WO2024075317A1 - Wireless communication system, user terminal, and wireless communication method - Google Patents

Abstract

[Problem] To stably ensure good communication between a user terminal and a base station even under a condition where degradation in communication quality arises due to a change in the orientation of a mobile body or due to shielding. [Solution] In a wireless communication system in which wireless communication takes place between a user terminal 7 mounted on an automobile V1 as a mobile body capable of moving on a road and an access point 4, the user terminal performs wireless communication with the access point by means of directional communication units 78, 79 that are capable of controlling directionality. In a case where the automobile having the user terminal mounted thereon changes the orientation thereof, for example, in a case of making a right or left turn at an intersection, the user terminal performs control on the directionality of the directional communication unit so as to improve the quality of communication with the access point. Specifically, the user terminal performs control on the directional communication unit so that the width and/or the direction of an area covered by the directional communication unit of the user terminal is caused to change. In addition, the user terminal comprises: a forward directional communication unit 78 that has a forward directionality; and a rearward directional communication unit 79 that has a rearward directionality.

Description

Wireless communication system, user terminal, and communication control method

The present disclosure relates to a wireless communication system in which a user terminal mounted on a mobile object capable of moving on roads and a base station perform wireless communication, a user terminal mounted on a mobile object capable of moving on roads and performing wireless communication with a base station, and a communication control method for controlling wireless communication with a base station in a user terminal mounted on a mobile object capable of moving on roads.

In the field of mobile networks, 5G (fifth generation mobile communications system) is at the stage of commercialization. With 5G, higher frequencies will be used and the service area of each base station will be smaller, making it necessary to place base stations more densely. For this reason, it is conceivable to build a backhaul line network using wireless multi-hop communication between multiple base stations.

A known technology for constructing a backhaul line network using such multi-hop communication is one in which base stations are grouped, wireless communication paths are constructed using multi-hop communication between base stations belonging to the same group, and edge servers are arranged corresponding to the base station groups (see Patent Document 1). Also known is a technology in which a communication terminal mounted on a moving object (such as a train) is equipped with a communication unit that has directionality in the direction of movement, and selects a communication destination based on the radio wave strength of the communication destination (see Patent Document 2).

JP 2021-57738 A JP 2009-188983 A

The technology disclosed in Patent Document 1 appropriately constructs wireless communication paths used for communication between edge servers and user terminals in a network in which the edge servers are located. In addition, the technology disclosed in Patent Document 2 can prevent interruptions in wireless communication when switching base stations.

On the other hand, for user terminals mounted on mobile objects that can move on roads, particularly automobiles traveling at relatively high speeds, the conditions of the mobile object itself change rapidly, and the conditions around the mobile object also change rapidly. For this reason, it is desirable to ensure good communication between the user terminal mounted on the mobile object and its surrounding base stations without being affected by changes in the conditions of the mobile object or its surroundings. Furthermore, the millimeter wave communication used in 5G has a narrow coverage area (beam), so changes in the orientation of the mobile object significantly degrade the communication quality. Furthermore, the millimeter waves used in 5G are vulnerable to obstruction due to their strong tendency to travel in a straight line, and obstruction significantly degrades the communication quality. However, conventional technology cannot adequately solve these problems.

The main objective of the present invention is to provide a wireless communication system, a user terminal, and a communication control method that can stably ensure good communication between a user terminal and a base station even in situations where communication quality deteriorates due to changes in the orientation of a moving object or due to obstruction.

The wireless communication system of the present invention is a wireless communication system in which a user terminal mounted on a mobile object capable of moving on roads and a base station perform wireless communication, and the user terminal is configured to include a directional communication unit capable of controlling directivity while performing wireless communication with the base station, and a control unit that controls the directivity of the directional communication unit so as to improve the quality of communication with the base station when the mobile object on which the user terminal is mounted changes direction.

The user terminal of the present invention is mounted on a mobile body that can move on roads and performs wireless communication with a base station, and is configured to include a directional communication unit that performs wireless communication with the base station and is capable of controlling directivity, and a control unit that controls the directivity of the directional communication unit so as to improve the quality of communication with the base station when the mobile body on which the device is mounted changes direction.

The communication control method of the present invention is a communication control method for controlling wireless communication with a base station in a user terminal mounted on a mobile object capable of moving on a road, and the control unit of the user terminal is configured to control the directivity of the directional communication unit so as to improve the quality of communication with the base station when the mobile object on which the user terminal is mounted changes its orientation.

The present invention can prevent communication quality between a user terminal and a base station from deteriorating and causing communication interruptions due to changes in the orientation of a mobile body carrying the user terminal, and can ensure stable, good communication between the user terminal and the base station.

Overall configuration diagram of a wireless communication system according to a first embodiment FIG. 1 is an explanatory diagram showing an example of control of a communication path between a user terminal and an edge server by a network control server; Block diagram showing the schematic configuration of an access point Block diagram showing the schematic configuration of an edge server A block diagram showing the schematic configuration of a network control server. A block diagram showing a schematic configuration of a user terminal. FIG. 1 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a first embodiment; FIG. 1 is a flow chart showing the flow of processing performed by a user terminal 7. FIG. 13 is a block diagram showing a schematic configuration of an access point according to a second embodiment. FIG. 11 is a block diagram showing a schematic configuration of a user terminal according to a second embodiment. FIG. 11 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a second embodiment; FIG. 11 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a second embodiment; FIG. 1 is a flow chart showing the flow of processing performed by a user terminal 7. FIG. 13 is an explanatory diagram showing a state of communication control of an access point according to a modification of the second embodiment; FIG. 13 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a third embodiment. FIG. 13 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a third embodiment. A flow chart showing the flow of processing performed on a user terminal. FIG. 13 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a fourth embodiment. FIG. 13 is an explanatory diagram showing an overview of communication control performed in a wireless communication system according to a fourth embodiment. FIG. 13 is an explanatory diagram showing an overview of a coverage area of an access point according to a fifth embodiment; FIG. 13 is an explanatory diagram showing an overview of a coverage area of an access point according to a fifth embodiment; FIG. 1 is an explanatory diagram showing a transition state of communication between a user terminal and an access point;

The first invention made to solve the above problem is a wireless communication system in which a user terminal mounted on a mobile object capable of moving on roads and a base station perform wireless communication, the user terminal being configured to include a directional communication unit capable of controlling directivity while performing wireless communication with the base station, and a control unit that controls the directivity of the directional communication unit so as to improve the quality of communication with the base station when the mobile object on which the user terminal is mounted changes direction.

This prevents communication quality between the user terminal and the base station from deteriorating and causing communication interruptions due to changes in the orientation of the mobile body carrying the user terminal, and ensures stable, good communication between the user terminal and the base station.

In addition, in the second invention, the user terminal is mounted on a vehicle as the moving body, and the control unit of the user terminal is configured to control the directivity of the directional communication unit when the vehicle in which the device is mounted makes a right or left turn at an intersection.

As a result, when a vehicle equipped with a user terminal makes a right or left turn at an intersection, good and stable communication between the user terminal and the base station can be ensured.

In addition, the third invention is configured such that the control unit of the user terminal controls the directional communication unit so as to change at least one of the width and direction of the coverage area of the directional communication unit of the user terminal.

By doing this, the directivity of the directional communication unit can be appropriately controlled, and good communication between the user terminal and the base station can be stably ensured. Note that the control of the directivity of the directional communication unit can be performed by beamforming, but the directivity of the directional communication unit may also be controlled mechanically.

In addition, in the fourth invention, the user terminal is configured to include a forward directional communication unit having forward directivity and a backward directional communication unit having backward directivity.

As a result, coverage areas (areas where good communication quality can be obtained) are formed at the front and rear, so that good communication between the user terminal and the base station can be stably ensured by using the base station located at the front or the base station located at the rear depending on the situation.

In addition, in the fifth invention, the base station has a directional communication unit that has directivity toward the upstream side of the lane.

This creates a coverage area on the upstream side of the lane, ensuring stable and good communication between the user terminal and the base station.

In addition, in the sixth invention, the base station has an upstream directional communication unit that has directivity on the upstream side of the lane, and a downstream directional communication unit that has directivity on the downstream side of the lane.

This creates coverage areas on both the upstream and downstream sides of the lane, ensuring good and stable communication between user terminals and the base station.

In addition, the seventh invention is configured such that the base station forms its own coverage area so as to overlap with the coverage area of another adjacent base station.

This ensures good communication between the user terminal and the base station regardless of the user terminal's location.

The eighth invention is a wireless communication system in which a user terminal mounted on a mobile body capable of moving on roads and a base station perform wireless communication, and the control unit of the user terminal is configured to first select the base station in front of the vehicle's lane as the connection destination, and if communication with the base station in front of the vehicle's lane is poor, switch the connection destination to the base station in the rear.

This prevents communication quality between the user terminal and the base station from deteriorating due to obstruction, resulting in interruption of communication, and ensures stable and good communication between the user terminal and the base station.

In addition, the ninth invention is configured such that the control unit of the user terminal switches the connection to the base station in the rear of the opposite lane when communication with the base station in front of the own lane is poor.

This allows user terminals to communicate with base stations that can ensure good communications.

In addition, the tenth invention is configured such that the control unit of the user terminal switches the connection to the base station at the rear of the own lane when communication with the base station at the front of the own lane is poor, and switches the connection to the base station at the rear of the opposite lane when communication with the base station at the rear of the own lane is poor.

This allows user terminals to communicate with base stations that can ensure good communications.

In addition, the eleventh invention is configured such that, when communication with the base station in the vicinity is poor, the control unit of the user terminal uses a user terminal mounted on another nearby mobile object as a relay device and carries out communication via that user terminal.

This makes it possible to ensure relatively high-speed communication even when communication with nearby base stations is poor. The user terminal acting as a relay device may be either a user terminal mounted on a car traveling in the opposite lane, or a user terminal mounted on an aircraft flying in the sky. This makes it possible to ensure relatively high-speed communication even when communication with nearby base stations is poor, and also when communication with other user terminals that can be used as relay devices is poor.

The twelfth invention is a wireless communication system in which a user terminal mounted on a mobile object capable of moving on a road and a base station perform wireless communication, the base station being configured to include a directional communication unit that performs wireless communication with the user terminal and is capable of controlling directivity, and a control unit that controls the directivity of the directional communication unit so as to improve the quality of communication with the user terminal when the mobile object on which the user terminal is mounted changes direction.

This prevents communication quality between the user terminal and the base station from deteriorating and causing communication interruptions due to changes in the orientation of the mobile body carrying the user terminal, and ensures stable, good communication between the user terminal and the base station.

In addition, the thirteenth invention is configured such that the base stations are grouped and perform multi-hop communication with other base stations belonging to the same group.

This allows the wireless communication path used for user terminal communications to be properly constructed.

The fourteenth invention is a user terminal mounted on a mobile body capable of moving on roads, which performs wireless communication with a base station, and is configured to include a directional communication unit that performs wireless communication with the base station and is capable of controlling directivity, and a control unit that controls the directivity of the directional communication unit so as to improve the quality of communication with the base station when the mobile body on which the device is mounted changes direction.

As with the first invention, this prevents communication quality between the user terminal and the base station from deteriorating and causing communication interruptions due to changes in the orientation of the mobile body carrying the user terminal, and ensures stable, good communication between the user terminal and the base station.

The fifteenth invention is a communication control method for controlling wireless communication with a base station in a user terminal mounted on a mobile object capable of moving on a road, in which a control unit of the user terminal is configured to control the directivity of a directional communication unit so as to improve the quality of communication with the base station when the mobile object on which the user terminal is mounted changes its orientation.

As with the first invention, this prevents communication quality between the user terminal and the base station from deteriorating and causing communication interruptions due to changes in the orientation of the mobile body carrying the user terminal, and ensures stable, good communication between the user terminal and the base station.

The following describes an embodiment of the present disclosure with reference to the drawings.

First Embodiment
FIG. 1 is a diagram showing the overall configuration of a wireless communication system 1 according to the first embodiment.

The wireless communication system 1 (abbreviated as system 1) includes a macro cell base station 2, a small cell base station 3, an access point (or base station) 4, an edge server 5, a network control server (abbreviated as NW control server 6), and a user terminal 7.

In a network to which system 1 is applied, small cell areas 11, which are the communication areas of multiple small cell base stations 3, are each superimposed on a macro cell area 12, which is the communication area of a macro cell base station 2.

The macrocell base station 2 performs wireless communication using a frequency band that makes it easy to build larger cells, such as the UHF band (frequency: 300 MHz to 3 GHz) for LTE (Long Term Evolution). The macrocell base station 2 is a base station for the control plane (CPlane) for transmitting control signals. The macrocell base station 2 may also be used as a base station for the user plane (U-Plane) for transmitting user data.

The small cell base station 3 performs wireless communication using a higher frequency than the macro cell base station 2, such as the low SHF band (frequency: 3 GHz to 6 GHz). The small cell base station 3 may also use the high SHF band (frequency: 6 GHz to 30 GHz). The small cell base station 3 is used as a user plane base station.

The access point 4 performs, for example, relatively small-capacity wireless communication using Wi-Fi (registered trademark) or relatively large-capacity wireless LAN communication using WiGig (registered trademark). The communication area 13 of the access point 4 is superimposed on at least one of the small cell area 11 and the macro cell area 12.

However, the access point 4 may be a microcell base station that performs wireless communication using a higher frequency band than the small cell base station 3. In that case, the wireless communication by the access point 4 can be performed using the high SHF band or EHF band (here, 28 GHz band, 40 GHz band, 70 GHz band, etc.) that is 5G NR (New Radio). Furthermore, the multiple access points 4 may include both such microcell base stations and base stations that perform wireless LAN communication. When a microcell base station is used as the access point 4, the communication area 13 corresponds to a microcell, which is the communication area of the microcell base station.

In the system 1, a communication environment in which multiple RATs (wireless communication methods) coexist, a so-called heterogeneous network, is configured. The macrocell base station 2, the small cell base station 3, and some of the access points 4 are wired-connected to a wired network consisting of a core network 15 and the Internet 16. The core network 15 includes an MME (Mobility Management Entity), an S-GW (Serving Gateway), and a P-GW (Packet data network Gateway) that configure an EPC (Evolved Packet Core) that corresponds to the LTE core network, an AMF (Access and Mobility Management Function), and a UPF (User Plane Function) that configure a 5GC (5G Core network) that corresponds to the 5G core network, and the like. In the system 1, the number and arrangement of the macrocell base station 2, the small cell base station 3, the access points 4, the edge server 5, the NW control server 6, and the user terminals 7 can be changed as appropriate.

The edge servers 5 are located physically close to the mobile user terminals 7 and execute various applications (programs) as services to the user terminals 7. There are no particular restrictions on the placement of each edge server 5, but here, they are connected to one of the access points 4.

The NW control server (network control device) 6 controls the communication paths used for communication between the edge servers 5 and user terminals 7 in the network to which the system 1 is applied. The NW control server 6 is connected to the core network 15. However, the NW control server 6 may be part of the core network 15, or may be connected to the Internet 16.

The user terminal 7 is an information device with wireless communication capabilities, such as a smartphone or tablet terminal, carried by each user (not shown). The user terminal 7 can be wirelessly connected to the macrocell base station 2, the small cell base station 3, and the access point 4. The user terminal 7 can also use applications of the edge server 5 by communicating with the edge server 5 via the macrocell base station 2, the small cell base station 3, and the access point 4. The user terminal 7 can also use applications of any server (not shown) by communicating with the server via a wired network consisting of the core network 15 and the Internet 16.

FIG. 2 is an explanatory diagram showing an example of control of a communication path between a user terminal 7 and an edge server 5 by a network control server 6. FIG. 2(A) shows a conventional communication path (comparative example), and FIG. 2(B) shows a communication path established by the network control server 6.

In FIG. 2, multiple access points 4 are arranged in a tree or mesh shape starting from a wired network connection point 18. The access points 4 are connected to each other via wireless communication to form a backhaul. In FIG. 2, the access points 4 are labeled AP1-AP12 to distinguish them from one another.

In FIG. 2(A), an example is shown in which an access point is selected based on wireless quality in communication between a user terminal 7 and an edge server 5. In this case, the user terminal 7 selects the nearby access point AP1 that offers the highest wireless quality as the connection destination, and as a result, it becomes necessary to communicate with the edge server 5 via more access points AP1-AP9. In FIG. 2(A), the communication path R1 between the user terminal 7 and the edge server 5 uses a backhaul to connect each access point to a connection point 18 in the wired network.

In contrast, in FIG. 2(B), multiple access points AP9-AP12, including access point AP9 to which edge server 5 is connected, are grouped (see the dashed circle in the figure). The NW control server 6 also forms wireless communication routes R2 and R3 using these grouped access points AP9-AP12. Furthermore, the NW control server 6 determines the connection priority of the access lines so that wireless communication routes R2 and R3 are used preferentially, and provides this to the user terminal 7. This enables the user terminal 7 to select access point AP10 or AP11 as the connection destination, and to communicate with edge server 5 using wireless communication routes R2 and R3.

FIG. 3 is a block diagram showing the general configuration of the access point 4.

In this embodiment, the access point 4 constitutes a roadside unit installed on the side of a road (roadside) or at an intersection. However, the access point 4 only needs to constitute a roadside unit, and may be constituted, for example, by an existing roadside unit and a communication device that cooperates with it.

The access point 4 includes a wireless communication unit 21, a backhaul communication unit 22, a wired communication unit 23, a memory unit 24, and a control unit 25.

The wireless communication unit 21 includes an antenna and a communication circuit for wireless communication with the user terminal 7. The wireless communication unit 21 has a directional communication unit 26. The directional communication unit 26 has directivity toward the upstream side in the lane direction. Furthermore, the directional communication unit 26 has variable directivity, that is, the directivity can be controlled. Specifically, the width and direction of the coverage area (beam) of the directional communication unit 26 can be controlled based on beamforming technology or the like. Furthermore, it is possible to change the direction of the directional communication unit itself.

The backhaul communication unit 22 is equipped with antennas and circuits for wireless communication with surrounding access points 4. This allows multi-hop communication between multiple access points 4, forming a wireless communication path used for communication between the user terminal 7 and the edge server 5.

The wired communication unit 23 includes a communication circuit for performing wired communication with the core network 15. However, the wired communication unit 23 does not necessarily need to be provided in all access points 4, and is provided in nearby access points 4 of the wired network as necessary.

The storage unit 24 stores information about the user terminal 7, information about the macrocell base station 2, small cell base station 3, and other access points 4 in the vicinity, as well as programs executed by the processor constituting the control unit 25.

The control unit 25 includes a wireless quality measurement unit 31, a location information acquisition unit 32, a route connection unit 33, a wireless control unit 34, a wired control unit 35, and a directivity control unit 36.

The wireless quality measurement unit 31 measures the quality of wireless communication with other nearby access points 4 based on known indicators such as received signal strength. The wireless quality measurement unit 31 also generates wireless quality information based on the measurement results of the wireless communication quality.

The location information acquisition unit 32 acquires location information of itself (the access point 4). The location information acquisition unit 32 can acquire location information by appropriately measuring the location of its own device, or can use location information previously stored in the storage unit 24, etc.

The route connection unit 33 establishes a communication route used for communication between the user terminal 7 and the edge server 5 based on a route establishment instruction received from the edge server 5. When establishing such a communication route, the route connection unit 33 realizes multi-hop communication with surrounding access points 4 by controlling wireless communication by the backhaul communication unit 22.

The wireless control unit 34 controls wireless communication with the user terminal 7 by the wireless communication unit 21.

The wired control unit 35 controls the communication by the wired communication unit 23. In addition, the wired control unit 35 can exchange information regarding the connection destination of the user terminal 7 through wired communication with a communication control device in the wired network and with the surrounding macrocell base station 2 and small cell base station 3.

The directivity control unit 36 controls the directivity of the directional communication unit 26. Specifically, the width and direction of the coverage area (beam) of the directional communication unit 26 are controlled so that the quality of communication with the user terminal 7 is good. The directivity control unit 36 also controls the direction of the directional communication unit itself. Note that directivity control can be performed individually for each user terminal 7.

In addition, at least some of the functions of each part in the control unit 25 described above can be realized by one or more processors executing a predetermined control program.

FIG. 4 is a block diagram showing the general configuration of the edge server 5.

The edge server 5 includes a communication unit 41, a memory unit 42, and a control unit 43.

The communication unit 41 has a communication circuit for communicating with the access point 4 to which the device is connected.

The memory unit 42 stores information about the user terminal 7, information about the macro cell base station 2, small cell base station 3, and access point 4 in the vicinity, and programs executed by the processor constituting the control unit 43.

The control unit 43 includes a route establishment instruction unit 45, a traffic information collection unit 46, an access point operation instruction unit 47, a communication control unit 48, and an application unit 49.

The route establishment instruction unit 45 sends a route establishment instruction to the access point 4 to establish a communication route based on the information received from the NW control server 6.

The traffic information collection unit 46 collects information on traffic between each access point 4 that forms a wireless communication path regarding communication between the user terminal 7 and the edge server 5. Note that the traffic information collection unit 46 may be omitted as appropriate.

The access point operation instruction unit 47 transmits operation instructions to the access point 4 based on information received from the NW control server 6. Such operation instructions include instructions to start or stop the access point 4. The access point operation instruction unit 47 may be omitted as appropriate.

The communication control unit 48 controls the communication by the communication unit 41. The communication control unit 48 also exchanges necessary information with nearby access points 4 and user terminals 7.

The application unit 49 executes various applications according to the service content for the user terminal 7. Processing by the application includes, for example, storing or providing the output (detection results) of sensors installed in a smart factory, and storing or providing traffic images of intersections and other detected information.

Note that at least some of the functions of each part in the control unit 43 described above can be realized by one or more processors executing a specific control program.

FIG. 5 is a block diagram showing the general configuration of the NW control server 6.

The network control server 6 includes a communication unit 51, a memory unit 52, and a control unit 53.

The communication unit 51 has a communication circuit for communicating with the edge server 5 and the user terminal 7 via the core network 15.

The storage unit 52 stores information about the user terminal 7, information about the macrocell base station 2, small cell base station 3, and access point 4 in the vicinity, and programs executed by the processor constituting the control unit 53.

The control unit 53 includes an information collection unit 61, a grouping unit 62, a route setting unit 63, a traffic analysis unit 64, a connection priority setting unit 65, a service area setting unit 66, an edge server operation control unit 67, an access point operation control unit 68, and a communication control unit 69.

The information collection unit 61 collects peripheral device information from each access point 4. This peripheral device information includes wireless quality information regarding the quality of wireless communication between each access point 4, location information of each access point 4, and edge server information regarding the presence or absence of an edge server 5 connected to each access point 4.

The grouping unit 62 extracts access points 4 that form a network in a specific area from the multiple access points 4 under its management based on the collected peripheral device information, and groups them. This generates at least one group of access points 4. A "specific area" includes, for example, a smart factory or a specific area including an intersection. At least some of the groups of access points 4 may be set by the operator. The grouping unit 62 can also reconfigure existing groups of access points 4 based on the results of traffic analysis by the traffic analysis unit 64, which will be described later. In this embodiment, each access point 4 can constitute a corresponding roadside unit.

The route setting unit 63 sets one or more wireless communication routes used for communication between the user terminal 7 and the edge server 5. Such wireless communication routes are formed by multi-hop communication of the grouped access points 4. Note that at least a part of such wireless communication routes may be set by the operator.

The traffic analysis unit 64 sequentially acquires from the edge server 5 traffic information on the wireless communication path used for communication between the user terminal 7 and the edge server 5. The acquired traffic information is stored in the memory unit 52. Based on the accumulated traffic information, the traffic analysis unit 64 also performs traffic analysis, such as predicting the traffic distribution of the wireless communication path set by the route setting unit 63. The traffic analysis unit 64 can also detect a detour route that uses an access point 4 outside the group that is not included in the target group.

The connection destination priority setting unit 65 sets the priority of connection destination candidates for the user terminal 7 according to the type of service of the edge server 5 used by the user terminal 7. The connection destination priority setting unit 65 also generates connection destination priority information based on the set priority of the connection destination candidates. The connection destination candidates for the user terminal 7 are usually any of the access points 4, but the macro cell base station 2 or small cell base station 3 can be connection destination candidates as necessary. The connection destination priority information also includes the priority of the connection destination candidates. Without being limited to this, the connection destination priority information may also include information regarding the criteria (rules) for determining the priority of the connection destination candidates, for example.

The service area setting unit 66 sets the service area (range of the communication area) based on peripheral device information from each access point 4. Such a service area is set according to the type of service of the edge server 5 used by the user terminal 7. The service area setting unit 66 also generates service area information related to the range of the set service area. Note that at least a part of the service area information may be set by the operator.

The edge server operation control unit 67 controls the operation of the edge server 5, including the launch of applications on the edge server 5.

The access point operation control unit 68 controls the operation of the access point 4, including starting and stopping the access point 4.

The communication control unit 69 controls the communication by the communication unit 51. The communication control unit 69 can also exchange necessary information with the surrounding access points 4, edge servers 5, and user terminals 7.

Note that at least some of the functions of each part in the control unit 53 described above can be realized by one or more processors executing a specific control program.

FIG. 6 is a block diagram showing the general configuration of the user terminal 7.

In this embodiment, the user terminal 7 is a terminal device mounted on a moving body (here, an automobile). The user terminal 7 may be configured, for example, by an on-board device provided in the automobile. The user terminal 7 may also be a portable computer carried by the user (driver or passenger) of the automobile.

The user terminal 7 includes a wireless communication unit 71, a memory unit 72, a location information acquisition unit 73, and a control unit 74.

The wireless communication unit 71 includes a macrocell/small cell communication unit 75 and an access point communication unit 76.

The macrocell/small cell communication unit 75 is equipped with an antenna and communication circuits for wireless communication with the macrocell base station 2 or the small cell base station 3.

The access point communication unit 76 is equipped with an antenna and a communication circuit for wireless communication with the access point 4. The access point communication unit 76 is equipped with a forward directional communication unit 78 and a rearward directional communication unit 79. The forward directional communication unit 78 has directivity in the forward direction (the direction in which the vehicle is moving). The rearward directional communication unit 79 has directivity in the rearward direction (the direction opposite to the direction in which the vehicle is moving). In addition, the forward directional communication unit 78 and the rearward directional communication unit 79 have variable directivity, that is, the directivity can be controlled. Specifically, the width and direction of the coverage area (beam) provided by each of the forward directional communication unit 78 and the rearward directional communication unit 79 can be controlled based on beamforming technology, etc.

The storage unit 72 stores information about the device itself, information about the macro cell base station 2, small cell base station 3, and access point 4 in the vicinity, and programs executed by the processor constituting the control unit 74.

The location information acquisition unit 73 acquires location information of the device itself using a known positioning system such as the Global Positioning System (GPS) or a system using a beacon transmitter. Note that the location information acquisition unit 73 may also acquire location information acquired by a device other than the user terminal 7, such as a LiDAR, camera, or radar installed at the access point 4 or on the roadside, via the access point 4, etc.

The control unit 74 includes a connection destination selection unit 81, an application unit 82, and a wireless control unit 83.

The connection destination selection unit 81 selects a connection destination such as an access point 4 based on the grouping information, connection destination priority information, and service area information received from the NW control server 6. This allows the user terminal 7 to communicate with the edge server 5 via the selected connection destination and the wireless communication path that includes it.

The application unit 82 executes processing according to the content of the application executed on the user terminal 7, and transmits and receives application data between the edge server 5 and the user terminal 71 via the wireless communication unit 71.

The wireless control unit 83 controls wireless communication by the wireless communication unit 71 with the access point 4, and with the macro cell base station 2 and small cell base station 3.

The directivity control unit 84 controls the directivity of the forward directional communication unit 78 and the backward directional communication unit 79. Specifically, the width and direction of the coverage area (beam) of each of the forward directional communication unit 78 and the backward directional communication unit 79 are controlled so that the communication quality with the access point 4 is good.

Note that at least some of the functions of each part in the control unit 74 described above can be realized by one or more processors executing a specific control program.

FIG. 7 is an explanatory diagram showing an overview of the communication control performed in the wireless communication system according to the first embodiment. FIG. 7(A) shows a case where the automobile V1 equipped with the user terminal 7 has moved away from the intersection ahead. FIG. 7(B) shows a case where the automobile V1 equipped with the user terminal 7 has approached the intersection ahead.

Access point 4 is installed at a traffic light L located at a road intersection or the like. In access point 4, the directional communication unit 26 forms a coverage area C1 (an area where good communication quality can be obtained) extending from approximately the center of the width of the lane toward the upstream side of the lane (one-way area communication). In other words, a beam is formed so that radio waves are emitted from the front toward cars traveling in the corresponding lane. Note that C1 is illustrated as the coverage range from the location of access point 4, but in reality, the beam from access point 4 also has vertical directionality, so at the height of user terminal 7, communication quality deteriorates near directly below access point 4.

Meanwhile, in the user terminal 7, the forward directional communication unit 78 forms a coverage area C21 that extends forward (in the direction in which the vehicle is moving), and the rearward directional communication unit 79 forms a coverage area C22 that extends backward (in the opposite direction to the direction in which the vehicle is moving).

In the user terminal 7, the forward directional communication unit 78 connects to the access point 4 ahead of it on the side of the user's own lane (the lane in which the automobile in which the user terminal 7 is mounted is traveling) to perform communication. Here, as shown in FIG. 7(A), when the user terminal 7, i.e., the automobile V1 in which the user terminal 7 is mounted, is away from the intersection ahead, the communication quality of the connected access point 4 is good.

On the other hand, as shown in FIG. 7(B), when the user terminal 7, i.e., the automobile V1 on which the user terminal 7 is mounted, approaches an intersection ahead, the user terminal 7 gets too close to the access point 4 ahead of it on the vehicle's own lane, causing the communication quality of the access point 4 to deteriorate. In this case, the user terminal 7 performs a handover to switch the connection to the access point 4 behind it on the opposite lane, and the rear directional communication unit 79 connects to the access point 4 behind it on the opposite lane to communicate.

At this time, the user terminal 7 controls the directivity of the rear directional communication unit 79. Specifically, the width and direction of the coverage area C22 (beam) of the rear directional communication unit 79 are controlled so that communication quality with the rear access point 4 on the opposite lane side is good. In controlling the direction of the coverage area C22 (beam), scanning is performed to swing the emitted beam left and right to search for the optimal direction of the coverage area C22 (beam). In addition, the coverage area C22 (beam) of the rear directional communication unit 79 is formed diagonally backward toward the rear access point 4 on the opposite lane side, and its direction changes depending on the distance between the user terminal 7 and the rear access point 4 on the opposite lane side.

FIG. 8 is a flow diagram showing the process flow performed by the user terminal 7.

The user terminal 7 selects the access point 4 ahead on the own lane side as the connection destination (ST101), and connects to that access point 4 to communicate (ST102). Next, the user terminal 7 determines whether the communication quality of the access point 4 ahead on the own lane side has deteriorated (ST103). Here, if the communication quality of the access point 4 ahead on the own lane side has not deteriorated (No in ST103), communication with the access point 4 ahead on the own lane side is continued.

On the other hand, if the communication quality of the access point 4 in front on the own lane side has deteriorated (Yes in ST103), the user terminal 7 then determines whether the communication quality of the access point 4 in the rear on the opposite lane side is good (ST104). Here, if the communication quality of the access point 4 in the rear on the opposite lane side is not good (No in ST104), communication with the access point 4 in front on the own lane side is continued.

On the other hand, if the communication quality of the rear access point 4 on the opposite lane side is good (Yes in ST104), the user terminal 7 then selects the rear access point 4 on the opposite lane side as the connection destination (ST105), performs a handover to switch the connection destination to the rear access point 4 on the opposite lane side, and connects to the rear access point 4 on the opposite lane side to communicate (ST106). Next, the user terminal 7 determines whether the communication quality of the rear access point 4 on the opposite lane side has deteriorated (ST107). Here, if the communication quality of the rear access point 4 on the opposite lane side has not deteriorated (No in ST107), communication with the rear access point 4 on the opposite lane side continues.

On the other hand, if the communication quality of the rear access point 4 on the opposite lane has deteriorated (Yes in ST107), the user terminal 7 then determines whether the communication quality of the front access point 4 on the own lane is better than the communication quality of the rear access point 4 on the opposite lane (ST108). Here, if the communication quality of the rear access point 4 on the opposite lane is better than the communication quality of the front access point 4 on the own lane (No in ST108), the user terminal 7 then controls the directivity of the rear directional communication unit 79 (ST109). At this time, the width and direction of the coverage area (beam) of the rear directional communication unit 79 are controlled so that the communication quality with the rear access point 4 on the opposite lane is good.

On the other hand, if the communication quality of the access point 4 in front on the own lane side is better than the communication quality of the access point 4 in the rear on the opposite lane side (Yes in ST108), the user terminal 7 then selects the access point 4 in front on the own lane side as the connection destination (ST110), performs a handover to switch the connection destination to the access point 4 in front on the own lane side, and connects to the access point 4 in front on the own lane side to communicate (ST111).

In this way, the user terminal 7 first communicates with the access point 4 ahead on the own lane (see FIG. 22(A)). When the vehicle in which the user terminal 7 is mounted is traveling and the user terminal 7 comes close to the access point 4 ahead on the own lane and the communication quality of that access point 4 deteriorates, a handover is performed to switch the connection to the access point 4 behind on the opposite lane (see FIG. 22(B)). Furthermore, when the vehicle in which the user terminal 7 is mounted is traveling and the communication quality of the access point 4 ahead on the own lane becomes higher than the access point 4 behind on the opposite lane, a handover is performed to switch the connection to the access point 4 ahead on the own lane (see FIG. 22(C)).

In addition, if the communication quality of the rear access point 4 on the opposite lane is better than the communication quality of the front access point 4 on the own lane, communication with the rear access point 4 on the opposite lane is continued, and directivity control is performed to control the directivity of the rear directional communication unit 79 in order to further improve the communication quality of the rear access point 4 on the opposite lane. In this case, as the user terminal 7 moves away from the rear access point 4 on the opposite lane as the car travels, the directivity of the rear directional communication unit 79 gradually changes due to directivity control in accordance with the change in the positional relationship between the rear access point 4 on the opposite lane and the user terminal 7.

Second Embodiment
Fig. 9 is a block diagram showing a schematic configuration of an access point 4 according to the second embodiment. In Fig. 9, the same components as those of the access point 4 according to the first embodiment shown in Fig. 3 are given the same reference numerals. Fig. 10 is a block diagram showing a schematic configuration of a user terminal 7 according to the second embodiment. In Fig. 10, the same components as those of the user terminal 7 according to the first embodiment shown in Fig. 6 are given the same reference numerals. In the second embodiment, matters that are not particularly mentioned below are the same as those in the first embodiment, and therefore detailed description thereof will be omitted.

As shown in FIG. 9, in the access point 4 according to the second embodiment, the wireless communication unit 21 includes an upstream directional communication unit 27 and a downstream directional communication unit 28. The upstream directional communication unit 27 has directivity in the upstream direction of the lane, similar to the direction of the traffic light. The downstream directional communication unit 28 has directivity in the downstream direction of the lane, which is opposite to the direction of the traffic light. Furthermore, the upstream directional communication unit 27 and the downstream directional communication unit 28 have variable directivity, that is, the directivity can be controlled. Specifically, the width and direction of the coverage area (beam) provided by each of the upstream directional communication unit 27 and the downstream directional communication unit 28 can be controlled based on beamforming technology or the like.

As shown in FIG. 10, the user terminal 7 according to the second embodiment is equipped with a direction sensor 80. The direction sensor 80 detects the direction of travel (body orientation) of the automobile, which is a moving body in which the user terminal 7 is mounted. Based on the detection result of the direction sensor 80, the control unit 74 can detect that the automobile in which the user terminal 7 is mounted is making a right or left turn at an intersection.

The configurations of the edge server 5 and the NW control server 6 are the same as those in the first embodiment (see Figures 4 and 5).

FIGS. 11 and 12 are explanatory diagrams showing an overview of communication control performed in the wireless communication system according to the second embodiment. FIG. 11 shows the state of communication control of the user terminal 7 when the automobile V1 equipped with the user terminal 7 is traveling straight along a road. FIG. 12 shows the state of communication control of the user terminal 7 when the automobile V1 equipped with the user terminal 7 is turning right at an intersection. Note that the case where the automobile V1 turns left at an intersection is similar to the case of turning right shown in FIG. 12.

As shown in FIG. 11, at access point 4, the upstream directional communication unit 27 forms a coverage area C11 extending from approximately the center of the lane width toward the upstream side in the lane direction, and the downstream directional communication unit 28 forms a coverage area C12 extending toward the downstream side in the lane direction (bidirectional area communication).

Also, as shown in FIG. 11(A), in a user terminal 7 mounted on an automobile V1 as a moving body, a forward directional communication unit 78 connects to an access point 4 ahead of the own lane to perform communication. Here, when the user terminal 7, i.e., the automobile V1 on which the user terminal 7 is mounted, is away from the intersection ahead, the communication quality of the access point 4 ahead of the own lane is good.

On the other hand, as shown in FIG. 11(B), when the user terminal 7, i.e., the automobile V1 on which the user terminal 7 is mounted, approaches an intersection ahead, the user terminal 7 gets too close to the access point 4 ahead on the own lane side, causing the communication quality of the access point 4 ahead on the own lane side to deteriorate. In this case, the user terminal 7 performs a handover to switch the connection to the access point 4 behind the own lane side, and the rear directional communication unit 79 connects to the access point 4 behind the own lane side to communicate.

Also, as shown in FIG. 12, when automobile V1 equipped with a user terminal 7 enters an intersection and starts to turn right, the communication quality of the rear access point 4 deteriorates in the user terminal 7, so the directivity of the rear directional communication unit 79 is controlled. Also, as automobile V1 continues to turn right at the intersection, the communication quality of the access point 4 ahead of the intersecting road becomes higher than the communication quality of the rear access point 4, so a handover is performed to switch the connection destination to the access point 4 ahead of the intersecting road. At this time, the directivity of the forward directional communication unit 78 is controlled.

12(A), the backward directional communication unit 79 and the forward directional communication unit 78 of the user terminal 7 perform control to adjust the direction of the cover areas C21, C22 (beams). At this time, the emitted beam is scanned left and right to search for the optimal direction of the cover areas C21, C22 (beams). In the example shown in FIG. 12(B), the backward directional communication unit 79 and the forward directional communication unit 78 perform control to expand the width of the cover areas C21, C22 (beams) left and right. In addition, a control may be performed that combines the adjustment of the direction of the cover areas C21, C22 (beams) shown in FIG. 12(A) and the expansion of the width of the cover areas C21, C22 (beams) shown in FIG. 12(B). Note that the communication distance becomes shorter when the beam width is expanded, so the control shown in FIG. 12(B) may be performed only when the user terminal 7 approaches the access point 4.

In the example shown in FIG. 12(A), when the automobile V1 equipped with the user terminal 7 makes a right turn at an intersection, the rear directional communication unit 79 of the user terminal 7 is maintained in a state connected to the rear access point 4 on the own lane side, and control is performed to adjust the direction of the cover area C22 so that the communication quality at that time is good (first state in the figure). On the other hand, when the automobile V1 continues to turn right at the intersection, the rear directional communication unit 79 of the user terminal 7 is in a state where it can connect to the rear access point 4 on the opposite lane side of the intersecting road. Therefore, control may be performed to adjust the direction of the cover area C22 so that the communication quality between the rear directional communication unit 79 of the user terminal 7 and the rear access point 4 on the opposite lane side of the intersecting road is good (second state in the figure).

FIG. 13 is a flow diagram showing the flow of processing performed by the user terminal 7.

The user terminal 7 selects the access point 4 ahead on the own lane as the connection destination (ST201), and connects to that access point 4 to communicate (ST202). Next, the user terminal 7 acquires the direction information that is the detection result of the direction sensor 80, and determines whether the direction has changed by a predetermined value or more (ST203). Here, if the direction has not changed by the predetermined value or more, that is, if the automobile in which the user terminal 7 is mounted is moving straight (No in ST203), communication with the access point 4 ahead on the own lane is continued.

On the other hand, if the direction has changed by more than a predetermined value, i.e., if the vehicle in which the user terminal 7 is mounted starts to turn right or left at an intersection (Yes in ST203), the user terminal 7 then determines whether the communication quality of the access point 4 ahead on the own lane side has deteriorated (ST204). Here, if the communication quality of the access point 4 ahead on the own lane side has not deteriorated (No in ST204), communication with the access point 4 ahead on the own lane side continues.

On the other hand, if the communication quality of the access point 4 in the front of the own lane has deteriorated (Yes in ST204), the user terminal 7 then selects the access point 4 in the rear of the own lane as the connection destination (ST205), performs a handover to switch the connection destination to the access point 4 in the rear of the own lane, and connects to the access point 4 in the rear of the own lane to communicate (ST206).

Next, the user terminal 7 controls the directivity of the rear directional communication unit 79 (ST207). At this time, the width and direction of the coverage area (beam) of the rear directional communication unit 79 are controlled so that the communication quality with the rear access point 4 on the opposite lane side is good.

Next, the user terminal 7 determines whether the communication quality of the access point 4 ahead is better than that of the access point 4 behind (ST208). At this time, since the vehicle is in the middle of making a right or left turn, the access point 4 ahead is the access point 4 located ahead on the crossroad (the road beyond which the vehicle turns right or left at the intersection). Here, if the communication quality of the access point 4 behind is better than that of the access point 4 ahead (No in ST208), communication with the access point 4 behind on the vehicle's own lane is continued.

On the other hand, if the communication quality of the forward access point 4 is better than that of the rearward access point 4 (Yes in ST208), the user terminal 7 then selects the forward access point 4 on the cross road side as the connection destination (ST209), performs handover to switch the connection destination to the forward access point 4 on the cross road side, and connects to the forward access point 4 on the cross road side to communicate (ST210).

Next, the user terminal 7 controls the directivity of the forward directional communication unit 78 (ST211). At this time, the width and direction of the coverage area (beam) of the forward directional communication unit 78 are controlled so that the communication quality with the forward access point 4 is good.

In this way, in the user terminal 7, first, when the automobile equipped with the user terminal 7 starts to turn right or left at the intersection, the communication quality of the access point 4 in front of the own lane deteriorates, so a handover is performed to switch the connection destination to the access point 4 in the rear of the own lane. Then, in order to further improve the communication quality of the access point 4 in the rear of the own lane, directivity control is performed to control the directivity of the rear directional communication unit 79. Furthermore, when the automobile continues to turn right or left at the intersection, the communication quality of the access point 4 in front of the cross road increases, so a handover is performed to switch the connection destination to the access point 4 in front of the cross road. Then, in order to further improve the communication quality of the access point 4 in front of the cross road, directivity control is performed to control the directivity of the forward directional communication unit 78. Note that in these directivity controls, the beam width may be expanded as shown in FIG. 12(B), or a combination of directivity control and beam width expansion may be used.

(Modification of the second embodiment)
FIG. 14 is an explanatory diagram showing a state of communication control of the access point 4 according to a modified example of the second embodiment.

In the second embodiment, when the automobile V1 equipped with the user terminal 7 is turning right or left at an intersection, the user terminal 7 controls the directivity of the forward directional communication unit 78 and the rearward directional communication unit 79, but in this modified example, the access point 4 controls the directivity of the upstream directional communication unit 27.

In the example shown in FIG. 14(A), the upstream directional communication unit 27 of the access point 4 performs control to adjust the direction of the cover area C11 (beam). At this time, the emitted beam is scanned left and right to search for the optimal direction of the cover area C11 (beam). In the example shown in FIG. 14(B), the upstream directional communication unit 27 performs control to expand the width of the cover area C11 (beam) left and right. Also, a control may be performed that combines the adjustment of the direction of the cover area C11 (beam) shown in FIG. 14(A) and the expansion of the width of the cover area C11 (beam) shown in FIG. 14(B). Note that, since expanding the beam width shortens the communication distance, the control shown in FIG. 14(B) may be performed only when the user terminal 7 approaches the access point 4.

In addition, the control of directivity at the access point 4 is performed individually for each user terminal 7, for example, by time-division control. Specifically, for example, the beam may be controlled to be wide for a user terminal 7 mounted on a car turning right or left at an intersection, and the beam may be controlled to be narrow for a user terminal 7 mounted on a car going straight through the intersection.

Third Embodiment
15 and 16 are explanatory diagrams showing an overview of communication control performed in the wireless communication system 1 according to the third embodiment. In the third embodiment, matters not specifically mentioned below are the same as those in the above-mentioned embodiments, and detailed explanations will be omitted. The configuration of the access point 4 is the same as that of the second embodiment (see FIG. 9). The configurations of the edge server 5, the NW control server 6, and the user terminal 7 are the same as those of the first embodiment (see FIG. 4, FIG. 5, FIG. 6).

In this embodiment, as in the second embodiment, the wireless communication unit 21 of the access point 4 includes an upstream directional communication unit 27 and a downstream directional communication unit 28.

In addition, in this embodiment, when communication between a user terminal 7 mounted on a mobile body and an access point 4 becomes poor due to obstruction by another mobile body, a handover is performed to switch the connection destination to another access point 4. In particular, here, a priority order is set for the access points 4 used for communication. Specifically, the connection destination is selected in the following order: the access point 4 in front on the own lane side, the access point 4 in the rear on the own lane side, and the access point 4 in the rear on the opposite lane side.

In the example shown in FIG. 15(A), a user terminal 7 mounted on an automobile V1 serving as a moving body communicates with an access point 4 located ahead on the vehicle's own lane.

In the example shown in FIG. 15(B), blocking occurs due to another moving object, automobile V2, in front of the own lane, causing poor communication between the user terminal 7 mounted on automobile V1 and the access point 4 in front of the own lane. In this case, the user terminal 7 mounted on automobile V1 performs a handover to switch the connection to the access point 4 in the rear of the own lane, and communicates with the access point 4 in the rear of the own lane.

In the example shown in FIG. 16, blocking occurs due to another moving object, automobile V3, located behind the own lane, causing poor communication between the user terminal 7 mounted on automobile V1 and the access point 4 located behind the own lane. In this case, the user terminal 7 mounted on automobile V1 performs a handover to switch the connection to the access point 4 located behind the own lane, and communicates with the access point 4 located behind the own lane.

At this time, the user terminal 7 controls the directivity of the rear directional communication unit 79. Specifically, the width and direction of the coverage area C22 (beam) of the rear directional communication unit 79 are controlled so that communication quality with the rear access point 4 on the opposite lane side is good. In controlling the direction of the coverage area C22 (beam), scanning is performed to swing the emitted beam left and right to search for the optimal direction of the coverage area C22 (beam). In addition, the coverage area C22 (beam) of the rear directional communication unit 79 is formed diagonally backward toward the rear access point 4 on the opposite lane side, and its direction changes depending on the distance between the user terminal 7 and the rear access point 4 on the opposite lane side.

FIG. 17 is a flow diagram showing the flow of processing performed by the user terminal 7.

The user terminal 7 selects the access point 4 ahead on the own lane side as the connection destination (ST301), and connects to that access point 4 to communicate (ST302). Next, the user terminal 7 determines whether the communication quality of the access point 4 ahead on the own lane side has deteriorated (ST303). Here, if the communication quality of the access point 4 ahead on the own lane side has not deteriorated (No in ST303), communication with the access point 4 ahead on the own lane side is continued.

On the other hand, if the communication quality of the access point 4 in front of the own lane has deteriorated (Yes in ST303), the user terminal 7 then selects the access point 4 in the rear of the own lane as the connection destination (ST304), performs a handover to switch the connection destination to the access point 4 in the rear of the own lane, and connects to the access point 4 in the rear of the own lane to communicate (ST305). At this time, the width and direction of the coverage area (beam) of the rear directional communication unit 79 may be controlled so that the communication quality with the access point 4 in the rear of the own lane is improved.

Next, the user terminal 7 determines whether the communication quality of the rear access point 4 on the own lane side has deteriorated (ST306). If the communication quality of the rear access point 4 on the own lane side has not deteriorated (No in ST306), communication with the rear access point 4 on the own lane side is continued.

On the other hand, if the communication quality of the rear access point 4 has deteriorated (Yes in ST306), the user terminal 7 then determines whether the communication quality of the rear access point 4 on the opposite lane is better than the communication quality of the rear access point 4 on the own lane (ST307). Here, if the communication quality of the rear access point 4 on the opposite lane is not better than the communication quality of the rear access point 4 on the own lane (No in ST307), communication with the rear access point 4 on the own lane continues.

On the other hand, if the communication quality of the rear access point 4 on the opposite lane is better than that of the rear access point 4 on the own lane (Yes in ST307), the user terminal 7 then determines whether the communication quality of the front access point 4 is better than that of the rear access point 4 (ST308). Here, if the communication quality of the rear access point 4 is better than that of the front access point 4 (No in ST308), the user terminal 7 then selects the rear access point 4 on the opposite lane as the connection destination (ST309), performs a handover to switch the connection destination to the rear access point 4 on the opposite lane, and connects to the rear access point 4 on the opposite lane to communicate (ST310).

Next, the user terminal 7 controls the directivity of the rear directional communication unit 79 (ST311). At this time, the width and direction of the coverage area (beam) of the rear directional communication unit 79 are controlled so that the communication quality with the rear access point 4 on the opposite lane side is good.

On the other hand, if the communication quality of the forward access point 4 is better than that of the rearward access point 4 (Yes in ST308), the user terminal 7 then selects the forward access point 4 on the own lane side as the connection destination (ST312), performs handover to switch the connection destination to the forward access point 4 on the own lane side, and connects to the forward access point 4 on the own lane side to communicate (ST313).

Fourth Embodiment
18 and 19 are explanatory diagrams showing an overview of communication control performed in the wireless communication system 1 according to the fourth embodiment. In the fourth embodiment, matters not specifically mentioned below are similar to those in the first embodiment, and detailed explanations will be omitted. The configuration of the access point 4 is similar to that of the second embodiment (see FIG. 9). The configurations of the edge server 5, the NW control server 6, and the user terminal 7 are similar to those of the first embodiment (see FIG. 4, FIG. 5, FIG. 6).

In the third embodiment, a user terminal 7 mounted on an automobile as a mobile body is controlled to connect to nearby access points 4, but due to obstruction by other mobile bodies in the vicinity, communication may be poor at all of the nearby access points 4, specifically, the access point 4 in front of the vehicle's own lane, the access point 4 in the rear of the vehicle's own lane, and the access point 4 in the rear of the opposite lane. In such a case, in this embodiment, a user terminal 7 mounted on another mobile body in the vicinity is used as a relay device, and communication is performed via the user terminal 7. The user terminal 7 as a relay device can connect to nearby access points 4 that can be connected to, and can perform communication required for itself as well as communication as a relay device.

In the example shown in FIG. 18(A), blocking occurs due to automobile V4 behind on the opposite lane, causing poor communication between the user terminal 7 mounted on automobile V1 and the access point 4 behind on the opposite lane. In this case, the user terminal 7 mounted on automobile V1 uses the user terminal 7 mounted on automobile V5, another moving body traveling in the opposite lane, as a relay device and transitions to a communication mode via that user terminal 7. In this communication mode, the user terminal 7 mounted on automobile V1 performs a handover to switch the connection destination to the user terminal 7 mounted on automobile V5, and communicates with the user terminal 7 mounted on automobile V5.

In the example shown in FIG. 18(B), blocking occurs due to automobile V6 traveling in the opposite lane, causing poor communication between the user terminal 7 mounted on automobile V1 and the user terminal 7 mounted on automobile V5 traveling in the opposite lane. In this case, the user terminal 7 mounted on automobile V1 transitions to a communication mode via a user terminal 7 acting as a relay device mounted on a drone D (aircraft) flying in the sky. In this communication mode, the user terminal 7 mounted on automobile V1 performs a handover to switch the connection destination to the user terminal 7 mounted on drone D, and communicates with the user terminal 7 mounted on drone D.

The flying object on which the user terminal 7 is mounted is not limited to the drone D, but may be, for example, a balloon.

The user terminal 7 is also provided with a forward directional communication unit 78 and a backward directional communication unit 79 for communicating with the access point 4, but an upward directional communication unit with directionality in the sky may also be provided to improve communication with the flying object. In this case, it is preferable for the upward directional communication unit to generate circularly polarized waves pointing toward the sky. Furthermore, the forward directional communication unit 78 and the backward directional communication unit 79 may be controlled to switch from horizontal polarization to vertical polarization.

In the example shown in FIG. 19, obstruction by a building or the like occurs, causing poor communication between the user terminal 7 mounted on the automobile V1 and the user terminal 7 mounted on the drone D. In this case, the user terminal 7 mounted on the automobile V1 performs a handover to switch the connection to the small cell base station 3 or macro cell base station 2 as a base station of the wide area communication network, and communicates with the small cell base station 3 or macro cell base station 2.

Fifth Embodiment
20 and 21 are explanatory diagrams showing an overview of the coverage area of the access point 4 according to the fifth embodiment. In the fifth embodiment, matters that are not particularly mentioned below are the same as those in the first embodiment, and therefore detailed descriptions thereof will be omitted.

The coverage area C1 (beam) by the directional communication unit 26 of the access point 4 has directionality not only in the left-right direction but also in the up-down direction, so communication quality deteriorates in the immediate vicinity of the access point 4. Therefore, it is advisable to configure the access point 4 so that a coverage area C1 is formed, as shown in Figures 20 and 21. This allows the immediate vicinity of the access point 4 to be covered by another coverage area C1, so that either the forward directional communication unit 78 or the backward directional communication unit 79 can connect to the access point 4 with good communication quality, regardless of the position of the user terminal 7 on the road.

The example shown in Figures 20(A) and (B) is a case where the access point 4 has a one-way area communication configuration, similar to the first embodiment. Specifically, the wireless communication unit 21 of the access point 4 has a directional communication unit 26 that has directionality toward the upstream side in the lane direction. The directional communication unit 26 forms a coverage area C1 (an area where good communication quality can be obtained) by extending toward the upstream side in the lane direction.

In the example shown in FIG. 20(A), the coverage area C1 of the directional communication unit 26 of the access point 4 partially overlaps with the coverage area C1 of the directional communication unit 26 of the adjacent access point 4.

In the example shown in FIG. 20(B), the coverage areas C1 of an access point 4 installed on the upbound lane side of a road and an access point 4 installed on the downbound lane side are formed alternately so that they partially overlap, and the coverage area C1 of the access point 4 is formed to cover the entire road.

The example shown in Figures 21 (A) and (B) is a case where the access point 4 has a bidirectional area communication configuration, similar to the second embodiment. Specifically, the wireless communication unit 21 of the access point 4 has an upstream directional communication unit 27 that has directivity toward the upstream side of the lane, and a downstream directional communication unit 28 that has directivity toward the downstream side of the lane. The upstream directional communication unit 27 forms a cover area C11 by extending toward the upstream side in the lane direction. The downstream directional communication unit 28 forms a cover area C12 by extending toward the downstream side in the lane direction.

In the example shown in FIG. 21(A), the coverage area C11 of the upstream directional communication unit 27 of an access point 4 partially overlaps with the coverage area C12 of the downstream directional communication unit 28 of an adjacent access point 4 on the upstream side of the lane.

In the example shown in FIG. 21(B), access point 4 is included in the coverage area C11 of the upstream directional communication unit 27 of the adjacent access point 4 on the downstream side of the lane, and access point 4 is included in the coverage area C12 of the downstream directional communication unit 28 of the adjacent access point 4 on the upstream side of the lane.

In the example shown in FIG. 21(C), at one access point 4, the coverage area C11 of the upstream directional communication unit 27 and the coverage area C12 of the downstream directional communication unit 28 are in a state of partial overlap. In other words, the downstream directional communication unit 28 is included in the coverage area C11 of the upstream directional communication unit 27, and the upstream directional communication unit 27 is included in the coverage area C12 of the downstream directional communication unit 28.

As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can also be applied to embodiments in which modifications, substitutions, additions, omissions, etc. have been made. It is also possible to combine the components described in the above embodiments to create new embodiments.

For example, in the present disclosure, the moving body on which the user terminal 7 is mounted is an automobile, but the moving body on which the user terminal 7 is mounted is not limited to an automobile. The moving body on which the user terminal 7 is mounted may be other vehicles such as a bicycle, a senior car, a wheelchair, or may be a moving body other than a vehicle such as a pedestrian.

In addition, in the present disclosure, an automobile as a mobile body on which the user terminal 7 is mounted moves on a road, but the route on which the mobile body on which the user terminal 7 is mounted can move is not limited to a road. The mobile body on which the user terminal 7 is mounted may move along a predetermined route, and for example, if the mobile body is a flying object (such as a drone) that flies along a predetermined flight route, the route on which the mobile body can move is the flight route.

Furthermore, in the present disclosure, a coverage area (beam) is formed by the access point 4 and the user terminal 7 so as to correspond to the lanes of the road along which the automobile, which is the mobile body on which the user terminal 7 is mounted, travels. On the other hand, when the mobile body moves along a route other than a road, such as a flight route, it is preferable to set multiple traffic segments on the path of the mobile body, which correspond to the lanes of a road. In the multiple traffic segments, the position and direction of the moving body are specified in advance so that two or more mobile bodies can move in opposition to each other (or in parallel).

In addition, in the present disclosure, in controlling the directionality of wireless communication performed by the access point 4 and the user terminal 7, at least one of the width and direction of the coverage area (beam) is changed based on beamforming technology, but is not limited to this. For example, the directionality may be mechanically controlled using a gimbal mechanism or the like.

In addition, in the present disclosure, the directivity of wireless communication is controlled when an automobile, as a moving body on which a user terminal 7 is mounted, turns right or left at an intersection, but this is not limited to this. For example, controlling the directivity of wireless communication is also useful when the direction of wireless communication at the base station and the direction of the automobile are misaligned due to a curve in the road.

In addition, in the present disclosure, the directivity of wireless communication performed by the access point 4 and the user terminal 7 is controlled based on the communication quality, i.e., the directivity is controlled so as to improve the communication quality, but the directivity may be controlled based on the position of the user terminal 7 on the road, i.e., information regarding the positional relationship between the user terminal 7 and the access point 4, which is obtained.

The wireless communication system, user terminal, and communication control method according to the present invention have the effect of being able to stably ensure good communication between a user terminal and a base station even in situations where communication quality deteriorates due to a change in the orientation of the mobile body or due to obstruction, and are useful as a wireless communication system in which a user terminal mounted on a mobile body that can move on roads and a base station perform wireless communication, a user terminal mounted on a mobile body that can move on roads and performs wireless communication with a base station, and a communication control method for controlling wireless communication with a base station in a user terminal mounted on a mobile body that can move on roads.

1: Wireless communication system 2: Macro cell base station 3: Small cell base station 4: Access point (base station)
5: Edge server 6: Network control server 7: User terminal 11: Small cell area 12: Macro cell area 13: Communication area 15: Core network 16: Internet 18: Connection point 21: Wireless communication unit 22: Backhaul communication unit 23: Wired communication unit 24: Memory unit 25: Control unit 26: Directional communication unit 27: Upstream directional communication unit 28: Downstream directional communication unit 31: Wireless quality measurement unit 32: Position information acquisition unit 33: Route connection unit 34: Wireless control unit 35: Wired control unit 36: Directional control unit 41: Communication unit 42: Memory unit 43: Control unit 45: Route establishment instruction unit 46: Traffic information collection unit 47: Access point operation instruction unit 48: Communication control unit 49: Application unit 51: Communication unit 52: Memory unit 53: Control unit 61: Information collection unit 62: Grouping unit 63: Route setting unit 64: Traffic analysis unit 65: Connection destination priority setting unit 66: Service area setting unit 67: Edge server operation control unit 68: Access point operation control unit 69: Communication control unit 71: Wireless communication unit 72: Memory unit 73: Location information acquisition unit 74: Control unit 75: Small cell communication unit 76: Access point communication unit 78: Forward directivity communication unit 79: Rear directivity communication unit 80: Orientation sensor 81: Connection destination selection unit 82: Application unit 83: Wireless control unit 84: Directivity control unit C1, C11, C12: Coverage areas C21, C22: Coverage area D: Drone L: Traffic lights V1-V6: Automobile

Claims (15)

A wireless communication system in which a user terminal mounted on a mobile object capable of moving on a road and a base station perform wireless communication,
The user terminal,
a directional communication unit capable of wirelessly communicating with the base station and controlling directivity;
A wireless communication system comprising: a control unit that controls the directivity of the directional communication unit so as to improve communication quality with the base station when a moving object on which the wireless communication system is mounted changes its orientation. The user terminal is mounted on a vehicle as the moving body,
The control unit of the user terminal
The wireless communication system according to claim 1 , wherein the directivity of the directional communication unit is controlled when a vehicle equipped with the wireless communication system makes a right or left turn at an intersection. The control unit of the user terminal
The wireless communication system according to claim 1 , wherein the directional communication unit of the wireless communication system is controlled so as to change at least one of a width and a direction of a coverage area of the directional communication unit of the wireless communication system. The user terminal,
The wireless communication system according to claim 1 , comprising: a forward directional communication unit having forward directivity; and a rearward directional communication unit having rearward directivity. The base station,
The wireless communication system according to claim 1 , further comprising a directional communication unit having directivity toward the upstream side of a lane. The base station,
2. The wireless communication system according to claim 1, further comprising an upstream directional communication unit having directivity on an upstream side of a lane, and a downstream directional communication unit having directivity on a downstream side of the lane. The base station,
2. The wireless communication system according to claim 1, wherein a base station forms its own coverage area so as to overlap with the coverage area of another adjacent base station. A wireless communication system in which a user terminal mounted on a mobile object capable of moving on a road and a base station perform wireless communication,
The control unit of the user terminal
First, the base station ahead of the vehicle in the vehicle's lane is selected as the connection destination.
A wireless communication system that switches the connection to the base station behind the vehicle when communication with the base station ahead of the vehicle in the vehicle's lane is poor. The control unit of the user terminal
The wireless communication system according to claim 8 , wherein when communication with the base station ahead on the vehicle's own lane side is poor, the connection destination is switched to the base station behind on the opposite lane side. The control unit of the user terminal
When communication with the base station in front of the vehicle lane is poor, the vehicle switches to the base station in the rear of the vehicle lane;
The wireless communication system according to claim 8 , wherein when communication with the base station behind the vehicle on the vehicle's own lane is poor, the connection is switched to the base station behind the vehicle on the opposite lane. The control unit of the user terminal
9. The wireless communication system according to claim 8, wherein when communication with the base station in the vicinity is poor, a user terminal mounted on another mobile object in the vicinity is used as a relay device to carry out communication via the user terminal. A wireless communication system in which a user terminal mounted on a mobile object capable of moving on a road and a base station perform wireless communication,
The base station,
a directional communication unit capable of wirelessly communicating with the user terminal and controlling directivity;
A wireless communication system comprising: a control unit that controls the directivity of the directional communication unit so as to improve communication quality with the user terminal when a moving body on which the user terminal is mounted changes its orientation. The wireless communication system according to any one of claims 1 to 12, wherein the base stations are grouped and perform multi-hop communication with other base stations belonging to the same group. A user terminal mounted on a mobile body capable of moving on a road and performing wireless communication with a base station,
a directional communication unit capable of wirelessly communicating with the base station and controlling directivity;
A user terminal comprising: a control unit that controls a directivity of the directional communication unit so as to improve communication quality with the base station when a moving body in which the user terminal is mounted changes its orientation. A communication control method for controlling wireless communication between a user terminal mounted on a mobile object capable of moving on a road and a base station, comprising:
The control unit of the user terminal
A communication control method for controlling a directivity of a directional communication unit so as to improve communication quality with the base station when a moving object in which the device is mounted changes direction.

Images