Radio communication system and radio terminal device

The present invention relates to a wireless communication system and a wireless terminal device, and more particularly to a battery-powered wireless terminal device and a wireless communication system including the same.

For example, in a wireless communication system using a wireless network such as ZigBee (registered trademark), the wireless terminal device is usually driven by a battery (see, for example, Non-Patent Document 1). Therefore, when the battery is exhausted and the wireless terminal device does not operate, a problem may occur in the wireless communication system. Therefore, various methods for managing the drive of the wireless terminal device have been conventionally proposed (see, for example, Patent Document 1). In Patent Document 1, the operation of the wireless terminal device is continued by changing the communication path according to the current remaining battery level.

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2004-350010</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 07-183896</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 06-164487</text></patcit><nplcit num="1"><text>Zigbee Alliance, [online], [Searched April 23, 2007], Internet, &lt;http://www.zigbee.org/en/index.asp&gt;</text></nplcit>

<p> However, since the frequency of operation of wireless terminal devices varies depending on the role and application in the network, it is difficult to predict how much more the wireless terminal device will operate even if the current battery level is known. For example, sensor-based wireless terminal devices that are frequently detected, wireless terminal devices used for multi-hop wireless relay, and wireless terminal devices that frequently retransmit wireless signals due to poor communication quality are other wireless terminal devices. Since the battery drains faster than this, if you pay attention only to the current remaining battery level, it may suddenly stop working, which may affect the operation of the entire wireless communication system.</p><p> Therefore, an object of the present invention is to provide a wireless communication system and a wireless terminal device capable of more accurately predicting the battery life of the wireless terminal device.</p><p> Another object of the present invention is to provide a wireless communication system and a wireless terminal device capable of driving the wireless terminal device for a longer period of time.</p>

<p> In order to solve the above-mentioned problems, the wireless communication system according to the present invention is a wireless communication system including a server and at least one wireless terminal device connected to the server via a wireless network. , The measuring unit that measures the remaining amount of the battery of the wireless terminal device, the storage unit that stores the remaining amount measured by this measuring unit, and the battery is consumed based on the past remaining amount stored in this storage unit. It is characterized by including a calculation unit for calculating the predicted time up to and an output unit for outputting the predicted time calculated by the calculation unit.</p><p> The wireless communication system further includes a communication control unit that controls wireless communication of the wireless terminal device and a determination unit that determines whether or not the predicted time is equal to or less than a threshold value. If it is determined that is less than or equal to the threshold value, the frequency of wireless communication may be reduced.</p><p> Further, in the above communication wireless system, the wireless terminal device is composed of a plurality of wireless terminal devices grouped, and the determination unit determines that the longest value of the predicted time of each wireless terminal device included in the group is equal to or less than the threshold value. If it is determined whether or not there is, and the determination unit determines that the longest value of the predicted time of each wireless terminal device included in the group is equal to or less than the threshold value, the longest value is sent to the destination associated with the group. May be further provided with a notification unit for notifying that is equal to or less than the threshold value.</p><p> Further, in the above wireless communication system, the wireless terminal device is composed of a plurality of wireless terminal devices grouped, and the determination unit has a determination unit in which the shortest value among the predicted times of each wireless terminal device included in the group is equal to or less than the threshold value. If it is determined whether or not there is, and the determination unit determines that the shortest value of the predicted time of each wireless terminal device included in the group is equal to or less than the threshold value, the shortest value is sent to the destination associated with the group. It may be further provided with a notification unit for notifying that the value is equal to or less than the threshold value.</p><p> Further, another wireless communication system according to the present invention is a wireless communication system including at least a wireless network, a wireless terminal device wirelessly connected to the wireless terminal device, and a server that communicates with the wireless terminal device. The wireless terminal device includes a measuring unit that measures the remaining amount of the battery of the wireless terminal device and a communication unit that transmits the remaining amount measured by the measuring unit to the server, and the server receives from the communication unit. A storage unit that stores the remaining amount, a calculation unit that calculates the estimated time until the battery is consumed based on the past remaining amount stored in this storage unit, and a calculation unit that calculates the estimated time calculated by this calculation unit are output. It is characterized by having an output unit.</p><p> Further, in the wireless communication system, the measuring unit measures the number of communications of the wireless terminal device instead of the remaining battery level, the storage unit stores the number of communications, and the calculation unit stores the number of communications stored in the storage unit. The estimated time until the battery is exhausted may be calculated based on the remaining amount and the remaining amount.</p><p> Further, in the wireless communication system, the measuring unit measures the communication quality of the wireless terminal device instead of the remaining battery level, the storage unit stores the communication quality, and the calculation unit stores the communication quality stored in the storage unit. The estimated time until the battery is exhausted may be calculated based on the remaining amount and the remaining amount.</p><p> Further, the wireless terminal device according to the present invention is a wireless terminal device connected to a server via a wireless network, and stores a measuring unit for measuring the remaining amount of a battery and a remaining amount measured by the measuring unit. A storage unit, a calculation unit that calculates the estimated time until the battery is consumed based on the past remaining amount stored in the storage unit, and an output unit that outputs the estimated time calculated by this calculation unit. It is characterized by being prepared.</p><p> The wireless terminal device further includes a communication control unit that controls wireless communication and a determination unit that determines whether or not the predicted time is equal to or less than the threshold value. The communication control unit further includes a determination unit that determines whether the predicted time is equal to or less than the threshold value. If it is determined that there is, the frequency of wireless communication may be reduced.</p><p> Further, in the wireless terminal device, the measuring unit measures the number of communications by wireless communication instead of the remaining battery level, the storage unit stores the number of communications, and the calculation unit stores the number of communications stored in the storage unit. The estimated time until the battery is exhausted may be calculated based on the remaining amount.</p><p> Further, in the wireless terminal device, the measuring unit measures the communication quality of wireless communication instead of the remaining battery level, the storage unit stores the communication quality, and the calculating unit stores the communication quality stored in the storage unit. The estimated time until the battery is exhausted may be calculated based on the remaining amount.</p>

<p> According to the present invention, the life of the battery of the wireless terminal device can be predicted more accurately by calculating the estimated time until the battery is consumed based on the past remaining amount of the battery of the wireless terminal device.</p><p> Further, according to the present invention, when it is determined that the predicted time is equal to or less than the threshold value, the amount of power consumed by the wireless terminal device is reduced by reducing the frequency of wireless communication. As a result, the wireless terminal device is used. Can be driven longer.</p>

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment] The wireless communication system according to the first embodiment of the present invention relates to a system that transmits sensor information from a wireless terminal device provided with a sensor at regular intervals or when an abnormality is detected. As shown in FIG. 1, such a wireless communication system 1 includes a plurality of wireless terminal devices 2 that form a wireless multi-hop network by mutually performing wireless communication, a multi-hop network, the Internet, and a LAN (Local Area Network). ), A reader 3 that communicates various information with the wireless terminal device 2 and other devices connected to the network 10 via a known network 10 such as WAN (Wide Area Network), and a reader 2 connected to the network 10. It is equipped with at least a server device 4 that sends and receives various information.

&lt;Wireless terminal device 2&gt; As shown in FIG. 2, the wireless terminal device 2 includes a wireless communication unit 21, a sensor unit 22, a battery level measuring unit 23, and a control unit 24. Such a wireless terminal device 2 is driven by the electric power stored in the battery 25.

The wireless communication unit 21 is composed of a communication interface device that transmits and receives various information to and from other wireless terminal devices 2 and readers 3 via wireless signals.

The sensor unit 22 is composed of a sensing device that detects a predetermined event and outputs the detected sensor information to the control unit 24.

The battery remaining amount measuring unit 23 is composed of a measuring device that measures the battery remaining amount of the battery 25 and outputs the measured remaining amount information to the control unit 24. Specifically, the battery remaining amount measuring unit 23 measures the voltage value of the battery 25. Therefore, the remaining amount information includes the voltage value of the battery 25.

The control unit 24 is a circuit unit that controls the operations of the wireless communication unit 21, the sensor unit 22, and the battery level measuring unit 23. Such a control unit 24 includes a communication control unit 24a, a sensor control unit 24b, and a measurement control unit 24c.

The communication control unit 24a controls the operation of the wireless communication unit 21. Specifically, when the sensor unit 22 detects the sensor information or the battery remaining amount measuring unit 23 measures the remaining amount information, these are transmitted to the reader 3 via the multi-hop network. Further, when various information is received from the wireless terminal device 2 of 1, the information is transmitted to the other wireless terminal device 2, so-called multi-hop relay is performed. Further, the frequency and timing of the operation of the wireless communication unit 21 are controlled based on the control information received from the server device 4.

The sensor control unit 24b controls the sensing operation by the sensor unit 22. Specifically, the sensor unit 22 performs a sensing operation at predetermined intervals, and the detected sensor information is output to the communication control unit 24a. Further, the sensor information detected by the sensor unit 22 when a predetermined event occurs is output to the communication control unit 24a. Further, the frequency and timing of the sensing operation by the sensor unit 22 are controlled based on the control information received from the server device 4.

The measurement control unit 24c controls the operation of measuring the remaining amount of the battery 25 by the battery remaining amount measuring unit 23. Specifically, the battery level measuring unit 23 performs a measurement operation at predetermined intervals, and the measured remaining amount information is output to the communication control unit 24a. Further, the frequency and timing of the measurement operation by the battery level measuring unit 23 are controlled based on the control information received from the server device 4.

&lt;Reader 3&gt; The reader 3 is an interface device that transmits and receives various information via the multi-hop network and the network 10. Specifically, the sensor information and the remaining amount information received from the wireless terminal device 2 via the multi-hop network are transmitted to the server device 4 via the network 10. Further, the control information received from the server device 4 via the network 10 is transmitted to the destination wireless terminal device 2 via the multi-hop network.

&lt;Server device 4&gt; The server device 4 is a device that manages the remaining battery level of each wireless terminal device 2, and includes a communication unit 41, a reception information analysis unit 42, a battery level DB (Date Base) 43, a timer unit 44, and the like. It includes a battery level collecting unit 45, an approximate expression calculation unit 46, a predicted time calculation unit 47, a determination unit 48, a display unit 49, a notification destination DB 50, and a notification control unit 51.

The communication unit 41 transmits and receives various information to and from the reader device 3 via the network 10. Specifically, the remaining amount information and the sensor information are received from the terminal device 2 via the multi-hop network, the reader device 3 and the network 10. In addition, control information is transmitted to the terminal device 2 via the network 10, the reader device 3, and the multi-hop network.

The reception information analysis unit 42 analyzes the information received by the communication unit 41, extracts the remaining amount information, and sends it to the battery remaining amount DB 44.

The battery remaining amount DB 43 stores the remaining amount information extracted by the reception information analysis unit 42. Here, the remaining amount information is stored for each wireless terminal device 2.

The timer unit 44 measures a predetermined time, generates a trigger signal when the predetermined time elapses, and sends the trigger signal to the battery remaining amount collecting unit 45.

When the battery remaining amount collecting unit 45 receives the trigger signal from the timer unit 44, the battery remaining amount collecting unit 45 collects and extracts the remaining amount information of each wireless terminal device 2 stored in the battery remaining amount DB 43. This remaining amount information can be freely extracted, for example, all the data stored in the battery remaining amount DB43 or within a predetermined period.

The approximate expression calculation unit 46 calculates an approximate expression based on the remaining amount information extracted by the battery remaining amount collecting unit 45.

The predicted time calculation unit 47 calculates the predicted time when the battery 25 is consumed and the predicted remaining time until the battery is consumed based on the approximate formula calculated by the approximate formula calculation unit 46.

The determination unit 48 determines whether or not the predicted remaining time until the battery 25 is consumed is equal to or less than the threshold value based on the predicted time calculated by the predicted time calculation unit 47. If it is below the threshold value, the notification control unit 51 causes the wireless communication terminal determined to be below the threshold value to send a control signal.

The display unit 49 displays the determination result by the determination unit 48.

The notification destination DB 50 stores identification information for identifying the wireless terminal device 2 included in the wireless communication system 1, information regarding the e-mail address and telephone number of the maintenance manager of each wireless terminal device 2.

The notification control unit 51 generates a control signal addressed to the wireless terminal device 2 whose predicted remaining time is equal to or less than the threshold value based on the determination result by the determination unit 48 and the notification destination DB 51, and transmits this to the communication unit 41.

Such a server device 4 is an input device that detects input of information from the outside such as a computing device such as a CPU, a memory, a storage device such as an HDD (Hard Disc Drive), a keyboard, a mouse, a pointing device, a button, and a touch panel. I / F devices that send and receive various information via communication lines such as the Internet, LAN (Local Area Network), and WAN (Wide Area Network), and CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), or FED. (Field Emission It consists of a computer equipped with a display device such as Display) and a program installed on this computer. That is, by the cooperation of the hardware device and the software, the above hardware resources are controlled by the program, and the above-mentioned communication unit 41, reception information analysis unit 42, battery remaining amount DB43, timer unit 44, and battery remaining amount collection A unit 45, an approximate expression calculation unit 46, a predicted time calculation unit 47, a determination unit 48, a display unit 49, a notification destination DB 50, and a notification control unit 51 are realized. The above program may be provided in a state of being recorded on a recording medium such as a flexible disc, a CD-ROM, a DVD-ROM, or a memory card.

&lt;Operation of wireless communication system&gt; Next, the operation of the wireless communication system will be described.

Information reception operation First, the information receiving operation by the server device 4 will be described with reference to FIG.

In the control unit 24 of the wireless communication terminal 2, the measurement control unit 24c causes the battery level measurement unit 23 to measure the remaining amount of the battery 25, and the sensor control unit 24b causes the sensor unit 22 to perform a sensing operation. When the sensor information and the remaining amount information are generated, the communication control unit 24a transmits the sensor information and the remaining amount information to the server device 4. The sensor information and the remaining amount information transmitted from the wireless terminal device 2 reach the server device 4 via the multi-hop network, the reader 3, and the network 10. When the server device 4 receives the sensor information and the remaining amount information by the communication unit 41 (step S1), the information analysis unit 42 extracts the remaining amount information from the received information (step S2) and stores it in the battery remaining amount DB 43. (Step S3).

Figure 5 shows an example of the remaining battery level DB43. FIG. 5 shows the remaining battery level DB43 in which the remaining amount information received from the wireless terminal devices 2a to 2c driven by the 3 [V] system circuit, that is, the voltage value [V] of the battery 25 is stored at intervals of 5 minutes. The data structure of is shown. In this way, the remaining battery level DB 43 stores the remaining battery level information separately for each wireless terminal device 2 included in the wireless communication system 1 and for each time zone when the server device 4 arrives. Generally, signals from each wireless terminal device 2 are received asynchronously, but may arrive in a plurality of signals in a predetermined time zone or may not reach in a predetermined time zone. When a plurality of values arrive, the information analysis unit 42 stores the average value, the maximum value, or the minimum value of the plurality of values in the battery remaining amount DB 43 as the value of the time zone. In addition, in FIG. 5, the blank part shows the case where the remaining amount information could not be received.

In this way, the remaining battery level DB 43 stores the remaining amount information of each wireless terminal device 2 at predetermined time intervals.

Predictive behavior Next, the predicted operation by the server device 4 will be described with reference to FIG.

First, when a predetermined time is timed by the timer unit 44 and a trigger signal is generated (step S11: YES), the battery remaining amount collecting unit 45 collects the remaining amount information of each wireless terminal device 2 from the battery remaining amount DB 43. collect.

When the remaining amount information is collected, the approximate expression calculation unit 46 calculates the approximate expression based on the remaining amount information (step S12). This calculation method will be described with reference to FIG. Note that FIG. 7 is a graph of the remaining amount information of the battery remaining amount DB43 shown in FIG.

The approximation formula calculation unit 46 calculates a first-order approximation formula by the least squares method or the like based on the remaining amount information within a predetermined period. For example, in the case of FIG. 7, the approximate expression is calculated based on the remaining amount information received from immediately before to 30 minutes before. The period of the remaining amount information, which is the basis for calculating the approximate expression, can be freely set as appropriate based on the interval at which the remaining amount information is received from each wireless terminal device 2, the amount of attenuation of the battery 25, and the like. .. Further, in FIG. 7, in the case of the wireless terminal device 2a, it is assumed that the approximate straight line indicated by the alternate long and short dash line of reference numeral a is calculated.

When the approximate expression is calculated, the predicted time calculation unit 47 calculates the estimated time when the battery 25 is consumed and the estimated remaining time until the battery 25 is exhausted based on the approximate expression (step S14). For example, in FIG. 7, it is assumed that the minimum value of the drive voltage of the wireless terminal devices 2a to 2c is set to 2.5 [V]. At this time, the approximate straight line a of the wireless terminal device 2a and the straight line showing 2.5 [V] intersect at 12:00. Therefore, the predicted time calculation unit 47 calculates the predicted time when the battery 25 of the wireless terminal device 2a is consumed as 12:00. Further, since the current time is 11:40, the predicted time calculation unit 47 calculates that the predicted remaining time until the battery 25 is exhausted is 20 minutes by subtracting the current time from the predicted time.

The minimum value of the drive voltage may be set based on the voltage value when the communication from the wireless terminal device 2 is interrupted in the past.

When the predicted time is calculated, the determination unit 48 determines whether or not there is a wireless terminal device 2 whose predicted remaining time until the battery 25 is consumed is equal to or less than the threshold value (step S15). Here, the threshold value can be freely set as appropriate according to the characteristics of the wireless communication system such as 10 minutes or 1 hour.

When there is a wireless terminal device 2 whose predicted remaining time is equal to or less than the threshold value (step S15: YES), the notification unit 51 notifies the wireless terminal device 2 and the maintenance manager of the wireless terminal device 2 from the notification destination DB50. It is extracted, and the communication unit 41 notifies that the predicted remaining time is equal to or less than the threshold value (step S17). Specifically, the notification unit 41 generates a control signal indicating that the predicted remaining time is equal to or less than the threshold value, and the communication unit 41 transmits this to the wireless terminal device 2. In addition, the notification unit 41 generates an e-mail indicating that the predicted remaining time is equal to or less than the threshold value, and the communication unit 41 sends this to the maintenance manager of the wireless terminal device 2. Further, the notification unit 41 calls the maintenance manager's telephone of the wireless terminal device 2 by the communication unit 41, and outputs a voice guidance message indicating that the predicted remaining time is equal to or less than the threshold value.

The control unit 24 of the wireless terminal device 2 that has received the control signal reduces the frequency of operation of the wireless communication unit 21 by, for example, the communication control unit 24a. In addition, the sensor control unit 24b reduces the frequency of sensing operations by the sensor unit 22. In addition, the measurement control unit 24c reduces the frequency of measurement operations by the battery level measurement unit 23. Further, the timing of each operation is changed so that each or at least two of the wireless communication unit 21, the sensor unit 22, and the battery level measuring unit 23 do not operate at the same time. By performing at least one of these operations, the operation of the wireless terminal device 2 is reduced, and the speed at which the battery 25 is consumed can be slowed down. Therefore, the wireless terminal device 2 should be operated for a long time. As a result, the frequency of maintenance can be reduced.

For example, when a certain wireless terminal device 2 performs a sensing operation once every 10 seconds and transmits sensor information to the server device 4, the amount of power required for the transmission operation of the wireless communication unit 21 and the sensor unit 22 It is assumed that the amount of power required for the sensing operation is larger than the amount of power required for the transmission operation. At this time, the control unit 24 maintains the sensing operation once every 10 seconds, but slows down the consumption speed of the battery 25 of the wireless terminal device 2 by setting the transmission operation once every 20 seconds. can do.

The interval of the transmission operation to be changed and the interval of the sensing operation may be calculated by back calculation from the threshold value so that the operation is longer than the threshold value of the predicted remaining time. For example, when it is determined that the predicted remaining time of a certain wireless terminal device 2 is less than the threshold value of 3 days, the transmission of the wireless terminal device 2 is performed based on the power consumption required for one transmission operation measured in advance. The interval may be calculated back and the server device 4 may send a control signal for changing the transmission interval to the terminal. By doing so, the speed at which the battery of the wireless terminal device 2 is consumed can be slowed down. At this time, the predicted remaining time used for the back calculation may be set to a value longer than the threshold value due to hysteresis.

When the frequency and timing of the transmission operation, the sensing operation, and the measurement operation are changed, the change information indicating the change may be recorded. This change information may be recorded in, for example, a wireless remaining amount DB 43, a database newly provided in the server device 4, or the like. As a result, the change information can be displayed on the display unit 49, and the user can easily grasp the operating status of the wireless terminal device 2.

In addition, the maintenance manager of the wireless terminal device 2 can more effectively recognize that the battery 25 of the wireless terminal device 2 has a short life by receiving an email or a voice guidance message, so that the wireless terminal device 2 can be used. By replacing or charging the battery 25 of 2, it is possible to prevent a malfunction of the wireless communication system 1 from occurring.

When there is no wireless terminal device 2 whose predicted remaining time is equal to or less than the threshold value (step S15: NO) or a control signal is transmitted, the display unit 49 displays the wireless terminal device 2 that the wireless communication system 1 has in the display device. Display the estimated remaining time of (step S16). For example, the predicted remaining time may be displayed as shown in FIG. In FIG. 8, rectangular icons with symbols 2a to 2l represent wireless terminal devices 2a to 2l, dotted lines connecting the icons represent communication paths, and each icon is located at the position of wireless terminal devices 2a to 2l. It is arranged on the display screen based on. In addition, each icon is filled with black for those with an estimated remaining time of 3 days or less, diagonal lines for those with 4 to 30 days, and white for those with an estimated remaining time of 30 days or more. Further, the estimated remaining time is displayed in the vicinity of each icon. By reflecting the predicted remaining time in the colors and characters in this way, the user of the wireless communication system 1 can easily identify the predicted remaining time of the wireless terminal device 2. Further, by displaying the arrangement of the wireless terminal device 2 and the communication path, it is possible to recognize the operating environment of each wireless terminal device 2, so that the degree of consumption of the battery 25 can be easily predicted. For example, in FIG. 8, the wireless terminal device 2a, 2f, 2i is frequently used as a relay device in a multi-hop network because many communication paths are generated with the other wireless terminal device 2, and the life of the battery 25 is extended. It can be predicted that it will be short.

As described above, according to the present embodiment, the life of the battery of the wireless terminal device is more accurate by calculating the estimated time until the battery is consumed based on the remaining amount information of the battery 25 of the wireless terminal device 2. Can be predicted.

In the present embodiment, the approximation formula calculation unit 46 calculates the first-order approximation formula, but it may also calculate the polynomial approximation, the logarithmic approximation, and the like. In particular, when predicting the past long enough, there is a possibility that it may include an inflection point where the tendency of the remaining battery level to drop changes within the specified period, so by calculating the approximate expression by curve approximation. , A more accurate predicted time can be calculated.

Further, in the present embodiment, the predicted time is calculated based on the time change of the remaining battery level, but for example, the prediction is made based on the number of communications, the amount of data, the communication quality, etc. of each wireless terminal device 2. The time may be calculated. Each case will be described below.

(Number of communications) When using the number of communications of the wireless terminal device 2, first, the amount of power of the battery 25 consumed in one communication is measured in advance, and this is measured in advance in the remaining battery DB 43 or the power consumption DB provided in the server device 4. Store in. In such a state, the wireless terminal device 2 measures the number of communications by the wireless communication unit 21 by the communication control unit 24a, and transmits this communication count information to the server device 4. In the server device 4, first, the received communication number information is stored in the battery remaining amount DB 43 or the communication number DB provided in advance in the server device 4. Then, when the trigger signal is generated, the battery remaining amount collecting unit 45 acquires the communication number information within a predetermined period from the battery remaining amount DB 43 or the communication number DB. The approximate expression calculation unit 46 relates to the time change of the power consumption by the same method as the case of using the time change of the remaining battery level described above based on the acquired number of times information and the amount of power consumed in one communication. Calculate an approximate expression. The estimated time calculation unit 47 calculates the estimated time when the battery 25 is consumed and the estimated remaining time until the battery 25 is exhausted based on the calculated approximation formula and the remaining amount information stored in the battery remaining amount DB 43. To do.

(amount of data) When using the amount of data transmitted from the wireless terminal device 2, first, the amount of power of the battery 25 consumed in one communication operation is measured in advance, and this is previously measured in the remaining battery DB 43 or the server device 4. Store in the provided power consumption DB. In such a state, the wireless terminal device 2 measures the number of communications by the wireless communication unit 21 by the communication control unit 24a, and transmits this communication count information to the server device 4. First, the server device 4 stores the received communication count information in the battery remaining amount DB 43 or the communication count DB provided in advance in the server device 4. At this time, the reception information analysis unit 42 analyzes the transmission signal received from the wireless terminal device 2 to detect the number of sensings and the packet length, and the data amount information is also obtained from the battery remaining amount DB43 or the communication number DB. Store. Then, when the trigger signal is generated, the battery remaining amount collecting unit 45 acquires the communication number information and the data amount information within a predetermined period from the battery remaining amount DB 43 or the communication number DB. The approximate expression calculation unit 46 calculates the power consumption of the wireless terminal device 2 required to deliver one transmission information to the server device 4 based on the power consumption and the data amount information in one communication operation. Based on this and the acquired number of times information, an approximate expression regarding the time change of the power consumption is calculated by the same method as in the case of using the time change of the remaining battery level described above. The estimated time calculation unit 47 calculates the estimated time when the battery 25 is consumed and the estimated remaining time until the battery 25 is exhausted based on the calculated approximation formula and the remaining amount information stored in the battery remaining amount DB 43. To do.

For example, in the case of the transmission signal of the wireless terminal device 2 shown in FIG. 9, the transmission signal includes two sensor information generated by the wireless terminal device 2. From this, the reception information analysis unit 42 detects that the number of times of sensing performed in one communication by the wireless terminal device 2 is two. Further, the time required for transmission is calculated from the signal length of the transmission signal, and the amount of power consumed in the transmission operation of the transmission signal in one communication is calculated from the amount of power with respect to the communication time of the wireless terminal device 2. Finally, one transmission signal is delivered to the server device 4 from the amount of power consumed in the sensing operation, the amount of power consumed in the transmission operation, and the amount of power consumed in normal operation such as standby power of the wireless terminal device 2. Calculate the amount of power consumed. An approximate expression is calculated based on this electric energy, the number of times the transmission signal is communicated, and the remaining amount information of the battery 25, and the estimated time when the battery 25 is consumed is calculated based on this approximate expression.

(Communication quality) When using the communication quality of the wireless terminal device 2, first, the wireless terminal device 2 is provided with a function for measuring the wireless communication quality, and this communication quality information is stored in the battery remaining amount DB 43 or the power consumption DB provided in advance in the server device 4. Store in. In such a state, the server device 4 stores the received communication quality information in the battery remaining amount DB 43 or the communication quality DB provided in advance in the server device 4. Then, when the trigger signal is generated, the battery remaining amount collecting unit 45 acquires the communication quality information within a predetermined period from the battery remaining amount DB 43 or the communication number DB. The approximate expression calculation unit 46 calculates the power consumption required to deliver one signal to the server from the number of retransmissions predicted for the communication quality based on the acquired communication quality information, and this power amount and the server The predicted time is calculated based on the number of signals delivered to the device 4 by calculating an approximate expression in the same manner as in the case of using the time change of the remaining battery level described above.

For example, the wireless terminal device 2 has a function of measuring the electric field strength (RSSI) for a wireless link with another wireless terminal device 2 and transmitting it to the server device 4, and the server device 4 has a wireless terminal as shown in FIG. A formula may be provided in advance by measuring the number of times retransmission occurs with respect to the electric field strength between the devices 2. In this case, the approximate expression calculation unit 46 of the server device 4 first calculates the expected value of the number of times retransmission occurs from the value of the electric field strength included in the signal received from the wireless terminal device 2. In the case of FIG. 10, the expected value of retransmission when the electric field strength is A is one. Next, the sum of this expected value and one time of the received signal itself is calculated as the expected value of the number of signal transmissions required for one signal transmission, and the power consumption is calculated based on the number of signal transmissions. To do. Based on this amount of power and the number of transmitted signals received within a predetermined period, an approximate expression regarding the time change of power consumption is calculated by the same method as in the case of using the time change of the remaining battery level described above. The estimated time calculation unit 47 calculates the estimated time when the battery 25 is consumed and the estimated remaining time until the battery 25 is exhausted based on the calculated approximation formula and the remaining amount information stored in the battery remaining amount DB 43. To do.

The server device 4 counts the communication frequency of the wireless terminal device 2 for a predetermined period, and divides the difference between the remaining battery level before counting and the remaining battery level after counting by the communication frequency to obtain a battery for one communication. The power consumption of 25 may be calculated. In this case, the predicted time is calculated based on the calculated electric energy and the number of times of communication of the transmission signal by calculating the approximate expression in the same manner as in the case of using the time change of the remaining battery level described above.

Further, in the present embodiment, the prediction operation is performed by the server device 4, but it may be performed by the wireless terminal device 2. In this case, the components of the server device 4 surrounded by the dotted line in FIG. 3, that is, the battery remaining amount DB 43, the timer unit 44, the battery remaining amount collecting unit 45, the approximate expression calculation unit 46, the predicted time calculation unit 47, and the determination unit. This can be achieved by providing 48 in the wireless terminal device 2. Specifically, it can be realized by storing the remaining amount information measured by the battery remaining amount measuring unit 23 in the battery remaining amount DB 43 and performing the prediction operation described with reference to FIG. This will

Further, in the present embodiment, various information is collected in the server device 4 via the network 10, but for example, the reader device 3 and the server device 4 may be directly connected by a USB cable or the like.

[Second Embodiment] Next, a second embodiment according to the present invention will be described. In this embodiment, the plurality of wireless terminal devices 2 included in the first embodiment described above are divided into a plurality of groups. Therefore, in the present embodiment, the same components as those in the first embodiment are designated by the same names and reference numerals, and the description thereof will be omitted as appropriate.

For example, in a wireless communication system arranged in a mountainous area or the like, maintenance is difficult, so that the installation of the wireless terminal device 2 may be provided with redundancy. In other words, there are cases where a large number of wireless terminal devices 2 are arranged in advance, and even if the batteries of the wireless terminal devices 2 are consumed to some extent, it is sufficient that any of the wireless terminal devices 2 is operating. is there. In such a case, a plurality of wireless terminal devices 2 are grouped in advance, and the longest predicted remaining time of the wireless terminal devices 2 included in the group is set as the predicted remaining time of the group.

As an example, in the case of FIG. 11, wireless terminal devices 2a, wireless terminal devices 2b and 2c, wireless terminal devices 2d and 2e, wireless terminal devices 2f and 2i, wireless terminal devices 2g and 2j, wireless terminal devices 2h, wireless terminal devices 2k. And 2l are grouped. Here, in the group of the wireless terminal devices 2b and 2c, the predicted remaining time of the wireless terminal device 2b is "3 days" and the predicted remaining time of the wireless terminal device 2c is "30 days or more". Is "30 days or more".

Group settings related to such grouping can be freely performed as appropriate based on the application, configuration, etc., depending on the physical positional relationship, the type of sensor, and the like. For this group setting, a group setting DB may be provided in advance in the server device 4 and registered in the group setting DB. In addition, the group setting may be registered in the notification destination DB50.

Predictive behavior Next, with reference to FIG. 12, the predicted operation by the server device 4 in the present embodiment will be described. In FIG. 12, the steps equivalent to the prediction operation described with reference to FIG. 6 in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

When the predicted time is calculated in steps S11 to S14, the determination unit 48 determines whether or not there is a wireless terminal device 2 in which the predicted remaining time until the battery 25 is consumed is equal to or less than the threshold value (step S15).

When there is a wireless terminal device 2 whose predicted remaining time is equal to or less than the threshold value (step S15: YES), the determination unit 48 confirms whether or not the wireless terminal device 2 is set as a group (step S21). This confirmation is performed by confirming the group setting DB and the notification destination DB50.

When the group is set (step S21: YES), the determination unit 48 acquires the estimated remaining time of other terminal devices in the group to which the wireless terminal device 2 determined to be below the threshold value belongs, and predicts the group. Calculate the remaining time (step S22). The estimated remaining time of this calculated group is displayed on the display unit 49. At this time, the display unit 49 may display information on whether or not the predicted remaining time of the group exceeds the above threshold value.

When the estimated remaining time of the group is calculated, the notification unit 51 extracts a preset destination associated with the group from the notification destination DB 50, and notifies the communication unit 41 that the estimated remaining time is equal to or less than the threshold value. Then (step S23), the process of step S17 is performed.

On the other hand, if the group is not set (step S21: NO), the server device 4 performs the process of step S17.

As described above, according to the present embodiment, when the plurality of wireless terminal devices 2 are divided into a plurality of groups and the predicted remaining time of the wireless terminal devices 2 set in the groups is equal to or less than the threshold value, this is notified to the group. Since the notification is sent to the associated destination, it is possible to prevent the entire system from malfunctioning by performing maintenance such as battery replacement and charging of the wireless terminal device 2 based on this notification.

In the present embodiment, the longest predicted remaining time of the wireless terminal device 2 included in the group is set as the predicted remaining time of the group, but conversely, the wireless terminal device 2 included in the group The shortest predicted remaining time of the group may be set as the predicted remaining time of the group. For example, in the case of a wireless terminal device 2 that functions as various sensors provided in a car, if a problem occurs even in one wireless terminal device 2, a major problem may occur as a whole. In such a case, by setting the shortest predicted remaining time of the wireless terminal device 2 included in the group as the predicted remaining time of the group, it is possible to prevent a malfunction in the entire system. ..

Further, in each of the above-described embodiments, the wireless communication system 1 including the wireless terminal device 2 for transmitting sensor information has been described. However, if the wireless communication system includes a wireless terminal device operated by a battery, various systems are used. Needless to say, it can be applied to.

Further, in each of the above-described embodiments, the wireless terminal device 2 and the server device 4 have been described as being connected via a multi-hop network, a reader 3, and a network, but are connected via a wireless network. If so, for example, a direct connection via a wireless network, a combination of a wireless network and a wired network, and the like can be freely connected as appropriate.

The present invention can be applied to a wireless terminal device driven by a battery and a wireless communication system having the wireless terminal device.

<figref num="1">It is a schematic diagram which shows the structure of the wireless communication system of this invention.</figref><figref num="2">It is a block diagram which shows the structure of a wireless communication terminal.</figref><figref num="3">It is a block diagram which shows the structure of a server apparatus.</figref><figref num="4">It is a flowchart which shows the information reception operation.</figref><figref num="5">It is a figure which shows the remaining amount information schematically.</figref><figref num="6">It is a flowchart which shows the prediction operation.</figref><figref num="7">It is the figure which graphed the remaining amount information shown in FIG.</figref><figref num="8">It is a figure which shows typically the display screen of the display part 49.</figref><figref num="9">It is a figure which shows typically the data structure of a transmission signal.</figref><figref num="10">It is a figure which shows an example of the relationship between the electric field strength and the number of retransmissions.</figref><figref num="11">It is a figure which shows typically the display screen of the display part 49 of the 2nd Embodiment.</figref><figref num="12">It is a flowchart which shows the prediction operation of the 2nd Embodiment.</figref>

Code description

1 ... communication system, 2 ... wireless terminal equipment, 3 ... reader, 4 ... server, 10 ... network, 21 ... wireless communication unit, 22 ... sensor unit, 23. .. Battery level measurement unit, 24 ... control unit, 24a ... communication control unit, 24b ... sensor control unit, 24c ... measurement control unit, 41 ... communication unit, 42 ... Received information analysis unit, 43 ... Battery level DB, 44 ... Timer unit, 45 ... Battery level collection unit, 46 ... Approximate formula calculation unit, 47 ... Predicted time calculation unit, 48 ... Judgment unit, 49 ... Display unit, 50 ... Notification destination DB, 51 ... Notification control unit.