JP2013026699A - Radio communication apparatus, radio communication method, and radio communications system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress electric power required for reception in radio communication.SOLUTION: A radio communication apparatus, radio communication method and radio communications system according to the present invention reads out history information from a circuit for storing start records as history information when the apparatus is driven by radio waves from the outside and receives the electric waves from the outside for starting, thereby conducting radio communication suited to the read-out history information for saving of standby power.

Description

  The present invention relates to wireless communication technology, and more particularly to reduction of power required for reception standby of a wireless communication device.

  As a wireless communication system having a base station and a wireless communication device, there is an active tag system. An active tag system is a system that performs wireless communication between an active tag, which is a wireless communication device, and a base station. A power source is provided on the active tag side, and a communication distance is generally several tens of meters. In an active tag system, a different carrier frequency is generally used for each base station in order to prevent interference. The carrier frequency is called a channel. In a wireless communication device mounted on a vehicle, it is possible to switch the channel to be received at every predetermined detection time, which solves the problem of high costs when the wireless communication device is provided with receiving means corresponding to the number of operated channels. A wireless communication device that waits for reception is known (Patent Document 1).

JP 2000-307506 A

  In the case of a wireless communication device mounted on a vehicle, power supply from the vehicle can be generally obtained, so that power consumption required for reception standby does not matter. However, in the case of a wireless communication device that has a limited power source such as a battery, such as an active tag carried by a person, power consumption required for standby for reception becomes a problem.

  The wireless communication apparatus of the present invention is driven by external radio waves, and when activated by receiving external radio waves, the first circuit for storing the activated recording as history information, a power source, and the power of the power source are driven. And a second circuit for reading the history information.

  A wireless communication method of the present invention is a wireless communication method with a base station that performs radio communication by transmitting a radio wave at one carrier frequency among a plurality of carrier frequency candidates. When a circuit driven by a radio wave of any carrier frequency is activated, the process of storing the activated record as history information in the memory, and referring to the memory, if there is a record activated by the circuit, the base station And a step of searching.

  The wireless communication system of the present invention includes a base station that transmits radio waves of one carrier frequency among a plurality of carrier frequency candidates and performs wireless communication, and a memory, and any radio wave of any carrier frequency among the candidates. When it is driven and activated by receiving a radio wave from the base station, the first circuit for storing the activated record in the memory as history information and the memory are referred to, and if there is an activated record, the base station is searched. A wireless communication device having a second circuit.

  In the present invention, history information recorded without depending on the power of a power source such as a battery is used, so that standby power can be reduced.

It is a figure which shows the structural example of the radio | wireless communications system of this invention. It is a figure which shows the structural example of the radio | wireless communication apparatus of this invention. It is a figure which shows the structural example of the 1st circuit in the radio | wireless communication apparatus of this invention. It is a figure which shows the example of operation | movement of the 1st circuit in the radio | wireless communication apparatus of this invention. It is a figure which shows the structural example of the radio | wireless communication apparatus of this invention. It is a figure which shows the example of the procedure which determines the priority of a channel search in the radio | wireless communication apparatus of this invention. It is a figure which shows an example of the communication history memorize | stored in the memory in the example of the radio | wireless communication apparatus of this invention. It is a figure which shows the structural example of the radio | wireless communication apparatus of this invention. It is a figure which shows the example of application to entrance / exit management. It is a figure which shows the example of application to a positioning system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 shows an active tag system 100 as a wireless communication system as an example of an embodiment of the present invention. In the active tag system 100, there are a plurality of base stations 101 and 102, and the base stations 101 and 102 communicate with the wireless communication device 103 and the wireless communication device 104 by transmitting radio waves. In the example illustrated in FIG. 1, the wireless communication device 103 receives data 105 transmitted on radio waves transmitted from the base station 101. In addition, the other wireless communication device 104 receives the data 106 transmitted on the radio wave transmitted from the base station 102.

  Here, when the base station 101 and the base station 102 are installed close to each other, the wireless communication apparatus 103 interferes with radio waves transmitted from the base station 102 in addition to the data 105 transmitted by the base station 101. It will be received as a wave 107. Therefore, there is a possibility that the wireless communication apparatus 103 cannot receive the data 105 correctly due to the influence of the interference wave 107.

  Therefore, in this embodiment, reception errors are prevented by using different channels for carrier wave frequencies (hereinafter referred to as channels) of radio waves transmitted by the base station 101 and the base station 102, respectively. That is, a plurality of channel candidates are prepared, and each base station uses one of the plurality of channel candidates. In this embodiment, the frequency band of each channel is selected from the 950 MHz band.

  Accordingly, the wireless communication apparatus 103 searches for a channel transmitted by the base station 101 from a plurality of channels (for example, 6 channels) (hereinafter referred to as channel search), and receives the data 105 by selecting the channel. . For example, the wireless communication device 103 activates a reception circuit of the wireless communication device 103 and sets a channel for reception. Then, the wireless communication apparatus 103 sequentially switches the receiving channel and searches for data 105 transmitted from the base station 101. For example, when there are 6 channels in all of channels 1 to 6, the wireless communication apparatus 103 performs channel search by scanning in the order of channel 1, channel 2, channel 3, channel 4, channel 5, and channel 6.

  FIG. 2 shows a wireless communication device 200 as an example of the wireless communication device 103. As shown in FIG. 2, the wireless communication apparatus 200 includes a first circuit 201 that generates and drives power using external radio waves, a power source 202, a second power source that is driven by the power source 202 and communicates with the first circuit 201. Circuit 203.

  The first circuit generates and drives power in any frequency band of channel candidates used by the base station 101. That is, the first circuit drives any channel candidate channel used for the base station 101. The first circuit 201 includes a memory. As the power source 202, for example, a battery or a capacitor can be used. In this embodiment, a battery is used for the power source 202. FIG. 2 shows an example in which the first circuit 201, the power source 202, and the second circuit 203 are included in the casing. However, as described later in the fourth embodiment, the power source 202 and the second circuit 203 are included in the casing. The first circuit 201 may be provided on a medium such as an IC card attached to the housing.

  The circuit configuration of the first circuit 201 is shown in FIG. As shown in FIG. 3, the first circuit 201 includes a rectifier circuit 301 that rectifies the received signal, a power detection circuit 302 that detects the power value of the output of the rectifier circuit 301, history information on the startup of the first circuit, and the like. A memory 303 to be stored, a logic circuit 304 for instructing each circuit to perform an operation, a demodulation circuit 305 for demodulating a signal from a passive reader / writer circuit 204 described later, and a signal generated by the logic circuit 304 in accordance with the demodulated data Is provided with a transmission circuit 306 and an antenna 307. The antenna 307 is, for example, a dipole antenna, and can receive a 950 MHz band radio wave transmitted from the base station of this embodiment, and can transmit a 950 MHz band radio wave. As the memory 303, for example, a nonvolatile memory such as a flash memory or a phase change memory is used.

  The second circuit 203 includes a passive reader / writer (hereinafter referred to as passive R / W) circuit 204 that wirelessly communicates with the first circuit 201, an active tag circuit 205 that wirelessly communicates with a base station that is an external wireless communication device, and a passive And a control circuit 206 that controls the R / W circuit 204 and the active tag circuit 205. The passive R / W circuit 204, the active tag circuit 205, and the control circuit 206 are supplied with power from the power source 202. The power supply 202 and the active tag circuit 205 constitute an active tag. In other words, the power supply 202 and the active tag circuit 205 constitute an IC tag capable of transmitting and receiving signals with a base station serving as a reader / writer over a long distance of about several tens of meters. In addition, the passive R / W circuit 204 performs a read operation and a write operation by sending a radio wave of 950 MHz band. Since the passive R / W circuit 204 uses radio waves in the same frequency band as the base station, the first circuit 201 can be supplied with power from the base station or the second circuit 203 using a common circuit. Therefore, the wireless communication device 103 can be manufactured at a low cost.

  In the basic communication procedure between the wireless communication apparatus 103 and the base station 101, the base station 101 transmits the data 105, the first circuit 201 is activated by the data 105, that is, the radio wave from the base station 101, and the first circuit 201 The activated history is stored in the memory 303 as history information. For example, by using 1 bit of the memory 303, “0” is stored as an initial value before activation, and history information is stored as “1” as a history of activation.

  Hereinafter, the details of the operation of each circuit in the basic communication procedure will be described.

  The operation of the first circuit 201 is shown in FIG. As shown in FIG. 4, the first circuit 201 rectifies the received signal with the rectifier circuit 301 to generate internal operating power (step S1). The output of the rectifier circuit 301 is transmitted to the power detection circuit 302 and the demodulation circuit 305. Thereafter, the power detection circuit 302 detects the power value of the received signal. The demodulation circuit 305 demodulates the received signal (step S2). Next, the logic circuit 304 determines whether or not the demodulated signal of the demodulating circuit 305 is a transmission signal from the passive R / W circuit 204 (step S3).

  When the demodulated signal is a transmission signal from the passive R / W circuit 204, processing according to the transmission signal of the passive R / W circuit 204 is performed (step S4). For example, if the transmission signal requests history information recorded in the memory 303, the transmission circuit 306 transmits the history information via the antenna 307.

  When the demodulated signal is not a transmission signal of the passive R / W circuit 204, “start-up” is stored as history information in the memory 303 of the first circuit 201 (step S6). If the history information is stored with 1 bit, the initial state is rewritten from “0” to “1”. Here, by providing step S5, when the power value detected by the power detection circuit 302 is lower than a preset threshold value, it is possible to perform processing that does not store “activated” in the history information. Accordingly, it is possible to set the wireless communication device 103 to start wireless communication in a radio wave state in which power larger than power sufficient to activate the first circuit 201 is supplied. It is possible to adjust the distance for communication between the station and the wireless communication device 103. Further, if the threshold value in step S5 is set to 0, for example, history information of “with activation” can be simply stored.

  In the second circuit 203, the control circuit 206 intermittently (for example, every few seconds to every few minutes) the history information stored in the memory 303 of the first circuit 201 with respect to the passive R / W circuit 204. Command reading. The passive R / W circuit 204 that has received the read command reads history information from the first circuit 201. As a history information reading procedure, for example, a wireless communication procedure compliant with ISO / IEC 18000-6C of the international standard is used.

  The passive R / W circuit 204 transmits the history information read from the first circuit 201 to the control circuit 206. When the read history information is “1”, which is the activation history, the control circuit 206 instructs the active tag circuit 205 to start wireless communication with the base station. Upon receiving the command, the active tag circuit 205 searches for a base station by activating a receiving circuit included in the active tag circuit 205 and performing a channel search.

  When the channel search succeeds in identifying the channel used by the base station 101, the active tag circuit 205 selects the identified channel and receives the data 105. Further, under the control of the control circuit 206, the passive R / W circuit 204 resets the history information of the memory 303 of the first circuit 201, that is, returns the bit of the memory 303 to “0”.

  On the other hand, when the history information is “0” indicating that there is no activated history, the control circuit 206 does not command the active tag circuit 205 to start wireless communication with the base station. Therefore, channel search is not performed. As described above, when there is no base station capable of communication, the operation of the wireless communication device 103 can be limited, and standby power of the wireless communication device 103 can be suppressed.

  Through the above steps, wireless communication between the wireless communication apparatus 103 and the base station 101 ends.

  As described above, the wireless communication apparatus 103 according to the present embodiment uses the power generated from the radio wave transmitted from the base station to activate the first circuit 201 and stores the activation history in the memory 303 as history information. leave. Then, the second circuit 203 of the wireless communication device 103 reads the history information. The wireless communication device 103 performs wireless communication according to the read history information. That is, when the read history information includes a start history, the wireless communication device 103 sets a receiving circuit included in the active tag circuit 205. It starts up, searches for a base station, and receives data carried on radio waves transmitted from the base station.

  The wireless communication apparatus 103 can confirm the presence of the base station from the history information of the first circuit 201 in an intermittent operation without waiting for the reception circuit of the active tag circuit 205 to be constantly activated, and can wait for reception with low power consumption. realizable. Also, the wireless communication device 103 does not perform a channel search when there is no activated history in the history information, such as when the distance between the wireless communication device 103 and the base station is outside the assumed distance range. Thus, the operation can be limited, and standby power can be further suppressed. Therefore, power consumption of the wireless communication apparatus 103, that is, consumption of the battery of the power source 202 can be prevented.

  FIG. 5 illustrates a wireless communication apparatus 501 to which a memory 500 is further added as an example of the wireless communication apparatus 103 according to the first embodiment. In the memory 500, a communication history of the active tag circuit 205 is recorded. Specifically, data 105 received by the active tag circuit 205 from the base station 101 and information on the reception channel are stored in the memory 500 via the control circuit 206.

  The wireless communication procedure between the wireless communication device 501 and the base station 101 of the present invention is basically the same as the wireless communication procedure between the wireless communication device 103 and the base station 101 of the first embodiment, but the difference is in the channel search. The search order of each channel is changed in accordance with the information of the reception channel stored in the memory 500.

  In the first embodiment, as an example of the channel search order, when there are 6 channels in total, the channel search order is shown in the order of channel 1, channel 2, channel 3, channel 4, channel 5, and channel 6. . In the wireless communication apparatus 501 of this embodiment, the reception circuit of the previous communication stored in the memory 500 is referred to by the reception circuit of the active tag circuit 205 via the control circuit 206, and the reception channel of the previous communication is referred to. The channel search order is set so that other channels are given priority. In the case where there are 6 channels in all of channels 1 to 6 and the previous reception channel is channel 2, channel 2 is the last, for example, channel 3, channel 4, channel 5, channel 6, Channel search is performed in the order of channel 1 and channel 2. Further, when there is communication with the base station 101, the active tag circuit 205 stores the data 105 and the information of the reception channel transmitted from the base station 101 in the memory 500 via the control circuit 206. Thereby, the information of the reception channel memorize | stored in the memory 500 is updated whenever it communicates.

  As described above, in the channel search of the active tag circuit 205, the wireless communication device 501 of this embodiment refers to the reception channel of the previous communication stored in the memory 500 and prioritizes channels other than the reception channel of the previous communication. Channel search. Therefore, when the wireless communication device 501 exists at a position where it can receive transmission data of a plurality of base stations, it is possible to prevent the wireless communication device 501 from continuously receiving transmission data of the same base station. .

  In the first embodiment and the second embodiment, a case where a plurality of base stations use different channels for each base station has been described. However, different base stations use the same channel to transmit data so that transmission times do not overlap. In some cases, the wireless communication device 501 needs to continuously receive transmission data of different base stations on the same channel.

  Therefore, in the present embodiment, in the wireless communication apparatus 501, the channel search priority of the active tag circuit 205 is set using the received data as well as the received channel stored in the memory 500 according to the procedure shown in FIG. decide.

  As shown in FIG. 6, the active tag circuit 205 reads the communication history stored in the memory 500 via the control circuit 206 (step S61). Then, it is determined whether or not the previous and previous reception channels are the same (step S62). FIG. 7 shows an example of the communication history stored in the memory 500. As shown in FIG. 7, when the previous and previous reception channels are the same, it is determined whether the previous and previous reception data are the same (step S63). If the previous and last received data are different as shown in FIG. 7, the previous channel is preferentially searched for a channel (step S64). For example, in the case of FIG. 7, when there are 6 channels in total, since the previous reception channel is channel 2, channel 2 is first, for example, channel 2, channel 3, channel 4, channel 5, channel 6, channel 1 Channel search in the order of.

  If the reception channel of the previous time is different from the previous time in the determination of step S62, or if the reception data of the previous time and the previous time is the same in the determination of step S63, the channel search is performed with priority other than the previous reception channel (step S65).

  As described above, in this embodiment, the channel search priority of the active tag circuit 205 is determined based on the communication history of the reception channel and reception data stored in the memory 500. Therefore, when different base stations use the same channel to transmit data so that transmission times do not overlap, the wireless communication device 501 continuously receives transmission data of different base stations using the same channel. Is possible.

  In this embodiment, the power source 202 and the second circuit 203 are provided in a casing, and the first circuit 201 is provided in a medium such as an IC card attached to the casing. By adopting this form, the wireless communication apparatus of the present invention can be realized at low cost by using a medium such as an existing housing or IC card.

  FIG. 8 shows a wireless communication device 802 provided as an example of the wireless communication device 103 in an IC card 801 in which a first circuit 201 is attached to a housing containing a power source 202 and a second circuit 203. Since the first circuit 201 is not built in the housing and is attached to the housing, the first circuit 201 is the same as the first to third embodiments, and thus the description of the operation is omitted.

  In addition, attachment of the medium to a housing | casing is realizable by sticking with an adhesive, for example. Moreover, as a housing | casing, you may utilize the housing | casing of a mobile telephone as shown in FIG. Further, in the case of using the casing of the mobile phone, it is possible to realize a wireless communication system that uses the wireless communication function of the mobile phone itself in addition to the active tag circuit 205.

  In this embodiment, an example in which the wireless communication system of the present invention is used for entrance / exit management is shown.

  FIG. 9 shows an example of application to entrance / exit management. A base station 101 is installed in the room 901, and a base station 102 is installed in the room 902. The walls of each room shall shield radio waves from each base station. Base station 101 and base station 102 are connected to a server (not shown). The server stores information on the time when a person carrying the wireless communication device 103 uses each room, for example, the start and end times of the conference. The data 105 includes information on the usage time of the room 901.

  The wireless communication apparatus 103 carried by the person 903 near the entrance of the room 901 activates the first circuit 201 using the transmission of the data 105 transmitted from the base station 101 and leaves the activation history in the memory 303. Then, the second circuit 203 of the wireless communication device 103 reads the history information. Thereafter, the receiving circuit included in the active tag circuit 205 is activated and the data 105 is received. As described above, the wireless communication apparatus 103 obtains information on the usage time of the room 901 from the data 105. Here, for example, when the mobile phone shown in the fourth embodiment is used, information on the usage time can be displayed on the display screen of the mobile phone, and the person carrying the wireless communication device 103 is scheduled at the meeting place. You can check if you can arrive on the street.

  On the other hand, the wireless communication device 104 carried by the person 904 leaving the room 901 cannot receive the data 105 because the transmission data 105 of the base station 101 is blocked by the wall of the room 901. Here, the wireless communication device 104 is the same type of device as the wireless communication device 103, and the identification number as an active tag stored in the active tag circuit 205 is different from that of the wireless communication device 103. Therefore, in the wireless communication device 104 carried by the person 904, the first circuit 201 is not activated, the active tag circuit 205 is suspended, and standby power is suppressed. Therefore, power consumption of the wireless communication device 104, that is, consumption of the battery of the power source 202 can be prevented.

  Here, when the history information is read and there is no history of the first circuit 201 being activated, the interval until the next history information is read is set to 10 seconds, for example, and the first circuit 201 is activated. If there is a history, the interval until the next history information is read out is made longer, for example, 60 seconds, so that data such as conference date and time information that is not frequently required as in this embodiment is used. When the wireless communication device 103 is in a place where it can communicate with the base station, power consumption can be further reduced.

  In this embodiment, an example in which the wireless communication system of the present invention is used for positioning will be described.

  FIG. 10 shows an example of application to positioning. Base stations 1001, 1002, and 1003 are arranged, a database (not shown) is provided with a database, and the positions of the base stations 1001, 1002, and 1003 are stored in the database. In this embodiment, the distances at which the first circuit 201 of the wireless communication apparatus 103 can be activated by the radio waves of the base stations 1001, 1002, and 1003 are set to 5 m, respectively. The data transmitted by each base station includes information on each base station.

  In the wireless communication apparatus 103 carried by a person 1004 within a range of 5 m from the base station 1001, the first circuit 201 is activated by the radio wave from the base station 1001, and the activation history remains in the memory 303. Then, the second circuit 203 of the wireless communication device 103 reads the history information. Thereafter, the reception circuit included in the active tag circuit 205 is activated, and the transmission data from the base station 1001 is received. As described above, the wireless communication apparatus 103 obtains information indicating that it is within 5 m from the base station 1001.

  Here, for example, when the mobile phone shown in the fourth embodiment is used, information can be displayed on the display screen of the mobile phone, and the person 1004 carrying the wireless communication device 103 is in the vicinity of the base station 1001. I can confirm that. The wireless communication apparatus 103 connects to a server in which the location information of the base stations 1001, 1002, and 1003 is stored in the database through a mobile phone line, acquires the location information of the base station, and sets the current location to about 5 m. It is possible to measure with a resolution of. In order to perform positioning with higher accuracy, in addition to the base station 1001, the transmission data of the base stations 1002 and 1003 is received by the active tag circuit 205, and wirelessly determined from the position information of each base station and the radio wave intensity from each base station. The position of the communication device 103 can also be derived. By connecting to the server via a mobile phone line, it is possible to save labor for wiring between the base station and the server, and a positioning system can be introduced at a low cost. Also, by providing the base station itself with a function of connecting to a mobile phone line, it is possible to connect to the server from the active tag circuit 205 via the base station, and to save the labor of wiring between the base station and the server. The positioning system can be introduced at a low cost. The system of the present embodiment is particularly suitable for indoor positioning where it is difficult to use GPS. In addition, by storing the measured position of the wireless communication device 103 in the database of the server through a mobile phone line, the current position of the wireless communication device 103 can be confirmed by connecting to the server.

  On the other hand, the wireless communication device 104 carried by the person 1005 located at a distance of more than 5 m from any of the base stations 1001, 1002, 1003 is not in an area where the current position can be measured. Here, the wireless communication device 104 is the same type of device as the wireless communication device 103, and the identification number as an active tag stored in the active tag circuit 205 is different from that of the wireless communication device 103. In this case, in the wireless communication device 104 carried by the person 1005, the first circuit 201 is not activated, the active tag circuit 205 is suspended, and standby power is suppressed. Therefore, power consumption of the wireless communication device 104, that is, consumption of the battery of the power source 202 can be prevented.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 100 ... Active tag system, 101, 102 ... Base station, 103, 104 ... Wireless communication apparatus, 105, 106 ... Data, 107 ... Interference wave, 201 ... First circuit, 202 ... Power supply, 203 ... Second circuit, 204 ... Passive reader / writer (passive R / W) circuit, 205 ... active tag circuit, 206 ... control circuit, 301 ... rectifier circuit, 302 ... power detection circuit, 303 ... memory, 304 ... logic circuit, 305 ... demodulation circuit, 306 ... transmission Circuit, 307 ... antenna.

Claims (15)

A first circuit that is driven by an external radio wave and receives a radio wave from the outside to activate and record the activated recording as history information;
Power supply,
And a second circuit that is driven by the power of the power source and reads the history information. The wireless communication device according to claim 1,
The wireless communication device selects one of a plurality of carrier frequency candidates and communicates with an external wireless communication device,
The wireless communication apparatus, wherein the first circuit is activated by any radio wave among the candidates. The wireless communication device according to claim 1,
A wireless communication apparatus that performs wireless communication according to the history information. The wireless communication device according to claim 1,
When the second circuit reads the history information, the wireless communication device searches for a carrier frequency of an external radio wave if there is a record that the first circuit is activated in the history information. A wireless communication device. The wireless communication device according to claim 1,
The second circuit intermittently reads the history information,
When the second circuit reads out the history information, the history information includes a record in which the first circuit is activated, compared to a case in which the history information has no record in which the first circuit is activated. A wireless communication apparatus characterized in that the time until the next reading of the history information is lengthened. The wireless communication device according to claim 1,
The second circuit is provided in a housing;
The wireless communication apparatus, wherein the first circuit is provided in a medium attached to the housing. The wireless communication apparatus according to claim 6, wherein
A wireless communication apparatus, wherein the casing is a casing of a mobile phone. The wireless communication apparatus according to claim 6, wherein
The wireless communication apparatus, wherein the medium is an IC card. The wireless communication device according to claim 1,
The wireless communication apparatus, wherein the power source is a battery. A wireless communication method with a base station that performs radio communication by transmitting a radio wave at one carrier frequency among a plurality of carrier frequency candidates,
When a circuit that has a memory and is driven by radio waves of any carrier frequency among the candidates is activated, the activated recording is stored in the memory as history information;
And a step of searching for the base station when there is a record of activation of the circuit with reference to the memory. The wireless communication method according to claim 10, wherein
In the step of performing the search, the plurality of carrier frequencies are scanned. The wireless communication method according to claim 10, wherein
A wireless communication method, wherein the memory is a flash memory. A base station that wirelessly communicates by transmitting radio waves of one of the plurality of carrier frequency candidates,
A first circuit that has a memory, is driven by radio waves of any of the carrier frequencies of the candidates, and that activates upon receipt of radio waves from the base station, stores the activated recording in the memory as history information; and A wireless communication apparatus comprising: a wireless communication device having a second circuit for searching for the base station when there is a record of the first circuit being activated with reference to a memory. The wireless communication system according to claim 13,
The base station is installed in a room;
The base station is connected to a server for storing reservation information for the room;
The wireless communication system, wherein the base station transmits the reservation information to the wireless communication device. The wireless communication system according to claim 13,
Having a database for storing location information of the base station;
A wireless communication system, wherein the position of the wireless communication device is measured based on the position information.

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