System, device and program

Abstract

To provide a convenient system and the like capable of more secure remote control than before.SOLUTION: The system comprises a first device and a second device that are capable of wireless communication, where the wireless communication of the first device and the second device is of a spread spectrum type. At least one of the first device and the second device is portable by a user, and signals transmitted by the one device include a signal for operating a function of the other of the first device and the second device. The spread spectrum type of the wireless communication of the first device and the second device is preferably the LoRa type, and uses a sub-gigahertz band, preferably a sub-gigahertz band frequency channel having a bandwidth wider than the bandwidth of a channel in a frequency band less than the sub-gigahertz band.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to, for example, a system, an apparatus, a program, and the like. [Background technology]

[0002] Remote engine starting devices (engine starters) that remotely start the engine for the purpose of warming up the engine and adjusting the temperature inside the vehicle are becoming popular. This remote engine starting device is installed in the vehicle and includes a relay drive circuit that controls the engine start and the operation of electrical equipment, and a main control circuit that controls the relay drive circuit when it receives a start command signal. The start command signal is sent from a wireless remote control transmitter (portable device) that the user holds in his or her hand. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3959146 Summary of the Invention [Problem to be solved by the invention]

[0004] For systems such as engine starters, which are equipped with a portable device and another communication device and which remotely control the functions of the other communication device by using the portable device, companies have generally used specific low-power radio devices with a frequency band of 420 MHz, a modulation method of FSK (frequency shift keying), and an output of 10 mW or 1 mW for signal transmission and reception. The problem with such systems is that the communication distance limit is roughly the same for all companies. The communication distance varies depending on the conditions, but the outlook is that it can be up to about 4 km, and depending on the conditions it can be as low as a few hundred meters, so companies are competing with each other like comparing chestnuts. None of the companies have been able to break out of this situation, and although there was a strong desire to break out of it, it was partly the common sense and stereotypes in the industry that prevented them from breaking out.

[0005] An object of the present invention is to provide a system or the like which can perform remote control more reliably and is easier to use than, for example, the conventional systems. [Means for solving the problem]

[0006] (1) For example, a system may include a first device and a second device capable of wireless communication, the wireless communication between the first device and the second device being based on a spread spectrum system, at least one of the first device and the second device being portable by a user, and a signal transmitted by one of the devices including a signal for activating a function of the other of the first device or the second device.

[0007] In this way, compared to conventional FSK methods other than the spread spectrum method (frequency spread method), the user can operate the functions of the device by remote control using wireless communication at a significantly longer distance than the conventional methods. According to the results of the inventors' experiments, the functions of the device can be operated at a distance that is roughly twice as long as the conventional method. For example, in the conventional FSK method, if the distance at which wireless communication is reliably possible is 1 km, the spread spectrum method allows communication at a distance of more than twice that distance, 2 km or more.

[0008] At least one of the first device and the second device that the user can carry may be any device, but may be, for example, a golf navigation system, and may be, in particular, a portable device or a remote controller (hereinafter, also referred to as "remote control" for short). For example, a signal transmitted from the remote control may include a signal that activates a function of the other of the first device and the second device. At least one of the first device and the second device that the user can carry may be, in particular, equipped with a function for inputting instructions from a user, and may be configured to transmit a signal that activates a function of the other device based on the input instruction. The function for inputting instructions from a user may be any device that can input instructions, but may be, for example, a sensor that can detect the user's movements, and may in particular be equipped with a means for inputting instructions from the user. At least one of the first device and the second device that the user can carry may be a wearable terminal that can be attached to the body. Desirably, at least one of the first device and the second device that the user can carry may be a device that can be held in the hand and may be equipped with a function for inputting instructions by hand. It is preferable to have a means for inputting instructions by pressing with a finger, and it is more preferable to configure the means for inputting instructions as a switch.

[0009] The other of the first device and the second device may be any device, but may be, for example, a device that is portable by the user, preferably a device that is not portable by the user, for example, a device fixed to an object, and more preferably a device installed indoors. When fixed to an object, it may be fixed to the ground, for example, preferably to a gas, electricity, or water meter. When fixed to the ground, it may be, for example, a water sprinkler. When fixed to a gas, electricity, or water meter, it may be a terminal device that transmits meter reading data to a remote control. When installed indoors, it may be installed in a golf clubhouse or inside a car. When installed in a clubhouse, it may be, for example, a digital signage. When installed in a car, it may be, for example, an in-car device. Most preferably, when the first device is a portable device, the second device is a device fixed to another object, or when the second device is a portable device, the first device is a device fixed to another object.

[0010] The system of the present invention may be any system, but may be, for example, a system used in consumer devices or various industrial devices, and in particular, a system used in automobile-related devices such as the engine starter described above, allowing a user to appropriately remotely control various devices.

[0011] For example, a system for use with consumer devices may be a system in which one of a first device or a second device that can be carried by a user is a remote control, and the other is a device fixed to the ground, and the signal transmitted from the remote control includes a signal that activates a function of the device.

[0012] As a system for use in consumer devices, it is preferable that one of the first device or the second device that can be carried by a user is a portable device, and the other is a transmitter fixed to a gas, electricity, water meter, etc. The signal transmitted from the transmitter to the portable device preferably includes meter reading data and a signal that causes the portable device to tally up the meter reading data (a signal that activates a function of the portable device).

[0013] In particular, it is preferable to use a wireless communication system that uses a standard called "Wi-SUN (Wireless Smart Utility Network)" and is equipped with a terminal device fixed to a gas, electricity, or water meter, and collects meter reading data using a portable device or the like by wireless communication. If the system of the present invention is used in Wi-SUN, a user can collect meter reading data from a more remote location than before, and the effort of moving around due to data collection can be minimized. For example, when reading an electric meter in a mountainous residence that is far from roads that can be traveled by car and cannot be approached without walking, the possibility that a meter reader carrying a portable device can collect meter reading data (hereinafter also referred to as "meter information") within the range that can be traveled by car is increased, and even if walking is required after traveling by car, the possibility of shortening the travel distance is increased. In particular, it is preferable that the portable device is one that the user can carry and move around on foot, and that instructions can be input manually.

[0014] More preferably, the present system is a system in which the first device is a golf navigation system and the second device is a digital signage installed in the clubhouse. In particular, the signal transmitted from the golf navigation system should include a signal that activates the display function and tallying function of the digital signage. In this case, it becomes possible to sequentially display rankings on the digital signage based on the player's results entered into the golf navigation system during the round, and the user can save the trouble of tallying up the player's results, etc.

[0015] A system used for automobile-related devices may be, for example, a system used for an automobile engine starter, car security, etc., with the first device being a remote control and the second device being an in-vehicle device. In particular, a signal transmitted from the remote control may include a signal for activating a function of the in-vehicle device, and a signal transmitted from the in-vehicle device may include a signal for activating a function of the remote control. Preferably, the signal transmitted from the remote control may be configured to be transmitted based on an instruction from a user.

[0016] Here, in the case of conventional engine starters and car security, for example, in large-scale apartment buildings, there were cases where the parking lot was very far from the user's room and the user was unable to use the device. This problem was particularly noticeable in tower apartment buildings. In addition, for example, there were cases where the user was unable to use the device unless he or she went out onto the balcony because radio waves were blocked by a concrete wall. However, even in such cases, the present invention allows the user to activate the function of the other device more reliably than before. For example, the engine starter or car security function can be activated more reliably than before. Therefore, for example, even if the user was previously unable to activate the function of the other device unless he or she moved to a place where radio waves could reach the car in the parking lot, such as a window or a balcony, the user is more likely to be able to activate the engine starter or car security by operating it at a position indoors, such as the bedside.

[0017] Furthermore, for example, a system for use in an automobile-related device having the above-mentioned remote control (portable device) and in-vehicle device may be combined with a wireless communication system for collecting Wi-SUN meter information, etc., so that the in-vehicle device acts as a gateway (gateway) to transmit meter information generated in the house to the portable device. Specifically, for example, the in-vehicle device may receive information such as meter reading data of gas, electricity, and water meters and power generation data of a solar power generation device installed in the house from a Wi-SUN device in Wi-SUN mode (a modulation method other than the spread spectrum method), and the in-vehicle device may transfer the received information to a portable device (remote control) carried by the user in spread spectrum mode. In this way, the user can receive information such as meter reading data within a bicycle range that is wider than the conventional walking range. For example, under conditions where radio waves could only reach about 1 km in the conventional Wi-SUN mode (a modulation method other than the spread spectrum method), a range of 6 km can be achieved by lowering the bit rate using the spread spectrum method. An area with a diameter of 1 km from a residential house is considered to be within the daily living area (walking distance), while an area with a diameter of 6 km is considered to be within the local living area (if necessary, refer to Table 5 on page vi, page 32, and Table 4-3 on page 37 of the following electronic technical information (Ishihara Hiroshi, "Basic Research on Daily Living Areas (Part 2)", [online], March 2008, Nagoya Urban Center, [accessed July 5, 2016], Internet <URL: http: / / www.nui.or.jp / user / media / document / investigation / h19 / nichijo.pdf>). Also, usually, almost everything can be done within the local living area (biking distance) from one's home (if necessary, refer to page 11 of the following electronic technical information (Ichimura Machio, "Method of Analyzing Commercial Demand Based on Living Area", [online], June 2006, Community Builders' Net, [accessed July 5, 2016], Internet <URL: http: / / www.geocities.jp / non_non_net2006 / p_rep / seikatukenn2.pdf>).

[0018] Preferably, the first device is fixed to an object, and the second device is portable by the user. The user carrying the second device can operate the function of the first device at the location of the object to which the first device is fixed without using the second device. The second device is carried by the user and moves with the user's movement on foot or bicycle from the location of the object to which the first device is fixed as a base point (for example, the starting point of the movement), and the second device returns to the base point again (for example, the original starting point as the end point after moving to a predetermined destination) by the user's movement to the location of the object to which the first device is fixed. The "movement on foot or bicycle" may be configured to be a line-of-sight distance of 5 km or more and 20 km or less. For example, the base point may be a home and the user may be an elderly person with dementia. Also, the base point may be a car, and the user may move on foot from the car, for example, shopping at a shopping center, start the engine while shopping, and return to the car as the base point again. For example, the base point may be an automobile, and the user may walk from the automobile to his / her house after returning home, and the next morning, start the engine of the automobile from inside the house and then return to the automobile. For example, the base point may be a clubhouse, and the user may walk or otherwise move around the golf course while playing, and return to the clubhouse after playing.

[0019] Also, for example, the first device may be a parent device installed in a nursing facility, and the second device may be a child device carried by each of a number of people residing in the nursing facility. For example, it is preferable that each child device has a different ID stored therein, and the parent device stores a correspondence between the ID stored in each child device and the name of the person carrying the child device. Each child device transmits radio waves containing ID data by a spectrum spreading method at a fixed time (for example, every minute). The parent device checks the ID data contained in the received radio waves and the RSSI (Received Signal Strength Indicator) of the received radio waves, and when the RSSI of the received radio waves falls below a set value, the parent device displays the approximate distance from the parent device to the child device that transmitted the radio waves, which is calculated based on the RSSI level, and the name of the person associated with the ID. The "RSSI setting value" may be set by previously calculating the relationship between the distance between the parent device and the child device and the RSSI value, and inputting it into the parent device as the distance. Alternatively, "when the RSSI falls below a set value" may be when the RSSI reaches a level equivalent to that outside the care facility, based on the difference in RSSI that has been measured and set in advance between inside and outside the care facility.

[0020] The parent unit may have a function for selecting a person's name stored in advance from a list or the like, and a function for wirelessly transmitting a signal requesting a reply to a child unit having an ID corresponding to that person's name. If the received ID is its own ID and a reply is requested by the parent unit, the child unit wirelessly transmits level information on the received electric field strength and its own ID. The parent unit obtains and displays the position of the child unit (e.g., the distance from the parent unit) from the level of electric field strength of the received ID.

[0021] Furthermore, for example, it is preferable to provide a function of relaying a wireless signal of an inquiry from the parent unit between the child units. For example, the parent unit is provided with a "normal search button (a button for searching without relaying)" and a "relay and search button", and when the "normal search button" is pressed, it requests a reply of the ID and the level of electric field strength from all child units within the range of the parent unit's radio waves, while when the "relay and search button" is pressed, it requests a reply from all child units within the range of the parent unit's radio waves and from all child units within the range of the radio waves from the child units. The reply (for example, the ID and the level of electric field strength of the other child units) is relayed by the child unit between the parent unit and the other child units. Note that it is also possible to further relay between the child units, and it is also preferable to set a limit on the number of times relaying between the child units. In addition, a position detector such as a GPS may be provided in each of the parent unit and the child unit, and only child units within a range specified by the parent unit from the position of the parent unit may relay.

[0022] In communication using the "spread spectrum method," for example, a narrowband signal obtained by modulating a signal to be transmitted may be spread to a wideband signal using a predetermined spreading method to reduce the power density, and then transmitted from the transmitting side. At the receiving side, the received signal may be despread to obtain the original narrowband signal with high power density. In addition, the "spread spectrum method" may be configured in such a way that, even if the spread signal received at the receiving side is a weak signal below the so-called noise floor, the signal may be restored to the original narrowband signal with high power density by despreading, and the restored original narrowband signal may be demodulated and reproduced as the signal to be transmitted. In this way, even signals that have attenuated to below the noise floor at long distances may be received.

[0023] In the case of "spread spectrum" communication, the modulation of the spread signal performed on the transmitting side and the demodulation of the spread signal performed on the receiving side may be performed using a hardware modulator or demodulator, or may be performed using a software radio. In particular, it is preferable to use an IC chip that performs the calculations corresponding to such modulation and demodulation.

[0024] Any communication method may be used as the "spread spectrum method", but it is particularly preferable to use a method that can increase the communication distance even at the expense of communication speed. Also, for example, a frequency hopping method is preferably used. It is preferable to use a method other than a direct sequence spread spread method. More preferably, the "spread spectrum method" is configured as a method (hereinafter referred to as a "chirp method") in which a chirp signal is generated by continuously changing the frequency, and a signal based on the data to be transmitted is spread and modulated by this (hereinafter referred to as a "chirp method"). In particular, it is preferable to combine the chirp method with another method. For example, it is preferable to combine the chirp method with at least one of the frequency hopping method and the direct sequence spread spread method. Also, for example, the LoRa method, which will be described in detail later, is the most preferable communication method using the "spread spectrum method". On the other hand, conventional modulation methods other than the spread spectrum method include, in addition to the above-mentioned FSK method, OOK (on-off keying), GFSK (phase-continuous FSK), MSK (minimum shift keying), GMSK (Gaussian minimum shift keying), etc. (hereinafter, these modulation methods are collectively referred to as "FSK, etc.").

[0025] Furthermore, "at least one of the first device and the second device" that is "portable by the user" may be any device, and may be, for example, a portable communication device, a portable information device, a wearable terminal, etc. Furthermore, "at least one of the first device and the second device" that is "portable by the user" may be, for example, a non-dedicated device that can perform functions other than remote control, and may be, in particular, a dedicated device for remote control, such as a remote control.

[0026] Also, the "signal transmitted by the one device" may be configured to include a signal that activates a function of the other of the first device or the second device. For example, in the case of an engine starter or a car security, the signal may be configured to include a signal for starting these devices, a signal for stopping them, a signal for changing settings, etc. Also, in the case of an engine starter or a car security, the signal may be configured to include a signal for activating an alarm function from these devices to a portable device or a remote control, etc. Desirably, the "signal transmitted by the one device" may be configured to include a signal other than a signal that activates a function of the other device. For example, the "signal other than a signal that activates a function of the other device" may be data detected by a sensor installed in the vehicle, such as the current temperature inside the vehicle in the case of an engine starter, or the degree of impact applied to the vehicle in the case of a car security.

[0027] Furthermore, in the case of consumer equipment such as a water sprinkler or various industrial equipment, the "signal transmitted by the one device" may include a start signal or a stop signal for the equipment. In the case of equipment such as a golf navigation system, the "signal transmitted by the one device" may include a signal such as a player's performance information input into the golf navigation system. In the case of using the system of the present invention in equipment such as gas, electricity, or water meters that use standards such as Wi-SUN, the "signal transmitted by the one device" may include various data such as meter reading data.

[0028] For example, when the first device is a portable device such as a remote control and the second device is an in-vehicle device, the portable device may have a single receive mode and the in-vehicle device may have a continuous receive mode. In this way, the battery of the portable device can be made to last longer, and the in-vehicle device can more reliably capture the signal transmitted from the portable device. In this case, it is preferable that the in-vehicle device transmits the same information multiple times. In this case, it is possible to reduce the occurrence of missed readings due to disturbances in the portable device. More preferably, the in-vehicle device may have a function for transmitting a signal to switch to the continuous receive mode from the in-vehicle device to the portable device, and when the portable device receives the signal to switch, it may operate in the continuous receive mode. In this case, it is particularly preferable that the time for operating in the continuous receive mode is set to a certain time. Such a communication mode can be implemented by using, for example, the communication chip "SX1272" described later.

[0029] "Single receive mode" is, for example, a mode in which only one packet is received within a set time, and in particular when communicating at a fixed receive timing, it is recommended that the receiver circuit be configured to be turned on only at the required receive timing. In this way, it is possible to reduce power consumption during standby for reception. "Continuous receive mode" is, for example, a mode in which signals are received continuously.

[0030] (2) The wireless communication between the first device and the second device using a spread spectrum method may be a LoRa method.

[0031] In this way, users can break away from the current situation where the distance at which remote control is possible is roughly uniform.

[0032] A wireless system using a spread spectrum method, particularly the LoRa method (hereinafter also referred to as a "LoRa wireless system"), can communicate at a higher transmission bit rate (hereinafter also referred to simply as "bit rate", "data rate" or "transmission speed") when designed for the same communication distance as the FSK method. Since a higher bit rate shortens communication time, a user can obtain a system that can quickly activate a function of the other device when a signal to activate the function of the other device is transmitted from either the first device or the second device.

[0033] In particular, it is preferable that at least one of the first device and the second device, which are portable by the user, has a function for inputting instructions from the user and transmits a signal to activate the function of the other device based on the input instruction. With this configuration, it is possible to obtain a system that quickly responds to the input operation of instructions.

[0034] Preferably, in the LoRa system, the bit rate is set low. In this way, higher sensitivity can be obtained. Most preferably, the bit rate is set to the lowest possible range. In particular, the bit rate of the first device or the second device, whichever is portable by the user, is set to the lowest possible range. In this way, the user can transmit a signal to activate a function of the other device from the portable device from a longer distance than before, and activate the function on the other device. Also, for example, the bit rate of the portable device is set to be lower than the bit rate of the device that activates the function by the signal transmitted from the portable device. Furthermore, it is preferable to have the configurations (3) and (3-1) described later. According to the results of experiments conducted by the inventors, with such a configuration, it was possible to obtain a transmission distance that is about four times longer and a coverage area that is about 16 times larger than that of the conventional 420 MHz band FSK system.

[0035] It is preferable to set the bit rate low in a system that transmits and receives a small amount of digital information, and it is even more preferable to set the bit rate low when transmitting digital information such as an automobile engine starter or car security.

[0036] The LoRa wireless communication can be implemented by using, for example, the communication chip "SX1272" manufactured by SEMTECH. This communication chip performs the modulation and demodulation of the above-mentioned signals through calculation processing.

[0037] (3) The wireless communication between the first device and the second device may use a sub-gigahertz band and a channel in the sub-gigahertz band having a bandwidth wider than a channel in a frequency band below the sub-gigahertz band.

[0038] In this way, a user can operate the functions of a device by remote control using wireless communication with a smaller device and at a longer distance than before. Although the sub-gigahertz band generally has a shorter propagation distance of radio waves than the bands of frequencies below the sub-gigahertz band, the problem of the short propagation distance of radio waves can be solved by using a channel of a sub-gigahertz band frequency whose bandwidth is wider than the bandwidth of a channel in the bands of frequencies below the sub-gigahertz band. For example, it is advisable to set a channel of a sub-gigahertz band frequency whose bandwidth of the channel to be used is wider than the bandwidth of a channel in the bands of frequencies below the sub-gigahertz band.

[0039] Also, for example, the frequency of an oscillator for wireless communication provided in the first device and the second device may be set as in (3). In particular, for example, the setting of the frequency for wireless communication may be performed by a control unit provided in the first device and the second device, and the set frequency may be set as in (3). Desirably, the control unit is a computer, and a value corresponding to the frequency to be set may be written in a register of the computer.

[0040] (3-1) The wireless communication between the first device and the second device should be specific low-power wireless communication using the sub-gigahertz band, and the transmittable power used should be a sub-gigahertz frequency that is greater than the transmittable power in a frequency band below the sub-gigahertz band.

[0041] The "frequency band below the sub-gigahertz band" may be the 400 MHz band, preferably, for example, 449.7125-449.8250 MHz, 449.8375-449.8875 MHz, or 469.4375-469.4875 MHz, and more preferably, for example, 426.0250-426.1375 MHz, 426.0375-426.1125 MHz, 429.1750-429.2375 MHz, 429.2500-429.7375 MHz, or 429.8125-429.9250 MHz. In each of these bands, the channel bandwidth may be, for example, 12.5 kHz, and, particularly, in the band of 426.0375-426.1125 MHz, it may be, for example, 25 kHz. Furthermore, the transmittable power may be set to, for example, 1 mW in the frequency bands below the sub-gigahertz band, 426.0250 to 426.1375 MHz and 426.0375 to 426.1125 MHz, and may be set to, for example, 10 mW in the other bands.

[0042] The "sub-gigahertz band" may be, for example, a frequency band slightly lower than 1 GHz, and preferably, for example, 800 to 950 MHz. More preferably, it may be the 920 MHz band defined by Japanese laws and regulations, and even more preferably, for example, a band with a center frequency of 928.15 to 929.65 MHz, and most preferably, for example, a band with a center frequency of 916.0 to 928.0 MHz. In the band with a center frequency of 928.15 to 929.65 MHz, the channel bandwidth may be, for example, 100 kHz, and in the band with a center frequency of 916.0 to 928.0 MHz, the channel bandwidth may be, for example, 200 kHz. In addition, the channel used in the sub-gigahertz band may be a channel with a bandwidth four or more times the bandwidth of the channel in the frequency band below the sub-gigahertz band. It is preferable to select a channel with a bandwidth of 200 kHz, which is 8 times the bandwidth of the channel in the range of 426.0375 to 426.1125 MHz (25 kHz). More preferable to select a channel in the sub-gigahertz band with a bandwidth of 200 kHz, which is 16 times the bandwidth of the channel in the range of 426.0250 to 426.1375 MHz, 429.1750 to 429.2375 MHz, 429.2500 to 429.7375 MHz, or 429.8125 to 429.9250 MHz. In addition, the transmittable power may be, for example, 1 mW in the range of 916.0 to 920.4 MHz and 928.15 to 929.65 MHz in the sub-gigahertz band, and 20 mW in the ranges other than these. A channel to be used in the sub-gigahertz band should have a transmittable power of 20 mW, which is 20 times the transmittable power of 1 mW or twice the transmittable power of 10 mW in the frequency band below the sub-gigahertz band.

[0043] In the 400 MHz band, which is included in the "frequency band below the sub-gigahertz band," the Japanese domestic regulations at the time of filing allocate a bandwidth of 12.5 kHz or 25 kHz per channel. On the other hand, in the sub-gigahertz band, there is the 920 MHz band, which allocates a bandwidth of 100 kHz or 200 kHz per channel. In this way, the sub-gigahertz band, especially the 920 MHz band, is a frequency band with a wider bandwidth per channel than the 400 MHz band, which is a frequency band below the sub-gigahertz band. Although the 400 MHz band has a narrower bandwidth per channel than the 920 MHz band, it has the advantage that radio waves can reach farther than the 920 MHz band and are less directional and more prone to diffraction, making it easier to receive even in the shadows of distant obstacles (mountains and buildings).

[0044] The inventors have found that the "channel to be used" may be any one of the channels in the 920.6-923.4MHz band, 200kHz bandwidth, 200kHz intervals, total of 15 channels, and the 920.7-923.3MHz band, 400kHz bandwidth, 200kHz intervals, total of 14 channels, and in particular, at least one of the six channels with center frequencies of 922.4MHz, 922.6MHz, 922.8MHz, 923.0MHz, 923.2MHz, and 923.4MHz (all with a bandwidth of 200kHz). In particular, it may be provided with a configuration that allows some of these channels to be switched, and preferably, it may be provided with a configuration that allows automatic switching to a channel that is determined to have no signal by Busy judgment among these channels. In addition, these channels may be configured to be used with a wider bandwidth by combining multiple adjacent channels; for example, five adjacent channels out of the six channels mentioned above may be combined to use a bandwidth of 1000 kHz.

[0045] Furthermore, a "channel" may be, for example, a frequency band allocated for use in communications, particularly a frequency band allocated by the laws and regulations of the country of use, and particularly a frequency band allocated by the laws and regulations of Japan.

[0046] When determining if a channel is busy (determining whether transmission is prohibited due to the presence of a signal), the signal level of the spread spectrum method is determined using, for example, CAD (Channel Acceleration and Delay Timer). The CAD function may be configured to detect the presence of a spread spectrum signal at such a low level that the presence of the signal cannot be detected by RSSI. The busy determination may be configured to determine whether a channel is busy when the signal level is -130 dBm or higher for a spread spectrum signal, and to determine whether the signal level is busy when the signal level is -80 dBm or higher for signals using other modulation methods. In this way, more appropriate channel busy determination is possible, and it is possible to operate the device's functions by remote control using wireless communication over a long distance.

[0047] Table 1 shows all the cases where the presence of a signal is confirmed by the CAD function and RSSI and where it is not, with the top row of each column indicating the Busy judgment content and the bottom row indicating what kind of signal may be transmitted. Table 1 shows the cases where signals using modulation methods other than spread spectrum methods can be transmitted in the first and second devices. In Table 1, the case where the presence of a signal is confirmed by the CAD function is indicated as "CAD present" and the case where it is not confirmed is indicated as "CAD not present," the case where the presence of a signal is confirmed by RSSI is indicated as "RSSI present" and the case where it is not confirmed is indicated as "RSSI not present."

[0048] [Table 1]

[0049] As shown in Table 1, in the cases of "RSSI present" and "CAD present", (A) a busy judgment is made due to the presence of both a spread spectrum signal and a signal using a modulation method other than spread spectrum, or (B) a busy judgment is made due to the presence of a relatively strong spread spectrum signal (-80 dBm or higher), so in the case of (A), the transmission of signals using all modulation methods is prohibited, while in the case of (B), the transmission of signals using modulation methods other than spread spectrum is possible. Furthermore, even in the case of (A), transmission is possible if the spread spectrum signal has a different bandwidth and spreading rate from the existing spread spectrum signal.

[0050] If "RSSI present" and "CAD absent", the signal is determined to be busy due to the presence of a signal using a modulation method other than spread spectrum. Since no spread spectrum signal is present, it is possible to transmit a spread spectrum signal.

[0051] In the cases of "RSSI not present" and "CAD present", the busy determination is due to the presence of a spread spectrum signal, and since there are no signals using modulation methods other than spread spectrum, it is possible to transmit signals using modulation methods other than spread spectrum. Furthermore, even if the signal is a spread spectrum signal, it is possible to transmit it as long as the bandwidth and spreading rate are different from those of the existing spread spectrum signal.

[0052] In the case of "No RSSI" and "No CAD", there is no Busy judgment and neither a spread spectrum signal nor a signal with a modulation method other than spread spectrum is present, so signals of all modulation methods can be transmitted.

[0053] (4) It is preferable that the strength of the signal transmitted from the first device or the second device is equal to or lower than the noise floor.

[0054] In this way, the possibility of jamming signals of modulation methods other than the spread spectrum method, such as signals of the FSK method, is extremely low. As a method of making the signal strength below the noise floor, for example, a configuration may be adopted in which the transmission power is controlled to be reduced, or a configuration may be adopted in which the transmitted signal is transmitted with a high spreading rate at which the signal strength is below the noise floor. When the spreading rate of the transmitted signal is increased, the transmission speed is slightly reduced, but the communication sensitivity is improved, and the communication distance is improved. Therefore, in this way, the user can operate the functions of the device by remote control using wireless communication at a longer distance than before. It is preferable to configure the "noise floor" to be -80 dBm.

[0055] (5) The wireless communication between the first device and the second device using the spread spectrum method may be such that signals can be transmitted with the same power at one of the quarter portions of the bandwidth of the channel used from both ends of the bandwidth to the inside of the band, and at the center of the bandwidth.

[0056] In this way, a user can operate the functions of the device by remote control using wireless communication over a longer distance than before. Such a system capable of communication at a high transmission bit rate with high modulation efficiency can be implemented, for example, by the spread spectrum method or the LoRa method. On the other hand, in the FSK method, the transmission power of the signal decreases at the high-frequency and low-frequency ends of the bandwidth, and the signal goes outside the bandwidth, resulting in low modulation efficiency.

[0057] In the wireless communication between the first device and the second device using the spread spectrum method, it is preferable that the signal can be transmitted at the same power near both ends of the bandwidth of the channel to be used, in the vicinity of a quarter of the bandwidth on the inside of the band, and near the center of the bandwidth. More preferable, it is preferable that the signal can be transmitted at the same power near at least one end of the bandwidth of the channel to be used and near the center. Even more preferable, it is preferable that the signal can be transmitted at the same power over the entire bandwidth of the channel to be used.

[0058] In the configuration of (5), it is particularly preferable to configure the power for transmitting signals outside the bandwidth of the channel to be smaller than a specified value. In this way, the amount of signal that goes outside the bandwidth is smaller than the specified value, so that the modulation efficiency is high. When the same communication distance is set in a communication system, the higher the modulation efficiency, the higher the bit rate at which communication can be performed.

[0059] At least one of the first device and the second device is preferably a device whose power consumption does not change even if the transmission bit rate is changed. When the transmission bit rate is increased and the communication time is shortened, the current consumption of the device decreases, and power consumption in the system can be reduced. In particular, it is preferable to use a battery as the power source for the device. In this way, the battery life (hereinafter also referred to as "battery lifespan") can be extended. This allows the user to minimize the hassle of battery replacement, etc.

[0060] At least one of the first device and the second device may be a device whose power consumption increases when the transmission bit rate is increased. In particular, it is preferable to set the transmission bit rate so that the transmission power reduced by shortening the communication time exceeds the increase in power consumption caused by increasing the transmission bit rate. In this way, the overall power consumption can be reduced and the battery life can be extended.

[0061] Also, for example, a first device and a second device capable of wireless communication may be provided, and the wireless communication between the first device and the second device may be configured to use a method that allows transmission of signals at the center of the entire width and at one peripheral end portion with the same power instead of or in addition to the spread spectrum method. In particular, a configuration that allows signals to be transmitted at the same power over the entire bandwidth of the channel used may be used. Also, for example, the wireless communication between the first device and the second device may use an OFDM modulation method instead of or in addition to the spread spectrum method. In particular, Wi-Fi HaLow (IEEE 820.11ah) may be used.

[0062] The wireless communication between the first device and the second device may be configured to use GFSK modulation instead of or in addition to the spread spectrum method. It is preferable to use GFSK modulation at a speed of several hundred bits per second or less. More preferable is Sigfox. However, the best method at present is the spread spectrum method, and the LoRa method (2) is particularly preferable.

[0063] Also, the wireless communication between the first device and the second device may be performed by wireless network communication, but it is preferable to perform it as one-to-one communication between the first device and the second device. For example, the communication chip "SX1272" may be configured to use, for example, 0x12 as the SyncWord value, instead of 0x34 used in LoRaWAN. It is preferable to use a value other than 0x34 or 0x12. In this way, it is possible to reduce the possibility of interference with commercially available devices that perform wireless communication using the Lora method.

[0064] (6) Of the first device and the second device, the one that is portable by the user may preferably include a built-in antenna for use in the wireless communication.

[0065] In this way, users can use devices with simple configurations in which the antenna is not exposed to the outside, particularly portable devices with excellent portability, as portable devices. This is because a wireless system using the spread spectrum method can use an antenna with a lower antenna gain when designed for the same communication distance and the same communication bit rate as a wireless system using the FSK method.

[0066] This effect is particularly noticeable when the wireless system uses the LoRa method as in (2). In addition, while typical spread spectrum wireless systems (WLAN, WCDMA (registered trademark), etc.) pursue interference prevention and high bit rates, the LoRa method can greatly improve sensitivity by consuming a large bandwidth while spreading low bit rate signals over a wide band using spread spectrum. Therefore, by adopting the LoRa communication method, it is possible to further miniaturize the built-in antenna. This makes it possible to provide a system that is not in the way when the user carries the portable device in a pocket, etc., and can be used stress-free.

[0067] In this way, the LoRa wireless system has high communication sensitivity, so a smaller antenna with low gain can be used. Therefore, by adopting the LoRa wireless system, it is possible to use a remote control (portable device) that has a built-in antenna but can achieve the same radio wave range as a remote control using a conventional rod antenna, providing a system with a highly portable remote control (portable device) for users.

[0068] Preferably, the configuration (3) is provided. More preferably, the configuration (3-1) is provided. Even more preferably, the configurations (3) and (3-1) are provided. Most preferably, the configurations (2), (3) and (3-1) are provided. In this way, the advantage of having a built-in antenna is particularly great.

[0069] (7) It is preferable that a user be able to change the magnitude of the transmission power of a signal directly or indirectly.

[0070] In this way, the user can use the system with the optimum transmission power according to the environment in which the user uses the system. For example, when the distance between the first device and the second device is small and the use in an environment with a relatively good communication environment is expected, the transmission power can be minimized by setting the transmission power low within a range where there is no problem in transmitting signals. Of the first device and the second device, the device that transmits the signal may use a battery as a power source. In this way, the user can extend the battery life and reduce the frequency of battery replacement, etc. On the other hand, when the user wants to prioritize the reliability of the signal transmission between the first device and the second device over minimizing the transmission power, the transmission power can be set high in consideration of the expected communication distance, etc. This ensures that the signal is transmitted reliably, and the user can accurately control the device in which the system of the present invention is installed.

[0071] Here, an example of a configuration in which "the user can directly change the magnitude of the transmission power of the signal" is a configuration in which the magnitude of the transmission power of the first device or the second device is set by inputting a power value. By making it possible for "the user to directly change the magnitude of the transmission power" in this way, the user can accurately adjust the transmission power so that it is suitable for his or her own usage conditions.

[0072] An example of a configuration in which the "user can indirectly change the magnitude of the transmission power of the signal" is a configuration in which the magnitude of the transmission power of the first device or the second device is set by a relative numerical value or index associated with a power value. Various indexes associated with the power value can be considered, such as "strong, medium, weak" and indexes according to the operation mode. In particular, a configuration in which a "long-distance communication mode (normal mode)" and a "long-life mode" with a long battery life can be selected, for example. In this way, it is possible to select whether to prioritize battery life or the distance at which the function of the device can be operated by remote control using wireless communication. By making the "user can indirectly change the magnitude of the transmission power" in this way, the user can intuitively or intuitively adjust the output to the magnitude of the transmission power suitable for his or her own usage conditions.

[0073] The configuration in which "the user can directly or indirectly change the magnitude of the signal transmission power" may be any configuration, and may be configured to do so via switches (e.g., dip switches) or control devices provided on the non-portable device of the first device or the second device, such as an engine starter or an in-vehicle device in a car security system, and may particularly be configured to do so on the portable device of the first device or the second device, such as a portable device such as a remote control.

[0074] The transmission power of the signal may be changed based on the operation of an operation unit provided on a remote control or other device. The operation unit may be configured, for example, as a slider, or may be configured as a slider displayed on a display screen provided on the remote control or other device.

[0075] It is preferable that the portable one of the first and second devices is configured to be selectable between the above-mentioned "long-distance communication mode (normal mode)" and "long-life mode." In this way, the user can extend the battery life by selecting the long-life mode in an area where communication is possible in the long-life mode, and when communication in the long-life mode becomes impossible in an area farther away than the area where communication is possible in the long-life mode, the user can switch to the long-distance communication mode to activate the function of the other device by remote control using wireless communication.

[0076] In addition, when the operation mode is set according to the magnitude of the transmission power of the signal, such as the "long distance communication mode (normal mode)" or the "long life mode," each mode may be set in multiple steps or steplessly according to the magnitude of the transmission power. By adopting these methods, the user can easily and accurately adjust the magnitude of the transmission power of the signal.

[0077] (8) It is preferable that a user be able to change the transmission bit rate of a signal directly or indirectly.

[0078] In this way, the user can use the system under optimal conditions for the environment in which the user uses it by adjusting the transmission bit rate. For example, the user can improve the communication sensitivity and ensure a large communication range by setting the transmission bit rate low. On the other hand, the user can minimize the communication time by sacrificing the communication sensitivity and communication distance by setting the transmission bit rate high, and can operate the device's functions by remote control using wireless communication over a long distance with quick communication operations.

[0079] At least one of the first device and the second device is preferably a device whose power consumption does not change even if the transmission bit rate is changed. When the transmission bit rate is increased and the communication time is shortened, the current consumption of the device decreases, so that the power consumption in the system can be reduced, and in particular, the power consumption of the device that transmits the signal can be reduced. In particular, it is preferable to use a battery as the power source for the device. In this way, the user can extend the battery life and minimize the trouble of battery replacement, etc.

[0080] At least one of the first device and the second device may be a device whose power consumption increases when the transmission bit rate is increased. In particular, it is preferable to set the transmission bit rate so that the transmission power reduced by shortening the communication time exceeds the increase in power consumption caused by increasing the transmission bit rate. In this way, the overall power consumption can be reduced and the battery life can be extended.

[0081] Here, an example of a configuration in which "the user can directly change the transmission bit rate of the signal" is a configuration in which the transmission bit rate of the first device or the second device is set by inputting a bit rate value. By making the magnitude of the transmission bit rate directly changeable by the user in this way, the user can precisely adjust the transmission bit rate to suit his or her own usage conditions.

[0082] An example of a configuration in which the "user can indirectly change the transmission bit rate of a signal" is a configuration in which the magnitude of the transmission bit rate of the first device or the second device is set by a relative numerical value or index associated with the transmission bit rate. Various indexes such as "large, medium, small" and indexes according to operation modes can be considered as indexes associated with the transmission bit rate. In particular, for example, it is preferable to be able to select between a "normal mode" and a "speed mode" in which communication operations are quick. In this way, it is possible to select whether to prioritize the distance at which the function of the device can be operated by remote control using wireless communication or to prioritize the speed of communication operations. By making the "user can indirectly change the transmission bit rate of a signal" in this way, the user can intuitively or intuitively adjust the transmission bit rate to a value suitable for his or her own usage conditions.

[0083] The configuration in which "the user can directly or indirectly change the transmission bit rate of the signal" may be any configuration, and may be configured to do so via switches (e.g., dip switches) or control devices provided on the non-portable device of the first device or the second device, such as an engine starter or an in-vehicle device in a car security system, and may particularly be configured to do so on the portable device of the first device or the second device, such as a portable device such as a remote control.

[0084] Preferably, the portable one of the first device and the second device is configured to be selectable between the above-mentioned "normal mode" and "speed mode." In this way, the user can select the speed mode in an area where communication is possible in the speed mode to make communication operation swift, and when communication in the speed mode becomes impossible in an area farther away than the area where communication is possible in the speed mode, the user can switch to the normal mode to operate the function of the other device by remote control using wireless communication.

[0085] The transmission bit rate may be changed by operating an operation unit of, for example, a remote control or other device. The operation unit may be configured, for example, as a slider, or may be configured as a slider displayed on a display screen of the remote control or other device.

[0086] In addition, when the operation mode is set according to the transmission bit rate, such as "normal mode" or "speed mode," each mode may be set in multiple steps or steplessly according to the transmission bit rate. By adopting these methods, the user can easily and accurately adjust the transmission bit rate of the signal.

[0087] (9) In the information regarding the strength of a signal received in the last communication between the first device and the second device, if the strength of the signal is equal to or greater than a predetermined value and the signal is transmitted within a predetermined time from the reception of the signal in the last communication, the transmission power is reduced, and if the strength of the signal is less than the predetermined value or the signal is transmitted after a predetermined time has elapsed from the reception of the signal in the last communication, the transmission power is maintained at least at the transmission power at the time of the last communication.

[0088] In this way, the user can optimize the transmission power consumption while ensuring the transmission and reception of signals in the system. For example, if the signal strength received by the device in the last communication is greater than necessary, the strength of the next signal to be transmitted may be reduced. Here, since at least one of the first and second devices is portable, even if the signal strength received by the device is greater than necessary, the distance between the first and second devices may increase over time due to the user's movement. In this way, when the transmission power in the next communication can be adjusted according to the strength of the signal received by the device in the last communication, for example, a change in the distance between the first and second devices may be assumed using time as an index, and adjustment may be performed based on this assumption. In the configuration of (9), the transmission power is reduced not only when the strength of the signal received in the last communication is equal to or greater than a predetermined value, but also when the next signal is transmitted within a predetermined time from the reception of the signal in the last communication. Furthermore, in the configuration of (9), the transmission power is at least maintained when the signal strength is less than a predetermined value or when the signal is transmitted after a predetermined time has elapsed since the reception of the signal in the last communication. In this way, the user can operate the functions of the device by remote control using wireless communication over a long distance, and the transmission power consumption can be reduced. Also, when using a battery as a power source, the battery life can be extended, so the user does not need to replace the battery frequently.

[0089] Here, the "predetermined time" may be set based on the distance at which communication between the first and second devices is assumed to be established even if the distance between the first and second devices is expanded, and the assumed speed of expansion of the distance between the first and second devices, when the transmission power of the next signal to be transmitted is to be reduced from the transmission power at the time of signal transmission in the last communication, for example. For example, assuming that one of the first and second devices is a portable device such as a remote control and the other is a fixed device that does not move, and assuming that the distance between the first and second devices is expanded as the user moves on foot, the "predetermined time" may be set based on the relationship between the average moving speed of an average adult moving on foot, the distance at which communication between the first and second devices is assumed to be established after the transmission power is reduced, and the communication distance that is likely to be reduced by the reduction of the transmission power. In this way, by using time as an index to estimate changes in the distance between the first device and the second device, setting a "predetermined time" based on this estimated result, and using this predetermined time as one of the standards for reducing transmission power, even when control is performed to suppress transmission power consumption, the user can operate the functions of the device by remote control using wireless communication over long distances without feeling inconvenienced.

[0090] The "predetermined time" for reducing the transmission power may be, for example, between 1 and 2 minutes. This "predetermined time" may be constant or may be changed according to the signal strength.

[0091] Here, for example, it is preferable to configure a system in which the first device is a portable device (e.g., a remote control) and the second device is a fixed device (e.g., an in-vehicle device, a home device, or the like that can obtain an external power source). In this way, in a system in which basic control begins with sending commands from a remote control, it is possible to reduce the transmission power consumption of the fixed device. In this case, for example, if the fixed device is configured to use a battery installed in an automobile as its power source, such as an engine starter or car security, it is possible to minimize the power consumption of this battery.

[0092] Also, it is advisable to configure a system in which the fixed device periodically transmits a link confirmation signal to the remote control. In this way, the radio wave strength of the link confirmation signal can be checked and the transmission power of the remote control's transmission signal can be reduced. If the remote control's transmission power can be reduced and its power consumption can be reduced, the life of the battery built into the remote control (portable device) can be extended, and users will no longer need to frequently replace the battery.

[0093] Also, for example, when the amount of information to be transmitted is large and the information is divided into multiple transmissions, the first transmission may be performed with high transmission power, and the second and subsequent transmissions may be adjusted based on the radio wave intensity of the first transmission. In this way, the transmission power can be optimized. In this case, for example, a battery may be used as the power source. In this way, the battery life can be extended, and the frequency of battery replacement by the user can be minimized.

[0094] Also, for example, in the case of car security, it is preferable to configure the remote control so that when a sensor detects that some kind of trouble has occurred in the car, a signal is sent from the in-vehicle device, which is a fixed device, to the remote control, even if no command is sent from the remote control. In this way, when a user who has learned that the car security is activated performs a process such as disabling the car security by operating the remote control, the transmission power of the remote control's transmission signal can be reduced based on the radio wave strength of the signal previously received from the in-vehicle device, minimizing power consumption in the battery built into the remote control and minimizing the frequency of battery replacement by the user.

[0095] Furthermore, it is preferable to configure the system so that a signal can be sent to the fixed device using a remote control, for example. In this way, the remote control can transmit a setting start command and the transmission power of the signal sent from the remote control can be reduced based on the radio wave strength of the response signal returned from the fixed device, minimizing power consumption of the battery built into the remote control and minimizing the frequency with which the user needs to replace the battery.

[0096] A user carrying a remote control may move after receiving a signal in the last communication in the system. Therefore, if the transmission power of the remote control or the fixed device is reduced after a predetermined time has passed, the distance between the remote control and the fixed device may become too large, causing the radio wave strength to be insufficient, and it may become impossible to operate the function of the device by remote control using wireless communication over a long distance. Therefore, it is preferable to reduce the transmission power within a predetermined time and maintain the transmission power after the predetermined time has passed. In this way, it is possible to operate the function of the device by remote control using wireless communication over a long distance, and to extend the battery life. This makes it possible to minimize the frequency with which the user has to perform troublesome tasks such as battery replacement.

[0097] Moreover, the configuration of "maintaining at least the transmission power" may be a configuration of maintaining the transmission power or a configuration of increasing the transmission power. As in the configuration of (9), when the strength of the signal received in the last communication is less than a predetermined value or when a predetermined time has elapsed since the reception of the signal in the last communication, the transmission power may be maintained at least at the transmission power at the time of the last communication. In this way, it is possible to prevent communication from being unable to be established due to lowering the transmission power, and to ensure the stability of communication. As a result, the user can operate the function of the device by remote control using wireless communication over a long distance without feeling any inconvenience, even when the strength of the signal received in the last communication is weak or a predetermined time has elapsed since the previous communication.

[0098] If the "predetermined time" for reducing the transmission power is changed according to the signal strength, the greater the signal strength, the shorter the predetermined time should be, and the smaller the signal strength, the longer the predetermined time should be. However, if the signal strength is below the predetermined value, the transmission power should at least be maintained.

[0099] In the configuration of (9), for example, if communication is not possible with the transmission power lowered, the transmission power is increased, and if communication is still not possible, the transmission power is increased further. The method of increasing the transmission power when communication is not possible with the transmission power lowered should be a stepwise or continuous increase, and in particular, a direct increase to the maximum. In this way, the user can obtain the advantage of being able to minimize power consumption.

[0100] In the configuration of (9), for example, the transmission power of the remote control and the fixed device may be set to maximum in the normal state and then automatically reduced, or the user may operate the remote control or set a dip switch on the vehicle-mounted device. The transmission power may be displayed on the display screen of the remote control. In this way, the user can check the transmission power from this display. The display screen of the remote control may also be configured to display the strength of the received radio waves. In this way, the user can use the remote control while checking whether communication is possible from the displayed radio wave strength.

[0101] (10) In regard to information regarding the strength of a signal received in the last communication between the first device and the second device, if the strength of the signal is equal to or greater than a predetermined value and the signal is transmitted within a predetermined time from the reception of the signal in the last communication, a transmission bit rate for transmitting the signal is increased, and if the strength of the signal is less than the predetermined value or the signal is transmitted after a predetermined time has elapsed from the reception of the signal in the last communication, the transmission bit rate is maintained at least at the transmission bit rate at the time of the last communication.

[0102] In this way, the user can optimize the transmission bit rate while ensuring the transmission and reception of signals in the system. For example, if the signal strength received by the device in the last communication is greater than necessary, the next signal strength to be transmitted may be reduced. Here, since at least one of the first and second devices is portable, even if the signal strength received by the device is greater than necessary, the distance between the first and second devices may increase over time due to the user's movement, etc. In this way, when the transmission bit rate in the next communication can be adjusted according to the signal strength received by the device in the last communication, for example, a change in the distance between the first and second devices may be assumed using time as an index, and adjustment may be performed based on this assumption. In the configuration of (10), the transmission bit rate is increased not only when the signal strength received in the last communication is equal to or greater than a predetermined value, but also when the next signal is transmitted within a predetermined time from the reception of the signal in the last communication. Furthermore, in the configuration of (10), the transmission bit rate is at least maintained when the signal strength is less than a predetermined value or when the signal is transmitted after a predetermined time has elapsed since the reception of the signal in the last communication. In this way, the user can operate the functions of the device by remote control using wireless communication over a long distance, and the transmission power consumption can be reduced. Also, when using a battery as a power source, the battery life can be extended, so the user does not need to replace the battery frequently.

[0103] Here, the "predetermined time" may be set based on the distance at which communication between the first and second devices is assumed to be established even if the distance between the first and second devices is expanded, and the assumed speed of expansion of the distance between the first and second devices, when the transmission bit rate of the next signal is to be increased from the transmission bit rate at the time of signal transmission in the last communication, for example. For example, assuming that one of the first and second devices is a portable device such as a remote control and the other is a stationary device that does not move, and assuming that the distance between the first and second devices is expanded as the user moves on foot, the "predetermined time" may be set based on the relationship between the average moving speed of an average adult moving on foot, the distance at which communication between the first and second devices is assumed to be established after the increase in the transmission bit rate is reduced, and the communication distance that will be reduced due to the increase in the transmission bit rate. In this way, by using time as an index to estimate changes in the distance between the first device and the second device, setting a "predetermined time" based on this estimated result, and using this predetermined time as one of the standards for increasing the transmission bit rate, even if control is performed to increase the transmission bit rate, the user can operate the functions of the device by remote control using wireless communication over a long distance without feeling inconvenienced.

[0104] The "predetermined time" for increasing the transmission bit rate may be, for example, between 1 and 2 minutes. This "predetermined time" may be constant or may be changed according to the signal strength.

[0105] Moreover, the configuration of "maintaining at least the transmission bit rate" may be a configuration of maintaining the transmission bit rate or a configuration of decreasing the transmission bit rate. As in the configuration of (10), when the strength of the signal received in the last communication is less than a predetermined value or when a predetermined time has elapsed since the reception of the signal in the last communication, the transmission bit rate may be maintained at least at the transmission bit rate at the time of the last communication. In this way, it is possible to prevent communication from being unable to be established due to an increase in the transmission bit rate, and to ensure the stability of communication. As a result, the user can operate the functions of the device by remote control using wireless communication over a long distance without feeling any inconvenience, even when the strength of the signal received in the last communication is weak or a predetermined time has elapsed since the previous communication.

[0106] In a communication system, if the bandwidth is the same, the transmission bit rate, the sensitivity (flying distance), and the transmission power are inversely proportional to each other. That is, in the system of the present invention, if the transmission bit rate is increased, the distance will not fly (the sensitivity will decrease) if the bandwidth and the transmission power are the same, and the distance at which the function of the device can be activated by remote control using wireless communication will become shorter, but the transmission time can be shortened and the communication operation of the system can be made quicker. Here, if the received signal strength is high, communication is possible even with low sensitivity, so communication is possible even if the transmission bit rate is increased. Therefore, in the configuration of (10), it is preferable to increase the transmission bit rate as the received radio wave is stronger. In this way, a user can obtain a system that can quickly activate the function of the other device when a signal to activate the function of the other device is transmitted from either the first device or the second device.

[0107] (11) In the wireless communication using the spread spectrum system, a plurality of spreading factors may be set, and the spreading factor may be changed when a predetermined condition is satisfied.

[0108] In this way, the user can create a wireless system that is extremely difficult to intercept.

[0109] The "change in spreading factor" may be configured to be performed in a predetermined pattern. The "predetermined pattern" of the "change in spreading factor" may be configured to be random or in a predetermined order. Here, in the system of the present invention, the higher the spreading factor, the longer the distance the device's functions can be operated by remote control using wireless communication. Therefore, in particular, the spreading factor may be configured to adopt the maximum spreading factor and the spreading factor one step lower. In such a configuration, the pattern of the change in spreading factor may be configured to alternate between the maximum spreading factor and the spreading factor one step lower in a predetermined pattern. In this way, it is possible to operate the device's functions by remote control using wireless communication over a long distance with low eavesdropping.

[0110] "When a specified condition is satisfied" may be configured to occur every time one packet is transmitted, every time a packet of a specified amount of data is transmitted, or every time a specified time period has elapsed.

[0111] The "spreading factor" may be, for example, the ratio (C / B) of the spreading code speed (also called the "chip rate"; C) to the transmission bit rate (B).

[0112] (12) It is advisable to enable communication by switching the channel used for communication.

[0113] In this way, the frequency band allocated for communication is switched while communication is performed, so that the user can obtain a system in which interference is unlikely to occur between spread spectrum communication systems. In this case, the receiver and the transmitter switch channels in sync with each other. For example, when the band used for wireless communication is 920 MHz, it is preferable to use six channels with center frequencies of 922.4 MHz, 922.6 MHz, 922.8 MHz, 923.0 MHz, 923.2 MHz, and 923.4 MHz by switching between them. Note that channels other than these channels may also be used.

[0114] The spread spectrum method, especially the LoRa method, allows communication over a much longer distance than the FSK method. Therefore, when a communication method with a long communication distance such as the LoRa method is adopted, there is a high possibility that interference will occur due to communication by other users interrupting the communication range. Therefore, when the spread spectrum method, especially the LoRa method, is adopted, it is preferable to suppress interference by appropriately switching the channel used for communication. This allows users to communicate stably without being affected even if other users nearby are using devices that communicate using the spread spectrum method.

[0115] (13) A system according to any one of (1) to (12), comprising a vehicle control device that starts a drive device of a vehicle based on a predetermined vehicle start signal, and a start permission device capable of transmitting a start permission signal to the vehicle control device to permit starting of the drive device, the system being used to receive a pin code transmitted from a pin code transmitter that is portable by a user and capable of transmitting a predetermined pin code, and to indirectly transmit the pin code to a vehicle to which the start permission signal is transmitted by the start permission device based on the received pin code and a reference code provided in the start permission device, the system being used to indirectly transmit the pin code to a vehicle to which the start permission signal is transmitted by the start permission device, the system being used to indirectly transmit the pin code to a vehicle to which the start permission signal is transmitted by the start permission device, the system being used to indirectly transmit the pin code to a vehicle to which the start permission signal is transmitted based on the received pin code and a reference code provided in ... The wireless communication with the first device can be selected between a spread spectrum method and a communication method other than the spread spectrum method, the first device can be carried by a user and can receive the PIN code from the PIN code transmitter, and can transmit to the second device a signal including a conversion code obtained by converting the received PIN code in a predetermined manner and a start instruction signal, and the second device can be mounted on the vehicle, can convert the received conversion code into the PIN code and transmit the converted PIN code to the start permission device, and can transmit the vehicle start signal to the vehicle control device upon receiving the start instruction signal.

[0116] In this way, in an automobile equipped with a start permission device (so-called immobilizer) using a personal identification code, for example, the user can start a drive device such as an engine or a motor using a remote control (a first device that can be carried by the user) without leaving a personal identification code transmitter inside the vehicle, but while carrying it with him / her. Generally, the personal identification code transmitter and the start permission device cannot transmit and receive a personal identification code unless they are in close proximity, for example, due to security concerns, and the start of the drive device cannot be permitted. However, in this way, even if the personal identification code transmitter and the start permission device are far apart, the personal identification code transmitted from the personal identification code transmitter is relayed by the remote control (a first device that can be carried by the user) and the in-vehicle device (a second device mounted on the vehicle) and can be received by the start permission device, allowing the start of the drive device to be permitted.

[0117] An "indirect transmission" configuration for a PIN code may be, for example, a configuration in which a first device receives a PIN code from a PIN code transmitter, converts the PIN code into a different conversion code and transmits it to a second device, and the second device converts the received conversion code back into the original PIN code before transmitting it to the start permission device.

[0118] Regarding the second device, the configuration of "mounting it on a vehicle" preferably means a configuration in which the device is originally attached to the vehicle when the vehicle is manufactured by the automobile manufacturer, and in particular, preferably a configuration in which the device is retrofitted to a sold vehicle.

[0119] The start instruction signal transmitted by the first device may be generated in response to an instruction from a user.

[0120] The wireless communication between the first device and the second device may be configured to select between a spread spectrum method and a communication method other than the spread spectrum method. In this way, even if it is difficult to permit the start of the drive device using one of the methods, the possibility of permitting the start of the drive device can be increased. The "selection of the communication method" may be configured in any way, for example, via switches (e.g., dip switches) or a control device provided on an in-vehicle device (second device mounted on a vehicle), and in particular, on the side of a remote control (portable first device). In addition, the selection of the communication method may be configured to be performed based on the operation of an operation unit provided on the remote control or another device. The operation unit may be configured, for example, as a slider, or may be configured as a slider displayed on a display screen provided on the remote control or another device.

[0121] It is preferable to configure the system so that a mode in which the PIN code transmitted from the PIN code transmitter is relayed by a first communication device carried by the user and a second communication device mounted on the vehicle (hereinafter referred to as a "relay mode"), and a mode in which the PIN code is not relayed (hereinafter referred to as a "non-relay mode") can be selected. In this way, users and retailers can handle both vehicle models with immobilizers and vehicle models without immobilizers by simply preparing one type of system equipped with a remote control and an on-board device, and can also accommodate users of vehicle models equipped with immobilizers who do not mind placing a PIN code transmitter in their vehicles. The configuration for selecting between the "relay mode" and the "non-relay mode" can be configured so that a selection means such as a switch is provided on the on-board device, for example, and the selection is made by using this selection means such as a switch.

[0122] When "relay mode" is selected, wireless communication should be configured as continuous mode using a communication method other than spread spectrum. In this case, the "communication method other than spread spectrum" should be FSK or similar. "Continuous mode" is a mode in which the level of the DIO2 / DATA pin is sent as is (without going through FIFO).

[0123] When the "non-relay mode" is selected, the "long distance mode" and the "short distance mode" can be selected. The "long distance mode" can be configured to select the packet mode of the spread spectrum method for wireless communication, and in particular, the packet mode of the LoRa method. The "packet mode" is a mode that uses SPI (Serial Peripheral It is preferable that the data provided via the FIFO be transmitted in packets.

[0124] The "short distance mode" may be configured such that wireless communication is in a packet mode of a communication method other than the spread spectrum method, and preferably the wireless communication is in a packet mode of the spread spectrum method with a higher transmission bit rate than the long distance communication mode, and more preferably the wireless communication is in the LoRa method with a higher transmission bit rate than the long distance communication mode. A communication device that can select between the LoRa method and the FSK method and can also select between the continuous mode and the packet mode may be, for example, the above-mentioned communication chip "SX1272".

[0125] Any of the configurations (1) to (13) may be arbitrarily combined to form a configuration. Also, any of the components described in the configurations (1) to (13) may be arbitrarily combined to form a configuration.

[0126] (14) For example, it may be configured as a first device in the system described in any one of (1) to (13) above.

[0127] (15) For example, it may be configured as a second device in any of the systems described in (1) to (13) above.

[0128] Such devices may be, for example, devices for systems used in the above-mentioned consumer devices and various industrial devices, devices for wireless communication systems that collect meter reading data, and in particular devices for systems used in automobile-related devices. Devices for systems used in automobile-related devices may be configured as remote controls or in-vehicle devices, for example, devices for systems used in engine starters.

[0129] (16) For example, the functions described in any one of (1) to (13) above may be configured as a program for causing a computer to realize the functions. Effect of the Invention

[0130] According to the present invention, for example, it is possible to provide a system or the like that can perform remote control more reliably and is easier to use than the conventional system. [Brief description of the drawings]

[0131] [Figure 1] FIG. 1 is a block diagram showing an outline of an example of the configuration of an engine starter using a system according to the present invention. [Diagram 2] FIG. 2 is an external view of an engine starter using the system according to the present invention, where (a) is a front view of the remote control, and (b) is a perspective view of the junction unit. [Diagram 3] FIG. 3 is a diagram showing a display on a display unit of the remote control and a sound emitted from the remote control when the engine is started using the remote control. [Figure 4] FIG. 4 is a diagram showing a display on a display unit of the remote control and a sound emitted from the remote control when the engine state is confirmed using the remote control. [Diagram 5] FIG. 5 is a diagram showing a display unit of the remote control and a sound emitted from the remote control when idling extension is performed using the remote control. [Figure 6] FIG. 6 is a diagram showing a display on a display unit of the remote control and a sound emitted from the remote control when the engine is stopped using the remote control. [Figure 7] FIG. 7 shows what is displayed on the display unit of the remote control and the sound emitted from the remote control when the door is locked or unlocked using the remote control. [Figure 8] FIG. 8 is an explanatory diagram of the first remote control registration method. [Figure 9] FIG. 9 is an explanatory diagram of the second remote control registration method. [Figure 10] FIG. 10 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention, and shows the case where a user carries and uses a genuine key in an automobile equipped with an immobilizer. [Figure 11]FIG. 11 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention, and shows the case where the original key is placed inside an automobile equipped with an immobilizer. [Figure 12] FIG. 12 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention, showing the case where the engine starter is used in an automobile not equipped with an immobilizer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0132] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. The system of this embodiment is a system used in an engine starter that starts an automobile engine (drive device) by remote control using a remote controller (hereinafter referred to as "remote control"). Note that the present invention is not limited to the examples in the embodiments described below, and it will be easily understood by those skilled in the art that other embodiments are possible within the scope of the claims within the teachings and spirit of the present invention.

[0133] 1. Engine starter configuration Fig. 1 is a block diagram showing an outline of an example of the configuration of an engine starter using the system according to the present invention. Fig. 2 is an external view of the engine starter using the system according to the present invention, in which Fig. 2(a) is a front view of the remote control, and Fig. 2(b) is a perspective view of the junction unit.

[0134] As shown in FIG. 1, the engine starter 10 includes a remote control 20 (first device) and a junction unit 40 (second device) mounted on an automobile. The remote control 20 can be held by the user for operation, movement, etc. As shown in FIG. 2(a), the remote control 20 includes a display unit 24 on the front of a flat, generally rectangular case 22 with rounded top and bottom, from the center to the top in the vertical direction. The display unit 24 is a monochrome two-tone segment type liquid crystal screen. The display unit 24 has a built-in seven-color backlight, and the backlight is turned on when an operation of the operation button 26 is detected, thereby improving visibility. However, since the battery will be consumed quickly if the backlight is turned on all the time, the backlight is turned off after being turned on for a set time. This time can be changed by the user (for example, select from 5 seconds / 10 seconds / 20 seconds (initial value is 5 seconds)). It is also possible to adopt a mode in which the backlight is not turned on at all. The color of the backlight can also be changed by the user (for example, white / yellow / purple / blue / orange / green / indigo). The display unit 24 displays the items and contents to be set during setting, and can display the operating status of the system and engine during use. Examples of various displays on the display unit 24 are shown in Figs. 3 to 8, which will be described later.

[0135] The case 22 has operation buttons 26 below the display unit 24 on the front side. The operation buttons 26 are used for operation and include a start button 26a, an engine button 26b, and a stop button 26c. The start button 26a also serves as a lock button, and the stop button 26c also serves as an unlock button. As shown in FIG. 2(a), the start button 26a on the left side and the stop button 26c on the right side are in contact with each other, and the engine button 26b is provided so as to be in contact with the lower parts of the start button 26a and the stop button 26c. A rod-type antenna 28 is provided on the upper left side of the case 22. The antenna 28 is pulled out far when the remote control 20 is in use, and is pushed in far when not in use. A battery cover (not shown) is provided on the back side of the case 22.

[0136] The remote control 20 includes, inside the case 22, a wireless communication circuit 30, a control unit 32, and a battery 34, all of which are shown in FIG.

[0137] The junction unit 40 is attached to the vehicle after the purchase of the vehicle. As shown in Fig. 2(b), the junction unit 40 includes a first connector 42 connected to the vehicle's key cylinder connector and vehicle connector via cables, a second connector 44 connected to a brake detection line, a door lock line, a door unlock line, etc. via cables, a third connector 46 connected to a temperature sensor 54, and a fourth connector 48 connected to an antenna unit 56.

[0138] The first connector 42, the key cylinder side connector, and the vehicle side connector are connected so that when the remote control 20 is operated, the same signal as that sent from the key cylinder to the vehicle side via the cable when the key cylinder is operated with a key is sent from the junction unit 40 to the vehicle side via the first connector 42 and the cable. Therefore, for example, when an operation to start the engine is performed using the remote control 20, the same vehicle start signal as that when an operation to start the engine of the automobile is performed using the key is sent to the vehicle control device on the vehicle side, and the engine starts.

[0139] The door lock line and door unlock line connected to the second connector 44 are connected to a door control device on the vehicle side. When the door is locked or unlocked using the remote control 20, the same door lock signal or door unlock signal that is sent to the door control device when the door is locked or unlocked using a key or a remote control originally provided on the key (a remote control different from the remote control 20) is sent from the junction unit 40 to the door control device, and the door is locked or unlocked.

[0140] Note that a unique ID is set to the remote control 20, and the junction unit 40 operates based on a signal when it receives the signal from a remote control 20 whose ID is paired with the junction unit 40. Therefore, for example, even if an operation to start the engine is performed using an unpaired remote control 20, the junction unit 40 does not respond to the vehicle start signal transmitted from the remote control 20, and therefore the engine cannot be started.

[0141] The junction unit 40 includes therein the wireless communication circuit 50 and the control unit 52 shown in Fig. 1. The junction unit 40 uses a battery provided in the automobile as its power source.

[0142] Both the remote control 20 and the junction unit 40 are equipped with a communication chip "SX1272" manufactured by SEMTECH, and both the wireless communication circuit 30 of the remote control 20 and the wireless communication circuit 50 of the junction unit 40 are configured around this communication chip. The wireless communication circuit 30 of the remote control 20 is connected to an antenna 28, and the wireless communication circuit 50 of the junction unit 40 is connected to an antenna unit 56.

[0143] Both the wireless communication circuit 30 and the wireless communication circuit 50 can switch between six channels from CH33 to CH38 in the 920 MHz band, which is a sub-gigahertz band. The center frequencies of the respective channels are 922.4 MHz for CH33, 922.6 MHz for CH34, 922.8 MHz for CH35, 923.0 MHz for CH36, 923.2 MHz for CH37, and 923.4 MHz for CH38. The bandwidth of each channel is 200 kHz, and the transmittable power is 20 mW. The wireless communication between the remote control 20 and the junction unit 40 is a specified low-power radio.

[0144] The 200 kHz bandwidth of these channels is 16 times the 12.5 kHz bandwidth of the channels in the 426.0250 to 426.1375 MHz, 429.1750 to 429.2375 MHz, 429.2500 to 429.7375 MHz or 429.8125 to 429.9250 MHz bands used in conventional engine starters. In addition, the transmittable power of 20 mW for these channels is 20 times the transmittable power of 1 mW for 426.0250 to 426.1375 MHz or 426.0375 to 426.1125 MHz used in conventional engine starters, and twice the transmittable power of 10 mW for 429.1750 to 429.2375 MHz, 429.2500 to 429.7375 MHz, or 429.8125 to 429.9250 MHz.

[0145] Wireless communication between the remote control 20 and the junction unit 40 is performed by the wireless communication circuit 30 and the wireless communication circuit 50. Radio waves used for wireless communication between the remote control 20 and the junction unit 40 are transmitted and received via the antenna 28 of the remote control 20 and the antenna unit 56 of the junction unit 40. Wireless communication between the remote control 20 and the junction unit 40 is performed by the LoRa method, which is one of the spread spectrum methods. In addition, wireless communication between the remote control 20 and the junction unit 40 transmits signals at the same power in one of the quarter portions of the bandwidth from both ends of the bandwidth of the channel used to the inside of the band, and at the center of the bandwidth.

[0146] The control unit 32 of the remote control 20 and the control unit 52 of the junction unit 40 each include a microcomputer equipped with a CPU, ROM, RAM, flash memory, various peripheral circuits, interfaces, etc. The control units 32 and 52 deploy the OS and application programs recorded in the flash memory onto the RAM by a boot loader recorded in the ROM, and execute the OS and application programs on the RAM to perform various processes and realize various functions. Unless otherwise specified, all functions are realized by the processing of the control units 32 and 52. The frequency or channel of an oscillator for wireless communication provided in the wireless communication circuit 30 of the remote control 20 and the wireless communication circuit 50 of the junction unit 40 is written into a register of the microcomputer provided in the control units 32 and 52.

[0147] 2. How to use and operate the engine starter Next, the use and operation of the engine starter 10 will be described.

[0148] 2-1.Starting the engine 3 is a diagram showing the display on the display unit of the remote control and the sound emitted from the remote control when starting the engine using the remote control. (a) to (i) in the following description correspond to (a) to (i) in the figure, respectively.

[0149] (a) When starting the engine of the vehicle, the engine button 26b is pressed until an operation confirmation sound "beep" is emitted from the remote control 20. The display unit 24 shows "E" in a flashing state.

[0150] (b) Next, while "E" is flashing (for about 3 seconds), press the start button 26a until the remote control 20 emits the sounds "Do Re Mi Fa So." The display unit 24 displays "START" along with a transmission animation, and a start instruction signal is sent from the remote control 20. When the junction unit 40 recognizes the start instruction signal, it sends a response signal back to the remote control 20. As shown in (b1), the transmission animation shows three horizontal bars lined up one above the other moving from right to left in order from the top, and then two vertical bars moving from right to left, repeating this action.

[0151] (c) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly blinks and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right.

[0152] (d) When the remote control 20 receives a response signal from the junction unit 40, the remote control 20 emits a receiving sound "Sofa-mi-re-do." Here, if the vehicle interior temperature display setting is ON, the current vehicle interior temperature is displayed on the display unit 24 for a certain period of time based on the temperature information included in the response signal, and then the temperature display disappears and the system waits for the reception of an engine start confirmation signal. The temperature information is the vehicle interior temperature detected by the temperature sensor 54.

[0153] (e) On the other hand, when the cabin temperature display setting is OFF, when the receiving sound "Sofa Mi Re Do" is emitted from the remote control 20, "oK" is displayed on the display unit 24 for a certain period of time, after which the oK display disappears and the reception of the engine start confirmation signal is awaited.

[0154] The junction unit 40 transmits a vehicle start signal to the vehicle control device to start the engine. When the engine starts, the junction unit 40 detects the engine start and transmits an engine start confirmation signal to the remote control 20. The vehicle start signal transmitted by the junction unit 40 is the same as the vehicle start signal transmitted from the key cylinder when an operation to start the engine is performed using a key.

[0155] (f) When the remote control 20 receives an engine start confirmation signal transmitted from the junction unit 40, the receiving sound "Do Re Mi Fa So Fa Mi Re Do" is emitted from the remote control 20. Here, when the auto-stop is disabled, the display unit 24 displays the engine start animation 24b and the idling setting time.

[0156] (g) On the other hand, when auto-stop is enabled, when the remote control 20 emits the received sound "Do-Re-Mi-Fa-So-Mi-Re-Do," the display unit 24 displays the engine start animation 24b and "AUTo." Auto-stop is a function that automatically stops idling if the temperature inside the vehicle reaches a preset temperature while idling in order to prevent unnecessary idling of the vehicle. If the temperature inside the vehicle when the engine is started is within ±2°C of the set temperature, the idling time is fixed to 5 minutes.

[0157] During idling, a series of "beep beep beep" sounds are emitted from the junction unit 40 to notify the user that the vehicle is idling.

[0158] When the junction unit 40 is unable to detect the engine start, it performs a restart (retry) twice.

[0159] (h) When a retry operation is performed, "RT" flashes on the display unit 24 to notify the user of the retry operation.

[0160] (i) If the engine does not start even after the second retry operation, a retry failure signal is sent from the junction unit 40, and the remote control 20 that receives the retry failure signal emits a "beep beep beep" sound, and "ER" flashes on the display 24, and the retry operation is stopped. Even if the retry setting is turned off, the display 24 will show the same as (i).

[0161] 2-2.Checking the engine condition 4 is a diagram showing the display on the display unit of the remote control and the sound emitted from the remote control when checking the engine status using the remote control. (a) to (i) in the following description correspond to (a) to (i) in the figure, respectively.

[0162] (a) To check the engine status, press the engine button 26b until a confirmation beep is heard from the remote control 20. The display unit 24 will show "E" in a flashing state.

[0163] (b) Next, while "E" is flashing (for about 3 seconds), the engine button 26b is pressed again until the "Do-Re-Mi-Fa-So" sounds are emitted from the remote control 20. The display unit 24 displays "chK."

[0164] (c) On the display unit 24, a transmission animation is displayed following "chK", and an engine state confirmation signal is transmitted from the remote control 20. When the junction unit 40 recognizes the engine state confirmation signal, it transmits a response signal back to the remote control 20.

[0165] (d) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly flashes and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right. If the engine fails to start, a start error sound can be heard by pressing the engine button 26b twice.

[0166] (e) When the vehicle interior temperature display setting is ON, the remote control 20 emits the receiving sound "Sofa Mi Re Do," and the temperature inside the vehicle interior is displayed on the display unit 24 based on the temperature information included in the response signal. The temperature information is the vehicle interior temperature detected by the temperature sensor 54. When the vehicle interior temperature display setting is OFF, this display is not performed.

[0167] (f, g) After displaying the vehicle interior temperature, the idling time is displayed on the display unit 24. Here, (f) if the auto-stop is disabled, in the "idling state", the remaining idling time is displayed on the display unit 24. (g) In the "engine stopped state", the set idling time is displayed on the display unit 24.

[0168] (h, i) On the other hand, when the auto-stop is enabled, (h) in the "idling state", the idling elapsed time is displayed on the display unit 24. (i) in the "engine stopped state", "AUTO" is displayed on the display unit 24.

[0169] 2-3.Extending idling time During idling using the engine starter according to this embodiment, the idling can be extended by 10 minutes once for the set idling time.

[0170] 5 is a diagram showing the display unit of the remote control and the sound emitted from the remote control when idling extension is performed using the remote control. (a) to (h) in the following description correspond to (a) to (h) in the figure, respectively.

[0171] (a) When extending the idling time, the engine button 26b is pressed until a confirmation beep is heard from the remote control 20. The display unit 24 shows "E" in a flashing state.

[0172] (b) Next, while "E" is flashing (for about 3 seconds), press the start button 26a until the remote control 20 emits the "Do-Re-Mi-Fa-So" sound. The display unit 24 displays "START" along with a transmission animation, and an idling time extension signal is transmitted from the remote control 20. When the junction unit 40 recognizes the idling time extension signal, it transmits a response signal back to the remote control 20.

[0173] (c) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly blinks and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right.

[0174] (d) When the remote control 20 receives a response signal from the junction unit 40, the remote control 20 emits the receiving sound "Do Re Mi Fa So Fa Mi Re Do," and (e, f) the display unit 24 alternates between showing "Ido" and "+10," notifying the user that the idling time has been extended.

[0175] (g, h) Here, when the auto-stop is valid, the idling extension is invalid, the receiving sound "Do Re Mi Fa So Fa Mi Re Do" is emitted from the remote control 20, and the elapsed time and "Ido" are alternately displayed on the display.

[0176] 2-4. Stopping the engine When the engine is started by the engine starter according to this embodiment, the engine can be stopped by the remote control 20.

[0177] 6 is a diagram showing the display on the display unit of the remote control and the sound emitted from the remote control when the engine is stopped using the remote control. (a) to (d) in the following description correspond to (a) to (d) in the figure, respectively.

[0178] (a) When stopping the engine of the vehicle, the engine button 26b is pressed until a confirmation beep is heard from the remote control 20. The display unit 24 shows "E" in a flashing state.

[0179] (b) Next, while "E" is flashing (for about 3 seconds), press the stop button 26c until the remote control 20 emits the "Do Re Mi Fa So" sound. The display unit 24 displays "STOP" along with a transmission animation, and a stop instruction signal is sent from the remote control 20. When the junction unit 40 recognizes the stop instruction signal, it sends an engine stop signal to the vehicle control device to stop the engine, and sends a response signal back to the remote control 20. The engine stop signal sent by the junction unit 40 is the same signal as the engine stop signal sent from the key cylinder when an operation to stop the engine is performed using a key.

[0180] (c) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly blinks and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right.

[0181] (d) When the remote control 20 receives a response signal from the junction unit 40, the remote control 20 emits the receiving sound "SoMiReDoRe," "oK" is displayed on the display 24, an engine stop animation is displayed, and the user is notified that the engine has stopped.

[0182] 2-5. Door lock / unlock operation The engine starter remote control 20 according to this embodiment can be used to lock and unlock the doors of a vehicle.

[0183] 7 is a diagram showing the display on the display unit of the remote control and the sound emitted from the remote control when the door is locked or unlocked using the remote control. (a) to (h) in the following description correspond to (a) to (h) in the figure, respectively.

[0184] (a) When locking the door, the start button 26a, which also serves as the lock button, is pressed until a confirmation beep is heard from the remote control 20. The display unit 24 shows "locked padlock" in a flashing state.

[0185] (b) Next, while "LOCKED PADLOCK" is flashing (for about 3 seconds), press the start button 26a again until the remote control 20 emits the "Do-Re-Mi-Fa-So" sound. "LOCKED PADLOCK" is momentarily displayed on the display unit 24, and a lock instruction signal is sent from the remote control 20. When the junction unit 40 recognizes the lock instruction signal, it sends a door lock signal to the door control device via the second connector 44 and the door lock line, and after the door is locked by the door control device, it sends a response signal back to the remote control 20.

[0186] (c) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly blinks and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right.

[0187] (d) When the remote control 20 receives a response signal from the junction unit 40, the remote control 20 emits a receiving sound “SofaMiReDo” and the display unit 24 shows “Locked padlock” and “oK”, notifying that the door is locked.

[0188] (e) To unlock the door, press the stop button 26c, which also serves as the unlock button, until a confirmation beep is heard from the remote control 20. The display unit 24 will show "unlocked padlock" in a flashing state.

[0189] (f) Next, while "UNLOCKED PADLOCK" is flashing (for about 3 seconds), press the stop button 26c again until the remote control 20 emits the "Do-Re-Mi-Fa-So" sound. "UNLOCKED PADLOCK" is displayed for a moment on the display unit 24, and an unlock instruction signal is sent from the remote control 20. When the junction unit 40 recognizes the unlock instruction signal, it sends a door unlock signal to the door control device via the second connector 44 and the door unlock line, and after the door control device unlocks the door, it sends a response signal back to the remote control 20.

[0190] (g) While waiting for a response signal from the junction unit 40, the backlight of the display unit 24 slowly blinks and a reception waiting animation is displayed in which the horizontal bars 24a light up in sequence from left to right.

[0191] (h) When the remote control 20 receives a response signal from the junction unit 40, the remote control 20 emits a receiving sound “SofaMiReDo” and the display unit 24 shows “Unlocked padlock” and “oK,” notifying that the door is unlocked.

[0192] 2-6. How to register the remote control The engine starter of this embodiment uses six channels: CH33 (922.4MHz), CH34 (922.6MHz), CH35 (922.8MHz), CH36 (923.0MHz), CH37 (923.2MHz), and CH38 (923.4MHz). When the product is shipped, the radio frequency is set to CH38. If the user uses the same remote control 20 to register the remote control again to the same junction unit 40, the wireless communication channel is changed to the next channel (or the next channel if there is a carrier sense error). The channel is changed in the following order: CH38 → CH33 → CH34 → ... → CH38 → CH33. Even if the signal of the remote control 20 cannot be received on CH38 and it is necessary to change the channel (even if it is being interfered with), this remote control registration work is performed at a position close to the junction unit 40, so there is no problem. Two types of remote control registration methods are described below. Since the remote control registration is completed when the product is shipped, the remote control registration is performed in order to register the ID of a new remote control in the junction unit and make the new remote control usable if the remote control currently in use is lost or broken.

[0193] (1) The first remote control registration method Fig. 8 is an explanatory diagram of the first remote control registration method. The first remote control registration method will be described below with reference to the same figure. <Step 1> to <Step 8> described in the following description correspond to <Step 1> to <Step 8> in the same figure, respectively. <Step 1> Press and hold both the start button 26a and the stop button 26c on the remote control 20 simultaneously for about 5 seconds. <Step 2> Press the stop button 26c until "Rmd" appears on the display 24 of the remote control 20. If no button is pressed for 20 seconds or more, the remote control 20 will emit a buzzer sound "beep beep beep" and the registration will be canceled. <Step 3> Press the engine button 26b on the remote control 20. "REC" appears on the display 24, and the remote control 20 emits a series of confirmation beeps. If no button is pressed for 20 seconds or more, the remote control 20 emits a buzzer beep and the registration is canceled.

[0194] Steps 4 to 7 below are to be performed while the confirmation beep "beep beep" is being emitted from the remote control 20 (for about 40 seconds). If 40 seconds pass before steps 4 to 7 are completed, the confirmation beep "beep beep" will disappear and the registration will be canceled. <Step 4> Insert the key 62 into the keyhole 64 provided on the vehicle body, and operate the key 62 to switch between ACC→ON→ACC→OFF three times within 7.5 seconds. <Step 5> With the key 62 in the OFF position, the junction unit 40 emits a beeping sound for 10 seconds, and then a beep. If the key 62 is operated while the beeping sound is being emitted, the registration is cancelled. <Step 6> Operate the key 62 to switch OFF → ACC → ON → ACC → OFF three times within 7.5 seconds after the junction unit 40 emits a beep. The junction unit 40 will emit a beep. If 7.5 seconds pass before the three switches are completed, the registration will be canceled. <Step 7> Press the engine button 26b until the remote control 20 emits the sounds "Do Re Mi." "REC" displayed on the display 24 flashes once, and a signal including the ID is sent from the remote control 20. When the junction unit 40 receives the signal including the ID and registers the ID, the junction unit 40 emits beeps, beeps, and beeps and sends a response signal to the remote control 20. When the remote control 20 receives the response signal sent from the junction unit 40, it emits the receiving sound "Mi Re Do," the display 24 displays "ok," and notifies you that remote control registration is complete. Step 8: Remove the key 62 from the keyhole 64.

[0195] (2) How to register a second remote control 9 is an explanatory diagram of the second remote control registration method. The second remote control registration method will be described below with reference to the diagram. <Step 1> to <Step 8> described in the following description correspond to <Step 1> to <Step 8> in the diagram, respectively. <Step 1> Disconnect and reconnect the connector 42a from the first connector 42 of the junction unit 40. The junction unit 40 will emit a series of confirmation beeps: "beep beep beep beep." <Step 2> Press and hold both the start button 26a and the stop button 26c on the remote control 20 simultaneously for about 5 seconds. <Step 3> Press the stop button 26c until "Rmd" appears on the display 24 of the remote control 20. If no button is pressed for 20 seconds or more, the remote control 20 will emit a buzzer sound "beep beep beep" and the registration will be canceled. <Step 4> Press the engine button 26b on the remote control 20. "REC" appears on the display 24, and the remote control 20 emits a series of confirmation beeps. If no button is pressed for 20 seconds or more, the remote control 20 emits a beep beep beep and the registration is canceled.

[0196] Steps 5 and 6 below are to be performed while the confirmation beep "beep beep" is being emitted from the remote control 20 (for about 40 seconds). If 40 seconds pass before steps 5 and 6 are completed, the confirmation beep "beep beep" will disappear and the registration will be canceled. Step 5: Insert the key 62 into the keyhole 64 provided on the vehicle body, and operate the key 62 to switch from OFF to ACC to ON. After about three seconds, the junction unit 40 will emit a beep. <Step 6> Press the engine button 26b until the remote control 20 emits the sounds "Do Re Mi." "REC" displayed on the display 24 flashes once, and a signal including the ID is sent from the remote control 20. When the junction unit 40 receives the signal including the ID and registers the ID, the junction unit 40 emits beeps, beeps, and beeps and sends a response signal to the remote control 20. When the remote control 20 receives the response signal sent from the junction unit 40, it emits the receiving sound "Mi Re Do," the display 24 displays "ok," and notifies you that remote control registration is complete. <Step 8> Operate key 62 to switch between ON → ACC → OFF, and remove key 62 from keyhole 64.

[0197] 3. Another embodiment of the engine starter 10 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention. The figure shows a state in which the engine starter 10 is used in an automobile 60 equipped with an immobilizer 66 (start permission device). In the figure, parts having substantially the same configuration as those of the engine starter shown in FIG. 1 are given the same reference numerals. The engine starter 10 of this embodiment can be used in an automobile 60 equipped with an immobilizer 66.

[0198] 3-1. Overall composition The automobile 60 is provided with an engine 70 (drive device), a vehicle control device 68, an immobilizer 66, and a junction unit 40, and the vehicle control device 68, the immobilizer 66, and the junction unit 40 are connected to each other by a cable 36. The remote control 20 and the original key 62a (password code transmitter) are carried by the user. In Fig. 10, the dashed lines indicate connections by wireless communication (the same applies to Figs. 11 and 12 described below).

[0199] The vehicle control device 68 starts the engine 70 based on the vehicle start signal. The vehicle start signal is transmitted from the remote control 20 when the user operates the remote control 20 to start the engine, and is then transmitted from the junction unit 40, which receives the vehicle start signal, to the vehicle control device 68. The vehicle start signal is also transmitted to the vehicle control device 68 by pressing a start button (not shown) provided on the automobile 60, or by inserting the genuine key 62a into a keyhole and turning it. The genuine key 62a is provided with the automobile at the time of sale, and transmits a pin code.

[0200] When the immobilizer 66 receives the pin code transmitted from the genuine key 62a, it compares this pin code with a reference code stored in a memory device provided in the immobilizer 66, and if they match, it transmits a start permission signal to the vehicle control device 68 to permit starting of the engine 70. When the vehicle control device 68 receives the vehicle start signal, it checks for the presence of the start permission signal for 20 ms, and if it confirms that the start permission signal is present during that time, it is able to start the engine 70.

[0201] In the engine starter 10 of this embodiment, the remote control 20 and the junction unit 40 are both equipped with the communication chip "SX1272", so that the LoRa method, which is one of the spread spectrum methods, and the FSK method, which is a communication method other than the spread spectrum method, can be selected for wireless communication between the remote control 20 and the junction unit 40. When used in an automobile 60 equipped with an immobilizer 66 and when the user carries the original key 62a, the wireless communication is the FSK method.

[0202] The remote control 20 can receive a personal identification code from the genuine key 62a, converts the received personal identification code into another code (hereinafter referred to as a "conversion code"), and transmits this conversion code to the junction unit 40. In the following, "converting the personal identification code transmitted from the genuine key 62a into a conversion code by the remote control 20 and transmitting it to the junction unit 40, and then converting the conversion code into the original personal identification code by the junction unit 40 and transmitting it to the immobilizer 66" is referred to as "relaying a personal identification code." In addition, the remote control 20 transmits a start instruction signal to the junction unit 40 in response to the user's engine start operation.

[0203] When the junction unit 40 receives a conversion code from the remote control 20, it converts the conversion code into the original personal identification code and wirelessly transmits the converted personal identification code to the immobilizer 66. When the junction unit 40 receives a start instruction signal from the remote control 20, it transmits a vehicle start signal to the vehicle control device 68 via the cable 36. Note that the communication distance between the genuine key 62a and the immobilizer 66 or the remote control 20 is shorter than the communication distance between the remote control 20 and the junction unit 40.

[0204] 3-2.Operation When a user performs an engine start operation using the remote control 20 , a signal including the conversion code and a start instruction signal are transmitted from the remote control 20 to the junction unit 40 .

[0205] The junction unit 40 receives the signal including the conversion code and the start instruction signal, and transmits a secret code to the immobilizer 66 and also transmits a vehicle start signal to the vehicle control device 68 .

[0206] When the immobilizer 66 receives the secret code, it compares the secret code with a reference code stored in a memory device provided in the immobilizer 66, and if they match, it transmits a start permission signal to the vehicle control device 68 to permit the starting of the engine 70.

[0207] When the vehicle control device 68 confirms the presence of the start permission signal within 20 ms after receiving the vehicle start signal, it starts the engine 70. Since the presence of the start permission signal must be confirmed within 20 ms after receiving the vehicle start signal, the FSK method, which has faster communication speed and response speed than the LoRa method, is selected. However, the distance over which remote control by the remote control 20 is possible is shorter than that of the LoRa method.

[0208] 3-3.Other forms of use (1) When using a genuine key in a vehicle equipped with an immobilizer The engine starter of this embodiment can also be used in automobiles equipped with an immobilizer when the original key is placed inside the vehicle.

[0209] 11 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention, showing the case where a genuine key is placed in the interior of an immobilizer-equipped automobile. In this case, the wireless communication between the remote control 20 and the junction unit 40 uses the LoRa system.

[0210] In this case, since the genuine key 62a is placed inside the automobile 60, the immobilizer 66 is capable of constantly receiving the pin code transmitted from the genuine key 62a, and also capable of constantly transmitting a start permission signal to the vehicle control device 68. In this case, since the "relay pin code" function is not used, the function is turned off and the "non-relay mode" is selected.

[0211] When the user performs an engine start operation, a start instruction signal is transmitted from the remote control 20, and the junction unit 40, upon receiving this start instruction signal, transmits a vehicle start signal to the vehicle control device 68. If the vehicle control device 68 receives a start permission signal within 20 ms after receiving the vehicle start signal, it starts the engine 70.

[0212] The communication method is selected from either the LoRa method or the FSK method, whichever is available. The presence of the start permission signal must be confirmed within 20 ms of receiving the vehicle start signal, but since the start permission signal is sent from the original key 62a placed inside the automobile 60, either method may be selected. If priority is given to the distance over which remote control is possible using the remote control 20, the packet mode of the LoRa method is selected (long distance mode). If priority is given to communication speed and response speed, the packet mode of the LoRa method with a setting that is higher in transmission bit rate than the long distance mode is selected (short distance mode).

[0213] (2) When used in a vehicle that is not equipped with an immobilizer The engine starter of this embodiment can also be used in automobiles that are not equipped with an immobilizer.

[0214] 12 is a block diagram showing an outline of another example of the configuration of an engine starter using the system according to the present invention, showing the case where the system is used in a car without an immobilizer. In this case, the wireless communication between the remote control 20 and the junction unit 40 uses the LoRa system.

[0215] In this case, since there is no immobilizer, when the user performs an engine start operation, a start instruction signal is transmitted from the remote control 20, and the junction unit 40, which receives this start instruction signal, transmits a vehicle start signal to the vehicle control device 68. When the vehicle control device 68 receives a start permission signal, it starts the engine 70. In this case, too, the "relaying the PIN code" function is not used, so this function is turned off.

[0216] The communication method is selected from the LoRa method and the FSK method, whichever is available. If communication speed and response speed are prioritized, the FSK method should be selected, and if the distance over which remote control by the remote control 20 is possible is prioritized, the LoRa method should be selected.

[0217] 4. Modifications of the System According to the Present Invention In the engine starter using the system according to the present invention, the above-mentioned two embodiments may be modified as follows.

[0218] In the engine starter according to the above-described embodiment, the strength of the signal transmitted from at least one of the remote control 20 and the junction unit 40 may be set to be equal to or lower than the noise floor.

[0219] The antenna used for wireless communication with the junction unit 40 included in the remote control 20 may be a built-in antenna disposed inside the case 22, in addition to the rod-type antenna 28 shown in FIG.

[0220] The remote control 20 or the junction unit 40 may allow the user to directly or indirectly change at least one of the magnitude of the transmission power of the signal and the bit rate of the signal.

[0221] The engine starter according to the above-described embodiment may be configured to reduce the transmission power when the signal strength received in the last communication between the remote control 20 and the junction unit 40 is -80 dBm or greater and the signal is transmitted within one minute of receiving the signal in the last communication, and to maintain the transmission power at least at the transmission power at the time of the last communication when the signal strength is less than -80 dBm or the signal is transmitted one minute after receiving the signal in the last communication.

[0222] Furthermore, the engine starter according to the above-described embodiment may be configured to increase the transmission bit rate at which the signal is transmitted if the signal strength received in the last communication between the remote control 20 and the junction unit 40 is -80 dBm or greater and the signal is transmitted within one minute of receiving the signal in the last communication, and to maintain the transmission bit rate at least at the transmission bit rate at the time of the last communication if the signal strength is less than -80 dBm or the signal is transmitted one minute after receiving the signal in the last communication.

[0223] The engine starter according to the above-described embodiment may be configured such that a plurality of spreading factors can be set in wireless communication using the spread spectrum system, and the spreading factor is changed for each transmission of a packet.

[0224] The engine starter according to the above embodiment may be configured to be able to communicate by switching the channel used for communication.

[0225] The engine starter according to the above embodiment may be configured to automatically switch to a channel for which it has been confirmed that no signal is present by the Busy judgment. The Busy judgment of a channel is performed by the control unit 32 of the remote control 20 and the control unit 52 of the junction unit 40, the level judgment of a spread spectrum signal is performed using a CAD function, and the level judgment of a signal of a modulation method other than the spread spectrum method is performed by RSSI. The Busy judgment is performed when the spread spectrum signal is -130 dBm or higher, and when the signal of another modulation method is -80 dBm or higher.

[0226] 1, the system described above includes a remote control 20 (first device) and a junction unit 40 (second device) capable of wireless communication, the wireless communication between the remote control 20 and the junction unit 40 is by a spread spectrum method, the remote control 20 is portable by the user, and the signal transmitted by the remote control 20 includes a signal for activating the function of the junction unit 40. The function of the junction unit 40 is, for example, to transmit a vehicle start signal to the vehicle control device 68.

[0227] In this way, compared to conventional FSK methods other than the spread spectrum method (frequency spread method), the user can operate the functions of the device by remote control using wireless communication at a significantly longer distance than the conventional methods. According to the results of the inventors' experiments, the functions of the device can be operated at a distance that is roughly twice as long as the conventional method. For example, in the conventional FSK method, if the distance at which wireless communication is reliably possible is 1 km, the spread spectrum method allows communication at a distance of more than twice that distance, 2 km or more.

[0228] At least one of the first device and the second device that the user can carry may be any device, for example, a golf navigation system, and may be a portable device or a remote control. In the above embodiment, the remote control 20 is used. For example, the signal transmitted from the remote control may include a signal that activates the function of the other device. At least one of the first device and the second device that the user can carry may be particularly equipped with a function for inputting instructions from a user, and may be configured to transmit a signal that activates the function of the other device based on the input instruction. The function for inputting instructions from a user may be any device that can input instructions, and may be a sensor that can detect the user's movements, etc., and may particularly be equipped with a means for inputting instructions from the user. At least one of the first device and the second device that the user can carry may be a wearable terminal that can be attached to the body. Preferably, at least one of the first device and the second device that the user can carry may be a device that can be held in the hand and may be equipped with a function for inputting instructions by hand. Preferably, it may be equipped with a means for inputting instructions by pressing with the fingers of the hand. More preferably, the means for inputting instructions is a switch.

[0229] The other of the first device and the second device may be any device, for example, a device that can be carried by the user, preferably a device that cannot be carried by the user, for example, a device fixed to an object, more preferably a device installed indoors. When fixed to an object, for example, it may be fixed to the ground, preferably to a gas, electricity, or water meter. When fixed to the ground, for example, it may be a water sprinkler. When fixed to a gas, electricity, or water meter, for example, it may be a terminal device that transmits meter reading data to a remote control. When installed indoors, it may be installed in a golf clubhouse or inside a car. When installed in a clubhouse, it may be, for example, a digital signage. When installed inside a car, it may be, for example, an in-vehicle device. In the above-mentioned embodiment, the junction unit 40 is installed in a car.

[0230] The system of the present invention may be any system, but may be, for example, a system used in consumer devices or various industrial devices, and in particular, a system used in automobile-related devices such as the engine starter described above, allowing a user to appropriately remotely control various devices.

[0231] For example, a system for use with consumer devices may be a system in which one of a first device or a second device that can be carried by a user is a remote control, and the other is a device fixed to the ground, and the signal transmitted from the remote control includes a signal that activates a function of the device.

[0232] As a system for use in consumer devices, it is preferable that one of the first device or the second device that can be carried by a user is a portable device, and the other is a transmitter fixed to a gas, electricity, water meter, etc. The signal transmitted from the transmitter to the portable device preferably includes meter reading data and a signal that causes the portable device to tally up the meter reading data (a signal that activates a function of the portable device).

[0233] In particular, it is preferable to use a wireless communication system that uses a standard called "Wi-SUN (Wireless Smart Utility Network)" and is equipped with a terminal device fixed to a gas, electricity, or water meter, and collects meter reading data using a portable device or the like by wireless communication. If the system of the present invention is used in Wi-SUN, a user can collect meter reading data from a more remote location than before, and the effort of moving around due to data collection can be minimized. For example, when reading an electric meter in a mountainous residence that is far from roads that can be traveled by car and cannot be approached without walking, the possibility that a meter reader carrying a portable device can collect meter reading data (hereinafter also referred to as "meter information") within the range that can be traveled by car is increased, and even if walking is required after traveling by car, the possibility of shortening the travel distance is increased. In particular, it is preferable that the portable device is one that the user can carry and move around on foot, and that instructions can be input manually.

[0234] More preferably, the present system is a system in which the first device is a golf navigation system and the second device is a digital signage installed in the clubhouse. In particular, the signal transmitted from the golf navigation system should include a signal that activates the display function and tallying function of the digital signage. In this case, it becomes possible to sequentially display rankings on the digital signage based on the player's results entered into the golf navigation system during the round, and the user can save the trouble of tallying up the player's results, etc.

[0235] As a system used for automobile-related devices, for example, a system using a car engine starter or car security with the first device as a remote control and the second device as an in-vehicle device may be used. In the above-mentioned embodiment, the car engine starter is used. In particular, the signal transmitted from the remote control may include a signal for activating a function of the in-vehicle device, and the signal transmitted from the in-vehicle device may include a signal for activating a function of the remote control. Desirably, the signal transmitted from the remote control may be configured to be transmitted based on a user's instruction.

[0236] Here, in the case of conventional engine starters and car security, for example, in large-scale apartment buildings, there were cases where the parking lot was very far from the user's room and the user was unable to use the device. This problem was particularly noticeable in tower apartment buildings. In addition, for example, there were cases where the user was unable to use the device unless he or she went out onto the balcony because radio waves were blocked by a concrete wall. However, even in such cases, the present invention allows the user to activate the function of the other device more reliably than before. For example, the engine starter or car security function can be activated more reliably than before. Therefore, for example, even if the user was previously unable to activate the function of the other device unless he or she moved to a place where radio waves could reach the car in the parking lot, such as a window or a balcony, the user is more likely to be able to activate the engine starter or car security by operating it at a position indoors, such as the bedside.

[0237] Furthermore, for example, a system for use in an automobile-related device having the above-mentioned remote control (portable device) and in-vehicle device may be combined with a wireless communication system for collecting Wi-SUN meter information, etc., so that the in-vehicle device acts as a gateway (gateway) to transmit meter information generated in the house to the portable device. Specifically, for example, the in-vehicle device may receive information such as meter reading data of gas, electricity, and water meters and power generation data of a solar power generation device installed in the house from a Wi-SUN device in Wi-SUN mode (a modulation method other than the spread spectrum method), and the in-vehicle device may transfer the received information to a portable device (remote control) carried by the user in spread spectrum mode. In this way, the user can receive information such as meter reading data within a bicycle range that is wider than the conventional walking range. For example, under conditions where radio waves could only reach about 1 km in the conventional Wi-SUN mode (a modulation method other than the spread spectrum method), a range of 6 km can be achieved by lowering the bit rate using the spread spectrum method. A 1km radius around the house you live in is considered to be within your daily living area (walking distance), while a 6km radius is considered to be within your local living area. Also, you can usually get almost everything you need within this local living area (biking distance) from your home.

[0238] Preferably, the first device is fixed to an object, and the second device is portable by the user. The user carrying the second device can operate the function of the first device at the location of the object to which the first device is fixed without using the second device. The second device is carried by the user and moves with the user's movement on foot or bicycle from the location of the object to which the first device is fixed as a base point (for example, the starting point of the movement), and the second device returns to the base point again (for example, the original starting point as the end point after moving to a predetermined destination) by the user's movement to the location of the object to which the first device is fixed. The "movement on foot or bicycle" may be configured to be a line-of-sight distance of 5 km or more and 20 km or less. For example, the base point may be a home and the user may be an elderly person with dementia. Also, the base point may be a car, and the user may move on foot from the car, for example, shopping at a shopping center, start the engine while shopping, and return to the car as the base point again. Alternatively, the base point may be an automobile, and the user may walk from the automobile to his / her house after returning home, and the next morning, start the engine of the automobile from inside the house and then return to the automobile. Alternatively, the base point may be a clubhouse, and the user may walk or otherwise move around the golf course while playing, and return to the clubhouse after playing.

[0239] Also, for example, the first device may be a parent device installed in a nursing facility, and the second device may be a child device carried by each of a number of people residing in the nursing facility. The IDs attached to the child devices are different, and the parent device stores the correspondence between the IDs attached to the child devices and the names of the people carrying the child devices. Each child device transmits radio waves including the IDs by a spread spectrum method at regular intervals (for example, every minute). The parent device checks the ID and Received Signal Strength Indicator (RSSI) of the received radio waves, and when the RSSI of the received radio waves falls below a set value, the parent device displays the approximate distance from the parent device to the child device that transmitted the radio waves and the name of the person associated with the ID. The "RSSI setting value" may be set by previously determining the relationship between the distance between the parent device and the child device and the RSSI value, and inputting it into the parent device as the distance. Alternatively, "when the RSSI falls below a set value" may be when the RSSI reaches a level equivalent to that outside the care facility, based on the difference in RSSI measured in advance between inside and outside the facility and set in advance.

[0240] The parent unit may have a function for selecting a person's name stored in advance from a list or the like, and a function for wirelessly transmitting a signal requesting a reply to a child unit having an ID corresponding to that person's name. If the received ID is its own ID and a reply is requested by the parent unit, the child unit wirelessly transmits level information on the received electric field strength and its own ID. The parent unit obtains and displays the position of the child unit (e.g., the distance from the parent unit) from the level of electric field strength of the received ID.

[0241] Furthermore, for example, it is preferable to provide a function of relaying a wireless signal of an inquiry from the parent unit between the child units. For example, the parent unit is provided with a "normal search button (a button for searching without relaying)" and a "relay and search button", and when the "normal search button" is pressed, it requests a reply of the ID and the level of electric field strength from all child units within the range of the parent unit's radio waves, while when the "relay and search button" is pressed, it requests a reply from all child units within the range of the parent unit's radio waves and from all child units within the range of the radio waves from the child units. The reply (for example, the ID and the level of electric field strength of the other child units) is relayed by the child unit between the parent unit and the other child units. Note that it is also possible to further relay between the child units, and it is also preferable to set a limit on the number of times relaying between the child units. In addition, a position detector such as a GPS may be provided in each of the parent unit and the child unit, and only child units within a range specified by the parent unit from the position of the parent unit may relay.

[0242] In communication using the "spread spectrum method," for example, a narrowband signal obtained by modulating a signal to be transmitted may be spread to a wideband signal using a predetermined spreading method to reduce the power density, and then transmitted from the transmitting side. At the receiving side, the received signal may be despread to obtain the original narrowband signal with high power density. In addition, the "spread spectrum method" may be configured in such a way that, even if the spread signal received at the receiving side is a weak signal below the so-called noise floor, the signal may be restored to the original narrowband signal with high power density by despreading, and the restored original narrowband signal may be demodulated and reproduced as the signal to be transmitted. In this way, even signals that have attenuated to below the noise floor at long distances may be received.

[0243] In the case of "spread spectrum" communication, the modulation of the spread signal performed on the transmitting side and the demodulation of the spread signal performed on the receiving side may be performed using a hardware modulator or demodulator, or may be performed using a software radio. In particular, it is preferable to use an IC chip that performs the calculations corresponding to such modulation and demodulation.

[0244] Any communication method may be used as the "spread spectrum method", but it is particularly preferable to use a method that can increase the communication distance even at the expense of communication speed. Also, for example, a frequency hopping method is preferably used. It is preferable to use a method other than a direct sequence spread spread method. More preferably, the "spread spectrum method" is configured as a method (hereinafter referred to as a "chirp method") in which a chirp signal is generated by continuously changing the frequency, and a signal based on the data to be transmitted is spread and modulated by this (hereinafter referred to as a "chirp method"). In particular, it is preferable to combine the chirp method with another method. For example, it is preferable to combine the chirp method with at least one of the frequency hopping method and the direct sequence spread spread method. Also, for example, the LoRa method, which will be described in detail later, is the most preferable communication method using the "spread spectrum method". On the other hand, conventional modulation methods other than the spread spectrum method include, in addition to the above-mentioned FSK method, OOK (on-off keying), GFSK (phase-continuous FSK), MSK (minimum shift keying), GMSK (Gaussian minimum shift keying), etc. (hereinafter, these modulation methods are collectively referred to as "FSK, etc.").

[0245] Furthermore, the "first device and / or the second device" that is "portable by the user" may be any device, and may be, for example, a portable communication device, a portable information device, a wearable terminal, etc. Furthermore, the "first device and / or the second device" that is "portable by the user" may be, for example, a non-dedicated device that can perform functions other than remote control, and may be, in particular, a dedicated device for remote control, such as a remote control.

[0246] Also, the "signal transmitted by the one device" may include a signal that activates the function of the other of the first device or the second device. For example, in the case of an engine starter or a car security, the signal may include a signal for starting these devices, a signal for stopping them, a signal for changing the settings, etc. Also, in the case of an engine starter or a car security, the signal may include a signal for activating a notification function from these devices to a portable device or a remote control, etc. Desirably, the "signal transmitted by the one device" may include a signal other than a signal that activates a function of the other device. In the case of a car security, the "signal other than a signal that activates a function of the other device" may be data detected by a sensor installed in the vehicle, such as the degree of impact applied to the vehicle. In this embodiment, the current temperature inside the vehicle of the engine starter is used.

[0247] Furthermore, in the case of consumer equipment such as a water sprinkler or various industrial equipment, the "signal transmitted by the one device" may include a start signal or a stop signal for the equipment. In the case of equipment such as a golf navigation system, the "signal transmitted by the one device" may include a signal such as a player's performance information input into the golf navigation system. In the case of using the system of the present invention in equipment such as gas, electricity, or water meters that use standards such as Wi-SUN, the "signal transmitted by the one device" may include various data such as meter reading data.

[0248] For example, when the first device is a portable device such as a remote control and the second device is an in-vehicle device, the portable device may be configured to have a single receive mode and the in-vehicle device may be configured to have a continuous receive mode. In this way, the battery of the portable device can be made to last longer, and the in-vehicle device can more reliably capture the signal transmitted from the portable device. In this case, it is preferable that the in-vehicle device transmits the same information multiple times. In this case, it is possible to reduce the occurrence of missed readings due to disturbances in the portable device. More preferably, the in-vehicle device may be provided with a function to transmit a signal to switch to the continuous receive mode from the in-vehicle device, and when the portable device receives the signal to switch, it may operate in the continuous receive mode. In this case, it is particularly preferable that the time during which the device operates in the continuous receive mode is set to a certain time. Such a communication mode can be implemented by using, for example, the communication chip "SX1272".

[0249] "Single receive mode" is, for example, a mode in which only one packet is received within a set time, and in particular when communicating at a fixed receive timing, it is recommended that the receiver circuit be configured to be turned on only at the required receive timing. In this way, it is possible to reduce power consumption during standby for reception. "Continuous receive mode" is, for example, a mode in which signals are received continuously.

[0250] In this embodiment, the wireless communication between the remote control 20 and the junction unit 40 using the spread spectrum method is the LoRa method.

[0251] Therefore, users can break away from the current situation where the distance at which remote control is possible is roughly uniform.

[0252] A wireless system using a spread spectrum method, particularly the LoRa method (hereinafter also referred to as a "LoRa wireless system"), when designed for the same communication distance as the FSK method, can communicate at a higher transmission bit rate (hereinafter also referred to simply as "bit rate", "data rate" or "transmission speed"). Since a higher bit rate shortens communication time, a user can obtain a system that can quickly activate a function of the other when a signal to activate the function of the other is transmitted from either the remote control 20 or the junction unit 40.

[0253] In this embodiment, the remote control 20 has a function for inputting instructions from a user, and is configured to transmit a signal for activating the function of the junction unit 40 based on the input instruction. This provides a system that quickly responds to the input operation of instructions.

[0254] It is preferable to set the bit rate low in the LoRa method. In this way, higher sensitivity can be obtained. It is most preferable to set the bit rate as low as possible. In particular, it is preferable to set the bit rate as low as possible in the remote control 20 that is portable by the user. In this way, the user can transmit a signal for activating the function of the junction unit 40 from the remote control 20 from a longer distance than before, and cause the junction unit 40 to activate the function. It is also preferable to set the bit rate of the remote control 20 lower than that of the junction unit 40, for example.

[0255] It is preferable to set the bit rate low in a system that transmits and receives a small amount of digital information. It is even more preferable to set the bit rate low when transmitting digital information such as car security and the engine starter of this embodiment.

[0256] In this embodiment, the LoRa wireless communication is implemented by using a communication chip "SX1272" manufactured by SEMTECH. This communication chip performs the modulation and demodulation of the above-mentioned signals through arithmetic processing.

[0257] In this embodiment, wireless communication between the remote control 20 and the junction unit 40 uses the sub-gigahertz band, and uses channels of frequencies in the sub-gigahertz band whose bandwidth is wider than the bandwidth of channels in frequency bands below the sub-gigahertz band.

[0258] Therefore, a user can operate the functions of the device by remote control using wireless communication with a smaller device and at a longer distance than before. Although the sub-gigahertz band generally has a shorter propagation distance of radio waves than the bands of frequencies below the sub-gigahertz band, the problem of the short propagation distance of radio waves can be solved by using a channel of a frequency in the sub-gigahertz band having a wider bandwidth than the channel bandwidth in the bands of frequencies below the sub-gigahertz band. In this embodiment, a channel of a frequency in the sub-gigahertz band is set, the bandwidth of the channel to be used being wider than the bandwidth of the channel in the bands of frequencies below the sub-gigahertz band.

[0259] In this embodiment, the sub-gigahertz band is used as the frequency of oscillators for wireless communication provided in the remote control 20 and the junction unit 40, and a channel of the sub-gigahertz band frequency is used, the bandwidth of the channel being used being wider than the bandwidth of a channel in a frequency band below the sub-gigahertz band. The frequency for wireless communication is set by a control unit 32 provided in the remote control 20 and a control unit 52 provided in the junction unit 40. Furthermore, both the control unit 32 and the control unit 52 include a microcomputer, and write a value corresponding to the frequency to be set into a register of the microcomputer.

[0260] Furthermore, in this embodiment, the wireless communication between the remote control 20 and the junction unit 40 is a specified low-power wireless communication, using the sub-gigahertz band, and the transmittable power used is a sub-gigahertz band frequency that is greater than the transmittable power in frequency bands below the sub-gigahertz band.

[0261] In this embodiment, the "frequency band below the sub-gigahertz band" is each of the bands of 426.0250 to 426.1375 MHz, 426.0375 to 426.1125 MHz, 429.1750 to 429.2375 MHz, 429.2500 to 429.7375 MHz, and 429.8125 to 429.9250 MHz. In each of these bands, the channel bandwidth is 12.5 kHz, and in particular, in the band of 426.0375 to 426.1125 MHz, it is 25 kHz. In addition, the transmittable power is 1 mW in the bands of 426.0250 to 426.1375 MHz and 426.0375 to 426.1125 MHz, and 10 mW in each band other than these.

[0262] In this embodiment, the "sub-gigahertz band" is a band with a center frequency of 916.0 to 928.0 MHz, and the channel bandwidth is 200 kHz. The channel used in the sub-gigahertz band is a sub-gigahertz channel with a bandwidth of 200 kHz, which is 16 times the bandwidth of 12.5 kHz for channels in 426.0250 to 426.1375 MHz, 429.1750 to 429.2375 MHz, 429.2500 to 429.7375 MHz, or 429.8125 to 429.9250 MHz. The transmittable power is 20 mW. The channel used in the sub-gigahertz band is a channel with a transmittable power of 20 mW, which is twice the transmittable power of 10 mW in the frequency band below the sub-gigahertz band.

[0263] In the 400 MHz band, which is included in the "frequency band below the sub-gigahertz band," the Japanese domestic regulations at the time of filing allocate a bandwidth of 12.5 kHz or 25 kHz per channel. On the other hand, in the sub-gigahertz band, there is the 920 MHz band, which allocates a bandwidth of 100 kHz or 200 kHz per channel. In this way, the sub-gigahertz band, especially the 920 MHz band, is a frequency band with a wider bandwidth per channel than the 400 MHz band, which is a frequency band below the sub-gigahertz band. Although the 400 MHz band has a narrower bandwidth per channel than the 920 MHz band, it has the advantage that radio waves can reach farther than the 920 MHz band and are less directional and more prone to diffraction, making it easier to receive even in the shadows of distant obstacles (mountains and buildings).

[0264] In this embodiment, the "channel to be used" is at least one of the six channels (each with a bandwidth of 200 kHz) with center frequencies of 922.4 MHz, 922.6 MHz, 922.8 MHz, 923.0 MHz, 923.2 MHz, and 923.4 MHz, and some of these channels can be switched. It is preferable to have a configuration in which it is automatically switched to a channel that is confirmed to have no signal by a busy judgment among these channels. In addition, these channels may be configured to be used with a wider bandwidth by combining multiple adjacent channels, for example, it is preferable to combine five adjacent channels out of the above six channels and use them with a bandwidth of 1000 kHz.

[0265] In this embodiment, a "channel" is a frequency band allocated for use in communication, and is a frequency band allocated by Japanese domestic regulations.

[0266] When judging whether a channel is busy, the level of the spread spectrum signal is judged using the CAD function, and the level of signals using modulation methods other than spread spectrum is judged by RSSI. The CAD function detects the presence of a spread spectrum signal at such a low level that the presence of the signal cannot be detected by RSSI. A busy judgment is made when the spread spectrum signal is -130 dBm or higher, and when the signal is -80 dBm or higher for signals using other modulation methods. This allows for more accurate channel busy judgment, and makes it possible to operate the device's functions by remote control using wireless communication over a long distance.

[0267] As shown in Table 1 above, in the cases of "RSSI present" and "CAD present", (A) a busy judgment is made due to the presence of both a spread spectrum signal and a signal using a modulation method other than spread spectrum, or (B) a busy judgment is made due to the presence of a relatively strong spread spectrum signal (-80 dBm or higher), so in the case of (A), the transmission of signals using all modulation methods is prohibited, while in the case of (B), the transmission of signals using modulation methods other than spread spectrum is possible. Furthermore, even in the case of (A), a spread spectrum signal with a different bandwidth and spreading rate from the existing spread spectrum signal is possible to transmit.

[0268] If "RSSI present" and "CAD absent", the signal is determined to be busy due to the presence of a signal using a modulation method other than spread spectrum. Since no spread spectrum signal is present, it is possible to transmit a spread spectrum signal.

[0269] In the cases of "RSSI not present" and "CAD present", the busy determination is due to the presence of a spread spectrum signal, and since there are no signals using modulation methods other than spread spectrum, it is possible to transmit signals using modulation methods other than spread spectrum. Furthermore, even if the signal is a spread spectrum signal, it is possible to transmit it as long as the bandwidth and spreading rate are different from those of the existing spread spectrum signal.

[0270] In the case of "No RSSI" and "No CAD", there is no Busy judgment and neither a spread spectrum signal nor a signal with a modulation method other than spread spectrum is present, so signals of all modulation methods can be transmitted.

[0271] In this embodiment, the strength of the signal transmitted from the remote control 20 or the junction unit 40 is not particularly specified, but it is preferable that the strength be equal to or lower than the noise floor.

[0272] In this way, the possibility of jamming signals of modulation methods other than the spread spectrum method, such as signals of the FSK method, is extremely low. As a method of making the signal strength below the noise floor, for example, a configuration may be adopted in which the transmission power is controlled to be reduced, or a configuration may be adopted in which the transmitted signal is transmitted with a high spreading rate at which the signal strength is below the noise floor. When the spreading rate of the transmitted signal is increased, the transmission speed is slightly reduced, but the communication sensitivity is improved, and the communication distance is improved. Therefore, in this way, the user can operate the functions of the device by remote control using wireless communication at a longer distance than before. It is preferable to configure the "noise floor" to be -80 dBm.

[0273] In this embodiment, wireless communication between the remote control 20 and the junction unit 40 using the spread spectrum method is such that signals can be transmitted with the same power at one of the quarter portions of the bandwidth from both ends of the bandwidth of the channel being used to the inside of the bandwidth, and at the center of the bandwidth.

[0274] Therefore, a user can operate the functions of the device by remote control using wireless communication over a longer distance than before. Such a system capable of communication at a high transmission bit rate with high modulation efficiency can be implemented, for example, by the spread spectrum method or the LoRa method. On the other hand, in the FSK method, the transmission power of the signal decreases at the high-frequency and low-frequency ends of the bandwidth, and the signal goes outside the bandwidth, resulting in low modulation efficiency.

[0275] In the wireless communication between the remote control 20 and the junction unit 40 using the spread spectrum method, it is preferable that the signal can be transmitted at the same power near both ends of the bandwidth of the channel used, inwardly from the quarter of the bandwidth, and near the center of the bandwidth. More preferable, it is preferable that the signal can be transmitted at the same power near at least one end and near the center of the bandwidth of the channel used. Even more preferable, it is preferable that the signal can be transmitted at the same power over the entire bandwidth of the channel used.

[0276] In particular, it is advisable to configure the power at which signals are transmitted outside the bandwidth of the channel being used to be less than a specified value. In this way, the amount of signal that goes outside the bandwidth is less than the specified value, and the modulation efficiency is high. When the same communication distance is set in a communication system, the higher the modulation efficiency, the higher the bit rate at which communication can be performed.

[0277] In this embodiment, the remote control 20 and the junction unit 40 use the communication chip "SX1272", and power consumption does not change even if the transmission bit rate is changed. Therefore, when the transmission bit rate is increased and the communication time is shortened, the current consumption of the device decreases, and power consumption in the system can be reduced. Since the remote control 20 uses a battery as the power source for the device, the battery life can be extended. This allows the user to minimize the trouble of battery replacement, etc.

[0278] At least one of the remote control 20 and the junction unit 40 may be a device whose power consumption increases when the transmission bit rate is increased. In particular, it is advisable to set the transmission bit rate so that the reduction in transmission power due to the shortening of communication time exceeds the increase in power consumption due to the increase in the transmission bit rate. In this way, the overall power consumption can be reduced and the battery life can be extended.

[0279] In this embodiment, the wireless communication between the remote control 20 and the junction unit 40 may be configured to use a method that allows transmission of signals at the center of the entire width and at one peripheral end portion with the same power, instead of or in addition to the spread spectrum method. In particular, it is preferable to use a method that allows transmission of signals at the same power over the entire bandwidth of the channel used. In addition, for example, the wireless communication between the remote control 20 and the junction unit 40 may use an OFDM modulation method, instead of or in addition to the spread spectrum method. In particular, it is preferable to use Wi-Fi HaLow (IEEE 820.11ah).

[0280] The wireless communication between the remote control 20 and the junction unit 40 may be configured to use GFSK modulation instead of or in addition to the spread spectrum method. Preferably, the GFSK modulation is performed at a speed of several hundred bits per second or less. More preferably, Sigfox is used.

[0281] Also, wireless communication between the remote control 20 and the junction unit 40 may be performed by wireless network communication, but it is preferable to perform one-to-one communication between the remote control 20 and the junction unit 40. The communication chip "SX1272" may be configured to use, for example, 0x12 as the SyncWord value, instead of 0x34 used in LoRaWAN. It is preferable to use a value other than 0x34 or 0x12. In this way, it is possible to reduce the possibility of interference with commercially available devices that perform wireless communication using the Lora method.

[0282] In this embodiment, the remote control 20 and the junction unit 40 use an externally exposed antenna 28 or antenna unit 56, but it is particularly preferable for the remote control 20 to have a built-in antenna for use in wireless communication.

[0283] This allows the user to use a device with a simple configuration in which the antenna is not exposed to the outside, particularly the highly portable remote control 20. This is because a wireless system using the spread spectrum method can use an antenna with a lower antenna gain when designed for the same communication distance and the same communication bit rate as a wireless system using the FSK method.

[0284] In particular, this effect is remarkable when the wireless system uses the LoRa method as in this embodiment. In addition, while typical spread spectrum wireless systems (WLAN, WCDMA, etc.) pursue interference prevention and high bit rates, the LoRa method can greatly improve sensitivity by consuming a large bandwidth while spreading low bit rate signals over a wide band by spectrum spreading. Therefore, by adopting the LoRa communication method, it is possible to further miniaturize the built-in antenna. This allows the user to carry the portable device in a pocket or the like without it being in the way, and allows the system to be used stress-free.

[0285] In this way, the LoRa wireless system has high communication sensitivity, so a smaller antenna with low gain can be used. Therefore, by adopting the LoRa wireless system, it is possible to use a remote control (portable device) that has a built-in antenna but can achieve the same radio wave range as a remote control using a conventional rod antenna, providing a system with a highly portable remote control (portable device) for users.

[0286] In this embodiment, the wireless communication between the remote control 20 and the junction unit 40 is based on the LoRa system, using the sub-gigahertz band, and the bandwidth and transmittable power of the channel used are wider than the bandwidth of channels in frequency bands below the sub-gigahertz band and greater than the transmittable power in those bands, and since the channel is of the sub-gigahertz band frequency, there is a great advantage to having a built-in antenna.

[0287] In this embodiment, the magnitude of the transmission power of the signal may be changed directly or indirectly by the user.

[0288] This allows the user to use the system with the optimal transmission power depending on the environment in which the user uses the system. For example, when the distance between the remote control 20 and the junction unit 40 is short and the use in an environment with a relatively good communication environment is expected, the transmission power can be minimized by setting the transmission power low within a range where there is no problem in transmitting signals. In the remote control 20 that uses the battery 34 as a power source, the user can extend the battery life and reduce the frequency of battery replacement, etc. On the other hand, when the user wants to prioritize the reliability of the signal transmission between the remote control 20 and the junction unit 40 over minimizing the transmission power, the transmission power can be set high, taking into account the expected communication distance, etc. This ensures that signals are transmitted reliably, and the user can accurately control the device in which the system of the present invention is installed.

[0289] Here, an example of a configuration in which "the user can directly change the magnitude of the signal transmission power" is a configuration in which the magnitude of the transmission power of the remote control 20 or the junction unit 40 is set by inputting a power value. By allowing "the user to directly change the magnitude of the transmission power" in this way, the user can accurately adjust the transmission power to a level suitable for his or her own usage conditions.

[0290] An example of a configuration in which the "user can indirectly change the magnitude of the signal transmission power" is a configuration in which the magnitude of the transmission power of the remote control 20 or the junction unit 40 is set by a relative numerical value or index associated with a power value. Various indexes associated with the power value can be considered, such as "strong, medium, weak" and indexes according to the operation mode. In particular, a configuration in which the "long-distance communication mode (normal mode)" and a "long-life mode" with a long battery life can be selected, for example. In this way, it is possible to select whether to prioritize the battery life or the distance at which the device's functions can be operated by remote control using wireless communication. By making the "user can indirectly change the magnitude of the transmission power" in this way, the user can intuitively or intuitively adjust the output to the magnitude of the transmission power suitable for his or her own usage conditions.

[0291] The configuration in which "the user can directly or indirectly change the magnitude of the signal transmission power" may be any configuration, and may be a configuration in which this is done via switches (e.g., dip switches) or a control device provided on a junction unit 40 that the user cannot carry, and in particular, a configuration in which this is done via a remote control 20 that the user can carry.

[0292] Also, it is preferable that the magnitude of the transmission power of the signal can be changed based on the operation of an operation unit provided on, for example, the remote control 20 or another device. The operation unit may be configured, for example, as a slider, or may be configured as a slider displayed on a display screen provided on the remote control 20 or another device.

[0293] It is preferable that the remote control 20 is configured to be selectable between the above-mentioned "long distance communication mode (normal mode)" and "long life mode." In this way, the user can extend the battery life by selecting the long life mode in an area where communication is possible in the long life mode, and when communication in the long life mode becomes impossible in an area farther away than the area where communication is possible in the long life mode, the user can operate the function of the other device by remote control using wireless communication by switching to the long distance communication mode.

[0294] In addition, when the operation mode is set according to the magnitude of the transmission power of the signal, such as the "long distance communication mode (normal mode)" or the "long life mode," each mode may be set in multiple steps or steplessly according to the magnitude of the transmission power. By adopting these methods, the user can easily and accurately adjust the magnitude of the transmission power of the signal.

[0295] In this embodiment, the transmission bit rate of the signal may be changed directly or indirectly by the user.

[0296] In this way, the user can use the system under optimal conditions for the environment in which the user uses it by adjusting the transmission bit rate. For example, the user can improve the communication sensitivity and ensure a large communication range by setting the transmission bit rate low. On the other hand, the user can minimize the communication time by sacrificing the communication sensitivity and communication distance by setting the transmission bit rate high, and can operate the device's functions by remote control using wireless communication over a long distance with quick communication operations.

[0297] In this embodiment, the remote control 20 and the junction unit 40 use the communication chip "SX1272", and power consumption does not change even if the transmission bit rate is changed. Therefore, when the transmission bit rate is increased and the communication time is shortened, the current consumption of the device decreases, so that the power consumption in the system can be reduced, and in particular, the power consumption of the device that transmits the signal can be reduced. The remote control 20 uses a battery as the power source for the device, so the battery life can be extended. This allows the user to minimize the trouble of battery replacement, etc.

[0298] At least one of the remote control 20 and the junction unit 40 may be a device whose power consumption increases when the transmission bit rate is increased. In particular, it is advisable to set the transmission bit rate so that the reduction in transmission power due to the shortening of communication time exceeds the increase in power consumption due to the increase in the transmission bit rate. In this way, the overall power consumption can be reduced and the battery life can be extended.

[0299] Here, an example of a configuration in which "the user can directly change the transmission bit rate of the signal" is a configuration in which the transmission bit rate of the remote control 20 or the junction unit 40 is set by inputting a bit rate value. By allowing "the user to directly change the magnitude of the transmission bit rate" in this way, the user can precisely adjust the transmission bit rate to suit his or her own usage conditions.

[0300] An example of a configuration in which the "user can indirectly change the transmission bit rate of a signal" is a configuration in which the magnitude of the transmission bit rate of the remote control 20 or the junction unit 40 is set by a relative numerical value or index associated with the transmission bit rate. Various indexes such as "large, medium, small" and indexes according to operation modes can be considered as indexes associated with the transmission bit rate. In particular, for example, it is preferable to be able to select between a "normal mode" and a "speed mode" in which communication operations are quick. In this way, it is possible to select whether to prioritize the distance at which the function of the device can be operated by remote control using wireless communication or the speed of communication operations. By making the "user can indirectly change the transmission bit rate of a signal" in this way, the user can intuitively or intuitively adjust the transmission bit rate to a value suitable for his or her own usage conditions.

[0301] The configuration in which "the user can directly or indirectly change the transmission bit rate of the signal" may be any configuration, and may be a configuration in which this is done via switches (e.g., dip switches) or a control device provided on a junction unit 40 that the user cannot carry, and in particular, a configuration in which this is done via a remote control 20 that the user can carry.

[0302] It is preferable to configure the remote controller 20 to be selectable between the above-mentioned "normal mode" and "speed mode." In this way, the user can make communication operations quicker by selecting the speed mode in an area where communication is possible in the speed mode, and when communication in the speed mode becomes impossible in an area farther away than the area where communication is possible in the speed mode, the user can operate the functions of the other device by remote control using wireless communication by switching to the normal mode.

[0303] The transmission bit rate may be changed by operating an operation unit of, for example, a remote control or other device. The operation unit may be configured, for example, as a slider, or may be configured as a slider displayed on a display screen of the remote control or other device.

[0304] In addition, when the operation mode is set according to the transmission bit rate, such as "normal mode" or "speed mode," each mode may be set in multiple steps or steplessly according to the transmission bit rate. By adopting these methods, the user can easily and accurately adjust the transmission bit rate of the signal.

[0305] In this embodiment, in the information regarding the strength of the signal received in the last communication between the remote control 20 and the junction unit 40, if the signal strength is -80 dBm or greater and the transmission is performed within one minute of receiving the signal in the last communication, the transmission power is reduced, and if the signal strength is less than -80 dBm or the transmission is performed one minute after receiving the signal in the last communication, the transmission power is maintained at least at the transmission power at the time of the last communication.

[0306] In this way, the user can optimize the transmission power consumption while ensuring the transmission and reception of signals in the system. For example, if the signal strength received by the device in the last communication is greater than necessary, the next signal strength to be transmitted may be reduced. Here, since at least one of the remote control 20 and the junction unit 40 is portable, even if the signal strength received by the device is greater than necessary, the distance between the remote control 20 and the junction unit 40 may increase over time due to the user's movement, etc. In this way, when the transmission power in the next communication can be adjusted according to the signal strength received by the device in the last communication, for example, a change in the distance between the remote control 20 and the junction unit 40 may be assumed using time as an index, and adjustment may be performed based on this assumption. In this embodiment, the transmission power is reduced not only when the signal strength received in the last communication is -80 dBm or more, but also when the next signal is transmitted within one minute after the signal is received in the last communication. Furthermore, in the configuration of this embodiment, the transmission power is at least maintained when the signal strength is less than a predetermined value or when the signal is transmitted after a predetermined time has elapsed since the signal is received in the last communication. In this way, the user can operate the functions of the device by remote control using wireless communication over a long distance, and the transmission power consumption can be reduced. Also, in the case of the remote control 20 that uses a battery as a power source, the battery life can be extended, so the user does not need to frequently replace the battery.

[0307] Here, the "predetermined time" for reducing the transmission power, specified as "1 minute", may be set based on the distance at which communication is assumed to be established between the remote control 20 and the junction unit 40 even if the distance between the remote control 20 and the junction unit 40 increases, and the assumed speed of the increase in the distance between the remote control 20 and the junction unit 40, when, for example, the transmission power of the next signal to be transmitted is to be reduced below the transmission power at the time of signal transmission in the last communication. For example, when assuming a case in which the distance between the remote control 20 and the junction unit 40 increases as a result of a user carrying the remote control 20 moving on foot, the "predetermined time" may be set based on the relationship between the average moving speed of an average adult moving on foot, the distance at which communication is assumed to be established between the remote control 20 and the junction unit 40 after the transmission power is reduced, and the magnitude of the communication distance that is likely to be reduced by the reduction in the transmission power. In this way, by estimating the change in the distance between the remote control 20 and the junction unit 40 using time as an index, setting a "predetermined time" based on this estimated result, and using this predetermined time as one of the standards for reducing transmission power, even when control is performed to suppress transmission power consumption, the user can operate the functions of the device by remote control using wireless communication over a long distance without feeling inconvenienced.

[0308] The "predetermined time" during which the transmission power is reduced may be constant or may be varied depending on the signal strength.

[0309] Here, in a system that includes a remote control 20 that can be carried by the user and a junction unit 40 that is powered by a battery installed in the vehicle, and in which basic control begins with sending a command from the remote control 20, the transmission power consumption on the junction unit 40 side can be reduced, and the power consumption of the battery installed in the vehicle can be kept to a minimum.

[0310] Also, for example, when the amount of information to be transmitted is large and the information is divided into several transmissions, the first transmission may be performed with high transmission power, and the second and subsequent transmissions may be adjusted based on the radio wave intensity of the first transmission. In this way, the transmission power can be optimized. In this case, the battery life of the remote control 20 can be extended, and the frequency of battery replacement by the user can be minimized.

[0311] Also, for example, in the case of car security, it is preferable to configure the remote control so that when a sensor detects that some kind of trouble has occurred in the car, a signal is sent from the in-vehicle device, which is a fixed device, to the remote control, even if no command is sent from the remote control. In this way, when a user who has learned that the car security is activated performs a process such as disabling the car security by operating the remote control, the transmission power of the remote control's transmission signal can be reduced based on the radio wave strength of the signal previously received from the in-vehicle device, minimizing power consumption in the battery built into the remote control and minimizing the frequency of battery replacement by the user.

[0312] Furthermore, it is preferable to configure the system so that, for example, the remote control 20 can transmit a signal to the junction unit 40 and perform system settings. In this way, the remote control 20 can transmit a setting start command and based on the radio wave strength of the response signal returned from the junction unit 40, the transmission power of the transmission signal from the remote control 20 can be reduced, minimizing power consumption of the battery 34 built into the remote control 20 and minimizing the frequency with which the user needs to replace the battery.

[0313] A user carrying the remote control 20 may move after receiving a signal in the last communication in the system. Therefore, if the transmission power of the remote control 20 or the junction unit 40 is reduced after a predetermined time (one minute in this embodiment) has elapsed, the distance between the remote control 20 and the junction unit 40 may become too large, causing the radio wave strength to be insufficient, and it may become impossible to operate the function of the device by remote control using wireless communication over a long distance. Therefore, it is preferable to reduce the transmission power within a predetermined time and maintain the transmission power after the predetermined time has elapsed. In this way, it is possible to operate the function of the device by remote control using wireless communication over a long distance, and to extend the battery life. This makes it possible to minimize the frequency with which the user performs bothersome tasks such as battery replacement.

[0314] In addition, the configuration of "maintaining at least the transmission power" may be a configuration of maintaining the transmission power or a configuration of increasing the transmission power. As in the present embodiment, when the strength of the signal received in the last communication is less than -80 dBm or when one minute has passed since the reception of the signal in the last communication, the transmission power may be maintained at least at the transmission power at the time of the last communication. In this way, it is possible to prevent the communication from being unable to be established due to the reduction in the transmission power, and to ensure the stability of the communication. As a result, the user can operate the function of the device by remote control using wireless communication over a long distance without feeling any inconvenience, even when the strength of the signal received in the last communication is weak or a predetermined time has passed since the previous communication.

[0315] If the "predetermined time" for reducing the transmission power is changed according to the signal strength, the greater the signal strength, the shorter the predetermined time should be, and the smaller the signal strength, the longer the predetermined time should be. However, if the signal strength is below the predetermined value, the transmission power should at least be maintained.

[0316] In the configuration of this embodiment, for example, if communication is not possible with the transmission power lowered, the transmission power is increased, and if communication is still not possible, the transmission power is further increased. When communication is not possible with the transmission power lowered, the transmission power is increased stepwise or continuously, and in particular, directly to the maximum. In this way, the user can obtain the advantage of being able to minimize power consumption.

[0317] In the configuration of this embodiment, the transmission power of the remote control 20 and the junction unit 40 may be set to maximum in the normal state and automatically reduced, or may be set by the user through operation of the remote control 20 or through setting of a dip switch provided on the junction unit 40. The transmission power may also be displayed on the display unit 24 of the remote control 20. In this way, the user can check the transmission power from this display. The display unit 24 of the remote control 20 may also be configured to display the strength of the received radio wave. In this way, the user can use the remote control 20 while checking whether communication is possible from the displayed radio wave strength.

[0318] In this embodiment, in the information regarding the strength of the signal received in the last communication between the remote control 20 and the junction unit 40, if the signal strength is -80 dBm or more and the signal is transmitted within one minute of receiving the signal in the last communication, the transmission bit rate for transmitting the signal is increased, and if the signal strength is less than -80 dBm or the signal is transmitted one minute after receiving the signal in the last communication, the transmission bit rate is maintained at least at the transmission bit rate at the time of the last communication.

[0319] In this way, the user can optimize the transmission bit rate while ensuring the transmission and reception of signals in the system. For example, if the signal strength received by the device in the last communication is greater than necessary, the next signal strength to be transmitted may be reduced. Here, since the remote control 20 is portable, even if the signal strength received by the device is greater than necessary, the distance between the remote control 20 and the junction unit 40 may increase over time due to the user's movement, etc. In this way, when the transmission bit rate in the next communication can be adjusted according to the signal strength received by the device in the last communication, for example, a change in the distance between the remote control 20 and the junction unit 40 may be assumed using time as an index, and adjustment may be performed based on this assumption. In the configuration of this embodiment, the transmission bit rate is increased not only when the signal strength received in the last communication is -80 dBm or more, but also when the next signal is transmitted within one minute after the signal is received in the last communication. Furthermore, in the configuration of this embodiment, the transmission bit rate is at least maintained when the signal strength is less than -80 dBm or when the signal is transmitted one minute after the signal is received in the last communication. In this way, the user can operate the functions of the device by remote control using wireless communication over a long distance, and the transmission power consumption can be reduced. Also, in the remote control 20 that uses the battery 34 as a power source, the battery life can be extended, so the user does not need to frequently replace the battery.

[0320] Here, the "predetermined time" for increasing the transmission bit rate, specified as "1 minute", may be set based on the distance at which communication is assumed to be established between the remote control 20 and the junction unit 40 even if the distance between the remote control 20 and the junction unit 40 increases, and the assumed speed of the expansion of the distance between the remote control 20 and the junction unit 40, when, for example, the transmission bit rate of the next signal to be transmitted is increased from the transmission bit rate at the time of signal transmission in the last communication. If a case is assumed in which the distance between the remote control 20 and the junction unit 40 increases as the user moves on foot, the "predetermined time" may be set based on the relationship between the average moving speed of an average adult moving on foot, the distance at which communication is assumed to be established between the remote control 20 and the junction unit 40 after the increase in the transmission bit rate is reduced, and the size of the communication distance that will be reduced due to the increase in the transmission bit rate. In this way, by estimating the change in the distance between the remote control 20 and the junction unit 40 using time as an index, setting a "predetermined time" based on this estimated result, and using this predetermined time as one of the standards for increasing the transmission bit rate, even if control is performed to increase the transmission bit rate, the user can operate the functions of the device by remote control using wireless communication over a long distance without feeling inconvenienced.

[0321] The "predetermined time" during which the transmission bit rate is increased may be constant or may be varied depending on the signal strength.

[0322] In addition, the configuration of "maintaining at least the transmission bit rate" may be a configuration of maintaining the transmission bit rate or a configuration of lowering the transmission bit rate. As in the present embodiment, when the strength of the signal received in the last communication is less than -80 dBm or when one minute has passed since the reception of the signal in the last communication, the transmission bit rate may be maintained at least at the transmission bit rate at the time of the last communication. In this way, it is possible to prevent communication from being unable to be established due to an increase in the transmission bit rate, and to ensure the stability of communication. As a result, the user can operate the function of the device by remote control using wireless communication over a long distance without feeling any inconvenience, even when the strength of the signal received in the last communication is weak or a predetermined time has passed since the previous communication.

[0323] In a communication system, if the bandwidth is the same, the transmission bit rate, the sensitivity (flying distance), and the transmission power are inversely proportional to each other. That is, in the system of the present invention, if the transmission bit rate is increased, the distance will not fly (the sensitivity will decrease) if the bandwidth and the transmission power are the same, and the distance at which the function of the device can be activated by remote control using wireless communication will become shorter, but the transmission time can be shortened and the communication operation of the system can be made quicker. Here, if the received signal strength is high, communication is possible even with low sensitivity, so communication is possible even if the transmission bit rate is increased. Therefore, in this embodiment, it is preferable to configure the transmission bit rate to be increased as the received radio wave is stronger. In this way, a user can obtain a system that can quickly activate one of the functions when a signal for activating the other function is transmitted from one of the remote control 20 and the junction unit 40.

[0324] In this embodiment, a plurality of spreading factors can be set in wireless communication using the spread spectrum method, and the spreading factor may be changed for each packet transmission.

[0325] This allows the user to build a wireless system that is extremely difficult to intercept.

[0326] The "change in spreading factor" may be configured to be performed in a predetermined pattern. The "predetermined pattern" of the "change in spreading factor" may be configured to be random or in a predetermined order. Here, in the system of the present invention, the higher the spreading factor, the longer the distance the device's functions can be operated by remote control using wireless communication. Therefore, in particular, the spreading factor may be configured to adopt the maximum spreading factor and the spreading factor one step lower. In such a configuration, the pattern of the change in spreading factor may be configured to alternate between the maximum spreading factor and the spreading factor one step lower in a predetermined pattern. In this way, it is possible to operate the device's functions by remote control using wireless communication over a long distance with low eavesdropping.

[0327] In this embodiment, the spreading factor is changed every time one packet is transmitted, but any configuration is acceptable, such as every time a packet of a predetermined amount of data is transmitted, or every time a predetermined amount of time has elapsed.

[0328] The "spreading factor" may be, for example, the ratio (C / B) of the spreading code speed (also called the "chip rate"; C) to the transmission bit rate (B).

[0329] In this embodiment, it is preferable to enable communication while switching the channel used for communication.

[0330] In this way, the frequency band allocated for communication is switched while communication is performed, so that the user can obtain a system in which interference is unlikely to occur between spread spectrum communication systems. In this case, the receiver and the transmitter switch channels in sync with each other. For example, when the band used for wireless communication is 920 MHz, it is preferable to use six channels with center frequencies of 922.4 MHz, 922.6 MHz, 922.8 MHz, 923.0 MHz, 923.2 MHz, and 923.4 MHz by switching between them. Note that channels other than these channels may also be used.

[0331] The spread spectrum method, especially the LoRa method, allows communication over a much longer distance than the FSK method. Therefore, when a communication method with a long communication distance such as the LoRa method is adopted, there is a high possibility that interference will occur due to communication by other users interrupting the communication range. Therefore, when the spread spectrum method, especially the LoRa method, is adopted, it is preferable to suppress interference by appropriately switching the channel used for communication. This allows users to communicate stably without being affected even if other users nearby are using devices that communicate using the spread spectrum method.

[0332] In this embodiment, the system includes a vehicle control device 68 that starts an engine based on a vehicle start signal, and an immobilizer 66 that can transmit a start permission signal to the vehicle control device 68 to permit starting of an engine 70. The system receives a personal identification code transmitted from a genuine key 62a that is portable by a user and capable of transmitting a personal identification code, and transmits the start permission signal from the immobilizer 66 to the automobile 60 based on the received personal identification code and a reference code provided in the immobilizer 66. The system is used to indirectly transmit a personal identification code to the automobile 60 to which the immobilizer 66 transmits the start permission signal, and the system includes a remote control 20 and a junction unit 40. For the wireless communication, a spread spectrum method or a communication method other than the spread spectrum method can be selected, and the remote control 20 that can be carried by the user can receive a PIN code from the original key 62a and can transmit a signal including a conversion code converted from the received PIN code and a start instruction signal to the junction unit 40, and the junction unit 40 is mounted on the automobile 60 and can convert the received conversion code into a PIN code and transmit the converted PIN code to the immobilizer 66, and can transmit a vehicle start signal to the vehicle control device 68 upon receiving the start instruction signal.

[0333] In this way, in an automobile 60 equipped with an immobilizer 66, the user can start the engine 70 by using the remote control 20 that the user can carry with him / her, without leaving the original key 62a inside the vehicle. Generally, the original key 62a and the immobilizer 66 cannot transmit and receive a secret code unless they are in close proximity, for example due to security concerns, and starting of the engine 70 cannot be permitted. However, in this way, even if the original key 62a and the immobilizer 66 are far apart, the secret code transmitted from the original key 62a is relayed by the remote control 20 that the user can carry with him / her and the junction unit 40 mounted on the automobile 60, and can be received by the immobilizer 66, allowing starting of the engine 70 to be permitted.

[0334] In this embodiment, the "indirect transmission" configuration for the PIN code is such that the remote control 20 receives the PIN code from the genuine key 62a, converts the PIN code into a different conversion code and transmits it to the junction unit 40, and the junction unit 40 converts the received conversion code back to the original PIN code before transmitting it to the immobilizer 66.

[0335] Regarding the junction unit 40, in this embodiment, the configuration of "mounting it on a vehicle" refers to a so-called retrofitting to a sold vehicle, but it may also be a configuration in which the junction unit 40 is originally attached to the vehicle when the vehicle is manufactured by the automobile manufacturer.

[0336] In this embodiment, the start instruction signal transmitted by the remote control 20 is issued in response to the user's operation of the operation button 26.

[0337] In this embodiment, the wireless communication between the remote control 20 and the junction unit 40 can select between the LoRa method and the FSK method. Therefore, even if it is difficult to permit the start of the engine 70 using one of the methods, the possibility of permitting the start of the engine 70 can be increased. The configuration for "selecting the communication method" may be any configuration, for example, via switches (e.g., dip switches) or a control device provided on the junction unit 40, and in particular, may be configured to be performed on the portable remote control 20 side. In addition, the communication method may be selected based on the operation of an operation unit provided on the remote control 20 or another device. The operation unit may be configured, for example, to be a slider, or may be configured to be a slider displayed on a display screen provided on the remote control 20 or another device.

[0338] It is preferable to configure the system so that a mode in which the personal identification code transmitted from the genuine key 62a is relayed by the remote control 20 and the junction unit 40 (hereinafter referred to as the "relay mode") and a mode in which the personal identification code is not relayed (hereinafter referred to as the "non-relay mode") can be selected. In this way, a user or retailer can handle both vehicle models equipped with an immobilizer 66 and vehicle models not equipped with an immobilizer 66 by simply preparing one type of system equipped with the remote control 20 and the junction unit 40, and can also accommodate users of vehicle models equipped with an immobilizer 66 who do not mind leaving the genuine key 26a in the vehicle 60. The configuration for selecting the "relay mode" and the "non-relay mode" can be configured so that the selection is made by using a switch provided, for example, on the vehicle-mounted device.

[0339] When "relay mode" is selected, it is recommended to configure the wireless communication on the transmitting side to be in continuous mode using the FSK method. "Continuous mode" is a mode in which the level of the DIO2 / DATA pin is transmitted as is (without going through the FIFO).

[0340] When the "non-relay mode" is selected, the "long distance mode" and the "short distance mode" can be selected. In this embodiment, the "long distance mode" selects the packet mode of the LoRa system for the wireless communication on the transmitting side. The "packet mode" is a mode that uses SPI (Serial It is preferable to configure the device so that data provided via a peripheral interface is packetized and transmitted via a FIFO.

[0341] In this embodiment, the “short distance mode” is a setting in which the wireless communication on the transmitting side is set to the LoRa method with a higher transmission bit rate than in the long distance communication mode, but the wireless communication on the transmitting side may also be set to the FSK method packet mode.

[0342] The components of the present embodiment may be arbitrarily combined. Also, the components described in the Summary of the Invention and the components of the present embodiment may be arbitrarily combined. [Explanation of symbols]

[0343] 10 Engine starter 20 Remote Control 22 cases 24 Display 24a Horizontal bar 24b engine start animation 26 Operation buttons 26a Start button 26b Engine button 26c Stop button 28 Antenna 30 Wireless communication circuit 32 Control section 34 Battery 36 Cable 40 Junction Unit 42 First Connector 42a Plug 44 Second Connector 46 Third Connector 48 4th Connector 50 Wireless communication circuit 52 Control section 54 Temperature Sensor 56 Antenna unit 60 Automobiles 62 keys 62a Original key 64 Keyhole 66 Immobilizer 68 Vehicle control device 70 Engine

Claims

1. A first device and a second device capable of wireless communication are provided, At least one of the first device and the second device is portable by a user, and a signal transmitted by the one device includes a signal for activating a function of the other of the first device or the second device; reducing transmission power when a strength of a signal received in a last communication between the first device and the second device is equal to or greater than a predetermined value and transmission is performed within a first predetermined time from reception of the signal in the last communication; A system characterized by maintaining the transmission power at least at the transmission power at the time of the last communication when the signal strength is less than the predetermined value or when transmitting after the first predetermined time has elapsed since receiving a signal in the last communication.

2. 2. The system according to claim 1, further comprising a function for changing the first predetermined time period depending on the signal strength.

3. increasing a transmission bit rate for transmitting a signal when a strength of a signal received in a last communication between the first device and the second device is equal to or greater than a predetermined value and the signal is transmitted within a second predetermined time from the reception of the signal in the last communication; The system described in claim 1 or 2, characterized in that when transmitting, the transmission bit rate is maintained at least at the transmission bit rate at the time of the last communication when the signal strength is less than the predetermined value or when transmitting after the second predetermined time has elapsed since receiving the signal in the last communication.

4. 4. The system according to claim 3, further comprising a function for changing the second predetermined time period in response to the signal strength.

5. The first device in the system according to any one of claims 1 to 4.

6. The second device in the system according to any one of claims 1 to 4.

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