Communication device, communication method, and communication program

Abstract

To provide a communication device, a method, and a program that transmit data used for estimating an available bandwidth by a communication device mounted on a mobile body such that an external device can accurately estimate the available bandwidth of the communication device.SOLUTION: A communication device 100 is mounted on a mobile body such as an automobile and performs wireless communication with an external device located outside the mobile body via a communication network includes a data acquisition unit that acquires data, an instruction unit that detects changes in the communication environment of the communication network. and instructs the external device to transmit data as estimation data to be used for estimating the available bandwidth of the communication network on the basis of the detection result, and a transmission unit that transmits the estimation data on the basis of an instruction from the instruction unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention mainly relates to a communication device mounted on a moving body such as an automobile, a communication device that communicates with a server device for estimating an available band, and a communication method and a communication program executed by the communication device.

Background Art

[0002] It is known that the band available in a communication network affects the communication quality of wireless communication. Therefore, in order to ensure comfortable communication quality and perform communication, it is important to grasp and manage the band available in the communication network, that is, the available band. Therefore, various techniques for estimating the available band have been proposed conventionally.

[0003] For example, Patent Document 1 describes estimating an available band with a small number of test packets by using test packets of different sizes.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, as a result of detailed examination, the present inventor has found the following problems. Conventional methods estimate available bandwidth by periodically sending test packets with a fixed amount of data. In communication devices installed in automobiles, the cell to which the communication device is connected changes as the automobile moves. Therefore, if conventional methods are used in automobile-mounted communication devices, the automobile may move from the currently connected cell to an adjacent cell while test packets are being sent. However, in the boundary region between adjacent cells, the available bandwidth changes significantly due to the congestion of the cell and the effects of frequency changes. Therefore, if the conventional method of periodically sending test packets to estimate available bandwidth is adopted, there is a risk that the available bandwidth cannot be accurately estimated in the cell boundary region.

[0006] Furthermore, it is known that estimating a wide bandwidth requires more data than estimating a narrow bandwidth. However, methods that send test packets with a fixed amount of data may either fail to send packets with enough data to perform bandwidth estimation, or send packets with too much data to perform bandwidth estimation.

[0007] Therefore, the present invention aims to realize a communication device, etc., that can appropriately transmit data used for bandwidth estimation, so that the available bandwidth of a communication device mounted on a mobile device can be accurately estimated. [Means for solving the problem]

[0008] A communication device (100) according to one aspect of the present disclosure is a communication device mounted on a mobile body and performing wireless communication with an external device located outside the mobile body via a communication network, comprising a data acquisition unit (101) for acquiring data, A splitting unit (102) divides the aforementioned data into a first number of packets, The external device detects changes in the communication environment of the aforementioned communication network and, according to the detection results, uses the aforementioned data as estimation data to estimate the available bandwidth of the communication network. Multiple packets An instruction unit (103) that instructs to transmit, and based on the instructions from the instruction unit, Multiple packets of At predetermined intervals, the external deviceThe transmitting unit (104) that transmits, The system includes a receiving unit (105) that receives estimation success / failure information from the external device indicating whether or not the available bandwidth could be estimated using the first number of packets, and if the estimation success / failure information indicates that the available bandwidth could not be estimated, the instruction unit further instructs the splitting unit to divide the data into a second number of packets greater than the first number.

[0009] Another aspect of the present disclosure, a communication device (100), is mounted on a mobile body and performs wireless communication via a communication network with an external device located outside the mobile body, wherein the external device is a device that estimates the available bandwidth of the communication network using a plurality of estimation packets obtained by dividing estimation data, and the communication device comprises: a data acquisition unit (101) that acquires data; a receiving unit (105) that receives estimation success / failure information from the external device indicating whether or not the available bandwidth could be estimated using a first number of estimation packets obtained by dividing the estimation data having a predetermined amount of data; an instruction unit (103) that, when the estimation success / failure information indicates that the available bandwidth could not be estimated, instructs the data having a predetermined amount of data to be divided into a second number of packets greater than the first number; a division unit (102) that, based on the instruction from the instruction unit, divides the data acquired by the data acquisition unit into the second number of packets; and a transmission unit (104) that transmits the second number of packets to the external device at predetermined intervals.

[0010] The numbers in parentheses attached to the claims and the constituent elements of the invention described in this section indicate the correspondence between the present invention and the embodiments described later, and are not intended to limit the present invention. [Effects of the Invention]

[0011] With the configuration described above, the communication device of this disclosure makes it possible to accurately estimate the available bandwidth even when the communication device is located in the cell boundary area. Furthermore, the communication device of this disclosure makes it possible to appropriately transmit the data necessary for bandwidth estimation according to the bandwidth estimation status of the external device. [Brief explanation of the drawing]

[0012] [Figure 1] Explanatory diagram illustrating the arrangement of the communication device in each embodiment and its relationship to related equipment. [Figure 2] Explanatory diagram for explaining the configuration example of the communication device of each embodiment [Figure 3] Diagram for explaining the method of calculating the available bandwidth by an external device [Figure 4] Flowchart for explaining the operation of the communication device of Embodiment 1 [Figure 5] Flowchart for explaining the operation of the communication device of the modification example of Embodiment 1 [Figure 6] Flowchart for explaining the operation of the communication device of Embodiment 2 [Figure 7] Flowchart for explaining the operation of the communication device of Embodiment 2

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] Note that the present invention means the invention described in the claims or the section of means for solving the problems, and is not limited to the following embodiments. Also, at least the words in parentheses mean the words described in the claims or the section of means for solving the problems, and are not similarly limited to the following embodiments.

[0015] The configurations and methods described in the dependent claims of the claims are arbitrary configurations and methods in the invention described in the independent claims of the claims. The configurations and methods of the embodiments corresponding to the configurations and methods described in the dependent claims, and the configurations and methods described only in the embodiments without description in the claims are arbitrary configurations and methods in the present invention. The configurations and methods described in the embodiments when the description of the claims is wider than the description of the embodiments are also arbitrary configurations and methods in the present invention in the sense that they are examples of the configurations and methods of the present invention. In any case, by being described in the independent claims of the claims, they become the essential configurations and methods of the present invention.

[0016] The effects described in the embodiments are the effects when having the configurations of the embodiments as examples of the present invention, and are not necessarily the effects of the present invention.

[0017] When there are a plurality of embodiments, the configurations disclosed in each embodiment are not limited to each embodiment only, and can be combined across embodiments. For example, the configuration disclosed in one embodiment may be combined with another embodiment. Also, the configurations disclosed in each of the plurality of embodiments may be collected and combined.

[0018] The problems described as the problems to be solved by the invention are not well-known problems, but are the findings uniquely made by the inventor, and are facts affirming the inventive step together with the configuration and method of the present invention.

[0019] 1. Configuration underlying each embodiment (1) Arrangement of communication device and relationship with related devices FIG. 1 is a diagram for explaining the communication device 100 of each embodiment and the relationship with related devices. As shown in FIG. 1, the communication device 100 is “mounted” on a vehicle which is a “mobile object”.

[0020] Here, the “mobile object” refers to an object that can move, and the moving speed is arbitrary. Also, the case where the mobile object is stopped is of course included. For example, it includes automobiles, motorcycles, bicycles, and things mounted on them, and is not limited thereto. “Mounted” includes not only the case of being directly fixed to the mobile object, but also the case of not being fixed to the mobile object but moving together with the mobile object. For example, the case of being held by a person riding in a vehicle which is a mobile object, and the case of being mounted on a load placed on the mobile object can be mentioned.

[0021] The communication device 100 is connected to an electronic control unit 10 (hereinafter, ECU: Electronic Control Unit) mounted on the vehicle together with the communication device 100. The ECU 10 is, for example, an ECU that controls the operation and running of the vehicle.

[0022] The communication device 100 further communicates wirelessly with an external device 20 located outside the vehicle via a communication network. The external device 20 is any device located outside the vehicle and estimates the available bandwidth of the communication network. Examples of external devices 20 include a server device located in a Security Operation Center (SOC) that manages vehicle security remotely, or a data center that collects data related to the vehicle.

[0023] In Figure 1, the communication device 100 and the external device 20 are connected via a communication network using wireless communication methods such as IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution), LTE-A (Long Term Evolution Advanced), 4G, and 5G. Alternatively, a line combining wireless and wired communication methods may be used. For example, the communication device 100 and the base station equipment in a cellular system may be connected using a wireless communication method such as 4G, and the base station equipment and the external device 20 may be connected using a wired communication method such as a backbone line of a telecommunications carrier or the internet. A gateway device may be provided at the point of contact between the backbone line and the internet.

[0024] (2) Configuration of the communication device 100 Next, the configuration of the communication device 100 will be described with reference to Figure 2. Note that for each component of the communication device 100, functions specific to each embodiment will be described in detail in each embodiment. Furthermore, among the components shown in Figure 2, those not used in each embodiment are not necessarily essential components of the communication device 100 in that embodiment.

[0025] Figure 2 is a block diagram showing an example configuration of the communication device 100. The communication device 100 includes a data acquisition unit 101, a splitting unit 102, an instruction unit 103, a transmission unit 104, a receiving unit 105, and a dummy data addition unit 106.

[0026] The data acquisition unit 101 acquires data to be transmitted to the external device 20. For example, the data acquisition unit 101 acquires vehicle data from the ECU 10 that indicates the status of the vehicle. The vehicle data may include, for example, information indicating the operating status of the vehicle, such as driving, steering, and speed, as well as information indicating the status of devices installed in the vehicle, such as the status of the ECU 10 and the communication device 100 installed in the vehicle. Examples of vehicle data indicating the status of the ECU 10 and the communication device 100 include so-called diagnostic data that shows the results of fault diagnosis of these devices.

[0027] The following embodiments describe a case where the data acquired by the data acquisition unit 101 is vehicle data, but the data acquired by the data acquisition unit 101 is not limited to vehicle data. For example, if the communication device 100 is mounted on a mobile body other than a vehicle, the data acquisition unit 101 will acquire data other than vehicle data.

[0028] Furthermore, the data acquisition unit 101 may acquire dedicated data for the external device 20 to perform bandwidth estimation instead of vehicle data. However, as will be described later, the data acquired by the data acquisition unit 101 is transmitted to the external device 20 as estimation data for estimating the available bandwidth. Therefore, it is desirable to reduce the amount of communication traffic to the communication device 100 by acquiring vehicle data that is originally scheduled to be transmitted to the external device 20 and using it as estimation data, rather than acquiring dedicated data used solely for bandwidth estimation.

[0029] The splitting unit 102 extracts all or part of the vehicle data acquired by the data acquisition unit 101 and divides it into multiple packets.

[0030] The instruction unit 103 instructs the transmission unit 104, described later, to transmit vehicle data as estimation data used by the external device 20 to estimate the available bandwidth of the communication network. For example, if a certain amount of time has elapsed since vehicle data was previously transmitted to the external device 20 as estimation data, the instruction unit 103 instructs the transmission unit 104 to transmit the next vehicle data as estimation data. Here, the instruction unit 103 may also instruct the transmission unit 104 to transmit vehicle data divided into multiple packets as estimation data.

[0031] In Embodiment 1, described later, the instruction unit 103 further instructs the transmission unit 104 on the timing to transmit vehicle data at a time different from the timing when a certain period of time has elapsed. In Embodiment 2, also described later, the instruction unit 103 further instructs the division unit 102 on the amount of vehicle data to be divided, etc. The content of the instructions that the instruction unit 103 gives to the division unit 102 and the transmission unit 104 will be described in detail in each embodiment.

[0032] The transmitting unit 104 transmits vehicle data to the external device 20 based on instructions from the instruction unit 103. If the splitting unit 102 has divided the vehicle data into multiple packets, the transmitting unit 104 transmits the vehicle data by sending the multiple packets at predetermined intervals. For example, if the splitting unit 102 has divided the vehicle data into eight packets, the transmitting unit 104 sequentially sends the eight packets to the external device 20 at predetermined intervals.

[0033] The receiving unit 105 receives information transmitted from the external device 20. For example, the receiving unit 105 receives estimated bandwidth information that indicates the available bandwidth estimated by the external device 20.

[0034] The communication device 100 can use the estimated bandwidth information received by the receiving unit 105 to control the transmission rate when transmitting various data acquired by the ECU 10, such as video captured by an in-vehicle camera, or to consider a driving plan for when the vehicle travels in the same area in the future.

[0035] The dummy data addition unit 106 generates dummy data as needed and adds it to the vehicle data acquired by the data acquisition unit 101.

[0036] As described above, the communication device 100 is assumed to transmit vehicle data to the external device 20 as estimation data at regular time intervals. However, this time interval may always be constant, or it may be variable. For example, the time interval for transmitting vehicle data may be changed according to the vehicle's speed. The available bandwidth of the communication network may differ depending on the vehicle's position. Therefore, when the vehicle is moving at high speed, the change in available bandwidth is greater than when it is moving at low speed. Thus, the faster the vehicle is moving, the shorter the time interval for transmitting vehicle data as estimation data may be.

[0037] Furthermore, the time interval for transmitting vehicle data as estimation data may be set based on instructions from the external device 20. For example, if the external device 20 has been able to sufficiently measure the available bandwidth in the area where the vehicle is located based on past performance, it instructs the communication device 100 to lengthen the time interval for transmitting vehicle data. Conversely, if the external device 20 has not been able to sufficiently measure the available bandwidth in the area where the vehicle is located, it instructs the communication device 100 to shorten the time interval for transmitting vehicle data. The instruction unit 103 then instructs the communication device 100 to transmit vehicle data as estimation data at the time interval instructed by the external device 20.

[0038] Alternatively, if the external device 20 can estimate the available bandwidth using data other than vehicle data transmitted from the communication device 100 or other communication devices (not shown) mounted on the vehicle, the time interval for transmitting vehicle data as estimation data may be increased.

[0039] Furthermore, if the vehicle data is diagnostic data and is particularly urgent, for example, if it relates to a critical error or cyberattack, the vehicle data may be immediately transmitted as estimation data.

[0040] (3) Estimation of available bandwidth by external device 20 External device 20 is a device that estimates the available bandwidth of the communication network used by communication device 100. External device 20 estimates the available bandwidth of the communication network using estimation data received from communication device 100. The estimation data may be divided into multiple estimation packets. The method of estimating the available bandwidth using multiple estimation packets is also called the packet train method. Here, the method of estimating the available bandwidth using the packet train method will be explained with reference to Figure 3.

[0041] Figure 3 shows multiple packets transmitted from the communication device 100 as estimation data and multiple estimation packets received by the external device 20. As shown in Figure 3, estimation data is a collection of multiple estimation packets. Figure 3 shows an example in which the external device 20 calculates available bandwidth using estimation data divided into eight estimation packets.

[0042] When the external device 20 receives an estimation packet from the communication device 100, it calculates the available bandwidth using the following formula (1).

[0043]

number

[0044] Here, the packet data amount in Equation 1 is the data amount of each of the multiple estimation packets, and the reception interval is the interval between the reception of the estimation packets (t1, t2, etc.). In the example in Figure 3, the external device 20 estimates the available bandwidth for eight estimation packets using Equation 1. Then, it derives the available bandwidth based on the calculation results for the eight estimation packets. For example, the average or median value of the calculation results for the eight estimation packets is calculated as the available bandwidth of the communication network.

[0045] When the external device 20 calculates the available bandwidth using the method described above, it notifies the communication device 100 of the calculation result of the available bandwidth.

[0046] 2. First Embodiment (1) Functions of each component of the communication device 100 In this embodiment, we will describe a configuration in which data for bandwidth estimation is transmitted to an external device 20 in response to changes in the communication environment of the communication device 100. First, we will describe the functions specific to this embodiment for each component of the communication device 100.

[0047] In this embodiment, the instruction unit 103 "detects" a change in the "communication environment" of the communication network, and in response to the detection result, instructs the transmission unit 104 to transmit the vehicle data, which has been divided into multiple packets by the splitting unit 102, as estimation data that the external device 20 will use to estimate the available bandwidth of the communication network.

[0048] Here, "communication environment" refers to, for example, the characteristics, attributes, or switching of communication cells to which base stations or communication equipment used for communication with external devices belong, as well as radio wave strength (RSRP: Reference Signal Received Power), radio wave quality (Reference Signal Received Quality), signal-to-noise ratio (RSSNR: Reference Signal Signal to Noise Ratio), or signal strength (Received Signal Strength Indicator). "Detection" includes not only cases where the instruction unit itself has a detection function to detect changes in the communication environment, but also cases where it detects changes by acquiring information indicating changes in the communication environment.

[0049] For example, if the detection result of a change in the communication environment is a switch in the base station to which the communication device 100 is connected, the instruction unit 103 instructs the transmission unit 104 to transmit vehicle data as estimation data.

[0050] The available bandwidth of the communication network differs depending on the base station to which the communication device 100 is connected. Therefore, when the base station to which the communication device 100 is connected switches, the estimated available bandwidth result by the external device 20 may change significantly. For example, if the communication device 100 transmits vehicle data as estimation data at 5-minute intervals, and the base station to which the communication device 100 is connected switches during these 5 minutes, the most recently estimated available bandwidth (i.e., the available bandwidth at the base station before the switch) and the actual available bandwidth (i.e., the available bandwidth at the base station after the switch) may differ significantly.

[0051] Therefore, in this embodiment, when the communication device 100 detects a switch in the base station to which it is connected, the external device 20 transmits estimation data used to estimate the available bandwidth. This enables the external device 20 to estimate the available bandwidth of the latest communication network used by the communication device 100.

[0052] Alternatively, if the detection result of a change in the communication environment indicates that the "amount of change" in the communication quality of the communication network is "greater than" a threshold, the instruction unit 103 instructs the transmission unit 104 to transmit vehicle data as estimation data.

[0053] Here, "amount of change" can refer not only to the rate of change, but also to the difference between the values ​​before and after the change. "Greater than or equal to" includes both cases where the value is the same as the comparison target and cases where it is not.

[0054] For example, if the communication quality of a communication network, which is represented by indicators such as RSRP (radio wave strength) and RSRQ (reception quality), changes rapidly, the available bandwidth may also change along with this change. Therefore, when the instruction unit 103 detects a rapid change in the communication quality of the communication device 100, it instructs the transmission unit 104 to transmit vehicle data as estimation data.

[0055] Furthermore, a sudden change in communication quality includes both cases where communication quality deteriorates rapidly and cases where communication quality improves rapidly.

[0056] Here, the instruction unit 103 may have a function to detect changes in the communication environment of the communication network. For example, the instruction unit 103 may acquire base station information acquired by the wireless environment acquisition unit (not shown) of the communication device 100 and use the base station information to detect the switching of the base station to which the communication device 100 is connected. Alternatively, the instruction unit 103 may detect changes in the communication environment by acquiring information notifying of changes in the communication environment from a configuration provided in the communication device 100 or ECU 10 that detects changes in the communication environment. For example, a detection unit (not shown) provided in the communication device 100 or ECU 10 may detect a base station switch, and the instruction unit 103 may acquire information notifying of the base station switch from the detection unit.

[0057] (2) Operation of the communication device 100 Next, the operation of the communication device 100 of this embodiment will be described with reference to Figure 4. Figure 4 not only shows the communication method executed by the communication device 100, but also the processing procedure of a communication program that can be executed by the communication device 100. These processes are not limited to the order shown in Figure 4. That is, the order can be changed unless there is a constraint such as a relationship where one step utilizes the result of the preceding step. The same applies to the drawings relating to other embodiments and modifications described later.

[0058] The data acquisition unit 101 acquires vehicle data (S101). The splitting unit 102 divides the vehicle data acquired in S101 into multiple packets (S102). Here, if a certain amount of time has elapsed since the transmission unit 104 last transmitted vehicle data to the external device 20 as estimation data (S103:Y), the instruction unit 103 instructs the transmission unit 103 to transmit the vehicle data, which has been divided into multiple packets, to the external device 20 as estimation data (S104). Then, based on the instructions from the instruction unit 103, the transmission unit 104 transmits the estimation data to the external device 20 (S105). Since the estimation data to be transmitted in S105 has been divided into multiple packets in S102, in S105 the multiple packets are transmitted sequentially to the external device 20.

[0059] In contrast, if a certain amount of time has not elapsed in S103 (S103:N), the instruction unit 103 determines whether it has detected a change in the communication environment of the communication network (S106). If a change in the communication environment is detected here (S106:Y), the instruction unit 103 further determines whether the detected change in the communication environment is a predetermined detection result (S107). Here, the predetermined detection result is, for example, a switch in the base station to which the communication device 100 is connected, or a sudden change in communication quality. Then, if the detection result is a predetermined detection result, the instruction unit 103 instructs the external device 20 to transmit the vehicle data, which has been divided into multiple packets in S102, as estimation data (S104). Then, the transmission unit 104 transmits the estimation data to the external device 20 (S105).

[0060] (3) Summary According to this embodiment, the communication device 100 can transmit data necessary for the external device 20 to estimate the available bandwidth in response to the detection result of a change in the communication environment. As a result, even in situations where the available bandwidth changes due to a change in the communication environment of the communication device 100, the external device 20 can accurately estimate the available bandwidth of the communication network used by the communication device 100.

[0061] 3. Modified form of the first embodiment Whether the external device 20 can estimate the available bandwidth using the estimation data depends on the amount of estimation data. Specifically, the larger the amount of estimation data, the wider the bandwidth that can be estimated. In other words, a larger amount of estimation data is needed to estimate a wider bandwidth, and a smaller amount of estimation data is not needed to estimate a narrower bandwidth. In short, an appropriate amount of estimation data is necessary to correctly estimate the available bandwidth.

[0062] Therefore, in this modified example, a configuration is described in which the amount of estimation data to be transmitted to the external device 20 is appropriately set based on instructions from the external device 20.

[0063] (1) Configuration of the communication device 100 In this modified example, the receiving unit 105 receives estimation data volume information from the external device 20. The estimation data volume information indicates the amount of estimation data necessary for the external device 20 to estimate the available bandwidth.

[0064] The receiving unit 105 may also receive, in addition to the estimated data amount information, estimated packet data amount information indicating the data amount of packets obtained by dividing the estimated data, and / or transmission interval information indicating the interval at which the communication device 100 transmits estimated packets.

[0065] In this modified example, the splitting unit 102 extracts data from the vehicle data acquired by the data acquisition unit 101 that has the data amount indicated by the estimated data amount information. Here, the data extracted from the vehicle data by the splitting unit 102 is called partial data. The splitting unit 102 further divides the partial data extracted from the vehicle data into multiple packets.

[0066] Here, the amount of vehicle data X (corresponding to the "first amount of data") acquired by the data acquisition unit 101 may be less than the amount of data Y (corresponding to the "second amount of data") indicated by the estimated data amount information. In such cases, the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X and the amount of data Y indicated by the estimated data amount information, and adds the generated dummy data to the vehicle data. Then, the splitting unit 102 divides the vehicle data with the added dummy data into multiple packets.

[0067] Even if vehicle data is not used as estimation data, it is data that will be sent to server devices, etc., to understand the vehicle's status. Therefore, by utilizing such vehicle data as data for bandwidth estimation, it is possible to reduce the overall communication volume compared to generating and sending data specifically for bandwidth estimation. However, since sufficient vehicle data for bandwidth estimation may not be acquired, only in such cases, dummy data, i.e., data specifically for bandwidth estimation, is used to cover the missing data amount.

[0068] Furthermore, if the receiving unit 105 has received estimated packet data volume information in addition to estimated data volume information, the splitting unit 102 divides the partial data into multiple packets, each having the data volume indicated by the estimated packet data volume information.

[0069] Furthermore, if the receiving unit 105 has received transmission interval information in addition to the estimated data volume information, the transmitting unit 104 transmits multiple packets so that the transmission interval is as indicated by the transmission interval information.

[0070] (2) Operation of the communication device 100 Figure 5 illustrates the operation of the communication device 100 in this modified example. The same processes as in Figure 4 are denoted by the same reference numerals, and detailed explanations are omitted.

[0071] The receiving unit 105 receives data volume information for estimation from the external device 20 (S111). The data acquisition unit 101 acquires vehicle data (S101). Here, if the amount of vehicle data X acquired by the data acquisition unit 101 in S101 is less than the amount of data Y indicated by the estimation data amount information (S112:Y), the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X and the amount of data Y indicated by the estimation data amount information, and adds it to the vehicle data (S113). The splitting unit 102 then divides the vehicle data, to which dummy data has been added, into multiple packets (S102).

[0072] (3) Summary In this modified example, the receiving unit 105 receives estimation data volume information from the external device 20 in advance, allowing it to transmit vehicle data containing the necessary amount of data for the external device 20 to estimate the available bandwidth as estimation data to the external device 20. Therefore, the external device 20, upon receiving the estimation data, can perform an appropriate estimation of the available bandwidth.

[0073] 4. Second Embodiment In this embodiment, we describe a configuration in which the communication device 100 controls the number of packets obtained by dividing the data, etc., depending on whether the external device 20 was able to estimate the available bandwidth using estimation data.

[0074] Here, this embodiment assumes that the external device 20 has performed an estimation of the available bandwidth at least once using estimation data transmitted from the communication device 100. Therefore, this embodiment can be applied as processing after vehicle data has been transmitted according to the first embodiment. Alternatively, it may be applied as processing after vehicle data has been transmitted at predetermined time intervals.

[0075] (1) Configuration of the communication device 100 The following explanation assumes that the communication device 100 has already divided vehicle data having a predetermined amount of data (hereinafter referred to as data amount Z0) into m packets and transmitted them to the external device 20 as estimation data.

[0076] In this embodiment, the receiving unit 105 receives "estimation success / failure information" from the external device 20 indicating whether or not the external device 20 was able to estimate the available bandwidth.

[0077] Here, "estimation success / failure information" may indicate not only whether or not it was possible to calculate an estimated value of the available bandwidth, but also whether or not a reliable estimated value of the available bandwidth was calculated. For example, even if it was possible to calculate an estimated value of the available bandwidth, if the reliability of the estimate is low, the estimation success / failure information may indicate that the estimation was not possible.

[0078] The receiving unit 105 also receives estimated bandwidth information, which indicates the value of the available bandwidth estimated by the external device 20, in addition to the estimation success / failure information. Here, even if the estimation success / failure information indicates that the external device 20 was unable to estimate the available bandwidth, the value of the estimated bandwidth information is not necessarily 0. For example, even if the available bandwidth is actually 50 Mbps, the external device 20 may be unable to estimate a 50 Mbps bandwidth due to, for example, insufficient data volume for estimation, and instead estimate a bandwidth of 30 Mbps. In such a case, the receiving unit 105 receives estimation success / failure information indicating that estimation was not possible, along with the estimated bandwidth information indicating 30 Mbps.

[0079] If the estimation success / failure information received by the receiving unit 105 indicates that the external device 20 was unable to estimate the available bandwidth, the instruction unit 103 instructs the splitting unit 102 to divide the vehicle data having data amount Z0 into n packets (corresponding to the "second number"), which is greater than m packets (corresponding to the "first number"). The value of n is set to, for example, a value obtained by adding any integer greater than or equal to 1 to m, or a value obtained by multiplying m by any value.

[0080] As described above in the modified version of the first embodiment, a larger amount of estimation data is required to estimate a wider bandwidth. However, increasing the amount of estimation data increases the communication volume of the communication device 100. Therefore, it is desirable to be able to estimate a wider bandwidth without increasing the amount of estimation data. In this embodiment, the number of packets is increased while maintaining a predetermined amount of data without increasing the amount of estimation data. This increases the number of packets that the external device 20 can use to estimate the available bandwidth, and consequently, enables the estimation of a wider bandwidth.

[0081] Furthermore, if the number of packets is increased while maintaining the data amount Z0, the data amount of each packet will decrease. However, as shown in Equation 1, when the data amount of each packet decreases, the measurable bandwidth also decreases. Therefore, the instruction unit 103 may further instruct the transmission unit 104 to make the predetermined interval for transmitting packets shorter than the interval between transmitting m packets.

[0082] As described above, if the estimation success / failure information indicates that the external device 20 was unable to estimate the available bandwidth, the instruction unit 103 instructs to increase the number of packets from m to n. However, as the number of packets increases, the amount of data in each packet decreases. However, if the amount of data in a packet falls below a predetermined amount, the base station may combine multiple packets transmitted from the communication device 100 and transfer the combined packets to the external device 20. In such cases, the external device 20 may be unable to estimate the available bandwidth, and as a result, the estimated value of the available bandwidth may become 0.

[0083] Therefore, if the amount of data in each of the m packets is the "predetermined" minimum packet data amount, the instruction unit 103 does not instruct the splitting unit 102 to split into n packets, which is less than m. Instead, the instruction unit 103 instructs the splitting unit 102 to extract partial data with a data amount Z1 (corresponding to the "second data amount") that is greater than the data amount Z0 (corresponding to the "first data amount") from the vehicle data acquired by the data acquisition unit 101, and to split the vehicle data with data amount Z1 into m packets. This prevents multiple packets from being combined at the base station due to the data amount of each packet becoming too small.

[0084] Here, "predetermined" includes not only cases that are always constant, but also cases that are uniquely determined depending on the conditions.

[0085] The value of the minimum packet data volume may be stored in the communication device 100 in advance by the manufacturer of the communication device 100 or the manufacturer of the vehicle on which the communication device 100 is installed. Alternatively, the communication device 100 may receive information regarding the minimum packet data volume derived from an external device 20 or the like, based on past estimated performance.

[0086] Alternatively, the instruction unit 103 may detect that the base station has combined multiple packets and forwarded them to the external device 20 based on the estimated bandwidth information received from the external device 20. For example, if the estimation success / failure information received by the receiving unit 105 indicates that the available bandwidth could not be estimated, and the bandwidth estimation information shows a value of 0, the instruction unit 103 can detect that the base station has combined multiple packets and forwarded them to the external device 20. Alternatively, if the bandwidth estimation information was a non-zero value (e.g., 30 Mbps), and then the number of packets was increased, resulting in the next bandwidth estimation information being 0, the instruction unit 103 may detect that multiple packets have been combined at the base station.

[0087] In this case, the instruction unit 103 instructs the splitting unit 102 to extract partial data with a data amount Z1 (corresponding to the "second data amount") that is greater than the data amount Z0 (corresponding to the "first data amount") from the vehicle data acquired by the data acquisition unit 101, and to split the vehicle data with data amount Z1 into m packets. This prevents multiple packets from being combined at the base station due to the data amount of each packet becoming too small.

[0088] In the example described above, the amount of vehicle data is increased from data amount Z0 to data amount Z1. However, the amount of vehicle data X acquired by the data acquisition unit 101 may be less than the amount of data Z1. In such cases, the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X (corresponding to the "third amount of data") acquired by the data acquisition unit 101 and the amount of data Z1, and adds the generated dummy data to the vehicle data. Then, the splitting unit 102 divides the vehicle data with the added dummy data into multiple packets.

[0089] As described above, in this embodiment, the external device 20 is enabled to estimate a wider bandwidth by increasing the number of packets. However, there is a limit to the number of packets that can be divided while maintaining a predetermined data amount. Therefore, the amount of data used for estimation is increased only if the external device 20 is unable to estimate the available bandwidth even after increasing the number of packets until the data amount of each packet is the minimum packet data amount.

[0090] Furthermore, the dummy data addition unit 106 does not only add dummy data to the vehicle data when the amount of data increases from Z0 to Z1. For example, even if the amount of data remains at Z0, if the amount of vehicle data X acquired by the data acquisition unit 101 is less than the amount of data Z0, the dummy data addition unit 106 will generate dummy data and add it to the vehicle data. The same applies when the amount of vehicle data decreases from Z0.

[0091] Next, we will explain the case where the estimation success / failure information received by the receiving unit 105 indicates that the external device 20 was able to estimate the available bandwidth.

[0092] If the estimation success / failure information received by the receiving unit 105 indicates that the external device was able to estimate the available bandwidth, the instruction unit 103 instructs the splitting unit 102 to extract vehicle data (corresponding to "partial data") with a data amount Z2 (corresponding to "second data amount") that is less than data amount Z0 (corresponding to "first data amount") from the vehicle data acquired by the data acquisition unit 101, and to split the extracted vehicle data into multiple packets.

[0093] If the external device 20 is able to estimate the available bandwidth, the communication device 100 may be transmitting more data to the external device 20 than is necessary to estimate the available bandwidth. Therefore, if the external device 20 is able to estimate the available bandwidth, the amount of data transmitted by the communication device 100 is reduced by decreasing the amount of data used for estimation.

[0094] Alternatively, the instruction unit 103 may instruct the splitting unit 102 to split the vehicle data into l packets (corresponding to the "third number") which is less than m packets (corresponding to the "first number").

[0095] As described above, an increase in the number of packets allows the external device 20 to estimate a wider bandwidth. However, since each packet needs to have a header containing destination information such as an IP address, the more packets there are, the more headers are sent, reducing communication efficiency. Furthermore, an increase in the number of packets increases the number of transmission processes performed by the transmission unit 104, which in turn increases the processing load on the communication device 100. Therefore, it is desirable to minimize the number of transmission processes performed by the transmission unit 104. Accordingly, when the external device 20 is able to estimate the available bandwidth, the number of packets is reduced to suppress the number of transmission processes.

[0096] In another example, if the estimation success / failure information indicates that the available bandwidth has been estimated, the instruction unit 103 may instruct the splitting unit 102 to reduce the amount of vehicle data and the number of packets transmitted as estimation data. Alternatively, the instruction unit 103 may first instruct the splitting unit 102 to reduce the amount of vehicle data transmitted as estimation data, and then, once the amount of vehicle data reaches a predetermined minimum amount, instruct the splitting unit 102 to reduce the number of packets.

[0097] Furthermore, in this embodiment, an example configuration is described in which the system is instructed to immediately reduce the amount of data or the number of packets when the estimation success / failure information indicates that the available bandwidth has been estimated. However, the system may also be instructed to reduce the amount of data and / or the number of packets only when the estimation success / failure information indicating that the available bandwidth has been estimated has been received consecutively for a predetermined number of times or more.

[0098] (2) Operation of the communication device 100 Next, the operation of the communication device 100 in this embodiment will be described with reference to Figure 6. Furthermore, the operation of the communication device 100 shown in Figure 6 will be described on the premise that vehicle data having a predetermined amount of data Z0 has already been divided into m packets and transmitted as estimation data.Therefore, the process shown in Figure 6 may be performed after the series of processes shown in Figure 4 or Figure 5.

[0099] The receiving unit 105 receives estimated success / failure information from the external device 20 (S201). If the estimation success / failure information received in S201 indicates that the external device 20 was unable to estimate the available bandwidth (S202:N), the instruction unit 103 determines whether the data amount of each of the m packets previously sent to the external device 20 is the minimum packet data amount (S203).

[0100] If the amount of data in each of the m packets is not the minimum packet data amount (S203:N), the instruction unit 103 instructs the splitting unit 102 to split the vehicle data with data amount Z0 into n packets, which is more than m packets (S204). The instruction unit 103 further instructs the transmission unit 104 to shorten the transmission interval for each packet (S205). The data acquisition unit 101 acquires vehicle data (S206). Here, if the amount of vehicle data X acquired by the data acquisition unit 101 in S206 is less than the amount of data Z0 (shown as amount of data Z in Figure 6) (S207:Y), the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X and the amount of data Z0, and adds it to the vehicle data (S208). The splitting unit 102 divides the vehicle data acquired in S206 into n packets based on the instructions from the instruction unit 103 (S209). The transmitting unit 104 transmits the m packets divided in S209 at a shorter transmission interval than the previous transmission interval (S210).

[0101] Furthermore, in S203, if the data amount of each of the m packets is the minimum packet data amount (S203:Y), the instruction unit 103 instructs the splitting unit 102 to set the data amount of the vehicle data to a data amount Z1 which is greater than the data amount Z0 (S211). The data acquisition unit 101 acquires vehicle data (S206). Here, if the amount of vehicle data X acquired by the data acquisition unit 101 in S206 is less than the amount of data Z1 (shown as amount of data Z in Figure 6) (S207:Y), the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X and the amount of data Z1, and adds it to the vehicle data (S208). The splitting unit 102 divides the vehicle data acquired in S206 into m packets (S209). The transmitting unit 104 transmits the m packets that were divided in S209 (S210).

[0102] In Figure 6, S203 determines whether the data amount of each of the m packets is the minimum packet data amount. However, instead of determining whether the data amount is the minimum packet amount, it is also possible to determine in S201 whether the estimated bandwidth information received along with the estimation feasibility information shows a value of 0.

[0103] Next, we will explain the case in S202 of Figure 6 where the estimation success / failure information indicates that the external device 20 was able to estimate the available bandwidth, referring to Figure 7.

[0104] If the estimation success / failure information received in S201 indicates that the external device 20 was able to estimate the available bandwidth (S202:Y), the instruction unit 103 instructs the splitting unit 102 to set the amount of vehicle data to a data amount Z2 which is less than the data amount Z0 (S221). The instruction unit 103 further instructs the splitting unit 102 to divide the vehicle data into l packets, which is less than m packets (S222). Returning to Figure 6, the data acquisition unit 101 acquires vehicle data (S206). Here, if the amount of vehicle data X acquired by the data acquisition unit 101 in S206 is less than the amount of data Z2 (shown as amount of data Z in Figure 6) (S207:Y), the dummy data addition unit 106 generates dummy data having the difference between the amount of vehicle data X and the amount of data Z2, and adds it to the vehicle data (S208). The splitting unit 102 divides the vehicle data acquired in S206 into l packets (S209). The transmitting unit 104 transmits the l packets that were divided in S209 (S210).

[0105] Figure 7 illustrates an example where, if the estimation success / failure information indicates that the available bandwidth has been estimated, instructions are given to change both the vehicle's data volume (S221) and the number of packets (S222). However, only one of the processes, S221 or S222, may be executed.

[0106] The series of processes shown in Figure 6 are repeatedly executed each time estimation feasibility information is received from the external device 20. For example, if the process shown in S204 of Figure 6 instructs the number of packets to increase from m (e.g., 8) to n (9), and 9 packets are sent to the external device 20 as estimation data, the external device 20 uses the estimation data, which has been divided into 9 estimation packets, to estimate the available bandwidth and sends estimation success / failure information indicating the result to the communication device 100. If this estimation success / failure information indicates that the available bandwidth could not be estimated, an instruction is given to further increase the number of packets from m (9).

[0107] (3) Summary As described above, according to this embodiment, the number of packets and the amount of data used to divide the estimation data are controlled according to whether the external device 20 succeeds in estimating the available bandwidth. This makes it possible for the external device 20 to transmit estimation data and estimation packets that are appropriate for estimating the available bandwidth.

[0108] 5. Other Inventions The second embodiment was described on the premise that estimation data is transmitted according to the first embodiment. However, the communication device 100 according to the second embodiment only needs to have received estimation data in the past, and does not necessarily have to be based on the first embodiment. If the first embodiment is not assumed, the invention described in the second embodiment can be understood as the invention of the following communication device 100.

[0109] A communication device mounted on a mobile body that performs wireless communication with an external device located outside the mobile body via a communication network, The external device is a device that estimates the available bandwidth of the communication network using multiple estimation packets obtained by dividing the estimation data. The communication device is A data acquisition unit (101) that acquires data, A receiving unit (105) receives estimation success / failure information from the external device, indicating whether or not the available bandwidth could be estimated using a first number of estimation packets obtained by dividing the estimation data having a predetermined amount of data. If the estimation success / failure information indicates that the available bandwidth could not be estimated, the instruction unit (103) instructs to divide the data having a predetermined amount of data into a second number of packets greater than the first number, A splitting unit (102) divides the data acquired by the data acquisition unit into the second number of packets based on the instructions from the instruction unit, A transmitting unit (104) transmits the second number of packets to the external device at predetermined intervals, A communication device (100) comprising the following:

[0110] 6. Summary The features of the communication devices and the like in each embodiment of the present invention have been described above.

[0111] The terms used in each embodiment are illustrative and may be replaced with synonymous terms or terms that include synonymous functions.

[0112] The block diagram used in describing the embodiment classifies and organizes the device configuration by function. Each block representing a function can be realized by any combination of hardware or software. Furthermore, since it represents a function, such a block diagram can also be understood as a disclosure of a method invention and a program invention that realizes said method.

[0113] The functional blocks that can be understood as processes, flows, and methods described in each embodiment may be reordered, unless there are constraints such as a relationship where one step utilizes the results of other preceding steps.

[0114] The terms "first," "second," through "nth" (where N is an integer) used in each embodiment and in the claims are used to distinguish between two or more configurations or methods of the same kind, and do not imply any order or hierarchy.

[0115] Furthermore, the following are examples of the form of the communication device of the present invention. Examples of component forms include semiconductor elements, electronic circuits, modules, and microcomputers. Examples of semi-finished products include electronic control units (ECUs) and system boards. Examples of finished products include mobile phones, smartphones, tablets, personal computers (PCs), workstations, and servers. Other devices with communication capabilities include, for example, video cameras, still cameras, and car navigation systems.

[0116] Furthermore, necessary functions such as antennas and communication interfaces may be added to the communication device.

[0117] The present invention can be realized not only with dedicated hardware having the configuration and functions described in each embodiment, but also as a combination of a program for realizing the present invention recorded on a recording medium such as memory or a hard disk, and general-purpose hardware having a dedicated or general-purpose CPU and memory capable of executing this program.

[0118] Programs stored on non-transitional physical recording media of dedicated or general-purpose hardware (e.g., external storage devices (hard disks, USB memory, CD / BD, etc.) or internal storage devices (RAM, ROM, etc.)) can also be provided to the dedicated or general-purpose hardware via the recording media, or via a communication line from a server without using the recording media. This allows for the provision of the latest functions at all times through program upgrades. [Industrial applicability]

[0119] The communication device of the present invention is primarily intended for use in automobiles, but may also be intended for use in any mobile device not mounted in an automobile. [Explanation of Symbols]

[0120] 100 Communication device, 101 Data acquisition unit, 102 Splitting unit, 103 Instruction unit, 104 Transmission unit, 105 Receiving unit, 106 Dummy data assignment unit

Claims

1. A communication device mounted on a mobile body that performs wireless communication with an external device located outside the mobile body via a communication network, A data acquisition unit (101) that acquires data, A splitting unit (102) divides the aforementioned data into a first number of packets, An instruction unit (103) detects changes in the communication environment of the communication network and, in accordance with the detection result, instructs the external device to transmit the plurality of packets as estimation data used to estimate the available bandwidth of the communication network, A transmitting unit (104) transmits the plurality of packets to the external device at predetermined intervals based on instructions from the instruction unit, The system includes a receiving unit (105) that receives estimation success / failure information from the external device indicating whether or not the available bandwidth could be estimated using the first number of packets, If the estimation success / failure information indicates that the available bandwidth could not be estimated, the instruction unit instructs the splitting unit to divide the data into a second number of packets greater than the first number. Communication device (100).

2. The instruction unit instructs the transmission of the multiple packets when it detects a switch in the base station to which the communication device is connected. The communication device according to claim 1.

3. The instruction unit instructs the transmission of the multiple packets when it detects that the amount of change in the communication quality of the communication network is greater than or equal to a threshold. The communication device according to claim 1.

4. If the estimation success / failure information indicates that the available bandwidth could not be estimated, the instruction unit further instructs the transmission unit to shorten the predetermined interval. The communication device according to claim 1.

5. If the estimation success / failure information indicates that the available bandwidth could not be estimated, and the data amount of each of the first number of packets is a predetermined minimum packet data amount, The instruction unit instructs the splitting unit to extract a portion of data from the data acquired by the data acquisition unit that has a second data amount greater than a first data amount which is the sum of the data amounts of the first number of packets, and to divide the extracted portion of data into the first number of packets. The communication device according to claim 1.

6. In addition to the estimation success / failure information, the receiving unit receives estimated bandwidth information indicating the available bandwidth estimated by the external device. If the estimation success / failure information indicates that the available bandwidth could not be estimated, and the estimated bandwidth information shows a value of 0, The instruction unit instructs the splitting unit to extract a portion of data from the data acquired by the data acquisition unit that has a second data amount greater than a first data amount which is the sum of the data amounts of the first number of packets, and to divide the extracted portion of data into the first number of packets. The communication device according to claim 1.

7. The aforementioned data is vehicle data indicating the state of the vehicle, which is the moving object. The communication device further includes a dummy data addition unit (106) that, when the third data amount, which is the amount of vehicle data acquired by the data acquisition unit, is less than the second data amount, adds dummy data having the difference between the third data amount and the second data amount to the vehicle data. The division section divides the vehicle data to which the dummy data has been added. The communication device according to claim 5 or 6.

8. If the estimation success / failure information indicates that the available bandwidth has been estimated, the instruction unit instructs the splitting unit to extract partial data from the data acquired by the data acquisition unit, the second data amount being less than the first data amount which is the sum of the data amounts of the first number of packets, and to split the extracted partial data into the first number of packets. The communication device according to claim 1.

9. If the estimation success / failure information indicates that the available bandwidth has been estimated, the instruction unit instructs the splitting unit to divide the data into a third number of packets that is less than the first number. The communication device according to claim 1.

10. A communication method performed by a communication device mounted on a mobile body and performing wireless communication via a communication network with an external device located outside the mobile body, Data is acquired (S101), The data is divided into a first number of packets (S102), The system detects changes in the communication environment of the communication network and, in accordance with the detection results, instructs the external device to transmit the multiple packets as estimation data used to estimate the available bandwidth of the communication network (S104). Based on the instructions, the plurality of packets are transmitted to the external device at predetermined intervals (S105), The external device receives estimation success / failure information indicating whether or not the available bandwidth could be estimated using the first number of packets (S201), If the estimation success / failure information indicates that the available bandwidth could not be estimated, the system instructs the data to be divided into a second number of packets greater than the first number (S204). Communication method.

11. A communication program executable by a communication device mounted on a mobile body and performing wireless communication with an external device located outside the mobile body via a communication network, Data is acquired (S101), The data is divided into a first number of packets (S102), The system detects changes in the communication environment of the communication network and, in accordance with the detection results, instructs the external device to transmit the multiple packets as estimation data used to estimate the available bandwidth of the communication network (S104). Based on the instructions, the plurality of packets are transmitted to the external device at predetermined intervals (S105), The external device receives estimation success / failure information indicating whether or not the available bandwidth could be estimated using the first number of packets (S201), If the estimation success / failure information indicates that the available bandwidth could not be estimated, the system instructs the data to be divided into a second number of packets greater than the first number (S204). A communication program that causes the communication device to perform a process that includes the following.

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