

[0063] At S514, the access network device 120 transmits an RRC Connection Reconfiguration (RRC) message to the terminal device 82. In this manner, when the terminal device 82 receives the SIB including information indicating an area where information on traffic risks is provided, an Idle To Active procedure is executed, and the terminal device 82 enters an active state. However, it should be noted that this sequence does not show all of the Idle To Active procedure.

[0064] The RRC connection reconfiguration message received in S514 includes information indicating the discontinuous reception cycle 1. Upon receiving the RRC connection reconfiguration message, the communication control unit 230 causes the communication unit 280 to transition to a state in which discontinuous reception is performed at cycle 1. This causes the communication unit 280 to enter a state in which it is possible to transmit the location information of the terminal device 82 to the server 140 at cycle 1 (S520). Cycle 1 may be, for example, 5 seconds, but is not limited to this.

[0065] In S530, the determination unit 420 of the server 140 determines a traffic risk around the terminal device 82 based on the location information transmitted from the terminal device 82. As described above, the determination unit 420 determines the risk of approaching the person 80 and the moving body 20 based on, for example, the location information transmitted from the terminal device 82, the location information of the moving body 20 transmitted from the information processing device 40, and the location information transmitted from the imaging device 70.

[0066] In S531, the determination unit 420 determines the intermittent reception cycle 2 based on the traffic risk around the terminal device 82. For example, the higher the traffic risk around the terminal device 82, the shorter the cycle the determination unit 420 determines as the intermittent reception cycle 2. The determination unit 420 may determine the intermittent reception cycle 2 further based on the moving speed of the terminal device 82. For example, the higher the moving speed of the terminal device 82, the shorter the cycle the determination unit 420 determines as the intermittent reception cycle 2. Here, it is assumed that the traffic risk determined in S531 exceeds the first threshold associated with cycle 2. In S532, the transmission control unit 434 causes the communication unit 480 to transmit cycle information indicating the determined cycle to the network device 130. The cycle 2 may be, for example, 100 milliseconds, but is not limited to this. The cycle information is an example of interval information.

[0067] At S534, the transmission control unit 334 of the network device 130 causes the communication unit 380 to transmit the periodicity information indicating Period 2 received at S532 to the access network device 120. At S534, the periodicity information may be transmitted to the access network device 120 by a Downlink NAS Transfer (NGAP: DL NAS TranSfer) message or a UE Context Modification message, which are NGAP messages.

[0068] In S536, the access network device 120 transmits the periodicity information indicating period 2 received in S534 to the terminal device 82. The periodicity information may be transmitted to the terminal device 82 by an RRC Connection Reconfiguration (RRC) message, which is an RRC message.

[0069] As a result, the communication control unit 230 causes the communication unit 280 to transition to a state in which it performs intermittent reception at period 2. As a result, the communication unit 280 enters a state in which it is possible to transmit the location information of the terminal device 82 to the server 140 at period 2 (S540).

[0070] In FIG. 5, the terminal device 82 is assumed to be in an idle state at the start of this sequence. However, if the terminal device 82 is powered on at the start of this sequence, an attach procedure will be executed instead of an Idle To Active procedure.

[0071] FIG. 6 shows an execution sequence of processing executed in the communication system 10. The sequence of FIG. 6 can be executed subsequent to the sequence shown in FIG. 5. In S550, the determination unit 420 determines a traffic risk around the terminal device 82 based on the location information transmitted from the terminal device 82 in S540. The processing of S550 is similar to the processing of S530. Here, it is assumed that the determination unit 420 determines a traffic risk that exceeds a predetermined second threshold. However, the second threshold is higher than the first threshold. In this case, the transmission control unit 434 causes the communication unit 480 to transmit a state transition message to the network device 130 (S552). The state transition message is a message indicating that the communication state of the terminal device 82 is to be transitioned to a non-intermittent communication state (i.e., a state in which wireless communication is performed continuously).

[0072] At S554, upon receiving the state transition message from the server 140, the transmission control unit 334 of the network device 130 transmits a state transition message for transitioning the communication state of the terminal device 82 to a continuous communication state to the access network device 120. The state transition message may be transmitted to the access network device 120 by a Downlink NAS Transfer (NGAP: DL NAS Transfer) message or a UE Context Modification message, which are NGAP messages.

[0073] In S556, upon receiving the state transition message in S554, the access network device 120 transmits a state transition message for transitioning the communication state of the terminal device 82 to a continuous communication state to the terminal device 82. The state transition message may be transmitted to the terminal device 82 by an RRC Connection Reconfiguration (RRC) message, which is an RRC message.

[0074] In S560, the server 140 transmits warning information indicating traffic risks around the terminal device 82 to the terminal device 82. The warning information is an example of "information about the location of the terminal device 82." The warning information is an example of "information about risks around the terminal device 82." The warning information may include instruction information that instructs the terminal device 82 to output a warning to the person 80. In S562, the warning control unit 220 of the terminal device 82 causes the output unit 290 to output a warning to the person 80 based on the warning information received from the server 140.

[0075] 6 , the server 140 transmits a state transition message to the network device 130 (S552), but the server 140 may transmit warning information to the terminal device 82 without executing S552. If a relatively large amount of warning information is transmitted to the terminal device 82 while the terminal device 82 is performing discontinuous reception, the amount of unsent data addressed to the terminal device 82 increases. In this case, the access network device 120 switches the communication state of the terminal device 82 to a continuous communication state in order to transmit the unsent data to the terminal device 82. Therefore, the server 140 may be able to switch the communication state of the terminal device 82 to a continuous communication state by transmitting warning information to the terminal device 82 without transmitting a state transition message to the network device 130.

[0076] 7 shows an execution sequence of processing executed in the communication system 10. The sequence of FIG. 7 can be executed following the sequence shown in FIG.

[0077] In S730, the determination unit 420 of the server 140 determines a traffic risk around the terminal device 82 based on the location information transmitted from the terminal device 82. The processing of S730 is similar to the processing of S530, etc. Here, it is assumed that the determination unit 420 determines a traffic risk around the terminal device 82 that is equal to or less than the second threshold and exceeds the first threshold. In this case, in S731, the determination unit 420 determines a cycle 2 of intermittent reception (e.g., 100 milliseconds) based on the traffic risk around the terminal device 82. In S732, the transmission control unit 434 causes the communication unit 480 to transmit cycle information indicating cycle 2 to the network device 130.

[0078] Subsequently, in S734, the transmission control unit 334 of the network device 130 causes the communication unit 380 to transmit the periodicity information indicating Period 2 received in S732 to the access network device 120. In S734, the periodicity information may be transmitted by a Downlink NAS Transfer (NGAP) message or a UE Context Modification message, which are NGAP messages.

[0079] In S736, the access network device 120 transmits the periodicity information indicating period 2 received in S534 to the terminal device 82. The periodicity information may be transmitted to the terminal device 82 by an RRC Connection Reconfiguration (RRC) message, which is an RRC message.

[0080] As a result, the communication control unit 230 transitions the wireless communication state of the communication unit 280 to a state in which intermittent reception is performed in period 2. As a result, the communication unit 280 enters a state in which it is possible to transmit the location information of the terminal device 82 to the server 140 in period 2 (S740).

[0081] In S750, the determination unit 420 of the server 140 determines a traffic risk around the terminal device 82 based on the location information transmitted from the terminal device 82 at period 2. The processing at S750 is similar to the processing at S530, etc. Here, it is assumed that the determination unit 420 determines that the traffic risk around the terminal device 82 is equal to or less than a first threshold. In this case, in S751, the determination unit 420 determines period 1 (e.g., 5 seconds) for intermittent reception based on the traffic risk around the terminal device 82. In S752, the transmission control unit 434 causes the communication unit 480 to transmit period information indicating period 1 to the network device 130.

[0082] Subsequently, in S754, the transmission control unit 334 of the network device 130 causes the communication unit 380 to transmit the periodicity information indicating period 1 received in S752 to the access network device 120. In S754, the periodicity information may be transmitted by a Downlink NAS Transfer (NGAP) message or a UE Context Modification message, which are NGAP messages.

[0083] In S756, the access network device 120 transmits the periodicity information indicating period 1 received in S754 to the terminal device 82. The periodicity information may be transmitted to the terminal device 82 by an RRC Connection Reconfiguration (RRC) message, which is an RRC message.

[0084] As a result, the communication control unit 230 causes the communication unit 280 to transition to a state in which it performs intermittent reception at period 1. As a result, the communication unit 280 enters a state in which it is possible to transmit the location information of the terminal device 82 to the server 140 at period 1 (S760).

[0085] Figure 8 shows an execution sequence of processing executed in the communication system 10. The sequence of Figure 8 is a modified version of the sequence of Figure 5. The sequence of Figure 8 differs from the sequence of Figure 5 in that the terminal device 82 transmits information related to traffic risks to the network device 130, and the network device 130 determines the period of discontinuous reception for the terminal device 82. The processing from S502 to S530 in the sequence of Figure 8 is the same as the processing already described in relation to Figure 5, and therefore will not be described again.

[0086] In S831, the transmission control unit 434 causes the communication unit 480 to transmit risk information indicating the level of traffic risk determined by the determination unit 420 in S530 to the network device 130. In S832, the determination unit 320 of the network device 130 determines the intermittent reception cycle 2 based on the risk information received from the server 140.

[0087] At S834, the transmission control unit 334 of the network device 130 causes the communication unit 380 to transmit periodicity information indicating the period 2 determined at S832 to the access network device 120. At S834, the periodicity information may be transmitted by a Downlink NAS Transfer (NGAP) message or a UE Context Modification message, which are NGAP messages. The transmission control unit 334 of the network device 130 may cause the communication unit 380 to transmit information indicating the period 2 determined at S832 to the terminal device 82, separately from the periodicity information transmitted to the access network device 120.

[0088] In S836, the access network device 120 transmits the periodicity information indicating period 2 received in S834 to the terminal device 82. The periodicity information may be transmitted to the terminal device 82 by an RRC Connection Reconfiguration (RRC) message, which is an RRC message.

[0089] 5 to 8 , the communication system 10 allows the terminal device 82 to change the time interval at which it transmits location information in accordance with the traffic risk around the terminal device 82. This allows the terminal device 82 to appropriately determine the traffic risk while reducing the amount of power consumed by wireless communication.

[0090] In the above, it has been described that the terminal device 82 transitions to a state of performing intermittent communication when it receives notification information indicating a predetermined area, changes the cycle of the intermittent communication in accordance with the traffic risk around the terminal device 82, and switches between the intermittent communication state and the non-intermittent communication state in accordance with the traffic risk around the terminal device 82. The information processing device 40 of the mobile body 20 may also perform the same processing as the terminal device 82 to transition to a state of performing intermittent communication when it receives notification information indicating a predetermined area, changes the cycle of the intermittent communication in accordance with the traffic risk around the mobile body 20, and switches between the intermittent communication state and the non-intermittent communication state in accordance with the traffic risk around the terminal device 82. In other words, the information processing device 40 may be the "terminal device" in this invention.

[0091] 5 to 8 and the like, the embodiments have been described in which various notifications and / or various information are transmitted using messages such as an SIB, an RRC setup request message, an RRC setup message, an RRC setup complete message, and an RRC connection reconfiguration message, but these messages are examples of messages for transmitting various notifications and / or various information. Messages for transmitting various notifications and / or various information are not limited to the above-mentioned messages.

[0092] 9 shows an example of a computer 2000 in which multiple embodiments of the present invention may be embodied in whole or in part. Programs installed on the computer 2000 may cause the computer 2000 to function as various devices, such as the terminal device 82, the network device 130, and the server 140, according to embodiments, or as each part of the devices, to perform operations associated with the devices or each part of the devices, and / or to perform processes or steps of the processes according to embodiments. Such programs may be executed by the CPU 2012 to cause the computer 2000 to perform specific operations associated with some or all of the processing procedures and blocks of the block diagrams described herein.

[0093] The computer 2000 according to this embodiment includes a CPU 2012 and a RAM 2014, which are interconnected by a host controller 2010. The computer 2000 also includes a ROM 2026, a flash memory 2024, a communication interface 2022, and an input / output chip 2040. The ROM 2026, the flash memory 2024, the communication interface 2022, and the input / output chip 2040 are connected to the host controller 2010 via the input / output controller 2020.

[0094] The CPU 2012 operates according to programs stored in the ROM 2026 and RAM 2014, thereby controlling each unit.

[0095] The communication interface 2022 communicates with other electronic devices via a network. The flash memory 2024 stores programs and data used by the CPU 2012 in the computer 2000. The ROM 2026 stores a boot program or the like executed by the computer 2000 upon activation and / or programs dependent on the hardware of the computer 2000. The input / output chip 2040 may also connect various input / output units such as a keyboard, mouse, and monitor to the input / output controller 2020 via input / output ports such as a serial port, a parallel port, a keyboard port, a mouse port, a monitor port, a USB port, an HDMI port, etc.

[0096] The programs are provided via a computer-readable storage medium such as a CD-ROM, DVD-ROM, or memory card, or via a network. RAM 2014, ROM 2026, and flash memory 2024 are examples of computer-readable storage media. The programs are installed in flash memory 2024, RAM 2014, or ROM 2026 and executed by CPU 2012. Information processing described in these programs is read by computer 2000, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing operations or processing of information in accordance with the use of computer 2000.

[0097] For example, when communication is performed between the computer 2000 and an external device, the CPU 2012 may execute a communication program loaded into the RAM 2014 and instruct the communication interface 2022 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 2012, the communication interface 2022 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as the RAM 2014 or flash memory 2024, transmits the read transmission data to a network, and writes received data received from the network to a reception buffer processing area or the like provided on the recording medium.

[0098] The CPU 2012 may also cause all or a necessary portion of a file or database stored on a recording medium such as the flash memory 2024 to be read into the RAM 2014, and may perform various types of processing on the data on the RAM 2014. The CPU 2012 then writes the processed data back to the recording medium.

[0099] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 2012 may perform various types of processing on data read from the RAM 2014, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described herein and specified by the instruction sequences of the programs, and write the results back to the RAM 2014. The CPU 2012 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored on the recording medium, the CPU 2012 may search for an entry that matches a condition and specifies an attribute value of the first attribute from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0100] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 2000. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer-readable storage medium. The programs stored in the computer-readable storage medium may be provided to the computer 2000 via a network.

[0101] A program installed in computer 2000 and causing computer 2000 to function as terminal device 82, when executed by the computer, may act on CPU 2012, etc., to cause computer 2000 to function as each unit of terminal device 82. When the information processing described in these programs is read into computer 2000, computer 2000 functions as each unit of terminal device 82, which is a specific means formed by the cooperation of software and the various hardware resources described above. These specific means then perform calculations or processing of information according to the intended use of computer 2000 in this embodiment, thereby constructing a specific terminal device 82 according to the intended use.

[0102] A program installed on computer 2000 that causes computer 2000 to function as network device 130 may, when executed by the computer, act on CPU 2012 and the like to cause computer 2000 to function as each part of network device 130. When the information processing described in these programs is read into computer 2000, computer 2000 functions as each part of network device 130, which is a specific means formed by the cooperation of software and the various hardware resources described above. These specific means then perform calculations or processing of information according to the intended use of computer 2000 in this embodiment, thereby constructing a specific network device 130 according to the intended use.

[0103] A program installed on computer 2000 that causes computer 2000 to function as server 140 may, when executed by the computer, act on CPU 2012 and the like to cause computer 2000 to function as each unit of server 140. When the information processing described in these programs is read into computer 2000, computer 2000 functions as each unit of server 140, which is a specific means formed by the cooperation of software and the various hardware resources described above. These specific means then perform calculations or processing of information according to the intended use of computer 2000 in this embodiment, thereby constructing a specific server 140 according to the intended use.

[0104] Various embodiments have been described with reference to block diagrams. In the block diagrams, each block may represent (1) a stage of a process in which an operation is performed or (2) a portion of an apparatus responsible for performing the operation. Particular stages and portions may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. Dedicated circuitry may include digital and / or analog hardware circuitry, and may include integrated circuits (ICs) and / or discrete circuits. Programmable circuitry may include reconfigurable hardware circuitry, including logical AND, OR, XOR, NAND, NOR, and other logic operations, flip-flops, registers, memory elements such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), and the like.

[0105] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that the computer-readable storage medium having instructions stored thereon constitutes at least a portion of an article of manufacture containing instructions that can be executed to provide means for performing the operations specified in a process or block diagram. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memories (RAMs), read-only memories (ROMs), erasable programmable read-only memories (EPROMs or flash memories), electrically erasable programmable read-only memories (EEPROMs), static random access memories (SRAMs), compact disc read-only memories (CD-ROMs), digital versatile discs (DVDs), Blu-ray discs, memory sticks, integrated circuit cards, etc.

[0106] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0107] The computer-readable instructions may be provided to a processor or programmable circuitry of a programmable data processing apparatus, such as a computer, locally or over a local area network (LAN), a wide area network (WAN) such as the Internet, etc., and the computer-readable instructions may be executed to provide means for performing the operations specified in the described procedures or block diagrams.

[0108] Here, the computer may be a computer such as a PC (personal computer), a tablet computer, a smartphone, a workstation, a server computer, or a general-purpose computer, or may be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system, which is a computer in the broad sense. In a distributed computing system, the multiple computers collectively execute a program by each executing a part of the program and transferring data between the computers as needed during program execution.

[0109] Examples of processors include computer processors, central processing units (CPUs), processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. A computer may have one processor or multiple processors. In a multiprocessor system with multiple processors, each processor executes a portion of a program and passes data between processors as needed during program execution, allowing the multiple processors to collectively execute the program. For example, in multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at each time slice. In this case, which portion of a program each processor executes changes dynamically. Alternatively, which portion of a program each of the multiple processors executes may be statically determined by multiprocessor-aware programming.

[0110] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0111] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0112] 10 Communication system 20 Mobile object 40 Information processing device 70 Imaging device 80 Person 90 Road 82 Terminal device 120 Access network device 130 Network device 132 Core network 140 Server 142 Data network 200 Control unit 210 Memory unit 220 Warning control unit 230 Communication control unit 280 Communication unit 290 Output unit 300 Control unit 310 Memory unit 320 Determination unit 332 Reception control unit 334 Transmission control unit 380 Communication unit 400 Control unit 410 Memory unit 420 Determination unit 432 Reception control unit 434 Transmission control unit 480 Communication unit 2000 Computer 2010 Host controller 2012 CPU 2014 RAM 2020 Input / output controller 2022 Communication interface 2024 Flash memory 2026 ROM 2040 Input / output chip

Claims

1. A terminal device comprising a communication unit that performs wireless communication and a communication control unit that controls the wireless communication by the communication unit, wherein the communication control unit causes the communication unit to perform intermittent communication when the communication unit receives notification information including information indicating a specific area from an access network device.

2. A terminal device as described in claim 1, wherein when the communication unit is performing intermittent communication and the communication control unit receives interval information indicating the communication interval in the intermittent communication, the communication control unit changes the communication interval in the intermittent communication by the communication unit based on the interval information.

3. A terminal device as described in claim 1 or 2, wherein the specific area is an area where information regarding the location of the terminal device is provided, and the communication control unit causes the communication unit to intermittently transmit the location information of the terminal device when the communication unit receives the notification information.

4. The terminal device according to claim 3, wherein the specific area is an area in which information regarding risks in the vicinity of the terminal device is provided.

5. A terminal device as described in claim 4, wherein the communication control unit, when performing intermittent communication by the communication unit, changes the communication interval in the intermittent communication by the communication unit depending on the level of risk in the surroundings of the terminal device.

6. A terminal device as described in claim 5, wherein, when intermittent communication is being performed by the communication unit, the communication control unit changes the communication interval in the intermittent communication by the communication unit to a shorter interval the higher the risk in the vicinity of the terminal device.

7. A terminal device described in any one of claims 4 to 6, wherein the communication control unit causes the communication unit to start non-intermittent communication when the risk around the terminal device exceeds a predetermined height while intermittent communication is being performed by the communication unit.

8. A terminal device according to any one of claims 3 to 7, wherein the terminal device is movable together with traffic participants, and the specific area is an area in which information regarding traffic risks around the terminal device is provided.

9. The terminal device according to claim 8, further comprising a warning control unit that performs control to output warning information to the traffic participants when the communication unit receives information indicating that a traffic risk exists around the terminal device.

10. A program for causing a computer to function as a terminal device according to any one of claims 1 to 9.

11. A network device comprising: a reception control unit that controls the reception of information indicating risks in the vicinity of a terminal device; a determination unit that determines the time interval at which the terminal device should transmit location information of the terminal device based on the risks in the vicinity of the terminal device; and a transmission control unit that controls the transmission of information indicating the time interval to an access network device.

12. A program for causing a computer to function as the network device according to claim 11.

13. A server comprising: a reception control unit that controls the reception of location information transmitted from a terminal device; a determination unit that determines the risk in the vicinity of the terminal device based on the location information received from the terminal device; and a transmission control unit that controls the transmission of information to a network device that is responsible for wireless communication with the terminal device, to shorten the transmission interval of the location information from the terminal device in accordance with the risk determined by the determination unit.

14. The server described in claim 13, wherein the determination unit determines a traffic risk around the terminal device based on the location information of the terminal device, and determines a transmission interval at which the terminal device should transmit the location information of the terminal device based on the determined risk, and the transmission control unit controls the transmission of information indicating the transmission interval determined by the determination unit to the network device.

15. A program for causing a computer to function as the server according to claim 13 or 14.

16. A communication system comprising: a server that includes a reception control unit that controls the reception of location information transmitted from a terminal device; a determination unit that determines the risk in the vicinity of the terminal device based on the location information received from the terminal device; and a transmission control unit that controls the transmission of information to a network device that is responsible for wireless communication with the terminal device, to shorten the transmission interval of the location information from the terminal device in accordance with the risk determined by the determination unit; and a terminal device described in any one of claims 1 to 9.

17. A communication control method comprising: a step of receiving notification information from an access network device; and a step of causing a communication unit that performs wireless communication to perform intermittent communication if the notification information includes information indicating a specific area.

18. A communication control method comprising the steps of: performing control to receive information indicating risks in the vicinity of a terminal device; determining a time interval at which the terminal device should transmit location information of the terminal device based on the risks in the vicinity of the terminal device; and performing control to transmit information indicating the time interval to an access network device.

19. A communication control method comprising the steps of: performing a control step for receiving location information transmitted from a terminal device; determining a risk in the vicinity of the terminal device based on the location information received from the terminal device; and performing a control step for transmitting information for shortening the transmission interval of the location information from the terminal device in accordance with the risk determined in the risk determination step to a network device responsible for wireless communication with the terminal device.

20. A communication control method comprising: a step in an access network device performing control to transmit notification information including information indicating a specific area; a step in a terminal device starting intermittent communication that performs wireless communication at predetermined time intervals when the notification information is received; and a step in a server transmitting information to a network device that handles wireless communication with the terminal device, based on location information transmitted from the terminal device, for changing the time intervals in accordance with the risk in the vicinity of the terminal device.

Images