JP2020120259A - Communication terminal device and base station device - Google Patents

Abstract

To reliably and efficiently perform communication while reducing the amount of data and the frequency of communication in a communication terminal device and a base station device using a low power wide area wireless communication (LPWA) method.SOLUTION: A communication terminal device 100 according to the present invention that is mounted on a moving body and communicates with a base station device using a low power consumption wide area wireless communication (LPWA) method includes a communication unit 102 that receives a response from the base station device to transmission of data while transmitting the data to be transmitted to the base station device, a moving distance detection unit 103 that detects moving distance of the moving body, and a transmission control unit 104 that controls the transmission of the data to the base station device, and the transmission control unit determines whether to include the information for requesting the response from the base station device in the data transmitted by the communication unit, on the basis of the moving distance.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mechanism for obtaining a response from a base station device in communication between a communication terminal device and a base station device in mobile communication, particularly low power wide area wireless communication ((LPWA) Low Power Wide Area). Is.

In recent years, the IoT (Internet of Things) era has come, which transcends the boundaries of conventional usage forms such as smartphones and mobile phones to create new added value by allowing all things to connect to the network and exchange information. Many of these objects are inaccessible and require only a small amount of data for a long period of time. In response to this request, 3GPP (Third Generation Partnership Project) has proposed eMTC (enhanced Machine Type Communication), NB-IoT (Narrow Band Internet of Things) optimized for smaller amount of data communication, and Sigfox. Specifications such as the developed SIGFOX (registered trademark) and LoRa (registered trademark) developed by Semtech have been established.

On the other hand, a technique has been disclosed in which a communication terminal device mounted on a mobile body determines a transmission cycle so as to transmit at least one packet during movement of a specified distance (Patent Document 1).
Also, in the data communication device installed in a moving vehicle, in order to avoid stacking of retransmitted data caused by prolonged interruption of wireless communication, the data acquired by the data communication device side on the vehicle side are compared and the same data is compared. In that case, a technique of discarding before transmission is disclosed (Patent Document 2).

JP, 2008-2444519, A JP-A-2005-94371

In order to realize wide area communication and reduction of power consumption, a communication terminal device for IoT has communication interruption due to frequency Doppler shift of a carrier wave that occurs during communication with a mobile object, which is implemented in LTE (Long Term Evolution). The prevention mechanism was omitted, and it was not necessarily suitable for mounting on a moving body.
In the low power consumption high frequency wireless communication (LPWA) system, the amount of data and communication frequency are reduced as much as possible in order to minimize power consumption. In addition, in the LPWA technology that uses a frequency band that can be used without a license, a total radio wave transmission time limit is provided in order to prevent congestion due to a specific wireless station occupying communication for a long time or at a high frequency. Therefore, it is not possible to send an acknowledgment (ACK) or information to a communication terminal device without limitation, which corresponds to a base station that needs to communicate with a large number of node terminals, especially in a star topology network. This is a major limitation in hub terminals.

An object of the present invention is to ensure reliable and efficient communication while reducing the frequency of communication in a communication terminal device and a base station device mounted on a mobile body and using a low power consumption wide area wireless communication (LPWA) system. There is something to do.

In order to solve the above problems, a communication terminal device of the present invention is mounted on a mobile body and communicates with a base station device by a low power wide area wireless communication (LPWA) system, and is a transmission target. A communication unit (102) that transmits certain data to the base station device and receives a response from the base station device to the transmission of the data, and a moving distance detection unit (103) that detects a moving distance of the moving body. And a transmission control unit (104) for controlling the transmission of the data to the base station device, wherein the transmission control unit adds the data to the data transmitted by the communication unit based on the moving distance. It is for determining whether to include the information for requesting the response from the base station device.

According to the communication terminal device and the base station device of the present invention, it is determined whether or not to include information for requesting a response from the base station device in the data transmitted by the communication terminal device, based on the moving distance of the mobile object. Communication can be performed reliably and efficiently while reducing the frequency, and as a result, the power consumption of the communication terminal device can be reduced.

A block diagram illustrating a configuration of a communication terminal device according to a first embodiment of the present invention. Format of data transmitted by the communication terminal device according to the first embodiment of the present invention Explanatory drawing explaining the method of calculating the predetermined distance in the communication terminal device of Embodiment 1 of this invention. The flowchart explaining operation|movement of the communication terminal device of Embodiment 1 of this invention. FIG. 3 is a block diagram illustrating the configuration of the base station device according to the first embodiment of the present invention. The flowchart explaining operation|movement of the base station apparatus of Embodiment 1 of this invention. The flowchart explaining operation|movement of the communication terminal device of Embodiment 2 of this invention. The flowchart explaining operation|movement of the communication terminal device of Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
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. Further, at least the word in the brackets means the word or phrase described in the scope of the claims or the means for solving the problem, and is not limited to the following embodiments.
Configurations and methods described in the dependent claims of the claims, configurations and methods of embodiments corresponding to the configurations and methods described in the dependent claims, and configurations and methods described only in the embodiments that are not described in the claims Are arbitrary configurations and methods in the present invention. In the sense that the configurations and methods described in the embodiments in the case where the scope of claims is broader than the description of the embodiments are also examples of the configurations and methods of the present invention, any configuration and method may be used in the present invention. is there. In any case, it is an essential configuration and method of the present invention by describing in the independent claims of the claims.
The effects described in the embodiments are the effects when the configuration of the embodiment as an example of the present invention is included, and are not necessarily the effects that the present invention has.
When there are a plurality of embodiments, the configuration disclosed in each embodiment is not limited to each embodiment alone, and it is possible to combine the embodiments. For example, the configuration disclosed in one embodiment may be combined with another embodiment. Further, the disclosed configurations may be collected and combined in each of the plurality of embodiments.
The knowledge and problems described in the problems to be solved by the invention are not known problems but are the findings of the present inventor, and are facts that affirm the inventive step as well as the configuration and method of the present invention.

(Embodiment 1)
1. Configuration of Communication Terminal Device First, the configuration of the communication terminal device 100 according to the first embodiment will be described with reference to FIG.
In the following embodiments, an in-vehicle communication terminal device mainly mounted in an automobile will be described as an example, but the present invention includes a communication terminal device other than in-vehicle use unless otherwise limited by the claims. It is a waste.

The communication terminal device 100 is mounted on a “moving body” such as an automobile and communicates with the base station device 200 by a “low power consumption wide area wireless communication (LPWA) system”. The terminal device 100 communicates using a low power consumption wide area wireless communication system, for example, SIGFOX developed by Sigfox or LoRa developed by Semtech. These communication schemes have a feature that communication starts from the uplink communication from the communication terminal device 100 to the base station device 200.
The communication terminal device 100 includes a RAM 101, a communication unit 102, a moving distance detection unit 103, a CPU 104, an external I/F 105, a power supply 106, and an antenna A1.
Here, the “moving body” of the present invention refers to a movable object, and the moving speed is arbitrary. It also naturally includes the case where the moving body is stopped. Examples include, but are not limited to, automobiles, motorcycles, bicycles, pedestrians, ships, aircraft, and objects mounted on these.
Further, the “low power consumption wide area wireless communication (LPWA) system” of the present invention is a generic term for wireless communication systems having low power consumption and a communication distance of a mobile phone level, and any system may be used.

The RAM 101 is a storage unit that stores data to be transmitted acquired from various sensors connected to the external interface (I/F) 105 via the CPU 104. The various sensors need not be connected to the external I/F 105 and may be built in the communication terminal device 100. Examples of various sensors include a thermometer, a hygrometer, a sunshine meter, a GPS, a drive system electronic control device that controls an engine, a steering wheel, a brake, and the like, and a vehicle body system electronic control device that controls a meter, a power window, and the like. Alternatively, a sensor connected to a safety control system electronic control device that performs control for preventing a collision with an obstacle or a pedestrian and may be mounted on an automobile.
Although the RAM 101 is assumed to be a random access memory, it may be a hard disk (HDD), a flash memory, or the like. In this case, the data can be saved without being erased even when the power is turned off.

The communication unit 102 transmits the data to be transmitted read from the RAM 101 via the CPU 104 to the base station device 200 from the antenna A1. Further, the communication unit 102 receives a response from the base station device 200 to the data transmission from the communication terminal device 100.

The moving distance detection unit 103 “detects the moving distance” of the vehicle in which the communication terminal device 100 is mounted. The moving distance detection unit 103 is, for example, a device that uses a global positioning system (GPS) or untethered dead reckoning (UDR). Since these devices do not need to be connected to an automobile, there is no need for installation work by a specialized business operator, and the communication terminal device 100 can be realized as a device mounted on a dashboard, for example. Of course, the moving distance detection unit 103 may be a sensor such as an integrator connected to the axle of the automobile.
The moving distance detection unit 103 continuously detects the moving distance. Then, if a specific time point is determined, the moving distance from this specific time point as a starting point is detected. Alternatively, the moving distance detecting unit 103 detects the moving distance periodically or based on a trigger input from the outside. Examples of the former include, for example, every 10 seconds, and examples of the latter include, for example, when the communication unit 102 transmits data and when the communication unit 102 receives a response from the base station device 200.
Here, “detecting the moving distance” of the present invention includes not only the case of directly obtaining the moving distance but also the case of indirectly detecting the moving distance by detecting the moving speed and time.

The power supply 106 supplies power to each unit of the communication terminal device 100. The power may be supplied directly from, for example, a cigar socket, or a primary battery or a secondary battery may be used. By using the battery, the communication terminal device 100 can be mounted on the dashboard of the automobile without using a cable or the like for power supply, and the mounting work becomes easy.

The CPU 104 (corresponding to the “transmission control unit” of the present invention) controls the external I/F 105, the RAM 101, the communication unit 102, and the moving distance detection unit 103 as described above, and also transmits from the communication unit 102 to the base station apparatus 200. Control the transmission of data. Specifically, based on the movement distance detected by the movement distance detection unit 103, it is determined whether or not the data transmitted by the communication unit 102 includes “information for requesting a response” from the base station device 200.
Here, “based on” in the present invention includes not only the case of determining only from the moving distance but also the case of determining together with other information. In addition to the case where the movement distance is directly determined, the case where the movement distance is determined from a physical quantity indirectly expressing the movement distance, such as a moving speed and its direction, an integral value of their durations, and the like are included.
Further, the “information requesting a response” of the present invention means information that becomes a trigger for transmitting a response from the base station device.
Hereinafter, an example of the control content of the CPU 104 will be described in detail.

(1) Specific Example of Control Contents It is assumed that the communication unit 102 transmits the first data and receives the first response from the base station device 200 for the first data. The moving distance detection unit 103 detects the moving distance of the vehicle up to the present time starting from the time of transmitting the first data or the time of receiving the first response. Then, when the communication unit 102 transmits the second data, if the moving distance detection unit 103 detects the moving distance of “predetermined distance” or “equal to or less than”, the CPU 104 sets the second data to the second data. The flag for requesting the second response from the base station device 200 for data transmission (corresponding to “information for requesting response” of the present invention) is not included. On the other hand, when the communication unit 102 transmits the second data, if the movement distance detection unit 103 detects the movement distance of “predetermined distance” or “greater than or equal to”, the CPU 104 outputs the second data. A flag (corresponding to “information for requesting response” of the present invention) for requesting a second response from the base station device 200 for transmission of the second data is included.
Here, the “predetermined distance” of the present invention is not limited to the case where the distance is constant, and for example, the predetermined distance is determined based on the position or the moving direction of the moving body. It suffices to decide uniquely with.
Further, “below” includes the case where the reference numerical value is included and the case where the reference numerical value is not included.
Furthermore, “greater than or equal to” includes not only the case where the standard numerical value is included but also the case where the standard numerical value is not included.

(2) Format of data to be transmitted An example of the format of data to be transmitted from the communication terminal device 100 to the base station device 200 will be described with reference to FIG. This example shows the frame structure in the physical layer of the data used for upstream and downstream communication of LoRaWAN.

The data format transmitted from the communication unit 102 to the base station apparatus 200 includes a preamble (Preamble), a physical header (PHDR), a physical header consistency check bit (PHDR CRC), a payload (PHYPayload), a consistency check bit ( CRC).
A synchronization code is stored in the preamble.
Data related to the system is stored in the physical header.
The checksum of the physical layer header is stored in the physical header consistency check bit.
The payload stores actual data to be transmitted.
The checksum of the payload is stored in the consistency check bit.

The upper 3 bits of the payload correspond to the data specifying the message type. For example, 100 is confirmed upstream data, that is, a flag for which a response is requested, and 010 is unconfirmed upstream data, that is, a flag for which a response is not requested. That is, if the upper 3 bits of the payload are 100, this corresponds to a flag for requesting a response in this embodiment. Alternatively, if the upper 2 bits of the payload are 10, it corresponds to a flag for requesting a response in this embodiment. If the upper 3 bits or the upper 2 bits of the payload are other bits, it means that the flag for requesting a response in the present embodiment is not included.

Of course, the flag for requesting a response may have a format other than this, for example, a specific 1 bit in the data specifying the message type.
Further, as the flag for requesting a response, an unused area in the data format may be used.

(3) Predetermined distance (p)
The predetermined distance (p) detected by the moving distance detection unit 103 can be determined by assuming a distance at which the communication terminal device 100 will not communicate with the same base station device 200 continuously a plurality of times. Hereinafter, as examples thereof, the communicable distance (r) of the base station device 200, the distance (x) of the mobile unit from the base station device 200, and the moving direction (θ) of the mobile unit based on the direction of the base station device 200. , And (b) the case of obtaining from r, (b) the case of obtaining from x, θ, r. Of course, it may be determined from other factors such as the density of the base station device 200.

(A) In the case of obtaining from r In the low power consumption high frequency wireless communication (LPWA) system, it is general that a plurality of base station devices 200 covers communication with the communication terminal device 100. Then, under the control of the network server, the base station device having a good radio wave condition communicates. In a wireless communication system based on this, a diameter of a communication cell covered by a single base station device, that is, 2r, which is twice the “communicable distance (r) of the base station device”, is set to a predetermined distance (p1 ) Can be specified.

Predetermined distance (p1)=2r... (1)

If the predetermined distance (p1) is set in this way, when the communication terminal device 100 moves the predetermined distance (p1) after communicating with the base station device 200, the communication cell of another base station device can be surely obtained. Have moved in.
Here, the “communicable distance (r) of the base station device” of the present invention is not limited to the physical communicable distance of the base station device, but is determined by the specifications, design, or use or installation conditions. It also includes the case where the distance indicates the communication range of the base station device.

That is, when the moving distance detection unit 103 detects at least 2r or more as the moving distance, starting from the time of transmitting the first data or the time of receiving the first response, the communication terminal device 100 determines the first It is certain that the mobile station is moving into a communication cell of a base station device different from the base station device 200 that transmitted and received the data and the first response. Therefore, the CPU 104 includes a flag for requesting the second response in the second data.
When the moving distance detection unit 103 detects 2r or less as the moving distance starting from the time of transmitting the first data or the time of receiving the first response, the communication terminal apparatus 100 determines that the first data is the first data. And the base station device 200 that has transmitted and received the first response may still belong to the same communication cell of the base station device 200. Therefore, the CPU 104 does not include the flag for requesting the second response in the second data.

Note that 2r may be multiplied by a predetermined coefficient as a safety factor or a margin factor. Also, the value of r may be changed according to the type of the base station apparatus 200 with which communication is performed and the density of the base station apparatus 200. The type of the base station device 200 can be identified by, for example, the ID of the base station device 200 transmitted from the base station device 200. For example, it depends on the magnitude of the radio wave output of the base station device 200, the topography, and the structure. If the communication range of each base station device 200 by radio wave propagation and the above-mentioned ID are associated with each other, the communication terminal device 100 changes the assumed value of r each time the base station device 200 transmits. Is also possible.

(B) Obtaining from x, θ, and r A method of obtaining the predetermined distance (p2) will be described with reference to FIG.
The position of the communication terminal apparatus 100 with respect to the base station apparatus 200 and the moving direction of the communication terminal apparatus 100 at the time of transmitting the first data or at the time of receiving the first response can take arbitrary places and directions. Therefore, in relation to the communicable distance (r) of the base station device, the predetermined distance (p2) is

0≦predetermined distance (p2)≦2r

Can take the value of. Therefore, the predetermined distance (p2) is the communicable distance (r) of the base station device 200, the distance (x) of the mobile unit from the base station device 200, and the movement of the mobile unit based on the direction of the base station device 200. In the case of the direction (θ), it can be calculated by the following formula.

Predetermined distance (p2)=xcos θ+rcos φ (2)
(However, xsin θ = rsin φ)

If the predetermined distance (p2) is set in this way, when the communication terminal device 100 moves the predetermined distance (p2) after communicating with the base station device 200, the edge of the communication cell of another base station device Has reached.

That is, when the moving distance detection unit 103 detects a moving distance that is equal to or greater than the distance obtained by the equation (2), starting from the time of transmitting the first data or the time of receiving the first response, the communication terminal device 100 is moving to the edge of the communication cell of the base station device different from the base station device 200 that has transmitted and received the first data and the first response. Therefore, the CPU 104 includes a flag for requesting the second response in the second data.
Further, when the moving distance detection unit 103 detects a moving distance less than or equal to the distance obtained by the equation (2) from the time of transmitting the first data or the time of receiving the first response, the communication terminal device Reference numeral 100 belongs to the communication cell of the base station device 200 that has transmitted and received the first data and the first response. Therefore, the CPU 104 does not include the flag for requesting the second response in the second data.

It should be noted that the distance (x) of the mobile body equipped with the communication terminal device 100 from the base station device 200 is the base station device 200, the network control, and the base station device 200 and the communication terminal device based on the network positioning performed by the cloud device. It is possible to cause the communication terminal apparatus 100 to recognize the relative position information of the moving body equipped with 100 by the first response communication from the base station apparatus 200 side. Then, the moving direction (θ) and the moving distance of the mobile body mounted with the communication terminal device 100 subsequent to that point are the UDR mounted on the mobile terminal, or the positioning of the GPS performed continuously or intermittently by the communication terminal. The device 100 itself can recognize it, and based on that, the subsequent relative position and the distance (x) to the base station device 200 that has transmitted the first response can be recognized.
In this way, the communicable distance (r) of the base station device 200, the distance (x) of the moving body from the base station device 200, and the moving direction (θ) of the moving body based on the direction of the base station device 200 are: The communication terminal device 100 does not necessarily have to make the request, and may receive a notification from the base station device 200, for example. The same applies to the predetermined distance (p2).

(4) Effect of control of the present embodiment With respect to the base station apparatus 200 that has succeeded in communication at least once, there is a relatively high possibility that communication will succeed. Therefore, after the first communication is successful, the same base is determined by determining whether or not to include the information for which the response is required when the distance is equal to or greater than the predetermined distance and when the distance is equal to or less than the predetermined distance, based on the predetermined distance. When belonging to the communication cell of the station device 200, the number of responses transmitted from the base station device 200 can be reduced, and when moving to the communication cell of a different base station device, by obtaining the response, It is possible to reliably detect the case where communication fails.
And
(A) When the predetermined distance (p1) is used, the communicable distance (r) of the base station device 200 is uniquely determined depending on the type of the base station device 200, so it may be held as a constant, and the predetermined distance Does not need to be calculated on the mobile communication terminal 100. Thereby, the power consumption of the communication terminal device 100 can be reduced.
(B) When the predetermined distance (p2) is used, it is possible to accurately determine that the communication terminal device 100 has moved into the communication cell of another base station device by UDR or GPS positioning. Further, it is possible to reliably detect a communication failure that occurs due to a change in the base station device with which the communication terminal device 100 communicates.

2. Operation of Communication Terminal Device Next, the operation of the communication terminal device 100 according to the first embodiment will be described with reference to FIG.
The RAM 101 stores the first data that is the transmission target acquired by the various sensors (S11).
The communication unit 102 transmits the first data stored in the RAM 101 to the base station device 200 (S12). The first data includes a flag for requesting a response from the base station device 200.
The communication unit 103 receives the first response to the transmission of the first data from the base station device 200 (S13).
The RAM 101 stores the second data that is the transmission target acquired by the various sensors (S14).
The moving distance detection unit 103 detects the moving distance that the vehicle equipped with the communication terminal device 100 has moved from when the first data is transmitted (S12) or when the first response is received (S13) (S15). ).
The CPU 104 determines whether the moving distance is less than or equal to a predetermined distance (S16). When the distance is equal to or less than the predetermined distance, the second data does not include the flag for requesting the second response to the transmission of the second data. If the distance is equal to or greater than the predetermined distance, the second data includes a flag for requesting a second response to the transmission of the second data (S17).
The communication unit 103 transmits the second data stored in the RAM 102 to the base station device 200 (S18).

Note that, in the flow of FIG. 4, when the subsequent process or determination does not assume the result of the previous process or determination, the order can be changed.

Further, FIG. 4 shows not only the communication method of the communication terminal device 100 but also the processing procedure of the program executed by the communication terminal device 100. The program can be realized as software in an arbitrary protocol stack of the communication protocol, and is not necessarily at the application level. At the application level, the drawbacks of the upper layer can be compensated while maintaining the communication protocol of the upper layer of the communication method.

3. Configuration of Base Station Device First, the configuration of the base station device 200 according to the first embodiment will be described with reference to FIG.
The base station device 200 receives data using the data format of FIG. 2 from the communication terminal device 100 described in the first embodiment. The MAC layer payload may or may not include information requesting a response to the reception of data transmitted from communication terminal apparatus 100.

The base station device 200 communicates with the communication terminal device 100 by a low power consumption wide area wireless communication (LPWA) method. The base station device 200 communicates using a low power consumption wide area wireless communication system, for example, SIGFOX developed by Sigfox or LoRa developed by Semtech.
The base station device 200 has a communication unit 201, a CPU 202, a RAM 203, a gateway (G/W) 204, and an antenna A2.

The communication unit 201 receives the data transmitted from the communication terminal device 100 via the antenna A2. Also, the communication unit 201 transmits a response to the reception of the data to the communication terminal device 100 via the antenna A2.

The CPU 202 (corresponding to the “analyzing unit” of the present invention) analyzes the data received by the communication unit 201. Specifically, the CPU 202 does not instruct the communication unit 201 to transmit a response when the data transmitted from the communication terminal device 100 does not include a flag requesting a response from the base station device 200. Further, when the data transmitted from communication terminal apparatus 100 includes a flag requesting a response from base station apparatus 200, CPU 202 instructs communication section 201 to transmit a response.

The RAM 203 stores the data received by the communication unit 201 via the CPU 202.
Although the RAM 203 is assumed to be a random access memory, it may be a hard disk (HDD), a flash memory, or the like.

The gateway (G/W) 204 is connected to the cloud device via a network and transfers the data stored in the RAM 203 to the cloud device.
The network control or the cloud device compares the differences in the RSSI (radio field strength) of the uplink signals received by the plurality of base station devices 200, and communicates from the communication terminal device 100 side using, for example, the precision time synchronization technology by GPS. The relative position and distance between the base station device 200 and the communication terminal device 100 can be calculated based on the comparison of the arrival times, and the communication terminal device 100 can be notified of the relative position and the distance by response communication. By the GPS positioning or the GPS positioning, it is possible to self-recognize the relative position and the distance to the base station device 200 which are changed by the subsequent movement.

The base station device 200 does not send a response if the data transmitted from the communication terminal device 100 does not include a flag for requesting a response from the base station device 200, so that the communication band used by the base station device 200 is determined. The use of included resources can be minimized.

4. Operation of Base Station Device Next, the operation of the base station device 200 will be described with reference to FIG.
The communication unit 201 receives the first data transmitted from the communication terminal device 100 (S21).
The communication unit 201 transmits the first response to the communication terminal device 100 (S22).
The communication unit 201 receives the second data transmitted from the communication terminal device 100 (S23).
The CPU 202 determines whether or not the second data received in S23 includes a flag for requesting a response from the base station device 200 (S24). If it is not included, the second response is not transmitted and the process ends. If included, it instructs the communication terminal device 100 to transmit the second response, and the communication unit 201 transmits the second response to the communication terminal device 100 (S25).

Note that, in the flow of FIG. 6, when the subsequent process or determination does not assume the result of the previous process or determination, the order can be changed.

Further, FIG. 6 shows not only the communication method of the base station device 200, but also the processing procedure of the program executed by the base station device 200. The program can be realized as software in an arbitrary protocol stack of the communication protocol, and is not necessarily at the application level. At the application level, the drawbacks of the upper layer can be compensated while maintaining the communication protocol of the upper layer of the communication method.

(Embodiment 2)
In the first embodiment, it is determined whether to include information for requesting a response from the base station device 200 in the data to be transmitted to the base station device 200, based on the moving distance of the vehicle equipped with the communication terminal device 100. In the present embodiment, in addition to this, a temporal element is added to determine whether to include information for requesting a response from the base station device 200.
The configuration of the communication terminal device 300 according to the present embodiment is the same as the configuration of the communication terminal device 100 according to the first embodiment except for the control content of the CPU 104.

The CPU 104 (corresponding to the “transmission control unit” of the present invention) has a “predetermined time” from the time of transmitting the first data or the time of receiving the first response, in addition to the control contents of the CPU 104 of the first embodiment. When “more than or equal to” has passed, the second data includes a flag for requesting the second response. If the “predetermined time”, “or more” has not elapsed from the time of transmitting the first data or the time of receiving the first response, the second data includes a flag for requesting the second response. Absent.
Here, the "predetermined time" of the present invention is not limited to the case where the time is constant, and for example, the predetermined time is determined based on the position or the moving direction of the moving body, or the like, even if it is not always constant. It suffices to decide uniquely with.
Further, the term “or more” in the present invention includes not only the case where the standard numerical value is included but also the case where the standard numerical value is not included.

Next, the operation of the communication terminal device 300 according to the second embodiment will be described with reference to FIG. The same processes as those of the first embodiment described with reference to FIG.
The CPU 104 determines whether or not a predetermined time or more has elapsed from the time of transmitting the first data or the time of receiving the second response (S31). When the predetermined time or more has elapsed, the second response is obtained from the second data as the second response to the transmission of the second data even when the movement distance equal to or shorter than the predetermined distance is detected in S16. A flag is included (S17). When the predetermined time or more has not elapsed, the second data does not include the flag for requesting the second response to the transmission of the second data.

Although the predetermined time can be set to any time, it can be set based on the characteristics of the communication method used by the communication terminal device 300, for example.
For example, the predetermined time can be determined based on the transmission frequency or interval (60 minutes total transmission time is within 6 minutes in the case of 920 MHz band) regulated by laws and guidelines such as ARIB. In addition, the assumed number of contracted terminals defined by the service of the communication carrier, the number of base station devices, the estimated communication time and frequency of each communication terminal device, the number of frequency channels used by them, and the congestion with the communication of other methods and carriers It can be determined based on a time constraint (for example, 4 times/day in the case of SIGFOX) that can be computationally defined under conditions such as prevention.

Even when the communication terminal device 300 communicates with the same base station device 200, the communication environment may change over time. According to the communication terminal device 300 of the present embodiment, even in such a case, it is possible to reliably detect the case where communication has failed.

(Embodiment 3)
In the first embodiment, it is determined whether to include information for requesting a response from the base station device 200 in the data to be transmitted to the base station device 200, based on the moving distance of the vehicle equipped with the communication terminal device 100. In this embodiment, in addition to this, the type and importance of data to be transmitted are taken into consideration to determine whether to include information for requesting a response from the base station device 200.
The configuration of the communication terminal device 400 according to the present embodiment is the same as the configuration of the communication terminal device 100 according to the first embodiment except for the control content of the CPU 104.

The CPU 104 (corresponding to the “transmission control unit” of the present invention) requests a second response for the second data based on the control content of the CPU 104 of the first embodiment and the type or importance of the second data. Include flags.

Next, the operation of the communication terminal device 400 according to the third embodiment will be described with reference to FIG. The same processes as those of the first embodiment described with reference to FIG.
The CPU 104 determines whether the type of the second data is a specific type of data or whether the second data is important data (S41). If the type of the second data is a specific type of data, or if the second data is important data, even if the movement distance of a predetermined distance or less is detected in S16, A flag for requesting a second response to the transmission of the second data is included in the second data (S17). If the second data type is not a specific type of data, and if the second data is not important data, the second data includes a flag for requesting a second response to the transmission of the second data. Absent.

Examples of specific types of data include the following.
For example, there are communication terminal devices equipped with sensors that can detect temperature, humidity, impact, ambient illuminance, and position information during traveling, and all data detected by these sensors may be included in the payload of one uplink communication. It is not possible, and it is assumed that a predetermined frequency and order are sent individually or sequentially by linking some data. For example, when the communication terminal device is attached to a refrigerating transportation device, temperature data or data including the temperature data is transmitted as a specific type of data including a flag for always requesting the second response. The other data is transmitted without including the flag for requesting the second response.
As another example, a communication terminal device that measures position information to watch over a child, that is, normally position information is automatically transmitted at a predetermined regular frequency, regardless of the regular frequency when abnormal, Assume a communication terminal device capable of transmitting position information at the timing when a manual switch is operated. In this case, the automatic periodic transmission is performed without including the flag for requesting the second response, and when the manual switch for an abnormality is operated, the specific type of data is transmitted. Assuming that there is, a second response is transmitted including a flag.
In this way, a specific type of data can be set according to the role or function of the object on which the communication terminal device is mounted.

Examples of important data include the following.
For example, in the case of a communication terminal device mounted on a vehicle, when a highly urgent log such as an accident or a failure of a device that controls running stop that is directly related to human life is detected, it is important regardless of whether it is a regular communication timing or not. As the data, the flag is transmitted including the flag for requesting the second response at the timing when the log is detected.
In addition, if a log of a warning sign that has enough time or extent to lead to an accident or human life is detected, or if a status log in the normal operation range is detected, it is determined whether it is the timing of regular communication or the timing of detecting the log. Regardless, the second response is transmitted without including the flag for requesting it.
In addition, although it is the same type of data, it is also possible to determine whether it is important data by a threshold value.

Depending on the type and importance of the data, it is desirable that the communication terminal device 400 confirms that the base station device 200 has surely received the data. According to the communication terminal device 400 of the present embodiment, it is possible to reliably detect a case where communication has failed, taking into consideration the type and importance of data.

Although the second and third embodiments are described separately as the additional functions of the first embodiment, the communication terminal device 500 may be provided with the functions of both the second and third embodiments in the first embodiment. .. In this case, the function and operation of the communication terminal device 500 include both steps of S31 of FIG. 7 and S41 of FIG. 8, and the order may be determined first.

(Summary)
The features of the communication terminal apparatus and the base station apparatus according to the embodiment of the present invention have been described above.

The terms used in each embodiment are exemplifications, and may be replaced with terms having the same meaning or terms having the same functions.

The block diagram used in the description of the embodiment shows the configurations of the communication terminal device and the base station device classified and organized by function. These functional blocks are realized by any combination of hardware and software. Further, since the functions are shown, the block diagram can be understood as the disclosure of the method invention.

The functional blocks that can be grasped as the processes, flows, and methods described in each embodiment may be rearranged in order unless there is a constraint such that the results of other steps are used in one step.

The terms "first" and "second" used in each embodiment and the present invention are used to distinguish two or more configurations and methods of the same kind, and do not limit the order or superiority or inferiority.

In the above embodiment, the case where the communication terminal device of the present invention is mounted on a vehicle, that is, the vehicle-mounted device has been described. However, the present invention is applied on the assumption that a pedestrian has the communication terminal device of the present invention. Good.

Examples of communication terminal devices include semiconductors, electronic circuits, modules, and ECUs (electronic control units) as parts and semi-finished products. Further, examples of completed products include drive recorders, car navigation systems, smartphones, personal computers, mobile phones, and personal digital assistants.

In addition, the present invention can be realized not only by dedicated hardware having the configuration and function described in each embodiment but also by a program for realizing the present invention recorded in a recording medium such as a memory or a hard disk, and It can also be realized as a combination with general-purpose hardware having an executable dedicated or general-purpose CPU and memory.

A program stored in a dedicated or general-purpose hardware recording medium (external storage device (hard disk, USB memory, CD/BD, etc.), internal storage device (RAM, ROM, etc.)) is recorded through the recording medium or recorded. It is also possible to provide dedicated or general-purpose hardware from a server via a communication line without using a medium. As a result, it is possible to always provide the latest functions through the program upgrade.

INDUSTRIAL APPLICABILITY The communication terminal device and the base station device according to the present invention are used not only for in-vehicle applications but also for low power consumption wide area wireless communication (LPWA) in general. For example, by setting the communication terminal device of the present invention to the package to be delivered, information indicating the delivery status of the package (for example, position information) and the environment at the time of delivery (for example, temperature and humidity) is transmitted to the base station device This information can be used.

100 communication terminal device, 101 RAM, 102 communication unit, 103 moving distance detection unit, 104 CPU, 200 base station device

Claims (10)

A communication terminal device which is mounted on a mobile body and communicates with a base station device by a low power wide area wireless communication (LPWA) system,
A communication unit (102) that transmits data to be transmitted to the base station device and receives a response from the base station device to the transmission of the data;
A moving distance detecting section (103) for detecting a moving distance of the moving body,
A transmission control unit (104) for controlling the transmission of the data to the base station device;
Have
The transmission control unit determines whether to include the information for requesting the response from the base station device, in the data transmitted by the communication unit, based on the moving distance.
Communication terminal device (100). The transmission control unit,
When the communication unit receives the first response, which is the response from the base station device, to the transmission of the first data, which is the data, at the time of the transmission of the first data or the first response. When the movement distance detection unit detects the movement distance that is less than or equal to a predetermined distance from the time of receiving the response of the above, the base station for transmitting the second data is included in the second data that is the data. Does not include information for requesting the second response, which is the response from the station device,
The communication terminal device according to claim 1. The transmission control unit,
Further, when a predetermined time or more has elapsed from the time of transmitting the first data or the time of receiving the first response, the second data includes information for requesting the second response,
The communication terminal device (300) according to claim 2. The transmission control unit,
Further, based on the type or importance of the second data, the second data includes information for requesting the second response,
The communication terminal device (400) according to claim 2. The transmission control unit,
When the communication unit receives the first response, which is the response from the base station device, to the transmission of the first data, which is the data, at the time of the transmission of the first data or the first response. When the movement distance detection unit detects the movement distance that is equal to or more than a predetermined distance from the time of receiving the response, the base for the transmission of the second data is included in the second data that is the data. Including information for requesting a second response, which is the response from the station device,
The communication terminal device according to claim 1. The predetermined distance is twice the communicable distance (r) of the base station device,
The communication terminal device according to claim 2. The predetermined distance is obtained from a distance (x) of the moving body from the base station apparatus, a moving direction (θ) of the moving body, and a communicable distance (r) of the base station apparatus.
The communication terminal device according to claim 2. The base station device for receiving the data from the communication terminal device according to claim 1,
A communication unit (201) for receiving the data from the communication terminal device and transmitting the response to the reception of the data;
An analysis unit (202) for analyzing the data,
The analysis unit does not instruct the communication unit to transmit the response when the data transmitted from the communication terminal device does not include information for requesting the response from the base station device,
Base station device (200). A communication method of a communication terminal device, which is mounted on a mobile unit and communicates with a base station device by a low power wide area wireless communication (LPWA) method,
The moving distance of the moving body is detected (S15),
Based on the moving distance, it is determined whether or not the data to be transmitted includes information for requesting a response from the base station device (S16, 17),
Transmitting the data to the base station device (S18),
Communication method. A communication control program executed by a communication terminal device, which is mounted on a mobile body and communicates with a base station device by a low power wide area wireless communication (LPWA) method,
The moving distance of the moving body is detected (S15),
Based on the moving distance, it is determined whether the data to be transmitted includes information for requesting a response from the base station device (S16, S17),
Transmitting the data to the base station device (S18),
Communication control program.