Patent Description:
Connected cars, which are automobiles that have communication functions and function as ICT terminals, are becoming more and more widespread. In order to improve the safety and comfort of automobiles, the connected cars transmit and receive information related to the automobiles, the drivers, or the surrounding conditions to and from a data center, thus allowing the data center to store and analyze the information. The connected cars transmit (upload) a wide variety of information (e.g. vehicle control and operation data, driver operation data, dynamic map data, moving image data from a dashboard camera, etc.) to a server installed in the data center via a network. The use of a cellular network is envisioned as a form of connection of such connected cars to the network.

With the spread of the connected cars, dynamic changes in terminal density or congestion with movement of the vehicles are expected as the number of in-vehicle terminals increases. For example, if a traffic jam of vehicles occurs and a particular cell is congested due to in-vehicle terminals, communication congestion occurs and the communication quality may deteriorate in that cell.

As a technology to address the aforementioned communication congestion, Patent Document <NUM> proposes a technology in which an overload and congestion of a server is detected on a server/infrastructure side, and a terminal is instructed to adjust the communication timing and wait. Further, congestion control with TCP is widely known as a type of congestion control. In the congestion control with TCP, an end terminal detects congestion in a network based on the response state of a communication counterpart, and adjusts its own communication traffic.

Further background art is provided in the following papers:.

In the above conventional technology, vehicle congestion is not considered in a communication network such as a cellular network, and the timing of transmission by vehicles is not controlled based on the vehicle congestion either. Moreover, although the occurrence of congestion is detected in a communication network, prediction of the occurrence of congestion is not performed. However, to prevent deterioration of the communication quality due to the occurrence of congestion, it is necessary to predict the occurrence of congestion based on the vehicle congestion, and control transmission by the vehicles in a communication network so as to prevent the occurrence of congestion.

The present invention has been made in view of the foregoing problem. The present invention aims to provide a technology for predicting the traffic volume in a cell formed by a base station and appropriately controlling uplink traffic from each vehicle in the cell, using edge computing.

The present invention provides a node apparatus as defined in Claim <NUM> of the appended claims. Also provided is a method as defined in Claim <NUM>, and a program as defined in Claim <NUM>. Details of certain embodiments are set out in the dependent claims.

According to the present invention, to prevent communication congestion in a cell formed by a base station, uplink traffic from vehicles can be appropriately controlled using edge computing.

Other features and advantages of the present invention will be apparent in the following description with reference to the attached drawings. Note that, in the attached drawings, the same or similar constituents are assigned the same reference numerals.

The attached drawings are included in the specification and constitute a part of the specification, illustrate embodiments of the present invention, and are used to describe the principle of the present invention together with the description of the specification.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Note that, in the following diagrams, constituent elements that are not necessary for the description of the embodiments are omitted from the diagrams.

<FIG> is a diagram showing an example configuration of a communication network that includes MEC nodes according to an embodiment of the present invention. MEC node <NUM> (each of MEC nodes 10a and 10b) of the present embodiment is a node apparatus for edge computing (MEC) that is connected to one or more base stations <NUM>, and is connected between the one or more base stations <NUM> and a host network <NUM>.

The MEC node <NUM> manages the one or more connected base stations <NUM>, and manages one or more cells formed by the respective base stations <NUM>. For example, the MEC node 10a manages cells <NUM> and <NUM>. The MEC nodes <NUM> control data transmission by vehicles <NUM> that moves (travels) in the respective cells to be managed. Note that the MEC node <NUM> may provide the vehicles <NUM> with a service such as an automatic travel assistance service.

Vehicles (connected cars) that have a function of connecting to a communication network can wirelessly connect to a base station <NUM> that forms a cell, while traveling in the cell of the base station <NUM>. The vehicles <NUM> that are wirelessly connected to the base station <NUM> can access the MEC node <NUM> and the host network <NUM> via the base station <NUM>, and can also access a data center <NUM> via the host network <NUM>. Thus, each of the vehicles <NUM> can transmit (upload) generated data (e.g. vehicle control and operation data, driver operation data, dynamic map data, moving image data from a dashboard camera, etc.) to the data center <NUM> via the connected base station <NUM>.

Although only two MEC nodes 10a and 10b are present in the example configuration in <FIG>, any number of MEC nodes can be arranged in the communication network. If an LTE (Long Term Evolution)/LTE-Advanced network is envisioned as the communication network, each of the base stations <NUM> is an eNodeB, and EPC (Evolved Packet Core), which is a core network, is included in the host network <NUM>. Furthermore, an external network (e.g. a packet data network (PDN) or the Internet) that is an upper-level network than the core network may also be included in the host network <NUM>.

Note that the communication network to which the present invention is applied may alternatively be a mobile network other than the LTE/LTE-Advanced network. For example, the communication network may alternatively be a fifth-generation (<NUM>) mobile network that is being standardized through the 3rd Generation Partnership Project (3GPP).

In the communication network such as a mobile network to which vehicles (connected cars) are connected, there is a possibility that communication congestion occurs depending on the vehicle congestion and the communication quality deteriorates, as mentioned above. In the present embodiment, to prevent the occurrence of such congestion, the MEC node <NUM> acquires data that indicates a traffic condition in the cells from the connected base stations, predicts the traffic volume in the cells based on the acquired data, and controls uplink traffic from vehicles in the cells.

Specifically, the MEC node <NUM> according to the present embodiment acquires, from each of the one or more connected base stations <NUM>, a measured traffic volume in a target cell, that is each of the cells formed by the one or more base stations <NUM>. The MEC node <NUM> predicts a traffic volume after a unit time in the target cell based on the acquired measured traffic volume. Furthermore, upon receiving, from a vehicle <NUM> in the target cell, an inquiry regarding whether or not data transmission is permitted, the MEC node <NUM> determines whether or not to permit the data transmission based on the result of predicting the traffic volume and the volume of data to be transmitted by the vehicle <NUM>, the volume of data being indicated by information included in the inquiry. The MEC node <NUM> transmits, to the vehicle <NUM> that has transmitted the inquiry, a response indicating whether or not to permit the data transmission in accordance with the result of the determination.

An example configuration of the MEC node <NUM> and an example of a specific processing procedure for realizing such processing will be described below.

<FIG> is a block diagram showing an example hardware configuration of the MEC node <NUM> according to the present embodiment. The MEC node <NUM> includes a CPU <NUM>, a ROM <NUM>, a RAM <NUM>, an external storage device <NUM> (such as an HDD), and a communication device <NUM> (communication interface).

In the MEC node <NUM>, for example, a program for realizing the functions of the MEC node <NUM>, that is stored in any of the ROM <NUM>, the RAM <NUM>, and the external storage device <NUM> is executed by the CPU <NUM>. Note that the CPU <NUM> may be replaced by one or more processors that are constituted by an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), or the like.

The communication device <NUM> communicates with the base stations <NUM> that are connected to the MEC node <NUM> (i.e. communicates with vehicles via the base stations <NUM>), and also communicates with nodes (e.g. the data center <NUM>) that are connected to the host network <NUM>, under the control of the CPU <NUM>. The MEC node <NUM> may have a plurality of communication devices <NUM> that are connected to different destinations.

<FIG> is a block diagram showing an example functional configuration of the MEC node <NUM>, the base station <NUM>, and the vehicle <NUM>. The functions of the MEC node <NUM> are logical functions that are realized by the hardware in <FIG>, for example, and may be realized by the CPU <NUM> executing a program stored in the ROM <NUM> or the like. Note that the MEC node <NUM> may include dedicated hardware for performing the functions, or may perform some of the functions by means of hardware and perform the other functions using a computer that operates a program. All of the functions may be performed by a computer and a program.

In the present embodiment, the MEC node <NUM> has a data transmission-reception unit <NUM>, a traffic monitoring unit <NUM>, a communication flow identification unit <NUM>, a communication control unit <NUM>, a traffic prediction unit <NUM>, a wait time setting unit <NUM>, a base station information DB (database) <NUM>, and a vehicle information DB <NUM>. The base station <NUM> has a data transmission-reception unit <NUM>, a control plane processing unit <NUM>, a data plane processing unit <NUM>, an operation management unit <NUM>, and a session information DB <NUM>. The vehicle <NUM> has a data transmission-reception unit <NUM> and an in-vehicle application <NUM>.

In the base station <NUM>, the data transmission-reception unit <NUM> communicates with one or more wireless terminals in a cell formed by the base station <NUM>, and also communicates with the MEC node <NUM> or an upper-level node. In the cell of the base station <NUM>, there may be not only in-vehicle terminals corresponding to the vehicles <NUM>, but also wireless terminals other than the vehicles.

The control plane processing unit <NUM> transmits and receives signals (control signals) of a control plane via the data transmission-reception unit <NUM> to and from the wireless terminals in the cell, the MEC node <NUM>, or the upper-level node. The data plane processing unit <NUM> transmits and receives signals of a data plane via the data transmission-reception unit <NUM> to and from the wireless terminals in the cell, the MEC node <NUM>, or the upper-level node.

The operation management unit <NUM> manages communication sessions used in communication performed by the control plane processing unit <NUM> and the data plane processing unit <NUM>, and ascertains the communication status of the base station <NUM>. The operation management unit <NUM> stores information related to a communication session to be managed in the session information DB <NUM>. The operation management unit <NUM> measures, as the communication status, the traffic volume (throughput) in the cell. The operation management unit <NUM> may also have a function of measuring, as the traffic volume, the total traffic volume in communication sessions performed by wireless terminals other than the vehicles in the cell. The operation management unit <NUM> transmits, to the MEC node <NUM>, a response that includes information indicating the communication status in the cell of the base station <NUM>, in accordance with an inquiry from the traffic monitoring unit <NUM> of the MEC node <NUM>. The information indicating the communication status in the cell is, for example, a measured traffic volume obtained by measurement. The measured traffic volume may be a measured value of the total traffic volume in communication sessions performed by vehicles and the wireless terminals other than the vehicles, or may be a measured value of the total traffic volume in communication sessions performed by the wireless terminals other than the vehicles.

The data transmission-reception unit <NUM> wirelessly connects to the base station <NUM> corresponding to the serving cell, and communicates, via the base station <NUM>, with the MEC node <NUM> or the data center <NUM> connected to the host network <NUM>. The in-vehicle application <NUM> controls application processing associated with various services for vehicles and controls transmission and reception of data associated with this application processing (such as CAN (Controlled Area Network) or point group data). The in-vehicle application <NUM> communicates, via the data transmission-reception unit <NUM>, with the MEC node <NUM> connected to the base station <NUM>, or a node such as the data center <NUM> connected to the host network <NUM>.

In the present embodiment, the in-vehicle application <NUM> transmits data to the base station <NUM> (i.e. transmits data to a node such as the data center <NUM> via the base station <NUM>) in accordance with transmission control performed by the MEC node <NUM>. When starting data transmission, the in-vehicle application <NUM> makes an inquiry regarding whether or not data transmission is permitted, to the MEC node <NUM>. If transmission is permitted by the MEC node <NUM>, data transmission is started. On the other hand, if data transmission is not permitted, the in-vehicle application <NUM> again makes an inquiry regarding whether or not data transmission is permitted, to the MEC node <NUM> after a wait time, which is set by the MEC node <NUM>, has elapsed.

The data transmission-reception unit <NUM> communicates with the base station <NUM>, and communicates via the base station <NUM> with in-vehicle terminals (vehicles <NUM>) in the cell of this base station. The communication flow identification unit <NUM> identifies a flow of a packet received by the data transmission-reception unit <NUM>, outputs a control packet associated with the communication with the vehicles <NUM> to the communication control unit <NUM>, and stores information obtained from this control packet in the vehicle information DB <NUM>. For example, upon receiving a control packet that includes an inquiry regarding whether or not data transmission is permitted, the communication flow identification unit <NUM> outputs this control packet to the communication control unit <NUM>.

The traffic monitoring unit <NUM> monitors the communication status (traffic) of the base station <NUM> by communicating with the operation management unit <NUM> of the base station <NUM> via the data transmission-reception unit <NUM>. The traffic monitoring unit <NUM> acquires, from the operation management unit <NUM> of the base station <NUM>, information (such as a measured traffic volume) indicating the communication status in the cell of the base station <NUM>, using a function of, for example, an RNI (Radio Network Information) service, which is provided in the standard specifications of MEC. The traffic monitoring unit <NUM> stores the information acquired from the base station <NUM> in the base station information DB <NUM>.

Upon receiving an inquiry regarding whether or not data transmission is permitted, from a vehicle <NUM> in the cell of the base station <NUM>, the communication control unit <NUM> determines whether or not to permit data transmission by this vehicle, and performs transmission control to control data transmission by the vehicle. As will be described later, this transmission control is performed based on the result of the traffic prediction unit <NUM> predicting future traffic, information stored in the vehicle information DB <NUM>, and, as necessary, a wait time set by the wait time setting unit <NUM>. If determining to permit data transmission, the communication control unit <NUM> transmits, to the vehicle that has transmitted the inquiry, a response that includes a permission notification to permit transmission, such that the vehicle <NUM> starts data transmission.

The traffic monitoring unit <NUM> predicts traffic after a unit time in the cell of the base station <NUM>, based on information acquired by the traffic monitoring unit <NUM> and stored in the base station information DB <NUM>, and information stored in the vehicle information DB <NUM>. If it is determined by the communication control unit <NUM> that the vehicle <NUM> is not permitted to transmit data, the wait time setting unit <NUM> sets a wait time until this vehicle makes the next inquiry to the MEC node <NUM>. As will be described later, setting of the wait time is performed based on the result of the traffic prediction unit <NUM> predicting the future traffic (after the unit time), and information stored in the vehicle information DB.

<FIG> and <FIG> show examples of information managed by the MEC node <NUM>. <FIG> shows an example of information stored in the base station information DB <NUM>, and <FIG> shows an example of information stored in the vehicle information DB <NUM>. Note that the information included in the base station information DB <NUM> and the vehicle information DB <NUM> are managed in a state in which it stored in the external storage device <NUM>.

As shown in <FIG>, in the base station information DB <NUM>, a cell ID of each of the cells formed by one or more base stations <NUM> connected to the MEC node <NUM>, and history of the traffic volume (information indicating the communication status) in the cell corresponding to the cell ID are registered. Every time the traffic monitoring unit <NUM> acquires information from the operation management unit <NUM> of the base station <NUM>, the acquired information may be registered in association with time information in the base station information DB <NUM>.

Note that the information stored in the base station information DB <NUM> is not limited to the information shown in <FIG>. For example, an average in-cell time during which the vehicle <NUM> is in each cell may be added. In this case, the traffic monitoring unit <NUM> monitors the average in-cell time of the vehicle in each of the cells formed by the base stations <NUM> connected to the MEC node <NUM>, based on the information acquired from the base station <NUM> (operation management unit <NUM>), and registers the average in-cell time in the base station information DB <NUM>.

As shown in <FIG>, in the vehicle information DB <NUM>, information included in an inquiry regarding whether or not data transmission is registered when this inquiry is received from the vehicle <NUM> in the cell of the base station <NUM>. The inquiry from the vehicle <NUM> at least includes information that indicates a vehicle ID, a service type, a volume of data to be transmitted, and a volume of transmitted data, and this information is registered in the vehicle information DB <NUM>.

The service type refers to a service type associated with the data transmitted by the vehicle <NUM>, and indicates, for example, whether the data to be transmitted by the vehicle <NUM> is CAN data, point group data, or other data. Thus, the service type may indicate the degree of urgency or the real-time property of transmission data.

The volume of data to be transmitted refers to the total volume of transmission data that the vehicle <NUM> has. The volume of transmitted data refers to the volume of data that has already been transmitted by the vehicle thus far, out of the volume of data to be transmitted. For example, in a case where data transmission is interrupted due to the vehicle <NUM> performing handover between cells, a value that is not <NUM> may be set as the volume of transmitted data.

In the vehicle information DB <NUM>, a cell ID (serving cell ID) of a cell by which the vehicle <NUM> is served is further registered. Note that, when an inquiry from the vehicle <NUM> is received, the cell ID included in the received packet is registered as the serving cell ID. Also, in the vehicle information DB <NUM>, the next scheduled communication time of the vehicle <NUM> corresponding to the vehicle ID is further registered. The next scheduled communication time is set as the result of the communication control unit <NUM> determining whether or not to permit data transmission by the vehicle <NUM>. If transmission is permitted, "now" is registered, and if transmission is not permitted, the time corresponding to the wait time set by the wait time setting unit <NUM> is registered.

Note that the information stored in the vehicle information DB <NUM> is not limited to the information shown in <FIG>. For example, history of the serving cell IDs may also be added. Thus, the history of movement between the cells formed by one or more base stations <NUM> may be held as the history of the serving cell IDs for each vehicle in the vehicle information DB <NUM>.

Next, a description will be given, with reference to <FIG> and <FIG>, of a specific procedure of transmission control for controlling data transmission from the vehicle <NUM>, performed by the MEC node <NUM>. <FIG> is a flowchart showing the procedure of the transmission control performed by the MEC node <NUM>. <FIG> is a diagram showing an example of a method of predicting a traffic volume performed by the traffic prediction unit <NUM>.

First, in step S1, the traffic monitoring unit <NUM> acquires, from the base station <NUM>, a measured value of the traffic volume (measured traffic volume) in a target cell, which is each of the cells that are to be managed by the MEC node <NUM>. Note that the traffic volume indicates throughput, for example. The measured traffic volume is acquired by the traffic monitoring unit <NUM> at time intervals (e.g. once in several minutes) that enable prediction of the traffic volume in step S2. The measured traffic volume is registered as traffic volume history in the base station information DB <NUM>.

Next, in step S2, the traffic prediction unit <NUM> predicts the traffic volume after the unit time based on the result of acquiring the measured value of the traffic volume. In the present embodiment, acquisition of the measured traffic volume and prediction of the traffic volume are performed at predetermined sampling intervals, as shown in <FIG>. Given that the current time is t, the traffic prediction unit <NUM> predicts the traffic volume at future times (time t+<NUM>, t+<NUM>,. ) based on the measured traffic volumes acquired before the time t. A specific method of predicting a traffic volume will be described later with reference to <FIG>.

Thereafter, in step S3, the communication control unit <NUM> determines whether or not an inquiry regarding whether or not data transmission is permitted has been received via the base station <NUM> from any of the vehicles <NUM> in the target cell.

Here, in the case of transmitting data (e.g. CAN data or point group data) associated with the in-vehicle application <NUM> to, as a destination, the data center <NUM>, the MEC node <NUM>, or the like, first, the vehicle <NUM> makes an inquiry regarding whether or not transmission is permitted, to the MEC node <NUM> that manages the serving cell. Then, if the vehicle <NUM> receives from the MEC node <NUM> a response including a permission notification indicating that transmission is permitted, the vehicle <NUM> starts data transmission. On the other hand, if the vehicle <NUM> receives from the MEC node <NUM> a response including a non-permission notification indicating that transmission is not permitted, the vehicle <NUM> again makes an inquiry regarding whether or not transmission is permitted, after a wait time designated in this response has elapsed.

If no inquiry has been received from a vehicle <NUM> in the target cell <NUM>, the communication control unit <NUM> returns the processing from step S3 to step S1, and if an inquiry has been received, the communication control unit <NUM> advances the processing from step S3 to step S4.

In step S4, the communication control unit <NUM> determines whether or not to permit data transmission by the vehicle <NUM> that has transmitted the inquiry, based on the result of predicting the traffic volume (predicted value of the traffic volume after the unit time) in step S2 and the volume of data to be transmitted that is included in the received inquiry.

Specifically, the communication control unit <NUM> permits transmission if the traffic volume for transmitting data to be transmitted does not exceed a communicable traffic volume that corresponds to a difference between the predicted value of the traffic volume and a target value of a traffic volume L shown in <FIG>. At this time, the communication control unit <NUM> may permit transmission if the traffic volume for transmitting a remaining data volume after excluding the volume of transmitted data from the volume of data to be transmitted does not exceed the communicable traffic volume.

Also, in such a case where inquiries are received from a plurality of vehicles, the communication control unit <NUM> may determine whether or not to permit data transmission for each of the vehicles, based on the priority corresponding to the service type indicated by information included in the inquiries. For example, the higher the degree of urgency or the real-time property indicated by the service type is, the higher the priority given to permitting data transmission is. Communication with a lower degree of urgency or real-time property is allowed to be performed while avoiding a congested area (cell), and communication with a higher degree of urgency or real-time property is allowed to be preferentially started so that its communication stability can be increased.

Also, in such a case where inquiries are received from a plurality of vehicles, the communication control unit <NUM> may make a determination to permit data transmission while giving priority to vehicles that have transmitted inquiries that include information indicating that the volume of transmitted data is not <NUM>. The communication control unit <NUM> may also make a determination to permit data transmission while giving priority to vehicles whose remaining data volume after excluding the volume of transmitted data from the volume of data to be transmitted is smaller. Thus, communication by a vehicle that has already started data transmission can be completed earlier.

Next, in step S5, the communication control unit <NUM> advances the processing to step S6 if transmission is permitted for the received inquiry, and advances the processing to step S7 if transmission is not permitted, in accordance with the determination made in step S4.

In step S6, the communication control unit <NUM> transmits a response that includes a permission notification indicating that transmission is permitted, to the vehicle <NUM> that has transmitted the inquiry, and returns the processing to step S1. The vehicle <NUM> in the target cell that has received the response that includes the permission notification starts data transmission to the base station <NUM>.

On the other hand, in step S7, the communication control unit <NUM> transmits a response that includes a non-permission notification indicating that transmission is not permitted, to the vehicle <NUM> that has transmitted the inquiry, and returns the processing to step S1. At this time, the communication control unit <NUM> includes a wait time set by the wait time setting unit <NUM> in the response to notify the vehicle <NUM> of the wait time. The wait time setting unit <NUM> calculates the remaining data volume after excluding the volume of transmitted data from the volume of data to be transmitted, based on the result of predicting the traffic volume and the information included in the received inquiry, and sets the wait time such that the vehicle <NUM> makes the next inquiry in accordance with the timing at which data of the remaining data volume can be transmitted. Thus, the communication control unit <NUM> controls the timing at which the vehicle <NUM> transmits the next inquiry to the MEC node <NUM> by designating the wait time for the vehicle <NUM>.

Next, a description will be given of a specific example of the method of predicting a traffic volume performed by the traffic prediction unit <NUM>, again referring to <FIG>. The traffic volume is predicted through the following processing (<NUM>) to (<NUM>).

First, the traffic prediction unit <NUM> acquires an estimated value of a base traffic volume, as shown in <FIG>, by estimating the base traffic volume at the current time t. The base traffic volume corresponds to the total traffic volume in communication sessions performed by wireless terminals other than vehicles, out of the measured traffic volume in the target cell. The base traffic volume is used in traffic prediction (i.e. the traffic volume in communication sessions performed by vehicles is excluded) because the traffic volume in the communication sessions performed by the vehicles may dynamically vary due to high moving speed of the vehicles, and is not appropriate for prediction of the traffic volume using an exponential smoothing method or the like.

The estimated value of the base traffic volume can be obtained by, for example, subtracting an estimated value of the total traffic volume in communication sessions performed by the vehicles <NUM> in the target cell, from the measured traffic volume. The estimated value of the total traffic volume of the vehicles can be estimated, to some extent, based on the inquiries regarding whether or not data transmission is permitted, that have been made by the vehicles <NUM> in the target cell. The timing at which each of the vehicles <NUM> transmits data and the traffic volume (transmission data volume) at this timing can be determined, to some extent, based on the inquiries made by the vehicles <NUM>, and these values can be used in the estimation of the total traffic volume.

Alternatively, in a case where the total traffic volume in communication sessions performed by wireless terminals other than the vehicles in the target cell can be acquired as a measured traffic volume from the base station <NUM>, the acquired measured traffic volume may be used as the estimated value of the base traffic volume.

Note that, in <FIG>, the difference between the measured value of the traffic volume (measured traffic volume) and the estimated value of the base traffic volume corresponds to the estimated value of the total traffic volume (vehicle traffic volume) in communication sessions performed by the vehicles in the target cell.

Next, the traffic prediction unit <NUM> obtains a predicted value (first predicted value) of the base traffic volume after the unit time (time t+<NUM>, t+<NUM>,. ) using a prediction algorithm such as an exponential smoothing method or the like, based on the acquired estimated values of the base traffic volume.

Next, the traffic prediction unit <NUM> obtains a predicted value (second predicted value) of the vehicle traffic volume after the unit time, based on the inquiries regarding whether or not data transmission is permitted, that have been made by the vehicles <NUM> in the target cell. Specifically, the traffic prediction unit <NUM> determines a vehicle that will possibly transmit data after the unit time (time t+<NUM>, t+<NUM>,. ), based on the inquiries made by the vehicles <NUM>, and uses, in the prediction of the vehicle traffic volume, the volume of data to be transmitted when the determined vehicle transmits data.

The accuracy of the vehicle traffic volume prediction can be increased by using an average in-cell time of the vehicles <NUM> in the target cell, for example. Specifically, the traffic prediction unit <NUM> determines whether or not there is a possibility that a specific vehicle in the target cell will transmit data in the target cell after the unit time, based on the average in-cell time in the target cell and the wait time that is set in accordance with the inquiry made by this specific vehicle. Furthermore, in a case where there is a possibility that data will be transmitted in the target cell, the traffic prediction unit <NUM> uses the data traffic volume that is scheduled for the specific vehicle to obtain the predicted value (second predicted value) of the vehicle traffic volume. Thus, if there is a possibility that a vehicle that has made an inquiry to the MEC node <NUM> will again make an inquiry in the same cell and transmit data, the volume of data that will be transmitted by the vehicle is used in the prediction of the vehicle traffic volume. As a result, the prediction accuracy can be increased.

The accuracy of the vehicle traffic volume prediction can also be increased by using movement history of the vehicles <NUM>, for example. Specifically, the traffic prediction unit <NUM> determines a vehicle that will possibly perform handover to the target cell and transmit data after the unit time, based on the movement history of each vehicle held in the vehicle information DB <NUM> and the inquiry made by each vehicle. Furthermore, the traffic prediction unit <NUM> uses the data traffic volume scheduled for the determined vehicle to obtain the predicted value (second predicted value) of the vehicle traffic volume. Thus, the prediction accuracy can be increased by predicting the vehicle traffic volume while giving consideration to the influence of handover by the vehicle.

As shown in <FIG>, the predicted value of the traffic volume can be obtained by adding the predicted value (second predicted value) of the vehicle traffic volume to the predicted value (first predicted value) of the base traffic volume. For this reason, the traffic prediction unit <NUM> outputs the sum of the first predicted value and the second predicted value as the predicted value of the traffic volume after the unit time (time t+<NUM>, t+<NUM>,. ) in the target cell.

As described above, in the present embodiment, the MEC node <NUM> acquires the measured traffic volume in each of the cells (target cell) formed by one or more connected base stations <NUM>, from each of the base stations <NUM>. The MEC node <NUM> predicts the traffic volume after the unit time in the target cell, based on the acquired measured traffic volumes. Furthermore, upon receiving, from a vehicle <NUM> in a target cell, an inquiry regarding whether or not data transmission is permitted, the MEC node <NUM> determines whether or not to permit the data transmission based on the result of predicting the traffic volume and the volume of data to be transmitted by this vehicle <NUM>, that is indicated by information included in the inquiry. The MEC node <NUM> transmits a response indicating whether or not to permit the data transmission, to the vehicle <NUM> that has transmitted the inquiry, in accordance with the determination result.

Thus, the MEC node <NUM> can appropriately control the timing at which each vehicle <NUM> in the cells of the connected base stations <NUM> transmits data, in accordance with the traffic volume predicted in the cells so as to avoid the occurrence of congestion. In addition, each vehicle <NUM> in the cells can be aware of an appropriate communication timing, and becomes possible to transmit data at an appropriate timing in accordance with the transmission control performed by the MEC node <NUM>. Accordingly, it becomes possible to suppress communication in a congested cell (area), prevent the occurrence of congestion, and avoid deterioration of the communication quality due to the occurrence of congestion.

Note that the above embodiment has described the case where the MEC node <NUM> performs, for each of the cells, transmission control for the vehicles <NUM>. However, if sectors are formed by the base station <NUM>, similar transmission control can also be applied to each of the sectors.

Claim 1:
A node apparatus (<NUM>) that is connectable to one or more base stations (<NUM>) and is configured to control uplink data transmission by vehicles (<NUM>) traveling in cells formed by the one or more base stations (<NUM>), the node apparatus (<NUM>) comprising:
acquiring means (<NUM>) for acquiring, from each of the one or more base stations (<NUM>), a measured traffic volume in a target cell, that is each of the cells formed by the one or more base stations (<NUM>);
prediction means (<NUM>) for predicting a traffic volume after a unit time in the target cell, based on the measured traffic volume acquired by the acquiring means (<NUM>);
determination means (<NUM>) for determining, upon an inquiry regarding whether or not uplink data transmission is permitted being received from a vehicle (<NUM>) in the target cell, whether or not to permit uplink data transmission by the vehicle (<NUM>), wherein the determination is performed based on a prediction result of the prediction means (<NUM>) predicting the traffic volume, and on a volume of data to be transmitted by the vehicle (<NUM>), and wherein the volume of data to be transmitted by the vehicle (<NUM>) is indicated by information included in the inquiry that has been received from the vehicle (<NUM>); and
transmission means (<NUM>) for transmitting, to the vehicle (<NUM>) that has transmitted the inquiry, a response indicating whether or not to permit uplink data transmission in accordance with the determination made by the determination means (<NUM>).