COMMUNICATION DEVICE, COMMUNICATION METHOD, AND COMMUNICATION PROGRAM

Abstract

To provide a communication device, a communication method, and a communication program that effectively utilize hardware and communication line resources when communication speed is limited by an event that does not depend on the communication environment of a communication line.SOLUTION: A communication device 100 for communicating with another communication device via a communication line includes: a receiving unit 101 that receives data from the other communication device; a communication speed limitation determination unit 102 that determines whether speed limitation has occurred that does not depend on the communication environment of a communication line; a bandwidth estimation timing determination unit 103 that determines timing for bandwidth estimation when the communication speed limitation determination unit has determined that speed limitation has occurred; a bandwidth estimation unit 104 that estimates the bandwidth of the communication line at the timing and generates a bandwidth estimation result; and a transmission unit 105 that transmits the bandwidth estimation result to the other communication device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a communication device, a communication method, and a communication program for performing bandwidth estimation. [Background technology]

[0002] 2. Description of the Related Art When transmitting and receiving data using a communication device, in order to prevent data loss during communication and the resulting need for retransmission, the amount of communication is controlled so as to match the bandwidth of the communication line.

[0003] Patent Document 1 discloses a communication terminal device capable of estimating an available bandwidth taking into consideration the influence of multiple applications using a network at the same time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-62720 A Summary of the Invention [Problem to be solved by the invention]

[0005] Here, the present inventors have found the following problem. In the case where the communication speed of a communication device is limited by an external factor, i.e., an event that is not dependent on the communication environment of the communication line, performing bandwidth estimation even though the upper limit of the communication speed is known results in waste of hardware and communication line resources. That is, performing a calculation for bandwidth estimation consumes resources of the calculation unit and increases power consumption. In addition, transmitting the bandwidth estimation result consumes resources of the communication line.

[0006] Therefore, an object of the present invention is to realize a communication device or the like that can effectively utilize hardware and communication line resources when the communication speed is limited by an event that is not dependent on the communication environment of the communication line. [Means for solving the problem]

[0007] The communication device (100) of the present disclosure is a communication device that communicates with other communication devices via a communication line, A receiving unit (101) for receiving data from the other communication device; A communication speed limit determination unit (102) that determines the occurrence of a speed limit that is not dependent on the communication environment of the communication line; a bandwidth estimation timing determination unit (103) that determines a timing for bandwidth estimation when the communication speed limit determination unit determines that the speed limit has occurred; a bandwidth estimation unit (104) that estimates a bandwidth of the communication line at the timing and generates a bandwidth estimation result; A transmission unit (105) that transmits the bandwidth estimation result to the other communication device; has.

[0008] In addition, the claims and the numbers in parentheses attached to the constituent elements of the invention described in this section indicate the correspondence between the present invention and the embodiments described below, and are not intended to limit the present invention. Effect of the Invention

[0009] With the above-described configuration, the communication device etc. disclosed herein can effectively utilize the resources of the hardware and communication lines when the communication speed is limited due to an event that is not dependent on the communication environment of the communication line. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration and operation of each embodiment; [Diagram 2] FIG. 1 is a diagram showing the configuration of a communication device according to first to fourth embodiments. [Diagram 3]FIG. 1 is an explanatory diagram for explaining data used by a communication speed detection unit of a communication device according to the first embodiment; [Figure 4] FIG. 1 is an explanatory diagram for explaining data used by a communication speed detection unit of a communication device according to the first embodiment; [Diagram 5] FIG. 1 is an explanatory diagram for explaining information stored in a storage unit of a communication device according to the first to fourth embodiments. [Figure 6] FIG. 1 is a flow diagram showing the operation of the communication device according to the first to fourth embodiments. [Figure 7] FIG. 1 is an explanatory diagram showing an example of an operation of a communication device according to the first embodiment; [Figure 8] FIG. 1 is a diagram showing the configuration of a communication device according to a fifth to sixth embodiment; [Figure 9] FIG. 23 is an explanatory diagram showing the operation of a communication device according to the first embodiment of the sixth embodiment; [Figure 10] FIG. 23 is an explanatory diagram showing the operation of a communication device according to the first embodiment of the sixth embodiment; [Figure 11] FIG. 23 is an explanatory diagram showing the operation of a communication device according to a second embodiment of the sixth embodiment. [Figure 12] FIG. 23 is an explanatory diagram for explaining the operation of a communication device according to a third embodiment of the sixth embodiment. [Figure 13] FIG. 23 is an explanatory diagram for explaining the operation of a communication device according to a fourth embodiment of the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] The present invention means the invention described in the claims or in the Summary of the Invention section, and is not limited to the following embodiments. Furthermore, at least the words in quotation marks mean the words described in the claims or in the Summary of the Invention section, and are not limited to the following embodiments.

[0013] The configurations and methods described in the dependent claims are optional configurations and methods in the invention described in the independent 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 being described in the claims, are optional configurations and methods in the present invention. The configurations and methods described in the embodiments when the description of the claims is broader than the description of the embodiments are also optional configurations and methods in the present invention in the sense that they are examples of the configurations and methods of the present invention. In either case, by being described in the independent claims, they become essential configurations and methods of the present invention.

[0014] The effects described in the embodiments are effects obtained when the configurations of the embodiments are provided as examples of the present invention, and are not necessarily effects that the present invention possesses.

[0015] When there are multiple embodiments, the configurations disclosed in each embodiment are not limited to each embodiment, but can be combined across the embodiments. For example, a configuration disclosed in one embodiment may be combined with another embodiment. Also, configurations disclosed in each of the multiple embodiments may be collected and combined.

[0016] The problem described in the section on problems that the invention is intended to solve is not a publicly known problem, but was discovered independently by the inventor, and this, together with the configuration and method of the present invention, is a fact that affirms the inventive step of the invention.

[0017] 1. Configuration and operation underlying each embodiment The configuration and operation of each embodiment will be outlined below with reference to FIG. The communication device 100 communicates with another communication device 150 via a communication line. Specifically, communication device 100 receives data transmitted from another communication device 150 via a reception line. Next, communication device 100 estimates the bandwidth of the communication line to generate a bandwidth estimation result. Then, communication device 100 transmits the generated bandwidth estimation result to other communication device 150 via a transmission line. The other communication device 150 receives the bandwidth estimation result. Then, the other communication device 150 controls communication with communication device 100 using the bandwidth estimation result. Here, the communication line for receiving data is expressed as a reception line and the communication line for transmitting data is expressed as a transmission line, but the same physical communication line may be used.

[0018] The communication line to be estimated is mainly a receiving line, but may also be a transmitting line. Also, the communication line to be estimated may be only a receiving line, only a transmitting line, or both a receiving line and a transmitting line.

[0019] The communication line is primarily a wireless communication line, but may also be a wired communication line. Examples of wireless communication lines include communication lines based on a mobile communication system, such as W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution), LTE-A (Long Term Evolution Advanced), 4G, 5G, 6G, or LPWA (Low Power Wide Area). In addition, communication lines based on wireless communication methods such as IEEE802.11 (Wi-Fi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), Bluetooth (registered trademark), UWB (Ultra Wide Band), ZigBee (registered trademark), or DSRC (Dedicated Short Range Communication) can also be used.

[0020] Examples of wired communication lines include a LAN (Local Area Network) such as Ethernet (registered trademark), an optical line, or a fixed telephone line.

[0021] Alternatively, the communication line may be a combination of a wireless communication line and a wired communication line. For example, when the communication device 100 is a terminal device and the other communication device 150 is a server device connected to the Internet, the communication line between the communication device 100 and the base station device is a 4G wireless communication system, and the communication line between the base station device and the server device is a wired communication system consisting of an optical line.

[0022] The communication device 100 may be either a terminal device or a server device. Furthermore, the other communication device 150 may also be either a terminal device or a server device. That is, as long as the prerequisite conditions are met, each embodiment is applicable to communication between terminal devices, communication between a terminal device and a server device, and communication between servers. Furthermore, the communication device 100 or the other communication device 150 may be a device interposed between a terminal device and a server device, such as a base station device or a gateway device.

[0023] The communication device 100 or other communication devices 150 may be "mounted" on a "mobile object" such as a vehicle. Where: "Mobile object" refers to an object that can move and can move at any speed. It also includes cases where the mobile object is stationary. For example, it includes, but is not limited to, automobiles, motorcycles, bicycles, pedestrians, ships, aircraft, and objects mounted on these. "Mounted" includes not only the case where the device is directly fixed to the moving body, but also the case where the device is not fixed to the moving body but moves with the moving body, such as the case where the device is carried by a person riding on the moving body, or the case where the device is mounted on cargo placed on the moving body.

[0024] The communication device 100 and the other communication device 150 can have the same configuration if they are devices of the same type. In the embodiments described below, the configuration and operation of the communication device 100 will be described.

[0025] 2. Embodiment 1 (1) Configuration of the communication device 100 according to the present embodiment The configuration of the communication device 100 of the first embodiment will be described with reference to Fig. 2. The communication device 100 includes a receiving unit 101, a communication speed limit determining unit 102, a bandwidth estimation timing determining unit 103, a bandwidth estimating unit 104, a transmitting unit 105, a bandwidth estimation data generating unit 106, and a storage unit 107. The communication speed limit determining unit 102 includes a communication speed detecting unit 108, a communication volume detecting unit 109, and a communication control unit 101. , Warm The communication device 100 includes at least one of a communication speed detection unit 110 and a voltage detection unit 111. In this embodiment, a case in which the communication device 100 includes a communication speed detection unit 108 will be described.

[0026] The communication device 100 can be configured with a general-purpose CPU (Central Processing Unit), a volatile memory such as a RAM, a non-volatile memory such as a ROM, a flash memory, or a hard disk, various interfaces, and an internal bus connecting these. The communication device 100 can be configured to perform the functions of each functional block shown in FIG. 2 by executing software on this hardware. Of course, the communication device 100 may be realized by dedicated hardware such as an LSI. The above also applies to the communication devices of the other embodiments.

[0027] In this embodiment, the communication device 100 is assumed to be in the form of an electronic control device (ECU (Electric Control Unit), hereinafter abbreviated as ECU) as a semi-finished product, but is not limited to this. For example, the form of a component may be a semiconductor circuit or a semiconductor module, the form of a semi-finished product may be an electronic control device, an electronic control unit, or a system board, and the form of a finished product may be a server, a workstation, a personal computer (PC), a tablet, a smartphone, a mobile phone, or a navigation system. Note that the communication device 100 may be configured with a single ECU or multiple ECUs. The above also applies to the communication devices of the other embodiments.

[0028] The receiving unit 101 receives "data" from another communication device 150 via a communication line. Here, "data" includes data stored in the payload, as well as data that is determined to be exchanged using a communication protocol such as an acknowledgement (ACK) packet used for transmission control in TCP (Transmission Control Protocol), or bandwidth estimation data that is generated and transmitted by another communication device for the purpose of bandwidth estimation.

[0029] The communication speed limit determination unit 102 determines the occurrence of a "speed limit" that is not dependent on an external factor, i.e., the communication environment of the communication line. An example of a speed limit that is not dependent on the communication environment of the communication line is when, for example, a wireless communication method is used, and when a predetermined communication amount per month is exceeded, the communication speed is limited to a certain value (e.g., 128 kbps). Alternatively, when the temperature of the communication device 100 becomes high, the communication device 100 goes into a degenerate mode for cooling and the communication speed is limited. Alternatively, when using a battery, for example, when the input voltage input to the communication device 100 drops and normal operation cannot be maintained, the communication device 100 goes into a degenerate mode to maintain a minimum communication function, and the communication limit is limited. The degenerate mode is a mode that does not stop the communication function itself, but aims to resolve an abnormal situation by temporarily limiting performance. In either case, the speed limit occurs regardless of the communication environment of the communication line. Here, "speed restriction" includes cases where the speed is restricted directly, as well as cases where the speed is restricted as a result of restricting the frequency band, bandwidth, etc.

[0030] In contrast, a speed limit that depends on the communication environment of a communication line is, for example, a case where the communication speed is reduced or limited when the traffic on the communication line is congested. Such a case does not fall under the speed limit of this embodiment.

[0031] In other words, the speed limit in this embodiment is a speed limit based on an event that is expected to continue for a certain period of time.

[0032] In this embodiment, the communication speed limit determination unit 102 includes a communication speed detection unit 108. The communication speed detection unit 108 detects the communication speed of the communication line “based on the data” received by the receiving unit 101. Here, "based on data" includes cases based on the contents of the data as well as cases based on attributes of the data, such as data size, data transmission time, data reception time, and data reception strength.

[0033] An example of detection of the communication speed by the communication speed detection unit 108 of this embodiment will be described. First, the other communication device 150 transmits data including a transmission time t1 [s] to the communication device 100. The data is received by the receiving unit 101 of the communication device 100, and the communication device 100 records the reception time t2 [s]. Then, the communication speed detection unit 108 extracts the data size D [bit] and t1 [s] of the received data from the data, and calculates the communication speed S [bps] on the receiving line using the following formula. S = D / (t2 - t1) It is assumed that the communication device 100 and the other communication device 150 are time-synchronized by a known method such as using GPS. Of course, the communication speed may be detected using a method other than the above.

[0034] Next, the data used by the communication speed detection unit 108 to detect the communication speed will be described with reference to FIGS. Although the transmission data load is small for data with a small data size, as shown in Figure 3, the transmission load is insufficient for the available communication band, making the communication speed appear to be low. Also, as shown in Figure 4, the transmission and reception of data with a small data size is completed in an extremely short time, resulting in low accuracy. Therefore, it is preferable that the communication speed detection unit 108 of this embodiment detects the communication speed based on data that is "larger than" a "predetermined data size" among the received data. Where: The "predetermined data size" may be a fixed value or may be a variable value that varies depending on conditions. The term "larger" encompasses both the case where the data size is included in comparison with a predetermined data size and the case where the data size is not included in the predetermined data size.

[0035] The predetermined data size can be determined by detecting an area where a statistically certain upper limit of communication speed exists, and setting the lower limit of the area as the predetermined data size, as shown in Figures 3 and 4. For example, in the case of Figure 3, the data size corresponding to the transmission data load p can be set as the predetermined data size, and in the case of Figure 4, the data size q can be set as the predetermined data size.

[0036] The storage unit 107 stores the cause of an event accompanied by a speed limit, and a reference communication speed that is a communication speed determined when an event accompanied by a speed limit occurs. A specific example of information stored in storage unit 107 will be described with reference to FIG.

[0037] Let us focus on line 1 in FIG. When using wireless communication, if a certain amount of data is exceeded in a certain period of time, the communication speed may be limited to a certain value. In the case of Figure 5, if the monthly communication volume exceeds 6 GB, the communication speed is limited to 128 kbps, which corresponds to the standard communication speed when event A, that is, exceeding the communication volume, occurs. Furthermore, when the temperature of the communication device 100 becomes higher than a predetermined temperature, the device goes into degenerate mode for cooling, and the communication speed is limited to a certain value. In the case of Fig. 5, when the temperature of the communication module exceeds 60°C, the communication speed is limited to 30 kbps, which corresponds to the reference communication speed when the event B occurs in which the temperature of the communication device 100 becomes higher than the predetermined temperature. Furthermore, if the input voltage of the communication device 100 falls below a predetermined input voltage, the device goes into degenerate mode in order to maintain a minimum level of communication functionality, and the communication speed is limited to a certain level. In the case of Fig. 5, it is shown that the communication speed is limited to 50 kbps when the input voltage of the communication module falls below this level, which corresponds to the reference communication speed when event C occurs, in which the input voltage of the communication device 100 falls below the predetermined input voltage.

[0038] 5, a certain range is set for the reference communication speed, but this is to take error into consideration. Also, when the reference communication speed is low, the error becomes large, so it is desirable to set a large range. As shown in FIG. 5, the reference communication speed may be determined by a median value and an error range, or may be determined by an upper limit value and a lower limit value, or a median value and a variance value.

[0039] The storage unit 107 further stores a reference timing corresponding to a reference communication speed. In the case of Fig. 5, the reference timing is specified by the number of decimations, which is the number of times the bandwidth estimation is decimated from the normal bandwidth estimation timing. For example, if the normal bandwidth estimation timing executes bandwidth estimation periodically at a predetermined time interval as [1, 2, 3, 4, 5, 6, 7, 8, 9], when the number of decimations +3 is applied, it becomes [1, 5, 9], the bandwidth estimation interval becomes four times, and the bandwidth estimation frequency becomes 1 / 4.

[0040] The first time in the bandwidth estimation timing refers to the number of times that the communication speed limit is determined to have occurred, when it is the first time. Similarly, the second time and onwards refers to the number of times that the communication speed limit is determined to have occurred, when it is the second time and onwards. For example, when event A occurs, +3 is applied the first time, and +2 is also applied the second time, so that a thinning count of +5 is applied to the normal bandwidth estimation timing. In other words, the longer the duration of the speed limit, the more the number of times that thinning is added. In contrast, for event B, the thinning count is not incremented because it is 0 from the second time onwards, and the thinning count remains constant while event B is ongoing. The same is true for event C.

[0041] In this embodiment, the reference timing is defined by the number of times of thinning out, but it may be defined by other methods. For example, it may be defined by a thinning out ratio, which is a ratio of thinning out, or a thinning out time, which is a time for thinning out. Alternatively, the band estimation frequency or the band estimation interval may be directly defined. Furthermore, multiple divisions defined by the number of times of thinning out or the elapsed time may be set. In addition, since the thinning ratio is the number of times thinning is performed relative to a reference number of times, it can also be evaluated as the "number of times thinning is performed."

[0042] Furthermore, when a plurality of communication lines are used, the reference communication speed and reference timing may be defined for each communication line, as shown in FIG.

[0043] In this embodiment, the communication speed limit determination unit 102 determines that a speed limit has been applied when the communication speed detected by the communication speed detection unit 108 is "constant" and "matches" the reference communication speed. Where: "Constant" does not necessarily mean that the absolute value is always constant, but rather that it is sufficient that the value is constant when observed statistically, taking into account errors and the like. The term "match" does not necessarily mean a perfect match, but rather a match that can be statistically observed while taking into account errors and the like.

[0044] Specifically, in this embodiment, the communication speed detection unit 108 detects the communication speed for a predetermined period of time, and determines that the communication speed has become constant if the variance of the communication speed during the predetermined period of time is within a certain value or if the difference from the average value is within a certain percentage. Then, the reference communication speed is read out from the storage unit 107, and it is determined whether the communication speed detected by the communication speed detection unit 108 matches the reference communication speed.

[0045] When the communication speed limit determining section 102 determines that a speed limit has occurred, the bandwidth estimation timing determining section 103 determines the "timing" of bandwidth estimation. Specifically, in this embodiment, the bandwidth estimation timing determination unit 103 reads out the reference timing corresponding to the communication speed detected by the communication speed detection unit 108 from the storage unit 107, and determines it as the timing for bandwidth estimation. For example, in the case of Fig. 5, when the communication speed detected by the communication speed detection unit 108 is 135 [kbps], which is within ±10% of 128 [kbps] of event A, the communication speed limit judgment unit 102 determines that the speed limit of event A has occurred. Then, the bandwidth estimation timing determination unit 103 reads out +3, which is the reference timing of event A, and determines this as the timing for bandwidth estimation. Here, "timing" may refer to any time element that can identify the bandwidth estimation, such as a bandwidth estimation interval, which is the time interval at which the bandwidth estimation is performed, a bandwidth estimation frequency, which is the number of times the bandwidth estimation is performed per unit time, and a bandwidth estimation time, which is an absolute time or a relative time at which the bandwidth estimation is performed. An example of a relative time is a timer.

[0046] The reference timing stored in the storage unit 107 specifies that bandwidth estimation should be thinned out with respect to the normal bandwidth estimation timing, so the timing determined by the bandwidth estimation timing determination unit 103 has a reduced number of bandwidth estimates per unit time compared to when no speed limit is occurring.

[0047] The bandwidth estimation unit 104 estimates the bandwidth of the communication line at the timing determined by the bandwidth estimation timing determination unit 103 to generate a bandwidth estimation result. The bandwidth of the communication line can be estimated by a known method, but in this embodiment, an estimation of the communication speed is used as the estimation of the bandwidth of the communication line. In this embodiment, the communication speed detection unit 108 performs the same calculation, so the detection result of the communication speed detection unit 108 can be used as is.

[0048] The bandwidth estimation data generating unit 106 generates bandwidth estimation data to be used for bandwidth estimation by the other communication device 150. The bandwidth estimation data can be configured of known data of a certain length, for example. In this embodiment, the bandwidth estimation data generating unit 106 generates the bandwidth estimation data in accordance with the timing determined by the bandwidth estimation timing determining unit 103 .

[0049] The transmission unit 105 transmits the bandwidth estimation result generated by the bandwidth estimation unit 104 to the other communication device 150. When the bandwidth estimation data generation unit 106 generates bandwidth estimation data, the transmission unit 105 transmits the bandwidth estimation data in addition to the bandwidth estimation result.

[0050] (2) Operation of the Communication Device 100 of the Present Embodiment The operation of the communication device 100 of the present embodiment will be described with reference to FIG. Note that the following operations not only indicate a communication method in communication device 100, but also indicate the processing procedure of a communication program executed by communication device 100. The order of these processes is not limited to the order shown in Fig. 6. In other words, the order may be changed as long as there is no constraint such as a relationship in which a certain step utilizes the result of the previous step. The above applies not only to this embodiment, but also to other embodiments and modified examples.

[0051] The receiving unit 101 of the communication device 100 receives "data" from another communication device 150 via a communication line (S101). The communication speed limit determination unit 102 determines whether a "speed limit" occurs that is not dependent on an external factor, that is, the communication environment of the communication line (S102). When the communication speed limit determining section 102 determines that a speed limit has occurred, the bandwidth estimation timing determining section 103 determines the "timing" of bandwidth estimation (S103). The bandwidth estimation unit 104 estimates the bandwidth of the communication line at the timing determined by the bandwidth estimation timing determination unit 103, and generates a bandwidth estimation result (S104). The transmitting unit 105 transmits the bandwidth estimation result generated by the bandwidth estimating unit 104 to the other communication device 150 (S105).

[0052] An example of the operation of the communication device 100 of the present embodiment will be described with reference to FIG. The period for determining whether a communication speed limit has been applied is defined as the judgment window. Whether the communication speed is constant or not is determined based on the communication speed detected during the period defined by the judgment window. Since the communication speed is not constant during periods h and i, it is not determined that a speed limit has been applied. However, it is assumed that the monthly communication volume exceeds a predetermined volume midway through period i.

[0053] In period j, the communication speed is constant and is within the range of the reference communication speed (128 kbps ±10%) specified for event A in Fig. 5, so it is determined that a speed limit has occurred. Therefore, the reference timing (first time) in Fig. 5 is read, and a thinning count of +3 is applied in period k.

[0054] In period k, a thinning count of +3 is applied, so that the bandwidth is estimated only once during the period in which the bandwidth is normally estimated four times. The communication speed detected in period k is within the range of the reference communication speed (128 kbps ±10%) specified for event A in Figure 5, so it is determined that a speed limit has occurred. Therefore, the reference timing (from the second time onwards) in Figure 5 is read, and a thinning count of +2 is applied in period l.

[0055] In period l, a total of +5 decimation times (+3 plus +2) are applied, so that the bandwidth is only estimated once during the period in which bandwidth estimation is normally performed six times. The communication speed detected in period l is within the range of the reference communication speed (128 kbps ±10%) specified for event A in Figure 5, so it is determined that a speed limit has occurred. Therefore, the reference timing (from the second time onwards) in Figure 5 is read, and a further +2 decimation time is applied in period m.

[0056] (3) Effects of this embodiment As described above, according to the communication device 100 of the present embodiment, when a speed limit occurs that is not dependent on the communication environment of the communication line, the timing of bandwidth estimation is reduced, so that the number of times the result of bandwidth estimation is transmitted can be reduced, and the resources of the transmission line among the communication lines of the communication device 100 can be effectively utilized. In addition, since the other communication device 150 can perform control to reduce the number of times that the bandwidth estimation data is transmitted, the resources of the reception line among the communication lines can be effectively utilized. Furthermore, according to the communication device 100 of this embodiment, the bandwidth estimation data is generated according to the timing determined by the bandwidth estimation timing determination unit 103, so that the number of times the bandwidth estimation data is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized.

[0057] (4) Modifications of this embodiment The communication speed detection unit 108 in the first embodiment described above detects the communication speed based on the data transmission time, data reception time, and data size. The communication speed detection unit 108 in this modification detects the communication speed from the bandwidth estimation result estimated and transmitted by the other communication device 150.

[0058] The communication speed detection unit 108 detects the bandwidth estimation result (corresponding to the “other party’s bandwidth estimation result”) estimated by the other communication device 150 from the bandwidth estimation result included in the data received by the receiving unit 101 by extracting it from the data. That is, in this modified example, the communication speed detection unit 108 detects the communication speed of the communication line "based on the data" received by the receiving unit 101, as in the first embodiment. However, the communication speed detection unit 108 in the first embodiment measures and detects the communication speed of the receiving line, whereas the communication speed detection unit 108 in this modified example acquires and detects the communication speed of the transmitting line.

[0059] Then, similarly to the first embodiment, the communication speed limit determination unit 102 determines that a speed limit has been imposed when the communication speed detected by the communication speed detection unit 108 is "constant" and "matches" the reference communication speed.

[0060] As described above, according to the communication device 100 of this embodiment, in addition to the effects of the first embodiment, it is not necessary for the communication speed detection unit 108 to perform calculations to obtain the communication speed, and the hardware resources of the communication device 100 can be used effectively.

[0061] 3. Embodiment 2 In the first embodiment, the occurrence of a speed limit is determined by comparing the communication speed detected by the communication speed detection unit 108 with the reference communication speed stored in the storage unit 107. In this embodiment, the occurrence of a speed limit is determined by using the amount of data received by the receiving unit 101 and / or the amount of data transmitted by the transmitting unit 105. Note that only the parts that differ from the first embodiment will be described below, and the description of the first embodiment will be quoted for the configurations that are common to the first embodiment.

[0062] (1) Configuration of the communication device 100 according to the present embodiment The configuration of the communication device 100 according to the second embodiment will be described with reference to FIG. In this embodiment, the communication speed limit determination unit 102 has a communication volume detection unit 109. The communication volume detection unit 109 detects the amount of data received by the receiving unit 101 and / or the amount of data transmitted by the transmitting unit 105. That is, it is sufficient for the communication volume detection unit 109 to detect any one of the reception volume, the transmission volume, or the sum of the reception volume and the transmission volume.

[0063] When the communication amount detection unit 109 detects the amount of data transmitted from the transmission unit 105, all data transmitted from the transmission unit 105 is targeted. That is, in addition to the bandwidth estimation result generated by the bandwidth estimation unit 104 and the bandwidth estimation data generated by the bandwidth estimation data generation unit 106, data transmitted from sensors and cameras connected to the communication device 100, and data transmitted from the ECU are also targeted.

[0064] When the communication amount detection unit 109 detects the amount of data received from the receiving unit 101, all data received from the receiving unit 101 is the target. That is, the target includes the bandwidth estimation result generated by another communication device 150, the sensor and the camera connected to the communication device 100, and the data received addressed to the ECU.

[0065] The communication speed limit determination unit 102 determines that a speed limit has occurred when the reception amount and / or transmission amount detected by the communication amount detection unit 109 exceeds a "predetermined amount". Whether to use the reception amount, transmission amount, or the total of the reception amount and transmission amount may be determined in light of the cause of the speed limit. For example, in the event A of the line 1 in FIG. 5, the communication speed is limited when the transmission and reception amount, i.e., the total of the reception amount and transmission amount, exceeds 6 GB in one month, so the communication amount detection unit 109 detects the total of the reception amount and transmission amount, and the communication speed limit determination unit 102 determines whether the total of the reception amount and transmission amount exceeds a predetermined amount. The cause of the speed limit may be specified as a union of multiple conditions. For example, the cause of the speed limit may be when the transmission amount exceeds 6 GB in one month or when the transmission amount exceeds 10 GB in three days. In this way, time information may be included as the cause of the speed limit. Here, the "predetermined amount" may be a fixed value or a variable value that varies depending on conditions. The "predetermined amount" may also include time information.

[0066] In the present embodiment, it is optional whether or not to provide the communication speed detection unit 108. In the first embodiment, the bandwidth estimation unit 104 estimates the bandwidth by estimating the communication speed, so the bandwidth estimation unit 104 uses the detection result of the communication speed detection unit 108 as is. In the present embodiment, if the communication speed detection unit 108 is not provided, the bandwidth estimation unit 104 executes estimation of the communication speed. The method of estimating the communication speed can be the same as the method used by the communication speed detection unit 108 in the first embodiment.

[0067] (2) Effects of this embodiment As described above, according to the communication device 100 of the present embodiment, when a speed limit occurs that is not dependent on the communication environment of the communication line, the timing of bandwidth estimation is reduced, so that the number of times that the bandwidth estimation result is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized. In addition, since the other communication device 150 can perform control to reduce the number of times that the bandwidth estimation data is transmitted, the resources of the reception line among the communication lines can be effectively utilized. Furthermore, according to the communication device 100 of the present embodiment, the number of times the bandwidth estimation calculations themselves are performed is reduced, so that the calculations required for bandwidth estimation can be reduced and hardware resources can be used effectively. Furthermore, according to the communication device 100 of this embodiment, the bandwidth estimation data is generated according to the timing determined by the bandwidth estimation timing determination unit 103, so that the number of times the bandwidth estimation data is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized.

[0068] (3) Modifications of this embodiment The communication traffic detection unit 109 in the second embodiment described above detects the amount of data transmitted and received by the communication device 100 itself. The communication traffic detection unit 109 in this modification acquires the communication traffic of the communication device 100 and other communication devices 150 from outside.

[0069] The communication traffic detection unit 109 acquires the communication traffic of the communication device 100 from an external communication traffic management server. For example, the current communication traffic is inquired of to the communication carrier server of the communication carrier with which the contract for use of the communication line has been concluded, and the communication traffic is acquired as a response. The communication traffic may be any of the received traffic, the transmitted traffic, or the sum of the received traffic and the transmitted traffic, in light of the cause of the speed limit. The communication traffic may be acquired periodically or at any timing. In addition, if the response from the communication carrier server of the communication carrier includes information indicating whether or not the speed is limited, the information may be used as is. In addition, if the response from the communication carrier server of the communication carrier includes communication speed information after the speed limit, the information may be used as is.

[0070] The cause of the speed limit may be not only when the communication device 100 exceeds a predetermined communication volume, but also when the communication device 150 exceeds a predetermined communication volume. Therefore, the communication volume detection unit 109 may acquire the communication volume of the other communication device 150 from an external communication volume management server.

[0071] Then, similarly to the second embodiment, the communication speed limit determination unit 102 determines that a speed limit has been imposed when the communication volume acquired by the communication volume detection unit 109 exceeds a "predetermined volume."

[0072] When the communication volume of the other communication device 150 exceeds a predetermined volume, the bandwidth estimation timing determination unit 103 needs to determine the bandwidth estimation timing only when communication with the other communication device 150 is performed.

[0073] As described above, according to the communication device 100 of this embodiment, in addition to the effects of the second embodiment, it is not necessary for the communication amount detector 109 to perform calculations to obtain the communication amount, and the hardware resources of the communication device 100 can be utilized effectively. In addition, since it is possible to know not only when the communication device 100 has exceeded a predetermined communication volume but also when another communication device 150 has exceeded a predetermined communication volume, it is possible to identify whether the cause of the speed limit is the own device or another device and determine an appropriate bandwidth estimation timing.

[0074] 4. Embodiment 3 The second embodiment is an embodiment in which the rate limit is caused by an excess of communication volume. The present embodiment is an embodiment in which the rate limit is caused by a temperature rise in the communication device 100. Note that only the parts that differ from the first embodiment will be described below, and the description of the first embodiment will be quoted for the configurations that are common to the first embodiment.

[0075] (1) Configuration of the communication device 100 according to the present embodiment The configuration of the communication device 100 according to the third embodiment will be described with reference to FIG. In this embodiment, the communication speed limit determination unit 102 has a temperature detection unit 110. The temperature detection unit 110 detects the "temperature" of the communication device 100 itself or a component constituting the communication device 100, for example, a CPU or a communication module. The temperature may be detected using information that directly indicates the temperature, such as a directly measured temperature or the output of a device such as a thermocouple, or information that indirectly indicates the temperature, such as status information transmitted from a component constituting the communication device 100. Here, "temperature" includes not only the temperature indicated in Celsius or Fahrenheit, but also information that indirectly indicates a temperature or a temperature range.

[0076] The communication speed limit determination unit 102 determines that a speed limit has occurred when the temperature detected by the temperature detection unit 110 exceeds a "predetermined temperature." For example, in the event B of the line 1 in Fig. 5, the communication speed is limited when the temperature of the communication module exceeds 60°C, so the temperature detection unit 110 detects the temperature, and the communication speed limit determination unit 102 determines whether the temperature exceeds the predetermined temperature. Here, the "predetermined temperature" may be a fixed value or may be a variable value that varies depending on conditions.

[0077] In the present embodiment as well, it is optional whether or not to provide the communication speed detection unit 108. In the first embodiment, the bandwidth estimation unit 104 estimates the bandwidth by estimating the communication speed, so the bandwidth estimation unit 104 uses the detection result of the communication speed detection unit 108 as is. In the present embodiment, if the communication speed detection unit 108 is not provided, the bandwidth estimation unit 104 executes estimation of the communication speed. The method of estimating the communication speed can be the same as the method used by the communication speed detection unit 108 in the first embodiment.

[0078] Note that an abnormality detection unit that detects abnormalities in parts that configure the communication device 100 may be provided instead of the temperature detection unit 110. The temperature detection unit 110 is an example of an abnormality detection unit. It is only necessary to determine in advance what type of abnormality is detected that will cause the device to transition to the degenerate mode. In this embodiment, it is determined that the speed limit has occurred when the temperature exceeds a predetermined temperature, but if the degenerate mode is also set when the temperature falls below the predetermined temperature, it may be determined that the speed limit has occurred when the temperature falls below the predetermined temperature. For example, the degenerate mode may be set when the temperature falls outside the range of -30°C to 60°C.

[0079] (2) Effects of this embodiment As described above, according to the communication device 100 of the present embodiment, when a speed limit occurs that is not dependent on the communication environment of the communication line, the timing of bandwidth estimation is reduced, so that the number of times that the bandwidth estimation result is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized. In addition, since the other communication device 150 can perform control to reduce the number of times that the bandwidth estimation data is transmitted, the resources of the reception line among the communication lines can be effectively utilized. Furthermore, according to the communication device 100 of the present embodiment, the number of times the bandwidth estimation calculations themselves are performed is also reduced, so that the calculations required for bandwidth estimation can be reduced and hardware resources can be used effectively. Furthermore, according to the communication device 100 of this embodiment, the bandwidth estimation data is generated according to the timing determined by the bandwidth estimation timing determination unit 103, so that the number of times the bandwidth estimation data is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized.

[0080] 5. Embodiment 4 The fourth embodiment is an embodiment in which the rate limit occurs due to a rise in temperature of the communication device 100. This embodiment is an embodiment in which the rate limit occurs due to an input voltage of the communication device 100. Note that only the parts that differ from the first embodiment will be described below, and the description of the first embodiment will be quoted for the configurations that are common to the first embodiment.

[0081] (1) Configuration of the communication device 100 according to the present embodiment Using Figure 2, EMBODIMENT 4 The configuration of the communication device 100 will be described. In this embodiment, the communication speed limit determination unit 102 has a voltage detection unit 111. The voltage detection unit 111 detects the "input voltage" of the communication device 100 itself or a component constituting the communication device 100, for example, a semiconductor module. The input voltage may be detected using information that directly indicates the input voltage, such as a directly measured voltage value or the output of a power supply IC, or information that indirectly indicates the input voltage, such as status information transmitted from a component constituting the communication device 100. Here, the "input voltage" includes information that directly indicates the input voltage as well as information that indirectly indicates the input voltage.

[0082] The communication speed limit determination unit 102 determines that a speed limit has occurred when the input voltage detected by the voltage detection unit 111 falls below a "predetermined input voltage." For example, in the event C of the line 1 in Fig. 5, the communication speed is limited when the input voltage of the semiconductor module falls below 3V, so the voltage detection unit 111 detects the input voltage, and the communication speed limit determination unit 102 determines whether the input voltage falls below the predetermined input voltage. Here, the "predetermined input voltage" may be a fixed value or may be a variable value that varies depending on conditions.

[0083] In the present embodiment as well, it is optional whether or not to provide the communication speed detection unit 108. In the first embodiment, the bandwidth estimation unit 104 estimates the bandwidth by estimating the communication speed, so the bandwidth estimation unit 104 uses the detection result of the communication speed detection unit 108 as is. In the present embodiment, if the communication speed detection unit 108 is not provided, the bandwidth estimation unit 104 executes estimation of the communication speed. The method of estimating the communication speed can be the same as the method used by the communication speed detection unit 108 in the first embodiment.

[0084] Note that an abnormality detection unit that detects abnormalities in parts that configure the communication device 100 may be provided instead of the voltage detection unit 111. The voltage detection unit 111 is an example of the abnormality detection unit. It is only necessary to determine in advance what type of abnormality is detected that will cause the device to transition to the degenerate mode. In this embodiment, it is determined that the speed limit has occurred when the input voltage falls below a predetermined value, but if the degenerate mode is also entered when the input voltage exceeds the predetermined value, it may be determined that the speed limit has occurred when the input voltage exceeds the predetermined value. For example, the degenerate mode may be entered when the input voltage falls outside the range of 3V to 4V.

[0085] (2) Effects of this embodiment As described above, according to the communication device 100 of the present embodiment, when a speed limit occurs that is not dependent on the communication environment of the communication line, the timing of bandwidth estimation is reduced, so that the number of times that the bandwidth estimation result is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized. In addition, since the other communication device 150 can perform control to reduce the number of times that the bandwidth estimation data is transmitted, the resources of the reception line among the communication lines can be effectively utilized. Furthermore, according to the communication device 100 of the present embodiment, the number of times the bandwidth estimation calculations themselves are performed is also reduced, so that the calculations required for bandwidth estimation can be reduced and hardware resources can be used effectively. Furthermore, according to the communication device 100 of this embodiment, the bandwidth estimation data is generated according to the timing determined by the bandwidth estimation timing determination unit 103, so that the number of times the bandwidth estimation data is transmitted can be reduced, and the resources of the transmission line among the communication lines can be effectively utilized.

[0086] 6. Relationship between embodiment 1, embodiment 2, embodiment 3, and embodiment 4 The first embodiment is an embodiment in which the communication speed limit determination unit 102 has a communication speed detection unit 108, the second embodiment is an embodiment in which the communication speed limit determination unit 102 has a communication volume detection unit 109, the third embodiment is an embodiment in which the communication speed limit determination unit 103 has a temperature detection unit 110, and the fourth embodiment is an embodiment in which the communication speed limit determination unit 103 has a voltage detection unit 111. These embodiments and their modified examples can be used alone or in any combination. For example, the communication device 100 in FIG. 2 can be understood as having all the configurations of the first, second, third, and fourth embodiments.

[0087] In the third and fourth embodiments, the abnormality detection unit detects abnormalities in temperature and input voltage, respectively, but may detect other abnormalities such as vibration, humidity, or ambient noise.

[0088] 7.Embodiment 5 The configuration of a communication device 200 according to the fifth embodiment will be described with reference to Fig. 8. This differs from Fig. 2 showing the configurations of the first to fourth embodiments in that a receiving unit 201 has a first receiving unit 211 connected to a first communication line and a second receiving unit 212 connected to a second communication line, and a transmitting unit 205 has a first transmitting unit 213 connected to the first communication line and a second transmitting unit 214 connected to the second communication line. Also, the communication speed limit determination unit 202, the bandwidth estimation timing determination unit 203, the bandwidth estimation unit 204, the bandwidth estimation data generation unit 206, the communication speed detection unit 208, and the communication volume detection unit 209 differ in that they process the first communication line and the second communication line, respectively.

[0089] The first and second communication lines may have different communication methods, or may have the same communication method but have different communication contracts, including different telecommunications carriers, communication providers, and communication fee structures and speed limits. Different telephone numbers may be assigned to the first and second communication lines. In addition, the first and second communication lines may be dedicated data communication lines that do not support voice calls, or dedicated lines using a VPN (Virtual Private Network). The communication destination of the first communication line and the communication destination of the second communication line may be different communication devices. The same applies to the sixth embodiment.

[0090] When the communication speed limit determination unit 202 determines that a speed limit has occurred on the first communication line, the bandwidth estimation unit 204 estimates the bandwidth of the first communication line at the timing determined by the bandwidth estimation timing determination unit 203 to generate a bandwidth estimation result. The determination by the communication speed limit determination unit 202 can be made by at least one of the methods according to the first to fourth embodiments.

[0091] Of the transmitting units 205 , the second transmitting unit 214 connected to the second communication line transmits the bandwidth estimation result of the first communication line estimated by the bandwidth estimating unit 204 to the other communication device 150 .

[0092] As described above, according to this embodiment, the bandwidth estimation result is transmitted via a communication line other than the communication line on which it is determined that a speed limit has occurred, so that the bandwidth estimation result can be transmitted without being affected by the speed limit, and the communication volume on the communication line on which the speed limit has occurred can be reduced. In particular, this is particularly effective when a speed limit is imposed on one communication line as a result of exceeding a certain communication volume in a certain period of time. For example, when multiple communication paths are to be established from the viewpoint of communication line redundancy, more data that requires redundant transmission can be transmitted to the communication line where the speed limit has occurred.

[0093] 8. Embodiment 6 The configuration of a communication device 200 according to the sixth embodiment will be described with reference to FIG. 8. This differs from FIG. 2, which shows the configurations of the first to fourth embodiments. EMBODIMENT 5 In addition to the differences described above, the difference is that the function of the bandwidth estimation timing determination unit 203 is added with processing for when the bandwidth estimation of the first communication line and the second communication line overlap in time.

[0094] When the communication speed limit judgment unit 202 judges that a speed limit has occurred, the bandwidth estimation timing decision unit 203 decides the timing of bandwidth estimation for the communication line in which the speed limit has occurred, and when the bandwidth estimations of the first communication line and the second communication line in the bandwidth estimation unit 204 overlap in time, the bandwidth estimation timing change the timing of bandwidth estimation for the first communication line and / or the second communication line.

[0095] The determination by the communication speed limit determination unit 202 can be made by at least one of the methods according to the first to fourth embodiments. Furthermore, the timing of the bandwidth estimation performed by the bandwidth estimation timing determination unit 203 can be determined by the method described in the first embodiment. The timing of bandwidth estimation may be changed for either the first communication line or the second communication line, or for both the first communication line and the second communication line.

[0096] Specific examples of changing the timing of bandwidth estimation will be described in the following Examples 1 to 4. (1) Example 1 The operation of the communication device 200 according to the first embodiment of the present invention will be described with reference to FIGS. 9, for example, when the temperature of a communication module of communication device 200 rises, communication speed limit determination unit 202 determines that a speed limit has been imposed on the first communication line and the second communication line. Then, bandwidth estimation timing decision unit 203 decides the timing of bandwidth estimation for the first communication line and the second communication line. However, when the timing of bandwidth estimation for the first communication line and the second communication line overlaps in time, the load on software and hardware (e.g., a CPU) that realizes the function of bandwidth estimation unit 204 is concentrated in time.

[0097] Therefore, the bandwidth estimation timing decision unit 203 shifts the timing of bandwidth estimation for the first communication line by a predetermined time. For example, as shown in FIG. 10, the bandwidth estimation timing is shifted by making the number of times of bandwidth estimation shorter by one than the number of times of initial thinning.

[0098] Whether the timings of bandwidth estimation overlap in time can be found by the bandwidth estimation timing decision unit 203 itself through calculation, but it may also be detected by measuring the load of the CPU. The same applies to the other embodiments.

[0099] In this embodiment, since the time when it was determined that the speed limit occurred was later for the first communication line than for the second communication line, the timing of the bandwidth estimation was changed for the first communication line. Instead of this, the bandwidth estimation timing for the second communication line may be changed midway. Of course, the bandwidth estimation timing for both communication lines may be changed. The same applies to the other embodiments.

[0100] In this embodiment, the timing of the bandwidth estimation is shifted by changing the number of times of initial thinning, but a predetermined time weight may be set.

[0101] In this embodiment, the case where the periods of the bandwidth estimation timing of the first communication line and the second communication line are the same has been described, but the periods do not necessarily have to be the same. For example, when the number of times of thinning out of the first communication line is 1 and the number of times of thinning out of the second communication line is 3, the bandwidth estimation timing of the second communication line necessarily coincides with the bandwidth estimation timing of the first communication line, and the processing of this embodiment is also effective in this case.

[0102] As described above, according to this embodiment, it is possible to prevent the load on software and hardware from being concentrated in time when a speed limit occurs. Specifically, it is possible to smooth out the load on software and hardware by utilizing the free time of bandwidth estimation that occurs when a speed limit occurs.

[0103] (2) Example 2 The operation of the communication device 200 according to the second embodiment of the present invention will be described with reference to FIG. Fig. 11 shows only the portions corresponding to the portions showing the timing of the bandwidth estimation process in Fig. 9 and Fig. 10. In the case of Fig. 11, when the bandwidth estimation timing decision unit 202 sets the number of decimation times of the bandwidth estimation of the first communication line to 2 (i.e., the estimation interval is tripled because the estimation is made once in three times) and the number of decimation times of the bandwidth estimation of the second communication line to 3 (i.e., the estimation interval is quadrupled because the estimation is made once in four times), the least common multiple of the estimation intervals is 12, so that the timing of the bandwidth estimation overlaps in time once in 12 times.

[0104] Therefore, the bandwidth estimation timing determination unit 202 changes the timing of the bandwidth estimation of one of the communication lines for the bandwidth estimation processes in which the timings of the bandwidth estimations overlap in time. In this embodiment, the bandwidth estimation timing of the second communication line in which a speed limit is subsequently generated is performed after the bandwidth estimation of the first communication line only in the portion where the bandwidth estimation timing of the second communication line overlaps with the bandwidth estimation timing of the first communication line.

[0105] As described above, according to this embodiment, it is possible to prevent the load on software and hardware from being concentrated in time when a speed limit occurs. Specifically, it is possible to smooth out the load on software and hardware by utilizing the free time of bandwidth estimation that occurs when a speed limit occurs.

[0106] (3) Example 3 The operation of the communication device 200 according to the third embodiment of the present invention will be described with reference to FIG. The bandwidth estimation timing determination unit 202 of the second embodiment changes the timing of the bandwidth estimation of one of the communication lines only at the timing when the bandwidth estimations overlap in time based on the least common multiple of the estimation interval of the first communication line and the estimation interval of the second communication line. In this embodiment, in order to minimize the frequency of changing the timing of the bandwidth estimation of one of the communication lines in advance, the timing of the bandwidth estimation of the communication lines is changed so that the least common multiple of the estimation intervals becomes large.

[0107] The bandwidth estimation timing determination unit 202 obtains the least common multiple of the estimation intervals of the first communication line and the second communication line based on the determined timing. For example, similar to the second embodiment, if the number of decimation times for the bandwidth estimation of the first communication line is 2 (i.e., the estimation interval is tripled because the estimation is performed once every three times) and the number of decimation times for the bandwidth estimation of the second communication line is 3 (i.e., the estimation interval is quadrupled because the estimation is performed once every four times), the least common multiple of the estimation intervals is 12.

[0108] Then, the bandwidth estimation timing determination unit 202 calculates the combination of the number of times of thinning out that has the largest common multiple when the number of times of thinning out is changed within a range of ±1 for each of the first communication line and the second communication line 2. In this case, as shown in Fig. 12, when 1 is added to the number of times of thinning out for the first communication line and 1 is added to the number of times of thinning out for the second communication line, the least common multiple of the estimation intervals becomes 20, which is the largest. Therefore, the bandwidth estimation timing determination unit 202 changes the number of times of thinning out for bandwidth estimation for the first communication line to 3 and the number of times of thinning out for bandwidth estimation for the second communication line to 4.

[0109] As another example, when the number of decimation times for the bandwidth estimation of the first communication line is 6 (i.e., the estimation interval is 7 times because the estimation is made once in 7 times) and the number of decimation times for the bandwidth estimation of the second communication line is 2 (i.e., the estimation interval is 3 times because the estimation is made once in 3 times), the least common multiple of the estimation intervals is 21. Then, the bandwidth estimation timing determination unit 202 calculates a combination of the number of decimation times with the largest least common multiple when the number of decimation times is changed within a range of ±1 for each of the first communication line and the second communication line 2. In this case, as shown in FIG. 12, when the number of decimation times for the first communication line is left unchanged and the number of decimation times for the second communication line is added by 1, the least common multiple of the estimation intervals becomes the largest, 28. Therefore, the bandwidth estimation timing determination unit 202 keeps the number of decimation times for the bandwidth estimation of the first communication line at 6 and changes the number of decimation times for the bandwidth estimation of the second communication line to 3.

[0110] In this embodiment, the number of times of thinning out the first communication line and the second communication line is changed within a range of ±1, but the combination is not limited to this. For example, the longest allowable bandwidth estimation interval may be set, and the number of times of thinning out may be changed within this range. The longest allowable bandwidth estimation interval may be determined based on the longest time allowed for detecting that an event involving a speed limit has been resolved, for example.

[0111] This embodiment may be combined with the second embodiment to change the timing of estimating the bandwidth of the communication line.

[0112] As described above, according to this embodiment, it is possible to prevent the load on software and hardware from being concentrated in time when a speed limit occurs. Specifically, by changing the least common multiple of the estimation intervals to a larger value, it is possible to smooth out the load on software and hardware.

[0113] (4) Example 4 The operation of the communication device 200 according to the fourth embodiment of the present invention will be described with reference to FIG. The bandwidth estimation timing determination unit 202 of the third embodiment changes the timing of the bandwidth estimation of the communication line so that the least common multiple of the estimation intervals becomes large. In this embodiment, the least common multiple of the estimation intervals is changed to become large as in the third embodiment, but the timing of the bandwidth estimation of the communication line is changed in consideration of the degree of change in the estimation interval.

[0114] The bandwidth estimation timing determination unit 202 obtains the least common multiple of the estimation intervals of the first communication line and the second communication line based on the determined timing. For example, similar to the second and third embodiments, when the number of decimation times of the bandwidth estimation of the first communication line is 2 (i.e., the estimation interval is tripled because the estimation is performed once every three times) and the number of decimation times of the bandwidth estimation of the second communication line is 3 (i.e., the estimation interval is quadrupled because the estimation is performed once every four times), the least common multiple of the estimation intervals is 12.

[0115] Then, the bandwidth estimation timing determination unit 202 calculates an evaluation value based on the following formula when the number of decimations to be added is changed within a range of 0 to 10 for each of the first communication line and the second communication line 2. Evaluation value = (Least common multiple after change - Least common multiple before change) ÷ (change in number of culls for the first communication line + change in number of culls for the second communication line) The numerator represents the degree of change in the least common multiple, and the evaluation value increases when the least common multiple is changed to one that results in a larger estimation interval. The numerator represents the degree of change in the thinning number, and the closer it is to the initially determined thinning number, the higher the evaluation value. The upper limit of the range of the number of times of thinning out is the longest allowable bandwidth estimation interval.

[0116] 13, the evaluation value becomes highest when 10 is added to the number of decimations for the first communication line and 10 is added to the number of decimations for the second communication line. Therefore, the bandwidth estimation timing determination unit 202 changes the number of decimations for the bandwidth estimation of the first communication line to 12 and the number of decimations for the bandwidth estimation of the second communication line to 13.

[0117] As described above, according to this embodiment, it is possible to prevent the load on software and hardware from being concentrated in time when a speed limit occurs. Specifically, the load on software and hardware can be smoothed by changing the estimation interval taking into consideration the least common multiple of the estimation intervals and the degree of change in the estimation interval.

[0118] 9. Summary The features of the communication devices and the like in each embodiment of the present invention have been described above. The terms used in each embodiment are merely examples and may be replaced with synonymous terms or terms having the same functions.

[0119] The block diagrams used to explain the embodiments classify and organize the configuration of the device by function. The blocks showing the respective functions are realized by any combination of hardware or software. In addition, since the block diagrams show the functions, they can also be understood as disclosures of a method invention and a program invention that realizes the method.

[0120] The order of the processes, flows, and blocks that can be understood as methods described in each embodiment may be changed as long as there are no constraints, such as one step utilizing the results of another step prior to it.

[0121] Unless otherwise specified in the claims, the communication device of the present invention may be for use in a vehicle, and also includes a dedicated or general-purpose communication device for use other than in a vehicle.

[0122] Moreover, examples of the form of the communication device of the present invention include a semiconductor element, an electronic circuit, a module, and a microcomputer. Examples of semi-finished products include electronic control units (ECUs (Electric Control Units)) and system boards. Finished product forms include mobile phones, smartphones, tablets, personal computers (PCs), workstations, and servers. Other examples include devices with communication functions, such as car navigation systems.

[0123] It is assumed that the communication device of the present invention is used for the purpose of providing various services. In providing such services, the communication device of the present invention is used, the method of the present invention is used, and / or the program of the present invention is executed.

[0124] In addition, the present invention can be realized not only by 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 a memory or a hard disk, and general-purpose hardware having a dedicated or general-purpose CPU and memory capable of executing the program.

[0125] A program for a communication device of the present invention, which is stored in a non-transient substantial recording medium (for example, an external storage device (hard disk, USB memory, CD / BD, etc.) or an internal storage device (RAM, ROM, etc.)) of dedicated or general-purpose hardware, can also be provided to the dedicated or general-purpose hardware via the recording medium, or via a communication line from a server without using a recording medium. This makes it possible to always provide the latest functions through program upgrades. [Industrial Applicability]

[0126] Although the communication device of the present invention has been described assuming that it is mainly a communication device mounted on an automobile, it can be realized in various communication devices that perform bandwidth estimation. In addition, it is not limited to the application layer level, but can also be applied to lower layers in the OSI7 layer reference model. [Explanation of symbols]

[0127] 100, 200 communication device, 101 receiving unit, 102 communication speed limit determination unit, 103 bandwidth estimation timing determination unit, 104 bandwidth estimation unit, 105 transmitting unit, 106 bandwidth estimation data generation unit, 107 storage unit, 108 communication speed detection unit, 109 communication volume detection unit, 110 temperature detection unit, voltage detection unit 111

Claims

1. A communication device that communicates with another communication device via a communication line, A receiving unit (101) for receiving data from the other communication device; A communication speed limit determination unit (102) that determines the occurrence of a speed limit that is not dependent on the communication environment of the communication line; a bandwidth estimation timing determination unit (103) that, when it is determined by the communication speed limit determination unit that the speed limit has occurred, determines a timing for bandwidth estimation that is less frequent per unit time than when the speed limit has not occurred; A bandwidth estimation unit (104) that estimates a bandwidth of the communication line at the timing and generates a bandwidth estimation result; A transmission unit (105) for transmitting the bandwidth estimation result to the other communication device. A communication device (100).

2. Further, a bandwidth estimation data generating unit (106) is provided for generating bandwidth estimation data to be used by the other communication device for bandwidth estimation, The transmission unit transmits the bandwidth estimation data in addition to the bandwidth estimation result. The communication device according to claim 1.

3. Further, a storage unit (107) is provided for storing a reference communication speed, which is a communication speed determined when an event involving the speed limit occurs, The communication speed limit determination unit has a communication speed detection unit (108) that detects the communication speed of the communication line based on the data, the communication speed limit determination unit determines that the speed limit has been applied when the communication speed detected by the communication speed detection unit is constant and coincides with the reference communication speed. The communication device (100) of claim 1.

4. The storage unit further stores a reference timing corresponding to the reference communication speed, the bandwidth estimation timing determination unit reads out from the storage unit the reference timing corresponding to the communication speed detected by the communication speed detection unit, and sets the reference timing as the timing; The communication device according to claim 3.

5. The reference timing is defined by a decimation count, which is the number of times the bandwidth estimation is decimated. The communication device according to claim 4.

6. The reference timing is such that the number of times of thinning out is increased as the duration of the speed limit becomes longer. The communication device according to claim 5.

7. the communication speed detection unit detects the communication speed of the communication line based on data that is larger than a predetermined data size among the data. The communication device according to claim 3.

8. Further, a storage unit (107) is provided for storing a reference communication speed, which is a communication speed determined when an event involving the speed limit occurs, The communication speed limit determination unit has a communication speed detection unit (108) that detects a peer bandwidth estimation result included in the data, the communication speed limit determination unit determines that the speed limit has occurred when the communication speed indicated by the peer bandwidth estimation result is constant and coincides with the reference communication speed. The communication device (100) of claim 1.

9. The communication speed limit determination unit has a communication volume detection unit (109) that detects the amount of data received by the receiving unit and / or the amount of data transmitted by the transmitting unit, the communication speed limit determination unit determines that the speed limit has occurred when the reception amount and / or the transmission amount exceeds a predetermined amount. The communication device (100) of claim 1.

10. The communication speed limit determination unit has a communication traffic detection unit (109) that acquires communication traffic of the communication device or the other communication device from an external communication traffic management server, The communication speed limit determination unit determines that the speed limit has occurred when the communication volume exceeds a predetermined volume. The communication device (100) of claim 1.

11. The communication speed limit determination unit has a temperature detection unit (110) that detects the temperature of the communication device itself or a component that constitutes the communication device, the communication speed limit determination unit determines that the speed limit has occurred when the temperature exceeds a predetermined temperature. The communication device (100) of claim 1.

12. The communication speed limit determination unit has a temperature detection unit (110) that detects the temperature of the communication device itself or a component that constitutes the communication device, the communication speed limit determination unit determines that the speed limit has occurred when the temperature is lower than a predetermined temperature. A communication device (100) according to claim 1 or 11.

13. The communication speed limit determination unit has a voltage detection unit (111) that detects an input voltage input to the communication device itself or a component that constitutes the communication device, the communication speed limit determination unit determines that the speed limit has occurred when the input voltage falls below a predetermined input voltage. The communication device (100) of claim 1.

14. The communication speed limit determination unit has a voltage detection unit (111) that detects an input voltage input to the communication device itself or a component that constitutes the communication device, the communication speed limit determination unit determines that the speed limit has occurred when the input voltage exceeds a predetermined input voltage. A communication device (100) according to claim 1 or 13.

15. A communication device that communicates with another communication device via a first communication line and a second communication line, the first communication line and the second communication line being a plurality of communication lines, When the communication speed limit determination unit (202) determines that the speed limit of the first communication line has occurred, the transmission unit (205, 214) transmits the bandwidth estimation result via the second communication line. The communication device (200) of claim 1.

16. A communication device that communicates with another communication device via a first communication line and a second communication line, the first communication line and the second communication line being a plurality of communication lines, the bandwidth estimation timing decision unit (203), when it is determined that the speed limit has occurred in the communication speed limit determination unit (202), determines a timing of bandwidth estimation of the communication line in which the speed limit has occurred, and, when the bandwidth estimations of the first communication line and the second communication line overlap in time, changes the timing of bandwidth estimation of the first communication line and / or the second communication line. The communication device (200) of claim 1.

17. The communication device is mounted on a mobile object. A communication device according to any one of claims 1 to 16.

18. A communication method executed by a communication device that communicates with another communication device via a communication line, comprising: Receiving data from the other communication device (S101); Determining whether a speed limit occurs that is not dependent on the communication environment of the communication line (S102); When it is determined that the speed limit has occurred, a bandwidth estimation timing that is less frequent per unit time than when the speed limit has not occurred is determined (S103); Estimating the bandwidth of the communication line at the timing to generate a bandwidth estimation result (S104); Transmitting the bandwidth estimation result to the other communication device (S105); Communication methods.

19. A communication program executable by a communication device that communicates with another communication device via a communication line, Receiving data from the other communication device (S101); Determining whether a speed limit occurs that is not dependent on the communication environment of the communication line (S102); When it is determined that the speed limit has occurred, a bandwidth estimation timing that is less frequent per unit time than when the speed limit has not occurred is determined (S103); Estimating the bandwidth of the communication line at the timing to generate a bandwidth estimation result (S104); Transmitting the bandwidth estimation result to the other communication device (S105); Communications program.

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