JP7167726B2 - Communication terminal equipment and base station equipment - Google Patents

Description

The present invention relates to retransmission when communication between a communication terminal device mounted on a mobile body and a base station device is interrupted in mobile communication, particularly in low power wide area wireless communication (LPWA). It's about how it works.

In recent years, the era of IoT (Internet of Things) has arrived, in which new added value is created by connecting all kinds of things to networks and exchanging information beyond the framework of conventional usage forms such as smartphones and mobile phones. And many of these things are characterized by being in hard-to-reach places and requiring only small amounts of data over time. In response to this request, eMTC (enhanced Machine Type Communication) advocated by 3GPP (Third Generation Partnership Project), NB-IoT (Narrow Band Internet of Things) optimized for smaller amounts of data communication, and Sigfox Specifications such as SIGFOX (registered trademark) developed by Semtech and LoRa (registered trademark) developed by Semtech have been established.

On the other hand, in a mobile wireless communication system mounted on a moving vehicle, in view of the fact that high-speed communication during high-speed movement causes communication to become unstable, a technique for switching the communication speed according to the speed has been disclosed. (Patent Document 1).

JP-A-11-98574

In order to achieve wide-area communication and reduce power consumption, such communication terminal equipment for IoT is implemented by LTE (Long Term Evolution). A mechanism to prevent communication interruption was omitted, and it was not necessarily suitable for being mounted on a mobile object. In addition, 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. For example, a base station apparatus is provided with a total radio transmission time limit, and cannot transmit acknowledgment (ack) or information to a communication terminal apparatus indefinitely.
The inventors of the present invention devised a retransmission mechanism that is performed when communication is interrupted in such a communication terminal device or the like mounted on a mobile object, so that retransmission can be properly performed within the range of the total radio wave transmission time limit. I found that I can do

SUMMARY OF THE INVENTION It is an object of the present invention to appropriately perform retransmission when communication is interrupted in a communication terminal device and a base station device mounted on a mobile object and using a low power consumption wide area wireless communication (LPWA) system.

In order to solve the above problems, the communication terminal device of the present invention includes:
A communication terminal device mounted on a mobile body and communicating with a base station device by a low power consumption wide area wireless communication (LPWA) method,
a storage unit (101) for storing data to be transmitted;
A communication unit that transmits the data to the base station device, transmits a request for reception history information that is a history of success or failure of reception of the data at the base station device, and receives the reception history information from the base station device. (102) and
a stop detection unit (103) for detecting the stop of the moving body;
a retransmission control unit (104) for controlling retransmission of the data to the base station device;
has
The retransmission control unit instructs the communication unit to transmit the request and instructs the communication unit to retransmit the data based on the reception history information when the stop detection unit detects the stop of the moving body. It is something to do.

According to the communication terminal apparatus and the base station apparatus of the present invention, since the communication terminal apparatus retransmits based on the reception history information when detecting the stoppage of the moving object, communication can be performed under an environment more suitable for communication. Data that could not be sent due to interruptions can be resent.

1 is a block diagram illustrating the configuration of a communication terminal device according to Embodiment 1 of the present invention; FIG. FIG. 2 is an explanatory diagram for explaining the format of data transmitted and received by the communication terminal device according to the first embodiment of the present invention; 3 is a flow chart for explaining the operation of the communication terminal device according to Embodiment 1 of the present invention; Flowchart for explaining the operation of the communication terminal device of Embodiment 2 of the present invention FIG. 3 is a block diagram for explaining the configuration of a base station apparatus according to Embodiment 3 of the present invention; Flowchart for explaining the operation of the base station apparatus of Embodiment 3 of the present invention

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the present invention means the invention described in the scope of claims or the section of Means for Solving the Problems, and is not limited to the following embodiments. In addition, at least the words and phrases in angle brackets mean the words and phrases described in the claims or the means for solving the problems section, and are not limited to the following embodiments.
Structures and methods described in dependent claims, structures and methods of embodiments corresponding to structures and methods described in dependent claims, and structures and methods described only in embodiments without claims are optional configurations and methods in the present invention. In the sense that the configuration and method described in the embodiment when the description of the claims is broader than the description of the embodiment are also examples of the configuration and method of the present invention, in the present invention, any configuration and method be. In either case, the essential features and methods of the invention are described in the independent claims.
The effects described in the embodiments are the effects when having the configuration of the embodiment as an example of the present invention, and are not necessarily the effects of the present invention.
When there are multiple embodiments, the configuration disclosed in each embodiment is 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. Further, the configurations disclosed in each of the plurality of embodiments may be collected and combined.
The findings and problems described in the problems to be solved by the invention are not known problems, but were independently found by the inventors, and are facts that affirm the inventive step of the invention together with the configuration and method of the 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 installed in an automobile will be mainly described as an example, but the present invention includes communication terminal devices other than those for in-vehicle use unless otherwise specified in the scope of claims. It is a thing.

The communication terminal device 100 is mounted on a “moving object” such as an automobile, and communicates with the base station device 200 described in the third embodiment by the “low power consumption wide area wireless communication (LPWA) system”. The terminal device 100 performs communication using a low power consumption wide area wireless communication system, such as SIGFOX developed by Sigfox, Inc., or LoRa developed by Semtech. These communication schemes are characterized in that communication starts with uplink communication from a communication terminal apparatus to a base station apparatus.
Communication terminal device 100 has RAM 101, communication section 102, stop detection section 103, CPU 104, external I/F 105, power supply 106, and antenna A1.
Here, the "moving body" of the present invention means a movable object, and the moving speed is arbitrary. Naturally, it also 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 thereon.
In addition, the "low power consumption wide area wireless communication (LPWA) system" of the present invention is a general term for wireless communication systems having low power consumption and a communication range of the level of a mobile phone, and any system can be used.

The RAM 101 (corresponding to the “storage unit” of the present invention) stores data to be transmitted acquired from various sensors connected to the external interface (I/F) 105 via the CPU 104 . Various sensors do not necessarily have to be connected to the external I/F 105 and may be built in the communication terminal device 100 . Examples of various sensors include thermometers, hygrometers, sunshine meters, GPS, etc., drive system electronic control units that control the engine, steering wheel, brakes, etc., and vehicle system electronic control units that control meters, power windows, etc. , or a safety control system electronic control device that performs control to prevent collisions with obstacles or pedestrians, and may be a sensor mounted on a vehicle.
The RAM 101 is assumed to be a random access memory, but may be a hard disk (HDD), 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 read via the CPU 104 to the base station apparatus 200 from the antenna A1. Further, communication section 102 transmits a request for reception history information, which is a history of success or failure of data reception in base station apparatus 200, to base station apparatus 200 from antenna A1. Further, communication section 102 receives the reception history information transmitted from base station apparatus 200 via antenna A1.
Details of the reception history information request and the reception history information will be described later with reference to FIG.

The stop detection unit 103 “detects” the “stop” of the moving object on which the communication terminal device 100 is mounted.
Here, the "stop" of the present invention means that the mobile object is not moving, or that it is moving at such a slow speed that communication is not hindered and can be regarded as being stopped. The cause is arbitrary.
Further, "detecting the stoppage" of the present invention is sufficient to detect the fact that it can be directly or indirectly inferred that the moving body is at rest.
Specifically, in this embodiment, the stop detection unit 103 “detects” “parking” of the automobile in which the communication terminal device 100 is mounted.
Here, "parking" in the present invention refers to continuously stopping the automobile.
Further, "detecting parking" in the present invention suffices as long as it is possible to directly or indirectly infer that the vehicle is parked. Also, it does not necessarily have to be parking defined by a legal concept.

The stop detection unit 103 is, for example, a speed sensor, and can use a device using the global positioning system (GPS) or untethered dead reckoning (UDR). Since these devices do not need to be connected to the automobile, there is no need for installation work by a professional business operator, and the communication terminal device 100 can be realized as a device that can be placed on a dashboard, for example. Of course, the speed sensor 103 could also be a sensor connected to the axle of the vehicle. Alternatively, an acceleration sensor may be used.
If the speed sensor detects zero speed, the stop of the moving body can be directly detected. That is, it is possible to directly detect parking or stoppage of the vehicle according to the present embodiment. A slow speed (for example, 10 km/h) that does not interfere with communication may also be included in the stop of the present embodiment.

In addition, parking or stopping of a car may be detected by using, for example, the following sensors to indirectly infer that the car is parked or stopped. Moreover, you may use these in combination. By combining these, it is possible to more accurately detect the parking or stopping of the vehicle.

(sensor) : (fact to detect)
Parking brake sensor: Parking brake ON
Shift sensor: The shift lever is in the P position Engine speed sensor: The engine speed is zero Ignition sensor: The ignition key is OFF or ACC Seat sensor: The load on the seat has become zero
(because the driver got off)
Door sensor: The opening and closing of the door Position information sensor: The car is in the parking lot
(combined with map information)

If it is necessary to distinguish between parking and stopping, it can be determined, for example, by whether the engine speed sensor indicates zero or a value greater than zero, or whether the ignition sensor is OFF or ON.

Furthermore, in combination with the detection results of these sensors, parking of the automobile may be detected using a timer. In Japan, it is legally stipulated that a vehicle must be stopped continuously for five minutes or more to exclude a stop for loading and unloading cargo. Therefore, it may be inferred that the vehicle is legally parked based on the detection results of these sensors and the passage of 5 minutes or more.

The power supply 106 supplies power to each unit of the communication terminal device 100 . The power may be supplied directly from a cigarette lighter socket, or a primary battery or a secondary battery may be used. By using a 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, which facilitates the mounting work.

The CPU 104 (corresponding to the "retransmission control unit" of the present invention) controls the external I/F 105, the RAM 101, the communication unit 102, and the stop detection unit 103 as described above. control the retransmission of That is, when the stop detection unit 103 “detects a stop” of the moving body, the CPU 104 instructs the communication unit 102 to transmit a request for reception history information, and retransmits data based on the received reception history information. 102.
Here, in the present invention, "when a stop is detected" means a necessary condition, and detection of a stop may be one of the conditions for transmitting a request.

In the present embodiment, the communication terminal apparatus 100 does not request an acknowledgment (ack) from the base station apparatus 200 in downlink communication each time it transmits data in uplink communication, but rather uses a vehicle in which communication is more stable than when the vehicle is running. When a stop is detected, a request for reception history information is transmitted from the communication terminal device 100 in uplink communication of the base station device 200, and reception history information is received from the base station device 200 in downlink communication of the communication terminal device 100, and communication is performed. Based on the received reception history information, the terminal device 100 retransmits only the data for which communication was interrupted.
Then, when receiving the reception history information from the base station apparatus 200, the base station apparatus 200 receives all the data transmitted by the communication terminal apparatus 100 within the maximum data size and transmission frequency limit permitted in downlink communication. It is necessary to convey the reception history of In the following, assuming a service in which the number of downlink acknowledgments (ack) is limited to 4 or less per day and the payload of each acknowledgment (ack) is limited to 8 bytes, transmission in uplink communication An example of a request for reception history information to be sent and an example of reception history information received in downstream communication will be described with reference to FIG.

FIG. 2 is an example of a frame format of data transmitted and received between communication terminal apparatus 100 and base station apparatus 200. In FIG. Although only the payload is shown in the figure, there is usually a header before the payload that stores the data necessary for synchronization, and a footer that stores the authentication code, checksum, etc. after the payload.

The payload of a frame transmitted from the communication terminal apparatus 100 to the base station apparatus 200 by uplink communication consists of 12 bytes. is stored.

The data ID is an identifier for identifying the type of communication terminal device 100 and the content of data. It is also used to distinguish between normal transmissions and retransmissions. Alternatively, an identifier for identifying retransmission may be stored in the data after the 3rd byte.

A communication sequence number indicates the order in which data is sent over a defined period of time, such as one day. For retransmission when communication is interrupted, a data ID indicating retransmission and the same communication sequence number as the data frame of the data for which communication was interrupted are assigned. As a result, data can be reproduced in the original transmission order on the base station apparatus 200 side. If data is periodically transmitted from the communication terminal device 100 at regular time intervals and there is no transmission due to an unexpected event or the like, the data is received and accumulated on the base station device 200 side based on the reception time of the existing communication data. By recognizing that there is no communication data that should have been received and accumulated at a certain time, it is possible to recognize a communication that has been interrupted, so a communication sequence number may not be necessary.

The data consists of transmission target data acquired by the communication terminal device 100 from a sensor or the like.

In this embodiment, a data ID indicating a request, for example, is set in a frame in which a request for reception history information is transmitted. For example, normal data and a request for reception history information are distinguished by the upper 4 bits of the first byte. Alternatively, an identifier indicating a request for reception history information may be stored in data after the third byte.
Alternatively, if the most significant bit or least significant bit of the 1-byte 8-bit data ID is set to 1, a request for reception history information may be made, and if it is 0, such a request may not be made.
Alternatively, without changing the data ID, a request for reception history information is made by setting all bits in the second byte, or after the second byte, or after the third byte to 0 or 1, which cannot be normal data. It is also possible to recognize that it is.

The payload of a frame transmitted from the base station apparatus 200 to the communication terminal apparatus 100 by downlink communication consists of 8 bytes, and the data ID is stored in the first two bytes, and the reception history information is stored in the third and subsequent bytes.

The first 4 bits of the data ID is an ID indicating that this frame is a notification of reception history information. In this embodiment, 0001 indicates that the reception history information is notified.
The next 1 bit indicates the year in which the reception history information was generated. Even if the history is lost, it is possible to identify whether the history is for the current year or the previous year.
The next 9 bits indicate the date on which the reception history information was generated, making it possible to identify the 1st day (January 1st) to the 365th day (December 31st) of the year. In the present embodiment, since it is 000100000, it can be understood that it was transmitted on February 1, which is the 32nd day.
The last two bits are the order of the reception history information for the day. In this embodiment, the number of downlink communication acknowledgments (acks) is limited to four times per day, so for example, the allocation is as follows.
First (00): Reception history information from 0:00:00 to 7:59:59 Second (01): Reception from 8:00:00 to 15:59:59 History information 3rd (10): Reception history information from 16:00:00 to 23:59:59 If one piece of reception history information is set for 8 hours in this way, the 4th (11) ) is unused, but another purpose may be defined and assigned here. Alternatively, the reception history information may be six hours.

The reception history information consists of 48 bits (6 bytes). For example, if the communication terminal apparatus 100 transmits data to the base station apparatus 200 every 10 minutes, success or failure of data reception for 48 times corresponding to 8 hours can be accumulated. In this embodiment, since the 11th, 19th to 20th, 30th to 32nd, and 43rd to 44th are 0, it can be seen that these communications fail to be received.

In this example, since data is periodically transmitted from the communication terminal device 100, the data transmitted from the communication device can be identified and distinguished if the base station device 200 is provided with counting means or timer means. can be done. When data is not transmitted periodically, the data transmitted from the communication device can be identified and distinguished by using the communication sequence number stored in the frame of uplink communication.

In this way, the reception history information indicates the reception history of a plurality of data transmitted from the communication terminal device 100 at different times. For example, when the communication terminal device 100 transmits the first data at 0:00 and transmits the second data at 0:10 10 minutes after the transmission of the first data, the first (00) The success or failure of reception of the first data is indicated in the 1st bit of the reception history information, and the success or failure of the reception of the second data is indicated in the 2nd bit.

Returning to FIG. 1 again, the retransmission control of the CPU 104, which is a retransmission control unit, will be described using the data format example of FIG.
When the stop detection unit 103 detects the stop of the automobile, the CPU 104 generates a request including information indicating that it is a request for reception history information in the data frame of upstream communication, and instructs the communication unit 102 to transmit the request, The communication unit 102 transmits this request.

Base station apparatus 200 transmits reception history information in response to this request, and communication terminal apparatus 100 receives this reception history information. According to the reception history information, the 11th, the 19th to the 20th, the 30th to the 32nd, and the 43rd to the 44th are 0, so it can be seen that these communications have failed to be received. Therefore, the CPU 104 reads these data from the RAM 101 and instructs the communication unit 102 to resend them, and the communication unit 102 resends these data.

Note that the CPU 104 may instruct to transmit the request when the stop detection unit 103 detects the stop of the automobile and when the "time condition" for generating the reception history information is satisfied. For example, in this embodiment, since the reception history information performed in downlink communication is recorded in units of eight hours, the storage period of the reception history is every eight hours, and requests are made in units of eight hours. Therefore, in light of the current time, it can be seen that the first (00) reception history information has been generated at least after 8:00. Therefore, if the current time has passed 8:00, an instruction may be given to send the request. By taking time conditions into account in this manner, it is possible to transmit only requests for which it is certain that the reception history information can be received, and to reliably acquire the reception history information.
Here, it suffices that the "temporal condition" of the present invention expresses time directly or indirectly. For example, examples of the former include the time and elapse of a predetermined time from the first data transmission, and examples of the latter include completion of transmission of a predetermined number of data periodically or aperiodically.

Furthermore, whether or not there is reception history information that has already been received may also be included in the determination. For example, if the current time is 12:00 and the first (00) reception history information has been received in the past, the second (01) reception history information has not yet been generated at this time. Therefore, the CPU 104 does not generate a request at this point, and does not issue an instruction to transmit the request. When the current time exceeds 16:00 and the stop detection unit 103 detects that the automobile has stopped, the CPU 104 generates a request and instructs the communication unit 102 to transmit the request. By taking into consideration the reception history information that has already been received in this way, it is possible to avoid acquiring the same reception history information repeatedly.

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 data to be transmitted (S11).
The communication unit 102 transmits the data saved in the RAM 101 to the base station device 200 (S12).
CPU 104 determines whether stop detection unit 103 has detected a stop of the vehicle in which communication terminal device 100 is mounted (S13). If no stop is detected, the process returns to S11 to continue normal communication. If a stop is detected, the process proceeds to S14.
CPU 104 determines whether or not the time conditions for generating reception history information are satisfied (S14). For example, it is determined whether or not the n-th (n=integer from 1 to 4) reception history information has already been generated. If the time condition is not satisfied, the process returns to S11 to continue normal communication. If the time condition is satisfied, the process proceeds to S15.
The CPU 104 instructs the communication unit 102 to transmit a request for the n-th reception history information, and the communication unit 102 transmits the request to the base station device 200 (S15).
The communication unit 102 receives the reception history information from the base station device 200 (S16).
Based on the reception history information, the CPU 104 instructs the communication section 102 to resend the data, and the communication section 102 resends the data (S17).
CPU 104 determines whether or not all data to be resent indicated in the reception history information has been resent (S18). If all the data have not been resent, the process returns to S17 to resend the data sequentially. If all have been retransmitted, the process proceeds to S19.
The CPU 104 determines whether or not it is the time when the n+1th reception history information, which is the next reception history information, has already been generated (S19). If the time condition is satisfied, the process returns to S15 and instructs the communication unit 102 to transmit the request for the (n+1)th reception history information, and the same processing as that for the nth reception history information is continued. If the time condition is not satisfied, it is determined that there is no reception history information to be received, and the process ends.

In the flow of FIG. 3, the order can be changed if the processing or determination in the latter stage does not depend on the result of the processing or determination in the previous stage. For example, S13 and S14 can be switched in order.

Moreover, FIG. 3 shows not only the communication method of the communication terminal device, but also the processing procedure of the program executed by the communication terminal device. A program can be implemented as software in any protocol stack of communication protocols, not necessarily at the application level. In the case of the application level, it is possible to compensate for the shortcomings of the upper layer while maintaining the communication protocol of the upper layer of the communication method.

(Embodiment 2)
1. Configuration of Communication Terminal Device In the first embodiment, when it is detected that the vehicle in which the communication terminal device 100 is mounted has stopped, the processing related to retransmission is performed. This embodiment relates to processing during and after data retransmission.
The configuration of the communication terminal device 100 according to this embodiment is the same as that of the communication terminal device 100 according to the first embodiment except for the detection target of the stop detection unit 103 and the control contents of the CPU 104 .

The stop detection unit 103 further detects that the mobile object has stopped.
The CPU 104 (corresponding to the "retransmission control unit" of the present invention) instructs the communication unit to interrupt data retransmission when the stop detection unit 103 detects that the moving body has stopped during data retransmission in the first embodiment. 102. The communication unit 102 then suspends data retransmission.
In the present invention, the term ``finishing the stoppage'' means that the fact that the moving object has stopped can be assumed to have disappeared, and the moving object does not necessarily have to start moving.

For example, the following sensors may be used to detect the fact that it can be indirectly inferred that the vehicle has finished parking or stopping. Moreover, you may use these in combination. By combining these, it is possible to more accurately detect the end of parking or stopping of the vehicle.

(sensor) : (fact to detect)
Parking brake sensor: Parking brake OFF
Shift sensor: The shift lever is in the D position Engine speed sensor: The engine speed is above idling Ignition sensor: The ignition key is ON Seat sensor: The weight of the seat is equivalent to that of a human to be
(because the driver was on board)
Door sensor: The opening and closing of the door Location information sensor: The car moving out of the parking lot
(combined with map information)

The CPU 104 may detect that the stop detection unit 103 has started moving the moving object during data retransmission in the first embodiment. The start of movement of the mobile is a concept implied by the end of the stop of the mobile.
For example, if a speed sensor detects a speed of zero or more, it can directly detect that the car has started running.

The CPU 104 instructs the communication unit 102 to resume data retransmission when the stop detection unit 103 detects the stop of the moving object again. Then, the communication unit 102 resumes data retransmission.

2. Operation of Communication Terminal Device Next, the operation of the communication terminal device 100 according to the second embodiment will be described with reference to FIG. The same step numbers are used for the same processes as in the first embodiment described with reference to FIG. 3, and the description thereof is omitted.
The CPU 104 detects movement of the moving object during retransmission of data to be retransmitted in S17 (S21). If movement is not detected, the process proceeds to S18, and if movement is detected, the process proceeds to process A.
The CPU 104 instructs the communication unit 102 to interrupt the data retransmission. Then, the communication unit 102 suspends data retransmission (S22).
CPU 104 determines whether stop detection unit 103 has again detected the stop of the vehicle in which communication terminal device 100 is mounted (S23). If no stop is detected, the process returns to S22 to continue the interruption. If a stop is detected, retransmission is resumed by ending process A. Then, based on the reception history information already received, CPU 104 instructs communication section 102 to resend data that has not been resent, except data that has already been resent, and communication section 102 resends data that has not been resent. (S18, S17).

Note that when processing A is terminated and retransmission is resumed, the process may return to S15 and the request for reception history information may be transmitted to the base station apparatus 200 again. In this case, retransmission may be performed based on new reception history information without distinguishing whether retransmission has been completed or retransmission has not been completed.
Also, during retransmission suspension, normal uplink data communication can be performed regardless of the detection state of movement or stoppage.

(Embodiment 3)
1. Configuration of Base Station Apparatus First, the configuration of the base station apparatus 200 of Embodiment 3 will be described using FIG.
The base station apparatus 200 receives requests for data and reception history information using the data format of FIG. 2 from the communication terminal apparatus 100 described in the first and second embodiments.

The base station apparatus 200 communicates with the communication terminal apparatus 100 described in the first and second embodiments using a low power consumption wide area wireless communication (LPWA) system. The base station apparatus 200 performs communication using a low power consumption wide area wireless communication system, for example, SIGFOX developed by Sigfox and LoRa developed by Semtech.
Base station apparatus 200 has communication section 201, CPU 202, RAM 203, gateway (G/W) 204, and antenna A2.

The communication unit 201 receives data and requests transmitted from the communication terminal device 100 via the antenna A2. In addition, communication section 201 transmits the reception history information to communication terminal device 100 via antenna A2.

The CPU 202 (corresponding to the “reception history information generation unit” of the present invention) analyzes the data transmitted from the communication terminal device 100 and generates reception history information based on whether the data reception was successful or not. The reception history information is as described with reference to FIG.

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

A gateway (G/W) 204 is connected to the cloud device via a network, and transfers data stored in the RAM 203 to the cloud device.

In this embodiment, analysis of received data and generation of reception history information are performed by the base station device 200, but may be performed by a cloud device connected via a gateway (G/W) 204. . In this case, the cloud device indirectly receives data from the communication terminal device via the base station device 200 .
In other words, the “base station device” of the present invention includes not only a narrowly defined base station device that directly communicates with a communication terminal device, but also a backbone device such as a cloud device connected to the base station device via a backhaul.

2. Operations of Base Station Apparatus Next, operations of the base station apparatus 200 according to the third embodiment will be described with reference to FIG.
The communication unit 201 receives data transmitted from the communication terminal device 100 (S31).
The CPU 202 generates reception history information based on the success or failure of data reception (S32).
The communication unit 201 determines whether or not the request for the reception history information transmitted from the communication terminal device 100 has been received (S33). If the request for reception history information is not received, the process returns to S31 to receive new data. If a request for reception history information has been received, the process proceeds to S34.
The communication unit 201 transmits the reception history information generated by the CPU 202 to the communication terminal device 100 (S34).
Note that the reception history information may be generated while updating each time data is received as shown in FIG. 6, or may be collectively generated after receiving a request. In this case, the order of S32 and S33 is exchanged.

Note that FIG. 6 shows not only the communication method of the base station apparatus, but also the processing procedure of the program executed by the base station apparatus. A program can be implemented as software in any protocol stack of communication protocols, not necessarily at the application level. In the case of the application level, it is possible to compensate for the shortcomings of the upper layer while maintaining the communication protocol of the upper layer of the communication method.

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

Since the terms used in each embodiment are examples, they may be replaced with synonymous terms or terms including synonymous functions.

The block diagrams used to describe the embodiments classify and organize the configurations of the communication terminal apparatus and the base station apparatus for each function. These functional blocks are realized by any combination of hardware or software. Moreover, such a block diagram can also be understood as a disclosure of the method invention, since it shows the function.

The order of the functional blocks that can be grasped as the processes, flows, and methods described in each embodiment may be changed unless there is a restriction such as that one step uses the result of another 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.

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

Examples of communication terminal devices include semiconductors, electronic circuits, modules, and ECUs (electronic control units) as parts and semi-finished products. Finished products include drive recorders, car navigation systems, smart phones, 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 functions described in each embodiment, but also by recording a program for realizing the present invention recorded on a recording medium such as a memory or a hard disk, and It can also be implemented in combination with general-purpose hardware having a dedicated or general-purpose CPU and memory, etc., capable of execution.

Programs stored in dedicated or general-purpose hardware recording media (external storage devices (hard disk, USB memory, CD/BD, etc.), internal storage devices (RAM, ROM, etc.)) It is also possible to provide dedicated or general-purpose hardware from a server via a communication line without using a medium. This allows us to always provide the latest features through program upgrades.

The communication terminal apparatus and base station apparatus according to the present invention are not limited to in-vehicle applications, and are used in general low power wide area wireless communication (LPWA). For example, by setting the communication terminal device of the present invention in a package to be delivered, information indicating the delivery status of the package (e.g. position information) and the environment at the time of delivery (e.g. temperature and humidity) is transmitted to the base station device, These information can be used.

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

Claims (9)

A communication terminal device mounted on a mobile body and communicating with a base station device (200) by a low power consumption wide area wireless communication (LPWA) method,
a storage unit (101) for storing data to be transmitted;
A communication unit that transmits the data to the base station device, transmits a request for reception history information that is a history of success or failure of reception of the data at the base station device, and receives the reception history information from the base station device. (102) and
a stop detection unit (103) for detecting the stop of the moving body;
a retransmission control unit (104) for controlling retransmission of the data to the base station device;
has
The retransmission control unit instructs the communication unit to transmit the request when the stop detection unit detects the stop of the moving object, and retransmits the data based on the reception history information received by the communication unit. to the communication unit,
A communication terminal device (100). the data includes first data and second data;
the first data and the second data are transmitted from the communication unit at different times;
The reception history information is a history of successful or unsuccessful reception of the first data and the second data.
The communication terminal device according to claim 1. the moving object is an automobile,
The stop detection unit detects parking of the automobile,
The communication terminal device according to claim 1. The retransmission control unit causes the communication unit to transmit the request when the stop detection unit detects the stop of the moving object and when the time condition for generating the reception history information is satisfied. and instructing the communication unit to resend the data based on the reception history information received by the communication unit;
3. The communication terminal device according to claim 1 or 2. The stop detection unit further detects that the moving object has stopped,
The retransmission control unit instructs the communication unit to interrupt retransmission of the data when the stop detection unit detects that the mobile unit has stopped during retransmission of the data.
The communication terminal device according to claim 1. The retransmission control unit instructs the communication unit to resume retransmission of the data when the stop detection unit detects the stop of the moving object again.
6. The communication terminal device according to claim 5. The base station apparatus for receiving the data and the request transmitted from the communication terminal apparatus according to claim 1,
a reception history information generation unit (202) for generating the reception history information based on whether the data has been successfully received;
a communication unit (201) for transmitting the reception history information to the communication terminal device when the request is received from the communication terminal device;
A base station device (200) having A communication method for a communication terminal device that is mounted on a mobile body and that communicates with a base station device using a low power consumption wide area wireless communication (LPWA) system,
save data to be transmitted (S11);
transmitting the data to the base station device (S12);
When the stoppage of the moving object is detected, a request for reception history information, which is a history of success or failure of reception of the data at the base station device, is transmitted (S13, S15);
receiving the reception history information from the base station device (S16);
retransmitting the data based on the received reception history information (S17);
Communication method. A communication control program to be executed by a communication terminal device that is mounted on a mobile body and that communicates with a base station device using a low power consumption wide area wireless communication (LPWA) method,
save data to be transmitted (S11);
transmitting the data to the base station device (S12);
When the stoppage of the moving object is detected, a request for reception history information, which is a history of success or failure of reception of the data at the base station device, is transmitted (S13, S15);
receiving the reception history information from the base station device (S16);
retransmitting the data based on the received reception history information (S17);
Communication control program.

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