Transmission device, reception device, communication system and communication method

Abstract

The present disclosure relates to a transmission device, a reception device, a communication system, and a communication method that can further improve communication success probability. The transmission device determines a schedule mode for specifying a transmission time and transmission channel for transmission data for data communication to be transmitted via one-way communication to the reception device, and transmits the schedule mode to the reception device as transmission data for control communication. The reception device receives the schedule mode, calculates the transmission time and transmission channel for the transmission data for data communication on the basis of the schedule mode, and controls the reception of the transmission data for data communication. The present disclosure can be applied to, for example, a communication system that uses an unlicensed band.

Description

Transmitting device, receiving device, communication system, and communication method

[0001] The present disclosure relates to a transmitting device, a receiving device, a communication system, and a communication method, and more particularly to a transmitting device, a receiving device, a communication system, and a communication method that can further improve the probability of successful communication.

[0002] In conventional communication systems using unlicensed bands, available channels are limited by applicable laws, regulations, standards, etc. Before transmitting data, a transmitting device performs carrier sensing to check whether a channel intended for data transmission is in use. If it is determined that the channel is in use, the transmitting device is restricted from transmitting data on that channel. Furthermore, if the restrictions imposed on channels used in a communication system are uniform, in order to efficiently use radio wave resources, a channel is selected (channel hopping) in a random and averaged manner based on a terminal ID and time so that the channels used by each terminal are averaged.

[0003] Patent Document 1 discloses a communication method in which data to be transmitted is chirp-modulated to generate transmission signals so that transmission signals can be multiplexed within the same channel, and the transmission timings of multiple transmission signals are shifted in the time direction when they are transmitted.

[0004] International Publication No. 2017 / 212810

[0005] However, recent legal changes have made it unnecessary to perform carrier sensing on some of the available channels. Therefore, when the restrictions imposed on the available channels in a communication system are uneven, it is expected that the probability of successful communication can be improved by devising channel selection.

[0006] The present disclosure has been made in consideration of such circumstances, and aims to further improve the probability of successful communication.

[0007] A transmitting device according to a first aspect of the present disclosure includes a transmitting / receiving control unit that determines a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication to be transmitted in one-way communication to a receiving device, and a transmitting unit that transmits the schedule mode to the receiving device in transmission data for control communication.

[0008] In a first aspect of the present disclosure, a schedule mode is determined to specify the transmission time and transmission channel of transmission data for data communication to be transmitted in one-way communication to a receiving device, and the schedule mode is transmitted to the receiving device in transmission data for control communication.

[0009] A receiving device according to a second aspect of the present disclosure includes a receiving unit that receives a schedule mode for identifying the transmission time and transmission channel of transmission data for data communication transmitted in one-way communication from a transmitting device, and a receiving control unit that calculates the transmission time and transmission channel of the transmission data for data communication based on the schedule mode and controls the reception of the transmission data for data communication.

[0010] In a second aspect of the present disclosure, a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication transmitted in one-way communication from a transmitting device is received, and the transmission time and transmission channel of the transmission data for data communication are calculated based on the schedule mode, and reception of the transmission data for data communication is controlled.

[0011] A communication system according to a third aspect of the present disclosure includes a transmitting device having a transmitting / receiving control unit that determines a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication to be transmitted to a receiving device via one-way communication, and a transmitting unit that transmits the schedule mode to the receiving device using transmission data for control communication; a receiving unit that receives the schedule mode transmitted from the transmitting device via one-way communication, and a receiving control unit that calculates the transmission time and transmission channel of the transmission data for data communication based on the schedule mode and controls the reception of the transmission data for data communication.

[0012] In a third aspect of the present disclosure, a schedule mode for specifying a transmission time and a transmission channel for data communication transmission data to be transmitted to a receiving device via one-way communication is determined, and the schedule mode is transmitted to the receiving device in transmission data for control communication. Then, the schedule mode for specifying a transmission time and a transmission channel for data communication transmission data transmitted via one-way communication from the transmitting device is received, and the transmission time and the transmission channel for data communication transmission data are calculated based on the schedule mode, thereby controlling reception of the data communication transmission data.

[0013] A communication method according to a fourth aspect of the present disclosure includes a transmitting device determining a schedule mode for specifying a transmission time and a transmission channel for transmission data for data communication to be transmitted in one-way communication to a receiving device, and transmitting the schedule mode to the receiving device in transmission data for control communication, wherein the receiving device receives the schedule mode transmitted in one-way communication from the transmitting device, calculates a transmission time and a transmission channel for the transmission data for data communication based on the schedule mode, and controls reception of the transmission data for data communication.

[0014] In a fourth aspect of the present disclosure, a schedule mode for specifying a transmission time and a transmission channel for data communication transmission data to be transmitted to a receiving device in one-way communication is determined, and the schedule mode is transmitted to the receiving device in transmission data for control communication. Then, the schedule mode for specifying a transmission time and a transmission channel for data communication transmission data transmitted in one-way communication from the transmitting device is received, and the transmission time and the transmission channel for data communication transmission data are calculated based on the schedule mode, thereby controlling reception of the data communication transmission data.

[0015] Fig. 1 is a block diagram showing a configuration example of an embodiment of a communication system to which the present technology is applied. Fig. 2 is a block diagram showing a configuration example of a transmission terminal. Fig. 3 is a block diagram showing a configuration example of a base station. Fig. 4 is a flowchart illustrating a calculation process. Fig. 5 is a flowchart illustrating a control communication transmission sequence. Fig. 6 is a flowchart illustrating a data communication transmission sequence. Fig. 7 is a flowchart illustrating a transmission sequence. Fig. 8 is a flowchart illustrating a customer transmission data generation process. Fig. 9 is a flowchart illustrating an initial setting process. Fig. 10 is a flowchart illustrating a control communication reception sequence. Fig. 11 is a flowchart illustrating a data communication reception sequence. Fig. 12 is a block diagram showing a configuration example of an embodiment of a computer to which the present technology is applied.

[0016] Hereinafter, specific embodiments to which the present technology is applied will be described in detail with reference to the drawings.

[0017] <Configuration Example of Communication System> FIG. 1 is a block diagram showing a configuration example of an embodiment of a communication system to which the present technology is applied.

[0018] As shown in Fig. 1, the communication system 11 is configured to include a plurality of mobile transmitting terminals 12 (three transmitting terminals 12-1 to 12-3 in the example shown in Fig. 1) and a fixed base station 13. The base station 13 is connected via a network 14 to information processing devices 15 of customers who are users of the respective transmitting terminals 12. Note that although the example shown in Fig. 1 illustrates three transmitting terminals 12-1 to 12-3, the communication system 11 can be configured to include a greater number of transmitting terminals 12.

[0019] For example, in the communication system 11, customer transmission data generated by each of the multiple transmission terminals 12 is transmitted by one-way communication from the transmission terminals 12 to the base station 13, and the customer transmission data is transmitted from the base station 13 to the information processing device 15 via the network 14. In the communication system 11, each transmission terminal 12 can be identified by a terminal ID assigned to it.

[0020] In the communication system 11, two types of communication, data communication and control communication, are carried out between the transmitting terminal 12 and the base station 13. The transmitting terminal 12 transmits various information necessary for data communication by control communication and transmits customer transmission data by data communication. In the communication system 11, in both data communication and control communication, the same communication content is transmitted four times over different transmission channels.

[0021] In the communication system 11, when a customer who will be a user of the transmission terminal 12 makes a contract to use the transmission terminal 12, the customer can determine the transmission interval for transmitting customer transmission data in data communication.

[0022] In the communication system 11, for example, up to three transmission intervals (Periodic1, Periodic2, and Event) can be set for the transmitting terminal 12. The Periodic1 and Periodic2 transmission intervals can specify two mutually exclusive communication periods within a day and the transmission intervals for each communication period. Specifically, the Periodic1 transmission interval can specify a three-minute interval from 9:00 to 18:00, and the Periodic2 transmission interval can specify a one-hour interval from 18:00 to 9:00. The Event transmission interval allows the user to forcibly switch the transmission interval. Specifically, when the user presses the Event button, the Event transmission interval switches the transmission interval to one minute.

[0023] In the communication system 11, the transmission interval can be selected from a wide range, for example, one minute intervals, three minutes intervals, five minutes intervals to 24 hours intervals. The user can decide the transmission interval when signing a contract with the network provider, and the network provider provides the customer with the transmission terminal 12 with the transmission interval already set.

[0024] In communication system 11, in order to perform data communication, transmitting terminal 12 and base station 13 need to share the transmission time, transmission channel, and terminal ID. Base station 13 needs the terminal ID for data processing after receiving customer transmission data. In practice, when transmitting terminal 12 transmits the terminal ID and transmission interval via control communication, base station 13 can calculate the transmission time and transmission channel based on a calculation formula that calculates the transmission time and transmission channel according to the terminal ID and transmission interval.

[0025] The transmitting terminal 12 performs control communication at a predetermined timing (e.g., 30 seconds before the start time of data communication) before the start time of data communication. Meanwhile, the base station 13 performs a reception process for receiving transmission data for control communication transmitted from the transmitting terminal 12 by control communication at periodic intervals (e.g., transmission timing reserved for control communication, such as every 5 seconds) for all transmission channels. In the reception process for receiving transmission data for control communication, unlike data communication, the base station 13 can restore the transmission data even if it does not know the terminal ID. Then, by acquiring the terminal ID included in the transmission data for control communication, the base station 13 can perform a reception process for receiving transmission data for data communication.

[0026] Conventionally, in certain regions or certain time periods, communications may be disrupted by jamming radio waves other than those used by the communication system 11. Therefore, when the transmitting terminal 12 performs carrier sense and finds that the transmission channel is in use, the transmitting terminal 12 stops transmitting data or is unable to transmit the planned data (hereinafter referred to as a communication disabled state). On the other hand, in a communication system 11 capable of long-distance communication, the base station 13 is often able to receive radio waves output from the transmitting terminal 12 without being affected by jamming radio waves in the vicinity of the transmitting terminal 12.

[0027] Therefore, in the communication system 11, even if the transmitting terminal 12 performs carrier sensing and confirms that the transmission channel is in use, the above-mentioned communication impossibility state can be avoided by using a transmission channel (hereinafter referred to as a carrier sense-free channel) that is permitted to transmit transmission data on that transmission channel.

[0028] However, carrier sense-free channels are less common than transmission channels (hereinafter referred to as carrier sense-required channels) that are restricted from transmitting data when carrier sense is performed and it is confirmed that the transmission channel is in use. For this reason, there is concern that frequent use of carrier sense-free channels even when communication is not unavailable may cause unnecessary interference with other terminals or increase the occurrence of communication unavailable states for other terminals. Therefore, using a carrier sense-free channel even when there is no need to use it may not improve the probability of successful communication.

[0029] Therefore, the communication system 11 of this embodiment uses a schedule mode to specify the transmission time and transmission channel. The schedule mode specifies the proportion of carrier sense-unnecessary channels that are allowed to transmit transmission data on a transmission channel even when carrier sense is performed and it is confirmed that the transmission channel is in use.

[0030] For example, when transmitting the same transmission data four times on different transmission channels, the transmitting terminal 12 can autonomously switch among the following schedule modes based on rational criteria: a first mode that specifies the use of each transmission channel equally for the four transmissions; a second mode that specifies the use of a channel that does not require carrier sense for at least one of the four transmissions; or a third mode that specifies the use of a channel that does not require carrier sense for at least two of the four transmissions. The transmitting terminal 12 then notifies the base station 13 of the schedule mode by control communication, and the base station 13 can perform data communication based on the schedule mode notified by the transmitting terminal 12.

[0031] This allows the communication system 11 to avoid communication failures by appropriately using channels that do not require carrier sense, thereby further improving the probability of successful communication.

[0032] FIG. 2 is a block diagram showing an example of the configuration of the transmitting terminal 12. As shown in FIG.

[0033] As shown in Figure 2, the transmitting terminal 12 is configured to include an antenna 21, an antenna 22, a location and time information detection unit 23, a transmission / reception switching unit 24, a receiving block 25, a transmitting block 26, an information holding unit 27, an information detection unit 28, a transmission data generation unit 29, and a transmission / reception control unit 30.

[0034] The antenna 21 receives radio signals output from, for example, a plurality of GNSS (Global Navigation Satellite System) satellites and supplies the signals to the position and time information detection unit 23 .

[0035] The antenna 22 transmits and receives radio waves, supplies a reception signal corresponding to the received radio waves to the transmission / reception switching unit 24 , and transmits radio waves corresponding to the transmission data supplied via the transmission / reception switching unit 24 .

[0036] The position and time information detection unit 23 detects position information and time information based on radio signals from a plurality of GNSS satellites supplied from the antenna 21 and notifies the transmission / reception control unit 30 of the detected position and time information.

[0037] The transmission / reception switching unit 24 switches its operation between a measurement mode in which the power of a channel to be transmitted is measured based on radio waves received by the antenna 22, and a transmission mode in which transmission data is transmitted from the transmitting terminal 12, under the control of the transmission / reception control unit 30. In the measurement mode, the transmission / reception switching unit 24 supplies the reception signal supplied from the antenna 22 to the reception block 25, and in the transmission mode, supplies the transmission data supplied from the transmission block 26 to the antenna 22.

[0038] The reception block 25 is configured to include a reception signal amplifier 41, a reception band limiting unit 42, and a reception power detector 43. In the reception block 25, the reception signal amplifier 41 amplifies the reception signal supplied from the transmission / reception switching unit 24, the reception band limiting unit 42 applies band limiting to the reception signal amplified by the reception signal amplifier 41 in accordance with control by the transmission / reception control unit 30, and the reception power detector 43 detects the power of the reception signal that has been band-limited by the reception band limiting unit 42. The transmission / reception control unit 30 is then notified of a power value indicating the magnitude of the power of the reception signal detected by the reception power detector 43.

[0039] The transmission block 26 is configured to include a transmission data shaping unit 51, a transmission data modulation unit 52, and a transmission data amplification unit 53. In the transmission block 26, the transmission data shaping unit 51 shapes the waveform of the transmission data supplied from the transmission / reception control unit 30, the transmission data modulation unit 52 modulates the transmission data whose waveform has been shaped by the transmission data shaping unit 51 in accordance with the control of the transmission / reception control unit 30, and the transmission data amplification unit 53 amplifies the transmission data modulated by the transmission data modulation unit 52. The transmission data amplified by the transmission data amplification unit 53 is then supplied to the antenna 22 via the transmission / reception switching unit 24, and radio waves corresponding to the transmission data are transmitted.

[0040] The information storage unit 27 stores various information such as a terminal ID for identifying the transmitting terminal 12, the transmission interval set in the transmitting terminal 12, customer transmission data, schedule mode, and additional information used to determine the schedule mode (scheduled transmission time, location where transmission is possible, scheduled transmission channel, and power value). The information storage unit 27 also stores customer transmission data generated by the transmission data generation unit 29.

[0041] The information detection unit 28 detects various types of information that the customer desires to obtain through the transmission terminal 12 and supplies the information to the transmission data generation unit 29 .

[0042] The transmission data generation unit 29 formats the various information supplied from the information detection unit 28 to generate customer transmission data to be transmitted to the customer, and supplies the data to the transmission / reception control unit 30. The customer transmission data is supplied from the transmission / reception control unit 30 to the information holding unit 27, and is held in the information holding unit 27 until the data communication start time arrives.

[0043] The transmission / reception control unit 30 executes various processes required for the transmitting terminal 12 to transmit customer-transmitted data. For example, upon initialization or after completing transmission of customer-transmitted data, the transmission / reception control unit 30 executes a calculation process (see the flowchart in FIG. 4, described below) to calculate the next control communication start time and the next data communication start time. At a predetermined timing before the next control communication start time, the transmission / reception control unit 30 starts a control communication transmission sequence (see the flowchart in FIG. 5, described below) to transmit control communication transmission data. At a predetermined timing before the next data communication start time, the transmission / reception control unit 30 starts a data communication transmission sequence (see the flowchart in FIG. 6, described below) to transmit data for data communication. The transmission / reception control unit 30 executes a customer-transmitted data generation process (see the flowchart in FIG. 8, described below) to generate customer-transmitted data at a timing controlled by the customer.

[0044] FIG. 3 is a block diagram showing an example of the configuration of the base station 13.

[0045] As shown in FIG. 3 , the base station 13 is configured to include an antenna 61, an antenna 62, a location and time information detection unit 63, a time-frequency separation unit 64, a time-frequency data storage unit for control communication 65, a demodulation processing unit for control communication 66, a time-frequency data storage unit for data communication 67, a demodulation processing unit for data communication 68, a terminal parameter storage unit 69, a terminal ID storage unit 70, a schedule mode storage unit 71, a customer transmission data aggregation unit 72, and a reception control unit 73.

[0046] The antenna 61 receives radio signals output from a plurality of GNSS satellites and supplies them to the position and time information detection unit 63 .

[0047] The antenna 62 receives radio waves that transmit data from the multiple transmitting terminals 12 , and supplies a received signal corresponding to the radio waves to the time-frequency separation unit 64 .

[0048] The position and time information detection unit 63 operates under the control of the reception control unit 73, detects position information and time information based on radio signals from multiple GNSS satellites supplied from the antenna 61, and supplies this information to the reception control unit 73. The position and time information detection unit 63 also supplies time information to the time-frequency separation unit 64 in accordance with settings made by the reception control unit 73.

[0049] The time-frequency separation unit 64 separates the received signal supplied from the antenna 62 into each channel in accordance with the time frequency based on the time information supplied from the position and time information detection unit 63. The time-frequency separation unit 64 then stores the received signal received in the control communication period specified by the communication standard of the communication system 11 in the control communication time-frequency data storage unit 65, and stores the received signal received in the data communication period specified by the communication standard of the communication system 11 in the data communication time-frequency data storage unit 67.

[0050] The control communication time-frequency data holding unit 65 holds the received signal for each channel received during the control communication period supplied from the time-frequency separating unit 64 .

[0051] After the control communication period ends, the control communication demodulation processing unit 66 demodulates the received signals of all channels stored in the control communication time-frequency data storage unit 65 during that control communication period, and supplies the transmission data for control communication obtained by successfully demodulating the received signals to the reception control unit 73.

[0052] The data communication time-frequency data holding unit 67 holds the received signal for each channel received during the data communication period supplied from the time-frequency separating unit 64 .

[0053] After the data communication period ends, the data communication demodulation processing unit 68 demodulates the received signals of all channels stored in the data communication time-frequency data storage unit 67 during that data communication period, and supplies the transmission data for data communication obtained by successfully demodulating the received signals to the reception control unit 73.

[0054] The terminal parameter storage unit 69 stores the transmission intervals already set for each transmitting terminal 12 in association with the terminal ID of each transmitting terminal 12 .

[0055] The terminal ID holding unit 70 holds the terminal ID included in the transmission data for control communication obtained by demodulation by the control communication demodulation processing unit 66 .

[0056] The schedule mode holding unit 71 holds the value of the schedule mode included in the transmission data for control communication obtained by demodulation by the control communication demodulation processing unit 66 .

[0057] The customer transmission data aggregation unit 72 aggregates the customer transmission data contained in the transmission data for data communication transmitted from all the transmitting terminals 12 obtained by demodulation by the data communication demodulation processing unit 68 .

[0058] The reception control unit 73 executes various processes required for the base station 13 to receive customer-transmitted data. For example, the reception control unit 73 executes an initial setting process (flowchart in FIG. 9 , described later) at initialization. The reception control unit 73 executes a control communication reception sequence (flowchart in FIG. 10 , described later) to receive transmission data for control communication at periodic intervals (e.g., every 5 seconds). The reception control unit 73 executes a data communication reception sequence (flowchart in FIG. 11 , described later) to receive transmission data for data communication at each transmission interval of each transmitting terminal 12.

[0059] In the communication system 11 configured as described above, the transmission / reception control unit 30 in the transmitting terminal 12 can switch the schedule mode depending on the frequency of communication unavailable states by performing carrier sense to confirm that a channel is in use. For example, if the frequency of communication unavailable states increases, the schedule mode is switched so that a higher proportion of channels not requiring carrier sense are used. The transmitting terminal 12 can detect the frequency of communication unavailable states by performing carrier sense even when using a channel not requiring carrier sense.

[0060] As a result, the communication system 11 can perform data communication while avoiding a communication failure state even in an environment where, for example, jamming radio waves exist in the communication band.

[0061] In the communication system 11, the transmission / reception control unit 30 stores location information indicating a location where the proportion of use of channels not requiring carrier sense has increased in the information holding unit 27, and can autonomously switch the schedule mode at that location so that the proportion of use of channels not requiring carrier sense is increased according to the current location acquired from the location and time information detection unit 23. Similarly, when the current location is far from the location where the proportion of use of channels not requiring carrier sense has increased, the transmission / reception control unit 30 can autonomously switch the schedule mode so that the proportion of use of channels not requiring carrier sense is decreased.

[0062] In this way, the communication system 11 can significantly reduce the transmission failure rate by switching the schedule mode depending on the current location of the transmitting terminal 12. For example, in a location where communication is impossible 100% of the time, the transmission success rate can be made 100% by using a schedule mode that always uses a channel that does not require carrier sense.

[0063] In the communication system 11, when the transmitting terminal 12 is shipped, location information that recommends switching the schedule mode may be stored in the information storage unit 27. In this case, when the transmission / reception control unit 30 detects that the transmitting terminal 12 has moved to the location specified by the location information, it can switch the schedule mode so that the proportion of using channels that do not require carrier sense is increased. For example, by using a large number of transmitting terminals 12 and compiling and analyzing location information that recommends switching the schedule mode in advance, the location information can be stored in the information storage unit 27 when the transmitting terminal 12 is subsequently shipped, allowing the schedule mode to be switched more effectively.

[0064] In the communication system 11, the schedule mode can be switched according to the transmission interval of the customer-transmitted data. For example, when the transmission interval of the customer-transmitted data is long (e.g., once a day or 30 minutes or more), the transmission failure loss due to a communication failure state is large and radio wave resource consumption is low. Therefore, when the transmission interval of the customer-transmitted data is long, the transmission / reception control unit 30 preferably switches the schedule mode so as to more actively use a channel that does not require carrier sense than when the transmission interval of the customer-transmitted data is short.

[0065] This allows for both efficient use of radio wave resources and customer satisfaction. For example, in a transmitting terminal 12 that communicates infrequently, a single transmission failure can result in a significant loss for the customer. Therefore, by switching the schedule mode according to the transmission interval of the customer-transmitted data, the transmission failure rate can be reduced while minimizing the impact on the entire communication system 11.

[0066] In the communication system 11, the transmission interval of customer transmission data is fixed, and in the transmission terminal 12 in which the transmission interval is set longer than a specified time, it is preferable to initially set a schedule mode that includes a carrier sense unnecessary channel at least once.

[0067] In the communication system 11, the transmission interval of customer transmission data is switchable, and the transmission / reception control unit 30 of the transmitting terminal 12, which can set multiple transmission intervals, can switch to a schedule mode that includes a carrier sense-unnecessary channel at least once when the transmission interval is switched to a transmission interval longer than a preset threshold. On the other hand, the transmission / reception control unit 30 can switch to a schedule mode that uses each transmission channel uniformly when the transmission interval is switched to a transmission interval shorter than a preset threshold.

[0068] <Example of Processing on the Transmitting Side> Each process executed in the transmitting terminal 12 will be described with reference to FIGS.

[0069] 4 is a flowchart illustrating the calculation process executed by the transmission / reception control unit 30. For example, the calculation process is executed when initialization is performed or after the transmission of the customer transmission data is completed.

[0070] In step S11, the transmission / reception control unit 30 operates the location and time information detection unit 23 to obtain the current time.

[0071] In step S12 , the transmission / reception control unit 30 acquires the terminal ID and the transmission interval stored in the information storage unit 27 .

[0072] In step S13, the transmission / reception control unit 30 determines the schedule mode using the additional information (scheduled transmission time, location where transmission is possible, scheduled transmission channel, and power value) stored in the information storage unit 27, and saves the schedule mode in the information storage unit 27.

[0073] In step S14, the transmission / reception control unit 30 calculates the start time of the next control communication and the start time of the next data communication based on the current time obtained in step S11, the terminal ID and transmission interval obtained in step S12, and the schedule mode determined in step S13.

[0074] After the process of step S13, the calculation process ends.

[0075] 5 is a flowchart illustrating a control communication transmission sequence executed by the transmission / reception control unit 30. For example, the control communication transmission sequence starts at a predetermined timing before the next control communication start time calculated in step S14 of FIG.

[0076] In step S21, the transmission / reception control unit 30 acquires the terminal ID and schedule mode stored in the information storage unit 27.

[0077] In step S22, the transmission / reception control unit 30 generates transmission data for control communication including the terminal ID and schedule mode acquired in step S21.

[0078] In step S23, the transmission / reception control unit 30 executes a transmission sequence (flowchart in FIG. 7, described later) for transmitting the transmission data for control communication generated in step S22, and then the control communication transmission sequence ends.

[0079] 6 is a flowchart illustrating a data communication transmission sequence executed by the transmission / reception control unit 30. For example, the data communication transmission sequence starts at a predetermined timing before the start time of the next data communication calculated in step S14 of FIG.

[0080] In step S31, the transmission / reception control unit 30 acquires the terminal ID and the customer transmission data stored in the information storage unit 27.

[0081] In step S32, the transmission / reception control unit 30 generates transmission data for data communication including the terminal ID and customer transmission data acquired in step S31.

[0082] In step S33, the transmission / reception control unit 30 executes a transmission sequence (flowchart in FIG. 7, described later) for transmitting the transmission data for data communication generated in step S32, and then the data communication transmission sequence ends.

[0083] FIG. 7 is a flowchart illustrating the transmission sequence executed in step S23 of FIG. 5 or step S33 of FIG.

[0084] In step S41, the transmission / reception control unit 30 measures the power of the scheduled transmission channel. For example, the transmission / reception control unit 30 switches the operation of the transmission / reception switching unit 24 to measurement mode, sets the reception band limiter 42 of the reception block 25 to a band limit corresponding to the scheduled transmission channel, and reads the power value of the scheduled transmission channel from the reception power detection unit 43 of the reception block 25.

[0085] In step S42, the transmission / reception control unit 30 compares the power value of the intended transmission channel read in the measurement in step S41 with a specified threshold value defined by the Radio Law and the like.

[0086] In step S43, the transmission / reception control unit 30 determines whether the scheduled transmission channel is a channel that does not require carrier sense.

[0087] If the transmission / reception control unit 30 determines in step S43 that the scheduled transmission channel is a channel that does not require carrier sense, the process proceeds to step S44.

[0088] In step S44, the transmission / reception control unit 30 sets the determination result indicating whether or not transmission of the transmission data using the scheduled transmission channel is possible to "transmittable." In other words, in this case, the determination result indicates "transmittable" regardless of the comparison result between the power value of the scheduled transmission channel and the specified threshold.

[0089] On the other hand, if the transmission / reception control unit 30 determines in step S43 that the scheduled transmission channel is not a channel that does not require carrier sense (is a channel that requires carrier sense), the process proceeds to step S45.

[0090] In step S45, the transmission / reception control unit 30 sets the determination result indicating whether or not transmission of the transmission data using the scheduled transmission channel is possible, in accordance with the comparison result of step S42. That is, if the power value of the scheduled transmission channel is equal to or greater than the specified threshold, the transmission / reception control unit 30 sets the determination result to "transmission not possible," and if the power value of the scheduled transmission channel is less than the specified threshold, the transmission control unit 30 sets the determination result to "transmission possible."

[0091] After steps S44 and S45, the process proceeds to step S46, where the transmission / reception control unit 30 acquires the current location (transmission possibility determination execution location) from the location and time information detection unit 23.

[0092] In step S47, the transmission / reception control unit 30 stores the judgment result of step S44 or step S45 together with the accompanying information (scheduled transmission time, location where transmission is possible judgment was made, scheduled transmission channel, and power value) in the information storage unit 27, and then the transmission sequence is terminated.

[0093] FIG. 8 is a flowchart illustrating the customer transmission data generation process executed by the transmission / reception control unit 30.

[0094] In step S51, the transmission data generating unit 29 formats the various information supplied from the information detecting unit 28 to generate customer transmission data to be transmitted to the customer, and supplies the data to the transmission / reception control unit 30.

[0095] In step S52, the transmission / reception control unit 30 stores the customer transmission data supplied in step S51 in the information storage unit 27 to be included in the transmission data for the next data communication, and then the customer transmission data generation process is terminated.

[0096] <Example of Receiving Side Processing> Each process executed in the base station 13 will be described with reference to FIGS.

[0097] FIG. 9 is a flowchart illustrating the initial setting process executed by the reception control unit 73.

[0098] In step S61, the reception control unit 73 operates the location and time information detection unit 63 to obtain the current time.

[0099] In step S62, the reception control unit 73 sets the time information output from the position and time information detection unit 63 to be supplied to the time-frequency separation unit 64, and then ends the initial setting process.

[0100] 10 is a flowchart illustrating a control communication reception sequence executed in the base station 13. For example, the control communication reception sequence is executed at periodic intervals (for example, every 5 seconds).

[0101] In step S71, the time-frequency separation unit 64 separates the received signal received during the control communication period defined by the communication standard of the communication system 11 into each channel in accordance with the time frequency based on the time information supplied from the position and time information detection unit 63, and supplies the separated signals to the control communication time-frequency data holding unit 65. The control communication time-frequency data holding unit 65 holds the received signal supplied from the time-frequency separation unit 64. After the control communication period ends, the process proceeds to step S72.

[0102] In step S72, the control communication demodulation processing unit 66 demodulates the received signals of all channels stored in the control communication time-frequency data storage unit 65 in step S71.

[0103] In step S73, the reception control unit 73 acquires from the control communication demodulation processing unit 66 the transmission data for control communication obtained by successfully demodulating the received signal in step S72.

[0104] In step S74, the reception control unit 73 stores the terminal ID and schedule mode values ​​contained in the transmission data for control communication acquired in step S73 in the terminal ID storage unit 70 and schedule mode storage unit 71, respectively.

[0105] In step S75, the reception control unit 73 acquires from the terminal parameter storage unit 69 the transmission interval associated with the terminal ID included in the transmission data for control communication acquired in step S73.

[0106] In step S76, the reception control unit 73 calculates the next data communication occurrence time and receiving channel for the transmitting terminal 12 identified by the terminal ID included in the transmission data for control communication acquired in step S73, based on the current time, terminal ID, transmission interval, and schedule mode.

[0107] After the process of step S76, the control communication reception sequence is ended.

[0108] 11 is a flowchart illustrating a data communication reception sequence executed in the base station 13. For example, the data communication reception sequence is executed for each transmitting terminal 12 at each transmission interval in accordance with the data communication occurrence time calculated in step S76 of FIG. 10 or the data communication occurrence time calculated in step S84, which will be described later.

[0109] In step S81, the time-frequency separation unit 64 separates the received signal received during the data communication period defined by the communication standard of the communication system 11 into each channel in accordance with the time frequency based on the time information supplied from the position and time information detection unit 63, and supplies the separated signals to the data communication time-frequency data holding unit 67. The data communication time-frequency data holding unit 67 holds the received signal supplied from the time-frequency separation unit 64.

[0110] In step S82, the data communication demodulation processing unit 68 demodulates the received signal stored in the data communication time-frequency data storage unit 67, which corresponds to the data communication occurrence time and receiving channel of the transmitting terminal 12 identified by the terminal ID being processed.

[0111] In step S83, the receiving control unit 73 acquires the transmission data for data communication obtained by successfully demodulating the received signal in step S82 from the data communication demodulation processing unit 68, and supplies the customer transmission data contained in the transmission data for data communication to the customer transmission data aggregation unit 72.

[0112] In step S84, the reception control unit 73 calculates the next data communication occurrence time and reception channel for the transmitting terminal 12 identified by the terminal ID included in the transmission data for control communication acquired in step S83, based on the current time, terminal ID, transmission interval, and schedule mode, and then the data communication reception sequence is terminated.

[0113] As described above, in communication system 11, transmitting terminal 12 determines a schedule mode for specifying the transmission time and transmission channel of data communication transmission data (step S13 in FIG. 4), and transmits the schedule mode to base station 13 in control communication transmission data (step S23 in FIG. 5). Base station 13 then receives the schedule mode (step S73 in FIG. 10), calculates the transmission time and transmission channel of data communication transmission data based on the schedule mode (step S76 in FIG. 10), and controls reception of data communication transmission data to execute the control communication reception sequence.

[0114] In this way, by using the schedule mode, the communication system 11 can avoid communication failures by appropriately using channels that do not require carrier sense, thereby further improving the probability of successful communication.

[0115] The communication system 11 can always use the carrier sense-free channel for communication, or the communication system 11 can use the carrier sense-required channel and the carrier sense-free channel uniformly for communication without distinguishing between them.

[0116] In addition, instead of switching the schedule mode, the communication system 11 may continuously change the usage ratio of channels that do not require carrier sensing, and when carrier sensing is performed and channels are frequently used, the usage ratio of channels that do not require carrier sensing may be set higher than usual to perform communication.

[0117] In the communication system 11 of this embodiment, the same communication content is repeatedly transmitted four times on different transmission channels in both data communication and control communication, but this number of times is not limited to four and can be any number of times greater than or equal to two. Furthermore, the number of times that a channel not requiring carrier sense is used can also be set arbitrarily as needed.

[0118] <Example of Computer Configuration> FIG. 12 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0119] In the computer, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and an EEPROM (Electronically Erasable and Programmable Read Only Memory) 104 are interconnected by a bus 105. An input / output interface 106 is further connected to the bus 105, and the input / output interface 106 is connected to the outside.

[0120] In a computer configured as described above, the CPU 101 performs the above-described series of processes by loading programs stored in, for example, the ROM 102 and EEPROM 104 into the RAM 103 via the bus 105 and executing the programs. In addition, the programs executed by the computer (CPU 101) can be written in advance in the ROM 102, or can be installed or updated in the EEPROM 104 from outside via the input / output interface 106.

[0121] In this specification, the processing performed by a computer according to a program does not necessarily have to be performed in chronological order according to the order described in the flowchart. In other words, the processing performed by a computer according to a program also includes processing that is executed in parallel or individually (for example, parallel processing or object-based processing).

[0122] The program may be processed by a single computer (processor), or may be distributed among multiple computers. Furthermore, the program may be transferred to and executed on a remote computer.

[0123] Furthermore, in this specification, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all of the components are contained in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device housed in a single housing with multiple modules, are both systems.

[0124] Also, for example, a configuration described as one device (or processing unit) may be divided and configured as multiple devices (or processing units). Conversely, configurations described above as multiple devices (or processing units) may be combined and configured as one device (or processing unit). Of course, configurations other than those described above may be added to the configuration of each device (or each processing unit). Furthermore, as long as the configuration and operation of the entire system are substantially the same, part of the configuration of one device (or processing unit) may be included in the configuration of another device (or other processing unit).

[0125] Furthermore, for example, the present technology can be configured as a cloud computing system in which a single function is shared and processed collaboratively by a plurality of devices via a network.

[0126] Furthermore, for example, the above-described program can be executed in any device, as long as the device has the necessary functions (functional blocks, etc.) and can obtain the necessary information.

[0127] Also, for example, each step described in the above flowchart can be executed by one device or can be shared and executed by multiple devices. Furthermore, if one step includes multiple processes, the multiple processes included in that one step can be executed by one device or can be shared and executed by multiple devices. In other words, multiple processes included in one step can be executed as multiple step processes. Conversely, processes described as multiple steps can be executed collectively as a single step.

[0128] In addition, the processing of the steps of a program executed by a computer may be executed in chronological order according to the order described in this specification, or may be executed in parallel or individually at the required timing, such as when a call is made. In other words, as long as no contradiction occurs, the processing of each step may be executed in an order different from the order described above. Furthermore, the processing of the steps of this program may be executed in parallel with the processing of another program, or may be executed in combination with the processing of another program.

[0129] It should be noted that the present technologies described in this specification can be implemented independently and singly, unless a contradiction arises. Of course, any two or more of the present technologies can also be implemented in combination. For example, part or all of the present technologies described in any embodiment can be implemented in combination with part or all of the present technologies described in other embodiments. Furthermore, part or all of any of the present technologies described above can also be implemented in combination with other technologies not described above.

[0130] <Examples of Combinations of Configurations> The present technology can also be configured as follows. (1) A transmitting device comprising: a transmission / reception control unit that determines a schedule mode for specifying a transmission time and a transmission channel for transmission data for data communication to be transmitted in one-way communication to a receiving device; and a transmitting unit that transmits the schedule mode to the receiving device in transmission data for control communication. (2) The transmitting device described in (1) above, in which the schedule mode specifies a proportion of use of a carrier-sense-free channel, which is a transmission channel that is allowed to transmit transmission data on that transmission channel, even when carrier sense is performed and it is confirmed that the transmission channel is in use. (3) The transmitting device described in (2) above, in which, when the same transmission data is repeatedly transmitted four times on different transmission channels, the schedule mode is switchable to one of: a first mode that specifies uniform use of each transmission channel for the four transmissions; a second mode that specifies use of the carrier-sense-free channel for at least one of the four transmissions; or a third mode that specifies use of the carrier-sense-free channel for at least two of the four transmissions. (4) The transmitting device according to (2) or (3) above, wherein the transmission and reception control unit switches to the schedule mode in which a proportion of the channel not requiring carrier sense is used is increased when carrier sense is performed to confirm that the channel is in use, resulting in a high frequency of communication unavailable states. (5) The transmitting device according to any of (2) to (4) above, wherein the transmission and reception control unit switches to the schedule mode in which a proportion of the channel not requiring carrier sense is used is increased at a location according to location information indicating a location where a proportion of the channel not requiring carrier sense is increased. (6) The transmitting device according to any of (2) to (5) above, wherein the transmission and reception control unit switches to the schedule mode in which a proportion of the channel not requiring carrier sense is used is increased when the transmission interval is long compared to when the transmission interval is short, according to a transmission interval of the transmission data for data communication.(7) The transmitting device according to any of (2) to (6) above, wherein the transmission and reception control unit initially sets the schedule mode to include the channel not requiring carrier sensing at least once when the transmission interval of the transmission data for data communication is fixed and the transmission interval is set longer than a specified time. (8) The transmitting device according to any of (2) to (7) above, wherein the transmission and reception control unit, when the transmission interval of the transmission data for data communication is switchable and a plurality of transmission intervals are setable, switches to the schedule mode to include the channel not requiring carrier sensing at least once when the transmission interval is switched to one longer than a preset threshold, and switches to the schedule mode to use each transmission channel evenly when the transmission interval is switched to one shorter than a preset threshold. (9) The transmitting device according to any of (2) to (8) above, wherein the transmission and reception control unit continuously changes the usage ratio of the channel not requiring carrier sensing. (10) A receiving device comprising: a receiving unit that receives a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication transmitted by one-way communication from a transmitting device, and a receiving control unit that calculates the transmission time and transmission channel of the transmission data for data communication based on the schedule mode and controls reception of the transmission data for data communication. (11) A communication system comprising: a transmitting device having: a transmitting / receiving control unit that determines a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication to be transmitted by one-way communication to the receiving device, and a transmitting unit that transmits the schedule mode to the receiving device by transmission data for control communication; a receiving unit that receives the schedule mode transmitted by one-way communication from the transmitting device, and a receiving control unit that calculates the transmission time and transmission channel of the transmission data for data communication based on the schedule mode and controls reception of the transmission data for data communication.(12) A communication method including: a transmitting device determining a schedule mode for specifying a transmission time and a transmission channel of transmission data for data communication to be transmitted in one-way communication to a receiving device; and transmitting the schedule mode to the receiving device in transmission data for control communication; and the receiving device receiving the schedule mode transmitted in one-way communication from the transmitting device; and calculating a transmission time and a transmission channel of the transmission data for data communication based on the schedule mode, and controlling reception of the transmission data for data communication.

[0131] It should be noted that the present embodiment is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0132] REFERENCE SIGNS LIST 11 communication system, 12 transmitting terminal, 13 base station, 14 network, 15 information processing device, 21 and 22 antenna, 23 position and time information detection unit, 24 transmission and reception switching unit, 25 reception block, 26 transmission block, 27 information storage unit, 28 information detection unit, 29 transmission data generation unit, 30 transmission and reception control unit, 41 reception signal amplification unit, 42 reception band limiting unit, 43 reception power detection unit, 51 transmission data shaping unit, 52 transmission data modulation unit, 53 transmission data amplification unit, 61 and 62 antenna, 63 position and time information detection unit, 64 time-frequency separation unit, 65 control communication time-frequency data storage unit, 66 control communication demodulation processing unit, 67 data communication time-frequency data storage unit, 68 data communication demodulation processing unit, 69 terminal parameter storage unit, 70 Terminal ID storage unit 71 Schedule mode storage unit 72 Customer transmission data aggregation unit 73 Reception control unit

Claims

1. A transmitting device comprising: a transmitting / receiving control unit that determines a schedule mode for specifying the transmission time and transmission channel of transmission data for data communication to be transmitted in one-way communication to a receiving device; and a transmitting unit that transmits the schedule mode to the receiving device using transmission data for control communication.

2. The transmitting device according to claim 1, wherein the schedule mode specifies a percentage of use of carrier sense-free channels, which are transmission channels that are permitted to transmit transmission data on a transmission channel even when carrier sense is performed and it is confirmed that the transmission channel is in use.

3. The transmitting device of claim 2, wherein the schedule mode is switchable between one of the following when the same transmission data is repeatedly transmitted four times on different transmission channels: a first mode that specifies that each transmission channel is used equally for the four transmissions; a second mode that specifies that the carrier sense-free channel is used for at least one of the four transmissions; or a third mode that specifies that the carrier sense-free channel is used for at least two of the four transmissions.

4. The transmitting device of claim 2, wherein the transmission / reception control unit switches to the schedule mode that increases the proportion of channels that do not require carrier sensing when carrier sensing is performed to confirm that the channel is in use, resulting in an increase in the frequency of communication being unavailable.

5. The transmitting device according to claim 2, wherein the transmission / reception control unit switches to the schedule mode that increases the rate of use of the carrier sense-unnecessary channel at the location according to location information indicating the location where the rate of use of the carrier sense-unnecessary channel has increased.

6. The transmitting device according to claim 2, wherein the transmission / reception control unit switches to the schedule mode in which the proportion of carrier sense-unnecessary channels used is higher when the transmission interval is long than when the transmission interval is short, according to the transmission interval of the transmission data for the data communication.

7. The transmitting device according to claim 2, wherein the transmission / reception control unit initially sets the schedule mode to include the carrier sense-free channel at least once when the transmission interval of the transmission data for the data communication is fixed and the transmission interval is set longer than a specified time.

8. The transmitting device according to claim 2, wherein, when the transmission interval of the transmission data for the data communication is switchable and multiple transmission intervals are settable, when the transmission interval is switched to one longer than a preset threshold, the transmitting / receiving control unit switches to the schedule mode that includes the carrier sense-unnecessary channel at least once, and when the transmission interval is switched to one shorter than a preset threshold, the transmitting device switches to the schedule mode that uses each transmission channel uniformly.

9. The transmitting device according to claim 2, wherein the transmission / reception control unit continuously changes the usage ratio of the carrier sense unnecessary channels.

10. A receiving device comprising: a receiving unit that receives a schedule mode for specifying the transmission time and transmission channel of data for data communication transmitted in one-way communication from a transmitting device; and a receiving control unit that calculates the transmission time and transmission channel of the data for data communication based on the schedule mode and controls the reception of the data for data communication.

11. A communication system comprising: a transmitting device having a transmitting / receiving control unit that determines a schedule mode for specifying the transmission time and transmission channel of data communication transmission data to be transmitted to a receiving device via one-way communication; and a transmitting unit that transmits the schedule mode to the receiving device using transmission data for control communication; a receiving unit that receives the schedule mode transmitted from the transmitting device via one-way communication; and a receiving control unit that calculates the transmission time and transmission channel of the data communication transmission data based on the schedule mode and controls the reception of the data communication transmission data.

12. A communication method comprising: a transmitting device determining a schedule mode for specifying the transmission time and transmission channel of data communication transmission data to be transmitted in one-way communication to a receiving device; and transmitting the schedule mode to the receiving device in control communication transmission data; and the receiving device receiving the schedule mode transmitted in one-way communication from the transmitting device; and calculating the transmission time and transmission channel of the data communication transmission data based on the schedule mode, and controlling reception of the data communication transmission data.

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