Communication method and information processing method

Abstract

To achieve high-speed roaming in radio communication.SOLUTION: A first access point capable of communicating with a moving user equipment receives mobility information regarding movement of the user equipment from the user equipment in a first frequency band, and the first access point communicates with the user equipment in a second frequency band in a communicable period in which communication with the user equipment is possible, the communicable period being determined based on the mobility information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to wireless communications. [Background technology]

[0002] In a wireless LAN environment, there is a technique for roaming a user terminal between a plurality of access points (for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE802.11r, [online], May 14, 2024, IEEE802, [Retrieved May 31, 2024], Internet<URL:https: / / www.ieee802.org / 11 / Reports / tgr_update.htm> Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to achieve high-speed roaming in wireless communication. [Means for solving the problem]

[0005] One aspect of the present disclosure is A communication method in which a first access point capable of communicating with a moving user equipment receives mobility information regarding the movement of the user equipment from the user equipment in a first frequency band, and the first access point communicates with the user equipment in a second frequency band during a communication period in which communication with the user equipment is possible, determined based on the mobility information.

[0006] One aspect of the present disclosure is A communication method performed by a first access point and a second access point capable of communicating with a moving user equipment, the communication method including: the first access point receiving mobility information regarding the movement of the user equipment from the user equipment in a first frequency band; the first access point sharing the mobility information with the second access point; and the second access point communicating with the user equipment in a second frequency band during a communication enabled period during which communication with the user equipment is possible, determined based on the mobility information.

[0007] One aspect of the present disclosure is An information processing method executed by an information processing device capable of communicating with first and second access points, the information processing method including: acquiring mobility information regarding the movement of a user device received by a first access point; and transmitting information to the first and second access points for determining a communication period during which communication with the user device is possible based on the acquired mobility information.

[0008] Other aspects include an apparatus for executing the above-described method, a program for causing a computer to execute the method, or a computer-readable storage medium that non-transitoryly stores the program. [Effects of the Invention]

[0009] According to the present disclosure, high-speed roaming can be achieved in wireless communication. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a hardware configuration of the in-vehicle device according to the embodiment. [Figure 3] FIG. 2 is a hardware configuration diagram of a roadside device according to the embodiment. [Figure 4] FIG. 2 is a hardware configuration diagram of a control device according to the embodiment. [Figure 5] FIG. 2 is a software configuration diagram of the in-vehicle device according to the embodiment. [Figure 6] FIG. 2 is a software configuration diagram of the roadside device according to the embodiment. [Figure 7] FIG. 2 is a software configuration diagram of a control device according to the embodiment. [Figure 8] 10 is a flowchart illustrating the phases executed by each device. [Figure 9] FIG. 1 is a sequence diagram showing the flow of data in the detection phase. [Figure 10] FIG. 1 is a sequence diagram showing the flow of data in a transmission / reception phase. [Figure 11] FIG. 10 is a sequence diagram showing a data flow in a detection phase according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] In a wireless LAN environment such as Wi-Fi (registered trademark), there is a system for roaming a user terminal between multiple access points. In this system, for example, the results of authenticating the user terminal are shared among the multiple access points. This makes it possible to skip the authentication phase and reconnect in a short time even if the user terminal moves and changes the access point to which it is connected.

[0012] There is also a movement to apply Wi-Fi communication methods to mobile devices that move at high speeds. For example, by placing multiple access points along major roads and enabling roaming, mobile communication can be realized at low cost.

[0013] However, the wireless signal output of a Wi-Fi access point is weaker than that of a cellular base station, and its coverage area is narrower. This means that the communication time per access point is short from the perspective of a mobile device. For example, if the communication range of an access point is 100 meters and a vehicle is moving at 72 kilometers per hour, the communication time will be 10 seconds. In such a case, the usual Wi-Fi roaming procedure, which "attempts connection to another access point when the field strength falls below a specified value," cannot ensure sufficient communication time and cannot increase throughput. The communication method in the present disclosure solves this problem.

[0014] A communication method according to one embodiment of the present disclosure includes a first access point capable of communicating with a moving user equipment receiving mobility information relating to the movement of the user equipment from the user equipment in a first frequency band, and the first access point communicating with the user equipment in a second frequency band during a communication period during which communication with the user equipment is possible, determined based on the mobility information.

[0015] The first access point is one of a plurality of access points that can communicate with the user device. The plurality of access points may be, for example, a plurality of roadside devices installed at predetermined intervals along a road.

[0016] The first access point receives mobility information from the user device prior to the start of data communication. The mobility information is information relating to the movement of the user device, and typically includes the current location, moving speed, moving direction, or planned route of the user device. If the user device is mounted on a vehicle, the mobility information may be acquired by a device that controls the autonomous driving of the vehicle or a car navigation device. Such mobility information may be By referring to the mobility information, it becomes possible to estimate how the user device will move in the future. The mobility information may be included in a connection request transmitted from the user device, for example.

[0017] The first access point receives mobility information in a first frequency band. The first frequency band is a sub-frequency band different from a frequency band (second frequency band) in which the access point and the user device mainly perform data communication. Typically, the first frequency band is a frequency band lower than the second frequency band. For example, if the second frequency band is in the gigahertz band, the first frequency may be in the megahertz band. Note that the boundary between the first frequency and the second frequency may be set appropriately within the range of 1 GHz to 5 GHz. For example, if the second frequency band is a frequency band of 5 GHz or higher, the first frequency may be a frequency band below 5 GHz.

[0018] According to this configuration, it is possible to determine a period during which communication between the first access point and the user device is possible based on the mobility information, which means that the first access point can know in advance when the user device will arrive within and leave the communication range of the first access point. In conventional Wi-Fi roaming, a user device needs to determine "which access point to communicate with" based on changes in electric field strength over time, etc. In contrast, in the method disclosed herein, an access point knows the period during which it can communicate with a user device, enabling high-speed roaming.

[0019] The first access point may share the received mobility information with the second access point. For example, a first access point installed along a road may transmit the received mobility information to a plurality of other access points (second access points) installed along the road. With this configuration, each of a plurality of access points that can communicate with the user device can know the period during which communication with the user device is possible.

[0020] The operation of sharing the mobility information may be performed by a center server (information processing device) that manages the first and second access points. For example, the information processing device may acquire the mobility information from the first access point and transmit the acquired mobility information to a second access point.

[0021] The process of calculating the communication available period based on the mobility information may be executed by a center server (information processing device). For example, an information processing device that manages the first and second access points may acquire the mobility information from the first access point, calculate the communication period for each of the first and second access points based on the mobility information, and notify each of the first and second access points of the calculated communication period.

[0022] The mobility information may include at least one of location information and a movement speed of the user device. The mobility information may further include at least one of a moving direction and a planned route of the user equipment. The mobility information is used by each access point to determine a period during which communication between the access point and the user device is possible, and therefore preferably includes information for determining changes in the location of the user device over time. When the mobility information consists of multiple pieces of information, each piece of information does not necessarily use the same protocol. For example, each piece of information may be transmitted in a different protocol corresponding to a different network layer.

[0023] The first frequency band may be a frequency band having a wider communication range than the second frequency band. The first frequency band is a frequency band for sharing mobility information prior to data communication. Therefore, it is preferable to set the first frequency band to a frequency band with a wider communication range than the second frequency band. This makes it possible to quickly obtain and share mobility information. For example, the first frequency band may be a frequency band below 5 GHz, and the second frequency band may be a frequency band above 5 GHz.

[0024] Furthermore, the first access point may further receive authentication information for authenticating the user device in the first frequency band, and transmit the authentication information to an information processing device for authenticating the user device. The first access point may also receive, from the information processing device, authentication result information indicating a result of authentication performed based on the authentication information.

[0025] The information processing device may be a device having a function of authenticating a user device. In this case, the information processing device may provide the result of authenticating the user device to multiple access points including the first access point. This allows each access point to omit the authentication phase, enabling high-speed roaming between multiple access points. The information processing device may not have a function for authenticating the user device. In this case, the information processing device may authenticate the user device using an external authentication device. Even in this case, authentication result information is transmitted from the information processing device to the first access point.

[0026] Specific embodiments of the present disclosure will be described below with reference to the accompanying drawings. Unless otherwise specified, the hardware configuration, module configuration, functional configuration, etc. described in each embodiment are not intended to limit the technical scope of the disclosure to those configurations.

[0027] (First embodiment) [System Overview] An overview of a communication system according to a first embodiment will be described with reference to Fig. 1. The communication system according to this embodiment includes a plurality of roadside devices 20 installed along roads and a control device 30 that controls the plurality of roadside devices 20. The roadside devices 20 are an example of an "access point." In the example of FIG. 1, roadside devices 20A, 20B, and 20C are illustrated, but when there is no need to distinguish between them, they will be collectively referred to as "roadside device 20."

[0028] The communication system according to this embodiment is a system that performs wireless communication according to the communication procedure defined by IEEE802.11. A plurality of roadside devices 20 have a common group address for identifying the group and a local address unique to each device. The group is defined as a mobility domain in the IEEE802.11 standard. It may be a corresponding one. A plurality of roadside devices 20 may belong to a common BSS (Basic Service Set). The on-board device 10, which is a user device, can access any of the roadside devices 20 and be authenticated by using a common identifier such as a group address or BSSID. The authentication result is shared among the multiple roadside devices 20, so that the on-board device 10 can change the roadside device 20 to which it is connected without having to perform the authentication procedure again. Each of the roadside devices 20A, 20B, and 20C has a range within which data communication with the vehicle-mounted device 10 is possible (for example, a radius of about 100 meters, as shown by the dotted line in FIG. 1). While moving, the vehicle-mounted device 10 can connect to and communicate with any of the roadside devices 20. Furthermore, the vehicle-mounted device 10 can switch the roadside device 20 to which it is connected during communication.

[0029] In conventional Wi-Fi roaming, the in-vehicle device 10 determines whether it is necessary to switch the roadside device to which it is connected (i.e., roam) based on the field strength of the radio waves received from the roadside device, etc. However, when the vehicle equipped with the in-vehicle device 10 is moving at high speed, there is often no time to measure the field strength, etc.

[0030] Therefore, in this embodiment, the in-vehicle device 10 transmits information about the movement of the vehicle (mobility information) to the communication system side in advance, and the mobility information is shared among the multiple roadside devices 20. This allows each of the multiple roadside devices 20 to determine the period during which the in-vehicle device 10 is present within the communication range of the respective device. In other words, the communication system side can determine the timing to switch the roadside device 20 to which the vehicle is connected, without measuring the electric field strength or the like on the vehicle side, thereby enabling high-speed roaming to be achieved.

[0031] Furthermore, in the communication system according to this embodiment, each roadside device 20 is configured to be able to communicate with the vehicle-mounted device 10 in two frequency bands, a first frequency band and a second frequency band.

[0032] The second frequency band is a frequency band primarily used for data communications, typically a frequency band above 5 GHz, such as 5 GHz or 60 GHz. While this frequency band allows for high-speed data communications, it has the characteristic of having a relatively short communication range of only a few tens to a few hundred meters. The first frequency band is a frequency band for secondary data communication, and is typically a sub-5 GHz frequency band such as 2.4 GHz. In the sub-5 GHz band, data communication speeds are slower than in frequency bands above 5 GHz (e.g., the 60 GHz band), but the communication range is several times longer (e.g., several hundred meters) than that of the sub-5 GHz frequency band. In the example of Figure 1, the dotted line indicates the communication range of the second frequency band. The communication range of the first frequency band is wider than the range shown by the dotted line.

[0033] In this embodiment, the in-vehicle device 10 has a function of performing primary data communication with the roadside device 20 in the second frequency band and a function of transmitting mobility information to the roadside device 20 in the first frequency band. Because the first frequency band has a wider communication range than the second frequency band, the in-vehicle device 10 can transmit mobility information to the communication system before starting primary data communication. This allows multiple roadside devices 20 included in the communication system to know in advance the time when data communication with the in-vehicle device 10 in the second frequency band will be possible and the time when the data communication should be terminated. For example, in the example of FIG. 1, the roadside device 20A can know at time t0 that data communication in the second frequency band is possible between time t1 and time t2.

[0034] [Hardware configuration] Next, the hardware configuration of each device that constitutes the system will be described. FIG. 2 is a diagram illustrating an example of a hardware configuration of the in-vehicle device 10 that can be mounted in a vehicle.

[0035] The in-vehicle device 10 can be configured as a computer having a processor (CPU, GPU, etc.), a main memory (RAM, ROM, etc.), and an auxiliary memory (EPROM, hard disk drive, removable media, etc.). The auxiliary memory stores an operating system (OS), various programs, various tables, etc., and the programs stored therein are By executing the program, various functions (software modules) that meet specific purposes, as described below, can be realized. However, some or all of the functions may be realized as hardware modules using hardware circuits such as ASICs, FPGAs, etc.

[0036] The in-vehicle device 10 includes a control unit 101 , a storage unit 102 , a communication unit 103 , a location information acquisition unit 104 , and an input / output unit 105 .

[0037] The control unit 101 is a computing unit that executes predetermined programs to realize various functions of the in-vehicle device 10. The control unit 101 can be realized by, for example, a hardware processor such as a CPU. The control unit 101 may also be configured to include a RAM, a ROM (Read Only Memory), a cache memory, and the like.

[0038] The storage unit 102 is a means for storing information, and is configured with storage media such as RAM, a magnetic disk, a flash memory, etc. The storage unit 102 stores programs executed by the control unit 101, data used by the programs, etc.

[0039] The communication unit 103 is a wireless communication interface for transmitting and receiving wireless signals. The communication unit 103 is configured to be able to transmit and receive wireless signals that comply with standards such as wireless LAN. Furthermore, the communication unit 103 can transmit and receive these wireless signals in two different frequency bands. In this embodiment, the communication unit 103 can transmit and receive wireless signals in two frequency bands: a frequency band below 5 GHz (first frequency band) and a frequency band above 5 GHz (second frequency band).

[0040] The position information acquisition unit 104 acquires the position information of the vehicle 1. The position information acquisition unit 104 includes a GPS antenna and a positioning module for determining the position information. The GPS antenna is an antenna that receives positioning signals transmitted from positioning satellites (also referred to as GNSS satellites). The positioning module is a module that calculates the position information based on the signals received by the GPS antenna. The position information acquisition unit 104 may determine the traveling direction of the vehicle 1 based on the transition of the position information.

[0041] The input / output unit 105 is a unit that receives input from vehicle occupants and presents information to them. Specifically, the input / output unit 105 is composed of a touch panel and its control means, and a liquid crystal display and its control means. In this embodiment, the touch panel and the liquid crystal display are combined into one touch panel display.

[0042] Next, a description will be given of the hardware configuration of the roadside device 20. FIG.

[0043] Similar to the vehicle-mounted device 10, the roadside device 20 can be configured as a computer having a processor (CPU, GPU, etc.), a main memory device (RAM, ROM, etc.), and an auxiliary memory device (EPROM, hard disk drive, removable media, etc.).

[0044] The roadside device 20 includes a control unit 201 , a storage unit 202 , a first communication unit 203 , and a second communication unit 204 .

[0045] The control unit 201 is a calculation unit that executes predetermined programs to realize various functions of the roadside device 20. The control unit 201 can be realized by a hardware processor such as a CPU. The control unit 201 may also be configured to include RAM, ROM (Read Only Memory), cache memory, etc.

[0046] The storage unit 202 is a means for storing information, and is configured with storage media such as RAM, a magnetic disk, a flash memory, etc. The storage unit 202 stores programs executed by the control unit 201, data used by the programs, etc.

[0047] The first communication unit 203 is a wireless communication interface for transmitting and receiving wireless signals to and from the in-vehicle device 10. The first communication unit 203 is configured to be able to transmit and receive wireless signals that comply with standards such as wireless LAN. Like the communication unit 103, the first communication unit 203 can transmit and receive these wireless signals in two different frequency bands.

[0048] The second communication unit 204 is a communication interface for communicating with the control device 30. The second communication unit 204 may be a wireless communication interface or a wired communication interface.

[0049] Next, a description will be given of the hardware configuration of the control device 30. Fig. 4 is a diagram showing a schematic diagram of an example of the hardware configuration of the control device 30.

[0050] Like the roadside device 20, the control device 30 can be configured as a computer having a processor (CPU, GPU, etc.), a main memory device (RAM, ROM, etc.), and an auxiliary memory device (EPROM, hard disk drive, removable media, etc.).

[0051] The control device 30 includes a control unit 301 , a storage unit 302 , and a communication unit 303 .

[0052] The control unit 301 is a computing unit that executes predetermined programs to realize various functions of the control device 30. The control unit 301 can be realized by a hardware processor such as a CPU. The control unit 301 may also be configured to include RAM, ROM (Read Only Memory), cache memory, etc.

[0053] The storage unit 302 is a means for storing information, and is configured with storage media such as RAM, a magnetic disk, a flash memory, etc. The storage unit 302 stores programs executed by the control unit 301, data used by the programs, etc.

[0054] The communication unit 303 is a communication interface for communicating with the roadside device 20 . The second communication unit 204 may be a wireless communication interface or a wired communication interface.

[0055] In this embodiment, the control device 30 is an independent computer, but the control device 30 may be virtually implemented as a logical entity. For example, a plurality of roadside devices 20 may execute the processing performed by the control device 30 described in this specification in a distributed manner. In this case, the plurality of roadside devices 20 fulfill the role of the control device 30 in this embodiment. In this case, the control unit 301 may also function as the control unit 201, the storage unit 302 may also function as the storage unit 202, and the communication unit 303 may also function as the second communication unit 204. Furthermore, if there is a device that connects a plurality of roadside devices 20 to each other, a virtual control device 30 may be implemented on that device.

[0056] [Software configuration] Next, the software configuration of each device constituting the system will be described. Fig. 5 is a diagram showing a schematic software configuration of the in-vehicle device 10 according to this embodiment. The hardware configuration of the in-vehicle device 10 is as shown in Fig. 2.

[0057] In this embodiment, the control unit 101 of the in-vehicle device 10 is configured to have two software modules: a mobility information generation unit 1011 and a communication control unit 1012. Each software module may be realized by the control unit 101 (CPU, etc.) executing a program stored in the storage unit 102. Note that the information processing executed by the software module is synonymous with the information processing executed by the control unit 101 (CPU, etc.).

[0058] The mobility information generation unit 1011 generates mobility information to be transmitted to the communication system. In this embodiment, the mobility information includes at least one of information regarding the current position, moving speed, traveling direction, and planned route of the vehicle in which the on-vehicle device 10 is installed. The mobility information generation unit 1011 may acquire this information from a computer (e.g., ECU) that controls the driving of the vehicle, a navigation device, or a user terminal associated with the occupant. The mobility information generation unit 1011 may also acquire this information based on the time-varying change in the position information acquired by the position information acquisition unit 104. The mobility information is transmitted to the roadside device 20 constituting the communication system via a communication control unit 1012, which will be described later.

[0059] The communication control unit 1012 executes two types of processing: (1) a process of requesting the communication system to start communication and performing a handshake, and (2) a process of establishing a connection with one of the multiple roadside devices 20 and transmitting and receiving data (including roaming).

[0060] First, the communication control unit 1012 executes a step of detecting the presence of the roadside unit 20 included in the communication system and requesting a connection to the communication system. In this step, the communication control unit 1012 receives a beacon signal transmitted from the roadside unit 20, and in response to this, executes an authentication procedure using pre-stored authentication information. The authentication information is, for example, an identifier for uniquely identifying the on-vehicle device 10, a key used when connecting the on-vehicle device 10 to a communication system, or an electronic certificate. Note that the authentication information stored in the on-vehicle device 10 may be different from the authentication information transmitted to the roadside device 20. For example, if a private key is stored in the on-vehicle device 10, a hash generated based on the private key may be transmitted to the roadside device 20. This allows a handshake to be performed between the in-vehicle device 10 and the communication system.

[0061] Second, the communication control unit 1012 establishes a connection between the in-vehicle device 10 and the roadside device 20, transmits and receives data, and, if necessary, switches the connection destination (roaming) between other roadside devices 20. A specific control method will be described later.

[0062] Next, a description will be given of the software configuration of the roadside device 20. Fig. 6 is a diagram schematically showing the software configuration of the roadside device 20 according to this embodiment. The hardware configuration of the roadside device 20 is as shown in Fig. 3.

[0063] In this embodiment, the control unit 201 of the roadside device 20 is configured to have a software module of a communication control unit 2011. The software module may be realized by the control unit 201 (CPU, etc.) executing a program stored in the storage unit 202. Note that the information processing executed by the software module is synonymous with the information processing executed by the control unit 201 (CPU, etc.).

[0064] The communication control unit 2011 communicates with the in-vehicle device 10 based on information acquired from the control device 30, which will be described later. Specifically, the communication control unit 2011 performs the following processes.

[0065] (1) A process of receiving a request to start communication from the in-vehicle device 10 and having the control device 30 perform authentication. The communication control unit 2011 receives data (hereinafter referred to as a start request) for requesting a handshake with the communication system from the in-vehicle device 10, and transfers the start request to the control device 30. As a result, the control device 30 authenticates the in-vehicle device 10. Note that if the control device 30 does not have an authentication function, the control device 30 may authenticate the in-vehicle device 10 using an external authentication device.

[0066] (2) Processing for receiving authentication results from the control device 30 The communication control unit 2011 receives the result of authentication of the in-vehicle device 10 from the control device 30. The authentication result is transmitted from the control device 30 to all roadside devices 20 included in the communication system. If the control device 30 successfully authenticates the in-vehicle device 10, all roadside devices 20 can confirm the authenticity of the in-vehicle device 10.

[0067] (3) Processing for receiving mobility information from the in-vehicle device 10 and transferring it to the control device 30 The communication control unit 2011 receives the mobility information from the in-vehicle device 10 that has transmitted the start request, and transfers the mobility information to the control device 30. As a result, the control device 30 allows the plurality of roadside devices 20 to share the mobility information.

[0068] (4) Processing for receiving mobility information from the control device 30 If the device itself (roadside device 20) does not receive the start request directly from the vehicle-mounted device 10 (i.e., if another roadside device 20 included in the communication system receives the start request), the communication control unit 2011 receives the mobility information transmitted by the control device 30.

[0069] (5) Processing for communicating with the in-vehicle device 10 based on the acquired mobility information The communication control unit 2011 calculates a period during which communication with the in-vehicle device 10 is possible based on the acquired mobility information, and establishes communication with the in-vehicle device 10 during that period. The mobility information may be received directly from the in-vehicle device 10, or may be transmitted from the control device 30 (that is, shared throughout the entire communication system). A specific control method will be described later.

[0070] Next, the software configuration of the control device 30 will be described. FIG. 7 is a diagram schematically showing the software configuration of the control device 30 according to this embodiment. The hardware configuration of the control device 30 is as shown in FIG.

[0071] In this embodiment, the control unit 301 included in the control device 30 is configured to have two software modules: an authentication unit 3011 and an information sharing unit 3012. Each software module may be realized by executing a program stored in the storage unit 302 by the control unit 301 (CPU, etc.). The information processing executed by the software module is synonymous with the information processing executed by the control unit 301 (CPU, etc.).

[0072] The authentication unit 3011 authenticates the on-vehicle device 10 based on authentication information acquired from the on-vehicle device 10 via the roadside device 20. The authentication unit 3011 may perform authentication using, for example, a PSK (Pre-Shared Key). In this case, the authentication information is a key generated based on a passphrase. The authentication unit 3011 may also perform, for example, IEEE802.1x authentication. In this case, the authentication information may be a username and password combination or a digital certificate.

[0073] It is also possible that the control device 30 does not have an authentication function. In this case, the authentication unit 3011 may relay the acquired authentication information to an external authentication device, causing the external authentication device to authenticate the in-vehicle device 10.

[0074] When mobility information corresponding to the vehicle-mounted device 10 is transmitted from a roadside device 20 included in the communication system, the information sharing unit 3012 transmits the mobility information to other roadside devices 20 included in the same communication system (e.g., having the same group address). Furthermore, the information sharing unit 3012 transmits the result of the authentication performed by the authentication unit 3011 to other roadside units 20 that belong to the same communication system. As a result, mobility information and authentication results are shared for the in-vehicle unit 10 that is newly connected to the communication system.

[0075] [Processing flowchart] Next, the flow of processing in communication will be described. Fig. 8 is a diagram illustrating the phases of processing executed by the in-vehicle device 10, the roadside device 20, and the control device 30 according to this embodiment. In this embodiment, communication is carried out in three phases.

[0076] The first phase (P1) is a phase (detection phase) in which the on-vehicle device 10 recognizes the presence of the roadside device 20 and performs a handshake with the communication system. In the detection phase, the on-vehicle device 10 receives a beacon signal transmitted from the roadside device 20, and in response transmits data (start request) to request a handshake to the communication system. Data transmission and reception in this phase is performed in the first frequency band. The roadside device 20 that has received the start request performs authentication of the in-vehicle device 10 via the control device 30, and receives mobility information from the in-vehicle device 10. The authentication result and the mobility information are shared with the other roadside devices 20 included in the communication system via the control device 30.

[0077] Each of the roadside devices 20 recognizes that the vehicle-mounted device 10 has been authenticated by the system based on the acquired authentication result. Furthermore, each of the roadside devices 20 calculates a period during which communication with the vehicle-mounted device 10 is possible based on the acquired mobility information.

[0078] The next phase (P2) is a phase in which data is transmitted and received between the in-vehicle device 10 and the roadside device 20. As described above, in the detection phase, each roadside device 20 can grasp the period during which communication with the in-vehicle device 10 is possible. In this phase, first, the in-vehicle device 10 broadcasts a request to transmit data (hereinafter referred to as a transmission request). Next, the roadside devices 20 that can communicate with the in-vehicle device 10 (in other words, within the communication period) respond to the request and transmit and receive data. When the communication period has elapsed, the roadside devices 20 transmit a notification to the in-vehicle device 10 that the communication will be terminated.

[0079] When the communication available period has elapsed, the process moves to a phase (P3) in which it is determined whether roaming is available. In this phase, the vehicle-mounted device 10 broadcasts a transmission request again. Of the roadside devices 20 that received the transmission request, roadside devices 20 that are capable of taking over communication (roaming) (i.e., roadside devices 20 that will soon enter a period in which communication with the vehicle-mounted device 10 is available) respond to the request and take over communication. If there are no roadside devices 20 that are capable of roaming, the communication ends.

[0080] Next, the processes executed by each device in each of the above-mentioned phases will be specifically described. . 9 is a sequence diagram of data transmitted and received during the detection phase among the in-vehicle device 10, the roadside device 20, and the control device 30. In this example, the device with which the in-vehicle device 10 first communicates is the roadside device 20A, and the device that takes over the communication is the roadside device 20B.

[0081] First, the in-vehicle device 10 (communication control unit 1012) receives a beacon frame. The beacon frame is data broadcast by the roadside device 20 in the first frequency band to announce its own presence. When the on-vehicle device 10 receives the beacon frame from the roadside device 20A, in step S11, the on-vehicle device 10 generates a start request. The start request is data requesting a handshake with the communication system. The generated start request is transmitted to the roadside device 20A by a radio signal in the first frequency band.

[0082] When the roadside device 20A receives the start request, the roadside device 20A (communication control unit 2011) proceeds to a step (step S12) of authenticating the on-vehicle device 10. In step S12, information for performing authentication is exchanged between the on-vehicle device 10 and the control device 30. The roadside device 20A relays this information to the control device 30. The control device 30 (authentication unit 3011) authenticates the on-vehicle device 10 based on the authentication information received from the on-vehicle device 10. The authentication may be performed by, for example, PSK (Pre-Shared Key) or IEEE802.1x authentication. The authentication may be performed by the control device 30, or may be performed by an external authentication device upon request from the control device 30. When the authentication is successfully completed, a notification to that effect (authentication completion notification) is transmitted to the vehicle-mounted device 10 via the roadside device 20A.

[0083] Next, in step S13, the control device 30 executes a process of sharing the result of authenticating the in-vehicle device 10 with multiple roadside devices 20 included in the communication system. In this step, the control device 30 (information sharing unit 3012) transmits the result of the authentication executed in step S12 to roadside devices 20 belonging to the same communication system (for example, roadside devices 20 having the same group address as the roadside device 20A). As a result, the authentication result of the in-vehicle device 10 is shared by all roadside devices 20 that are capable of roaming. This eliminates the need for each roadside device 20 to individually authenticate the in-vehicle device 10.

[0084] The in-vehicle device 10 (mobility information generation unit 1011) that has received the authentication completion notification generates mobility information (step S14). In this embodiment, the mobility information includes the current location, moving speed, and moving direction of the vehicle in which the in-vehicle device 10 is installed. The mobility information generation unit 1011 may acquire this information from components (e.g., a vehicle speed sensor, a gyro, an engine ECU, a body ECU, etc.) that the vehicle 1 has. The generated mobility information is transmitted to the roadside device 20A.

[0085] Next, in step S15, the roadside device 20A executes a process for sharing the mobility information received from the in-vehicle device 10 with multiple roadside devices 20 included in the communication system. In this step, the roadside device 20A transmits the mobility information received from the in-vehicle device 10 to the control device 30, and the control device 30 (information sharing unit 3012) transmits the mobility information to roadside devices 20 that belong to the same communication system (have the same ESS-ID). As a result, the mobility information transmitted from the in-vehicle device 10 is shared by all roadside devices 20 that are capable of roaming. When this step is completed, the roadside device 20A transmits to the vehicle-mounted device 10 a notification that the handshake has been completed.

[0086] In step S16, each roadside device 20 (communication control unit 2011) that has acquired the mobility information calculates a period during which communication with the in-vehicle device 10 is possible. The roadside device 20 calculates a period during which communication between the in-vehicle device 10 and the roadside device 20 itself is possible based on, for example, the current position, speed, moving direction, position, and communication range of the in-vehicle device 10. The calculation result is held in each roadside device 20 until communication with the in-vehicle device 10 is terminated.

[0087] Data exchange in the above process is performed in a first frequency band. The first frequency band is a frequency band lower than a frequency band (second frequency band) for main data communication. Generally, as the frequency of radio waves becomes lower, the communication range becomes wider due to diffraction attenuation characteristics. Therefore, the communication system completes authentication of the in-vehicle device 10 before the in-vehicle device 10 enters the communication range of the second frequency band, and the mobility information thereof can be shared.

[0088] 10 is a sequence diagram of data transmitted and received between the in-vehicle device 10, the roadside device 20, and the control device 30 in the transmission / reception phase (and the roaming determination phase). The illustrated process is repeatedly executed from the completion of a handshake between the in-vehicle device 10 and the communication system until the completion of communication. In this example, data is transmitted from the in-vehicle device 10 to the communication system.

[0089] First, the on-vehicle device 10 generates a transmission request (step S21). The transmission request is data broadcast from the on-vehicle device 10 to search for a connectable roadside device 20 after the handshake between the on-vehicle device 10 and the communication system is completed. The transmission request is transmitted in the second frequency band.

[0090] The transmission request is received by the roadside device 20 (here, the roadside device 20A) that is closest to the vehicle-mounted device 10. Note that step S21A is not essential and will be described later.

[0091] Upon receiving the transmission request, the roadside unit 20A generates a response for starting communication (step S22). In this embodiment, the response includes the following information: - Identifier of the own device (roadside device) Location information of your device Mobility information held by the device itself The communication period determined based on the mobility information The communication available period may be expressed by, for example, time. By referring to the response, the on-vehicle device 10 can grasp the period during which communication between the on-vehicle device 10 and the roadside device 20A is available.

[0092] The vehicle-mounted device 10 that has received the response generates data (transmission data) to be transmitted to the communication system (step S23). When the communication available period indicated by the roadside device 20A arrives, the transmission data is transmitted from the vehicle-mounted device 10 (communication control unit 1012) and received by the roadside device 20A (communication control unit 2011). The roadside device 20A (communication control unit 2011) may sequentially transfer the received data to the control device 30 or a gateway to the external network.

[0093] While receiving data, the roadside device 20A periodically determines whether the communication period has elapsed (step S24). If the communication period has not elapsed, the roadside device 20A continues receiving data. If the communication period has elapsed, the roadside device 20A completes the data reception and transmits an acknowledgment (Block Ack) to the in-vehicle device 10. Upon receiving the acknowledgment, the vehicle-mounted device 10 determines that communication with the roadside device 20A has ended. The in-vehicle device 10 recognizes this and executes a process to complete the data transmission (step S25). In this step, the in-vehicle device 10 distinguishes, for example, between blocks for which data transmission has been completed and blocks for which data transmission has not yet been completed.

[0094] When the process of step S25 is completed and unsent data remains, the in-vehicle device 10 restarts the process shown in FIG. 10. That is, the in-vehicle device 10 generates a new transmission request and broadcasts it. In the example of FIG. 1, when communication with the roadside device 20A ends, communication with the roadside device 20B becomes possible next. In this case, the transmission request is received by the roadside device 20B that is next available for communication, and the roadside device 20B transmits a response to the in-vehicle device 10. In this way, the multiple roadside devices 20 communicate with the in-vehicle device 10 in sequence.

[0095] As described above, the communication system according to the first embodiment acquires mobility information from the in-vehicle device 10 using the first frequency band, and shares this information among the plurality of roadside devices 20. Furthermore, each of the plurality of roadside devices 20 determines a period during which communication with the in-vehicle device 10 is possible, based on the mobility information. In this way, by calculating the communication possible period in advance by the plurality of roadside devices 20, high-speed roaming becomes possible.

[0096] 10, the roadside device 20 determines that the communication enabled period has elapsed (step S24), but this determination may also be made by the vehicle-mounted device 10. In this case, the vehicle-mounted device 10 may notify the roadside device 20 that the communication enabled period has elapsed (or will soon elapse), and the roadside device 20 may respond by ending data reception and returning an acknowledgement.

[0097] (Modification of the first embodiment) Depending on the positional relationship between the vehicle and the roadside devices 20, the transmission request may be received by multiple roadside devices 20. For example, the transmission request may be received by both roadside devices 20A and 20B. In this case, each roadside device may generate a response and transmit it individually to the in-vehicle device 10. Even in this case, since the communication available period for each roadside device 20 is different, the in-vehicle device 10 can communicate with each roadside device 20 in turn. If the communication available periods overlap, the in-vehicle device 10 may switch the roadside device 20 to which it is connected at an appropriate timing.

[0098] Furthermore, in consideration of the fact that a plurality of roadside devices 20 may simultaneously receive a transmission request, a step (step S21A in FIG. 10) of determining which roadside device 20 should respond to the vehicle-mounted device 10 may be executed on the communication system side. In this step, for example, each of the plurality of roadside devices 20 that have received the transmission request may inquire of the control device 30, and the control device 30 may determine whether it is OK to respond to the vehicle-mounted device 10, and if a plurality of roadside devices 20 have received the transmission request, which roadside device 20 should respond (or in what order they should respond). For example, the control device 30 may determine the order in which the multiple roadside devices 20 should respond based on mobility information and the locations of the multiple roadside devices 20, and instruct each roadside device 20 on the result of the determination.

[0099] (Second embodiment) In the first embodiment, the mobility information transmitted from the in-vehicle device 10 is shared by each roadside device 20, and each roadside device 20 calculates the communication possible period with the in-vehicle device 10 based on the mobility information. On the other hand, the process of calculating the communication possible period may be executed by the control device 30. In the second embodiment, the control device 10 controls the vehicle based on the mobility information transmitted from the vehicle-mounted device 10. In this embodiment, the device 30 calculates the communication available period for each roadside device 20 and notifies each roadside device 20 of the calculated communication available period.

[0100] FIG. 11 is a sequence diagram of transmitted and received data in the second embodiment. The processing up to step S14 is the same as in the first embodiment, and therefore a description thereof will be omitted.

[0101] In this embodiment, the roadside device 20A receives mobility information from the in-vehicle device 10 and transfers it to the control device 30. The control device 30 calculates a period during which communication between each roadside device 20 and the in-vehicle device 10 is possible based on the received mobility information and the installation positions of the multiple roadside devices 20. The calculation result is transmitted to each roadside device 20 and temporarily stored in each roadside device 20. In this way, the period during which each roadside device 20 can communicate with the vehicle-mounted device 10 may be determined by the control device 30.

[0102] In the present embodiment, the control device 30 notifies each roadside device 20 of the communication available period individually, but the control device 30 may generate an overall roaming plan based on the mobility information and share this with all. The roaming plan may include the order and times (communication start time, communication end time) in which the in-vehicle device 10 connects to each roadside device 20. In this case, the control device 30 may transmit the generated roaming plan to each roadside device 20, and each roadside device 20 may connect to the in-vehicle device 10 in accordance with the plan. In this case, each roadside device 20 may report its status to the control device 30 when roaming occurs.

[0103] (Variation) The above-described embodiment is merely an example, and the present disclosure can be modified and implemented as appropriate within the scope that does not deviate from the gist of the disclosure. For example, the processes and means described in this disclosure can be freely combined and implemented as long as no technical contradiction occurs.

[0104] In addition, in the embodiment, an example has been given in which data is transmitted (uploaded) from the in-vehicle device 10 to the communication system, but the direction of communication is not limited to this. Data can also be transmitted from the communication system to the in-vehicle device 10, and data can also be freely transmitted and received within a communication enabled period.

[0105] In addition, in the embodiment, the first frequency band is a frequency band below 5 GHz and the second frequency band is a frequency band above 5 GHz, but other frequency bands may also be used.

[0106] In the embodiment, the current location, moving speed, traveling direction, and planned route of the vehicle are transmitted as mobility information, but these pieces of information do not necessarily need to be transmitted using the same protocol. For example, the current location and moving speed may be transmitted using a first protocol, and the traveling direction and planned route may be transmitted using a second protocol. Furthermore, the first protocol and the second protocol do not necessarily need to correspond to the same network layer. For example, the first protocol may be a protocol corresponding to the physical layer or MAC layer, and the second protocol may be a protocol corresponding to the application layer. The mobility information may also include information (received data, etc.) obtained by communication with a GPS satellite.

[0107] In addition, the processing described as being performed by one device may be shared and executed by multiple devices. Alternatively, processes that have been described as being performed by different devices may be executed by a single device. In a computer system, the hardware configuration (server configuration) by which each function is realized can be flexibly changed.

[0108] The present disclosure can also be realized by providing a computer program implementing the functions described in the above embodiments to a computer, and having one or more processors in the computer read and execute the program. Such a computer program may be provided to the computer via a non-transitory computer-readable storage medium connectable to the computer's system bus or via a network. Non-transitory computer-readable storage media include, for example, any type of disk, such as a magnetic disk (e.g., a floppy disk, a hard disk drive (HDD), etc.), an optical disk (e.g., a CD-ROM, a DVD disk, a Blu-ray disk), a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic card, a flash memory, an optical card, or any type of medium suitable for storing electronic instructions. [Explanation of symbols]

[0109] 10...In-vehicle equipment 20...Roadside equipment 30. Control device 101, 201, 301...Control unit 102,202,302...Storage section 103,303···Communications Department 203···1st Communications Department 204···Second Communications Department 104...Location information acquisition unit 105...Input / output section

Claims

1. a first access point capable of communicating with a moving user equipment receiving mobility information relating to movement of the user equipment from the user equipment in a first frequency band; The first access point communicates with the user equipment in a second frequency band during a communication enabled period in which communication with the user equipment is possible, the communication enabled period being determined based on the mobility information; and A communication method that performs the following.

2. the first access point shares the received mobility information with a second access point; The communication method according to claim 1 .

3. The mobility information includes at least one of location information of the user device and a moving speed of the user device. The communication method according to claim 1 .

4. The mobility information further includes at least one of a moving direction of the user device and a planned route of the user device. The communication method according to claim 3 .

5. the first frequency band is a frequency band below 5 GHz; The second frequency band is a frequency band of 5 GHz or higher. The communication method according to claim 1 .

6. The first frequency band is a frequency band having a wider communication range than the second frequency band. The communication method according to claim 1 .

7. the first access point further receives authentication information for authenticating the user device in the first frequency band, and transmits the authentication information to an information processing device for authenticating the user device; The communication method according to claim 1 .

8. The first access point: receiving, from the information processing device, authentication result information representing a result of authentication performed based on the authentication information; The communication method according to claim 7.

9. A communication method performed by a first access point and a second access point capable of communicating with a mobile user device, the method comprising: receiving, by the first access point, mobility information relating to movement of the user equipment from the user equipment over a first frequency band; the first access point sharing the mobility information with the second access point; The second access point communicates with the user equipment in a second frequency band during a communication available period in which communication with the user equipment is available, the communication period being determined based on the mobility information; and A communication method, including:

10. The second access point determines whether or not the second access point is a mobile station. Calculating the period during which communication with the device is possible; The communication method according to claim 9.

11. The first access point: transmitting the mobility information to the second access point via a predetermined information processing device; The communication method according to claim 9.

12. The mobility information includes at least one of location information of the user device and a moving speed of the user device. The communication method according to claim 9.

13. The mobility information further includes at least one of a moving direction of the user device and a planned route of the user device. The communication method according to claim 12.

14. the first frequency band is a frequency band below 5 GHz; The second frequency band is a frequency band of 5 GHz or higher. The communication method according to claim 9.

15. The first frequency band is a frequency band having a wider communication range than the second frequency band. The communication method according to claim 9.

16. the first access point further receives authentication information for authenticating the user device in the first frequency band, and transmits the authentication information to an information processing device for authenticating the user device; The communication method according to claim 9.

17. the first and second access points receive, from the information processing device, authentication result information representing a result of authenticating the user device; 17. The communication method of claim 16.

18. when the communication enabled period arrives, the first and second access points start communication with the user device without authenticating the user device based on the authentication result information.

18. The communication method of claim 17.

19. An information processing method executed by an information processing device capable of communicating with a first and a second access point, comprising: Obtaining mobility information regarding movement of a user equipment, the mobility information being received by a first access point; transmitting, to the first and second access points, information for determining a communication available period during which communication with the user device is possible based on the acquired mobility information; An information processing method, including:

20. calculating the communication available period for each of the first and second access points based on the mobility information, and transmitting information relating to the calculated communication available period to each of the first and second access points; 20. The information processing method according to claim 19.

21. acquiring authentication information for authenticating the user device from the first access point, and transmitting information representing a result of authentication performed based on the authentication information to each of the first and second access points; 20. The information processing method according to claim 19.

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