JP2003023367A - Method and system for radio communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform radio communication without complicated operation when performing the radio communication while specifying radio communication equipment to be communicated. SOLUTION: Radio POS terminal equipment transmits an inquiry signal to portable terminal equipment and when this signal is received, the portable terminal equipment returns a response. Then, the radio POS terminal equipment transmits a transmitting power minimizing request to the portable terminal equipment. When this request is received, the portable terminal equipment sets a transmitting power to a minimum and transmits a transmitting power value and a response to the POS terminal equipment. The POS terminal equipment, which receives these value and response, estimates a distance to the portable terminal equipment from the transmitting power value contained in the received signal and actually received power and when that distance is within a threshold, communication with the portable terminal equipment is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication method and a wireless communication system in which a wireless communication device specifies wireless communication devices to communicate with from a large number of unspecified wireless communication devices and performs wireless communication.

[0002]

2. Description of the Related Art A system in which a wireless communication device specifies wireless communication devices to communicate with from a large number of unspecified wireless communication devices and performs wireless communication is disclosed in, for example, Japanese Patent Laid-Open No. 11-18494.
The one described in Japanese Patent Publication No. 7 is known. This is because the PHS terminal that holds electronic money and the electronic value receiving device that has the function of the base station of the PHS terminal in addition to the function of the POS terminal device that is arranged at the cash payment location of the store perform electronic communication. It is designed to make payments. As a procedure for establishing a communication link between the PHS terminal and the electronic value receiving device, the number for identifying the PHS terminal used by the user is input from the number input keyboard connected to the electronic value receiving device, and the electronic value receiving device is input. Makes a call to the PHS terminal specified by the number to specify the PHS terminal for electronic payment.

[0003]

In this system, when performing electronic payment, a customer must enter a number from a number input keyboard in order to identify his or her own PHS terminal before making electronic payment. Therefore, there is a problem that it takes a lot of time and it takes time to settle the electronic value receiving device. In addition, the customer has the trouble of remembering the number for identifying the PHS, and if he / she forgets the number, there is a problem that electronic payment cannot be performed.

Therefore, the invention according to claims 1 to 8 is troublesome when the wireless communication device specifies a wireless communication device to communicate with from an unspecified number of wireless communication devices and performs wireless communication. Provided is a wireless communication method capable of performing wireless communication without the need. Further, in the invention according to claims 9 to 12, when the wireless communication device specifies a wireless communication device that communicates from an unspecified number of wireless communication devices and performs wireless communication, the wireless communication is performed without troublesome work. A wireless communication system capable of performing the above.

[0005]

The invention according to claim 1 is
A wireless signal including transmission power information is transmitted from the first wireless communication device to the second wireless communication device, the second wireless communication device receives the wireless signal, acquires reception power information, and acquires this. A wireless communication method of calculating a distance to the first wireless communication device from the received power information and the transmission power information of the wireless signal, and performing wireless communication with the first wireless communication device if the calculated distance is within a predetermined value. It is in.

According to a second aspect of the present invention, in the wireless communication method according to the first aspect, the first wireless communication device transmits the wireless signal by including the transmission power information set when transmitting the wireless signal. Then, the second wireless communication device is to calculate the distance to the first wireless communication device from the acquired reception power information and the transmission power information included in the wireless signal.

According to a third aspect of the present invention, in the wireless communication method according to the second aspect, the second wireless communication device transmits to the first wireless communication device a wireless signal including transmission power designation information. The first wireless communication device sets the transmission power based on the designation information of the transmission power included in the wireless signal, includes the transmission power in the wireless signal as the transmission power information, and transmits the transmission power to the second wireless communication device. It is in.

According to a fourth aspect of the present invention, in the wireless communication method according to the third aspect, the transmission power designation information transmitted from the second wireless communication device to the first wireless communication device minimizes the transmission power. It is in the designated information.

According to a fifth aspect of the present invention, in the wireless communication method according to the third aspect, the inquiry signal is transmitted from the first or second wireless communication device to the second or first wireless communication device, and the second signal is transmitted. Alternatively, after confirming the other party by transmitting a response signal to the inquiry signal from the first wireless communication device to the first or second wireless communication device, the second wireless communication device transmits the wireless signal including the designation information of the transmission power. Transmitting to the first wireless communication device.

According to a sixth aspect of the present invention, in the wireless communication method according to the first aspect, the first wireless communication device transmits a reference signal having a fixed transmission power as a wireless signal, and the second wireless communication device. The device is to calculate the distance to the first wireless communication device from the received power information and the transmission power of the reference signal acquired.

According to a seventh aspect of the present invention, in the wireless communication method according to the sixth aspect, the inquiry signal is transmitted from the first or second wireless communication device to the second or first wireless communication device, and the second signal is transmitted. Alternatively, after the first wireless communication device transmits a response signal to the inquiry signal to the first or second wireless communication device to confirm the other party, the second wireless communication device sets the first wireless communication device to the first wireless communication device.
And transmitting the reference signal based on the request signal to the first wireless communication device.

According to an eighth aspect of the present invention, in the wireless communication method according to the fifth or seventh aspect, the first wireless communication device is a mobile terminal device, the second wireless communication device is a master station, and the master station is calculated. When the distance from the mobile terminal device exceeds the predetermined value, a standby signal is transmitted to the mobile terminal device, and when the mobile terminal device receives the standby signal, the mobile terminal device waits for reception while maintaining the synchronization of transmission / reception timing with the master station. To be in a state.

According to a ninth aspect of the present invention, in a wireless communication system for performing wireless communication between the first wireless communication device and the second wireless communication device, the second wireless communication device is the first wireless communication device. A first means is obtained from an acquisition unit that receives a wireless signal including transmission power information transmitted from the device and acquires the reception power of this wireless signal, and the reception power acquired by this acquisition unit and the transmission power information included in the wireless signal. It is provided with calculating means for calculating the distance to the wireless communication device and wireless communication means for performing wireless communication with the first wireless communication device when the distance calculated by the calculating means is within a predetermined value.

According to a tenth aspect of the present invention, in the radio communication system according to the ninth aspect, the first radio communication device sets a setting means for setting its own transmission power and transmission power information set by this setting means. And a transmitting means for transmitting a wireless signal including the signal.

According to an eleventh aspect of the present invention, in a wireless communication system for performing wireless communication between the first wireless communication device and the second wireless communication device, the second wireless communication device is the first wireless communication device. A first radio based on an acquisition unit that receives a reference signal transmitted from the device and acquires the reception power of the reference signal, and the reception power acquired by the acquisition unit and transmission power information preset for the reference signal. It is provided with calculating means for calculating the distance to the communication device and wireless communication means for performing wireless communication with the first wireless communication device when the distance calculated by the calculating means is within a predetermined value.

According to a twelfth aspect of the present invention, in the radio communication system according to the eleventh aspect, the first radio communication device is
A setting means for setting the transmission power of the reference signal to be transmitted to the second wireless communication device to a preset transmission power and a transmission means for transmitting the reference signal with the transmission power set by the setting means are provided. is there.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a configuration of a wireless POS system which is a wireless communication system. Reference numerals 1 and 2 denote a mobile terminal device as a first wireless communication device, and 3 denotes a second wireless communication device. It is a wireless POS (point of sale information management) terminal device.

The wireless POS terminal device 3 is installed in a payment section, which is a payment place in a store, registers products purchased by a customer, receives payment from the customer, performs payment processing, and receives a receipt. It is designed to be issued. Electronic money that can be used in the same manner as cash, such as mobile cash, is stored in the mobile terminal devices 1 and 2 as data, and by communicating with the wireless POS terminal device 3 when registering a product, electronic money is stored. You can now pay with your money.

As shown in FIG. 2, the wireless POS terminal device 3 performs a second wireless communication with the portable terminal devices 1 and 2.
Wireless unit 100 that configures the wireless communication device, a cash register management unit 111 that manages the overall operation, self-identification information, P
A storage device 112 for storing a part of OS data, data for operating the device, an input / output device 113 including an input device such as a keyboard and a scanner, and an output device such as a receipt issuing machine having a display and a printer, and a local area LAN 1
A local area LAN communication unit 115 that communicates with the store server via 14 is provided.

The radio section 100 includes an antenna 101, an antenna switching section 102, a receiving section 103, and this receiving section 10.
3, a reception data conversion unit 104 that demodulates the radio signal received by the receiver 3 and converts it into digital data, a reception signal strength display (RSSI) unit 105 that outputs the RSSI value of the radio signal received by the reception unit 103, and a radio communication control unit 106. The transmission unit 107 includes a transmission data conversion unit 108 that modulates digital data into a transmission signal and outputs the transmission signal to the transmission unit 107, and a transmission power control unit 109 that controls the transmission power of the transmission unit 107.

As shown in FIG. 3, the radio communication control section 106 receives the RSSI from the received signal strength display section 105.
Reception power acquisition means 121 for acquiring the reception power value from the value,
It is possible to determine the presence or absence of a transmission error from the digital data from the received data conversion unit 104, remove the preamble and the code for controlling the transmission error to obtain the received data, and the transmission power value is included in the digital data. If the received power value is received, the received data acquisition unit 122 acquires the transmitted power value, the received power value acquired by the received power acquisition unit 121, and the transmitted power value acquired by the received data acquisition unit 122. Distance estimation means 123 for estimating the distance to 1 or 2 is provided.

The radio communication control unit 106 also creates transmission data by performing encoding for header information and transmission error control so that the transmission data is suitable for the transmission format of the radio section and outputting it to the transmission data conversion unit 108. Means 12
4. Transmission power setting means 125 for setting a transmission power value for transmitting transmission data and outputting it to the transmission power control section 109; transmission power acquisition means for obtaining the transmission power value set by the transmission power setting means 125. 126 is provided.
The transmission data creation means 124 may include the transmission power value acquired by the transmission power acquisition means 126 in the transmission data.

The radio communication control section 106 is further provided with an antenna switching setting means 127 for setting the antenna switching of the antenna switching section 102, and a transmission means 128 for performing data transmission with the cash register management section 111. . Further, the wireless communication control unit 106 includes a timer unit 129 so that an interrupt is generated after a set time has elapsed, and transmission or reception waiting time-out after the set time has elapsed. It is designed to be used for processing.

When the wireless unit 100 of the wireless POS terminal 3 is activated, the antenna switching setting means 127 in the wireless communication control unit 106 sets the antenna switching unit 102 so that the antenna 101 and the receiving unit 103 are connected, The wireless unit 100 is placed in a reception waiting state.

When the radio signal is received by the antenna 101, the received signal is input to the receiving unit 103 via the antenna switching unit 102. The receiving unit 103 amplifies the received signal and converts the frequency into a low frequency. The reception data conversion unit 104 demodulates the signal from the reception unit 103, converts the signal into digital data, and outputs the digital data to the reception data acquisition unit 122 of the wireless communication control unit 106. The reception signal strength display unit 105 outputs the RSSI value of the reception output of the reception unit 103 to the reception power acquisition unit 121 of the wireless communication control unit 106.

In the wireless communication control section 106, the reception power acquisition means 121 acquires the reception power value from the RSSI value, the reception data acquisition means 122 acquires the transmission power value from the digital data, and the distance estimation means 123 receives it. The distance to the mobile terminal device is estimated from the power value and the transmission power value. For example, if the person who owns the mobile terminal device 1 is in a position for settlement and the person who owns the mobile terminal device 2 is lined up after that, first, the wireless signal from the mobile terminal device 1 is received and the The distance to the mobile terminal device 1 will be estimated. The wireless communication control unit 106 performs a transmission operation or an operation of transmitting the reception data from the transmission means 128 to the cash register management unit 111 according to the content of the received data.

Further, when transmission data is generated in the wireless communication control unit 106, the transmission power setting means 125 sets a transmission power value at the time of transmitting the transmission data, whereby the transmission power control unit 109 sets the set transmission power. The transmission power of the transmission unit 107 is controlled according to the power value, and the transmission output of the transmission unit 107 is set to the set value. The transmission power acquisition unit 126 acquires the transmission power value set by the transmission power setting unit 125, and the transmission data creation unit 124 creates digital transmission data including the transmission power value and outputs the digital transmission data to the transmission data conversion unit 108.

The antenna switching setting means 127 controls the antenna switching section 102 to control the antenna 101 and the transmission section 10.
7, the transmission data conversion unit 108 modulates the created digital transmission data and outputs the modulated transmission data to the transmission unit 107. The transmission unit 107 converts the modulated signal into a radio frequency and sets the set transmission power value. Output the transmission signal with. The transmission signal is transmitted as a radio signal from the antenna 101 via the antenna switching unit 102. Although not shown, the data acquired by the received data acquisition unit 122 is transmitted to the transmission unit 12.
It is also possible to transmit the data to the transmission data No. 8 and to transmit the data from the transmission unit 128 to the transmission data creation unit 124.

As shown in FIG. 4, the portable terminal devices 1 and 2 have a wireless unit 200 that performs wireless communication with the wireless POS terminal device 3, a terminal management unit 211 that manages the overall operation,
A display 212 for displaying information, a storage device 21 for storing information such as terminal identification information, a telephone directory, a mobile cash, etc.
3, an input key 214 provided with keys used by the user to input numbers and make outgoing calls, a voice input / output device 215 used when calling the other party using the public line, and wireless communication with the base station of the public line Public line wireless communication unit 2
16 is provided.

The radio section 200 includes an antenna 201, an antenna switching section 202, a receiving section 203, and the receiving section 20.
3 is a reception data conversion unit 204 that demodulates the signal output by the device 3 and converts it into digital data, and a reception signal strength display (RS that outputs the RSSI value of the radio signal received by the reception unit 203.
SI) unit 205, wireless communication control unit 206, transmission unit 20
7. A transmission data conversion unit 208 that modulates digital data and converts it into a transmission signal and outputs it to the transmission unit 207, and a transmission power control unit 20 that controls the transmission power of the transmission unit 207.
It is composed of 9.

As shown in FIG. 5, the radio communication control section 206 receives the RSSI from the received signal strength display section 205.
Reception power acquisition means 221 for acquiring the reception power value from the value,
It is possible to determine the presence / absence of a transmission error from the digital data from the reception data conversion unit 204, remove the preamble and the code for transmission error control, and obtain the reception data, and the transmission power value is included in the digital data. If the received power value is received, the received data acquisition unit 222 acquires the transmitted power value, the received power value acquired by the received power acquisition unit 221 and the transmitted power value acquired by the received data acquisition unit 222 are used to determine the wireless POS terminal. Distance estimation means 223 for estimating the distance to the device 3 is provided.

The radio communication control section 206 also creates transmission data by performing coding for header information and transmission error control so that the transmission data is suitable for the transmission format of the wireless section, and outputting it to the transmission data conversion section 208. Means 22
4. Transmission power setting means 225 for setting the transmission power value for transmitting the transmission data and outputting it to the transmission power control section 209; Transmission power acquisition means for acquiring the transmission power value set by the transmission power setting means 225. 226 is provided.
The transmission data creation means 224 may include the transmission power value acquired by the transmission power acquisition means 226 in the transmission data.

The radio communication control section 206 further includes an antenna switching setting means 227 for setting the antenna switching of the antenna switching section 202 and the terminal management section 211.
A transmission means 228 for transmitting data to and from is provided. Further, the wireless communication control unit 206 includes timer means 22.
9 is included, an interrupt is generated after the set time has elapsed, and is used for processing such as transmission or timeout of the reception waiting time after the set time has elapsed.

When the radio section 200 is activated in the portable terminal device 1 or 2, the antenna switching setting means 227 in the radio communication control section 206 sets the antenna switching section 202 so that the antenna 201 and the receiving section 203 are connected. , Puts the wireless unit 200 in a waiting state.

When the radio signal is received by the antenna 201, the received signal is input to the receiving unit 203 via the antenna switching unit 202. The receiving unit 203 amplifies the received signal and converts the frequency into a low frequency. The reception data conversion unit 204 demodulates the signal from the reception unit 203, converts it into digital data, and outputs the digital data to the reception data acquisition unit 222 of the wireless communication control unit 206. The reception signal strength display unit 205 outputs the RSSI value of the reception output of the reception unit 203 to the reception power acquisition unit 221 of the wireless communication control unit 206.

Then, in the radio communication control section 206, the reception power acquisition means 221 acquires the reception power value from the RSSI value, the reception data acquisition means 222 acquires the transmission power value from the digital data, and the distance estimation means 223 receives it. The distance to the wireless POS terminal device 3 is estimated from the power value and the transmission power value. The wireless communication control unit 206 controls the transmission operation and the transmission unit 228 from the terminal management unit 2 according to the content of the received data.
11 performs operations such as transmitting received data.

When transmission data is generated in the wireless communication control unit 206, the transmission power setting means 225 sets the transmission power value at which the transmission data is transmitted, whereby the transmission power control unit 209 sets the set transmission power. The transmission power of the transmission unit 207 is controlled according to the power value, and the transmission output of the transmission unit 207 is set to the set value. The transmission power acquisition unit 226 acquires the transmission power value set by the transmission power setting unit 225, and the transmission data creation unit 224 creates digital transmission data including the transmission power value and outputs it to the transmission data conversion unit 208.

The antenna switching setting means 227 controls the antenna switching unit 202 to control the antenna 201 and the transmission unit 20.
7, the transmission data conversion unit 208 modulates the created digital transmission data and outputs the modulated transmission data to the transmission unit 207. The transmission unit 207 converts the modulated signal into a radio frequency and sets the set transmission power value. Output the transmission signal with. The transmission signal is transmitted as a radio signal from the antenna 201 via the antenna switching unit 202. Although not shown, the data acquired by the reception data acquisition unit 222 is transmitted to the transmission unit 22.
It is also possible to transmit the data from the transmission means 228 to the transmission data creation means 224.

FIG. 6 is a flow chart showing the exchange of signals between the wireless POS terminal device and the portable terminal device when the wireless POS terminal device 3 determines the portable terminal device with which the wireless POS terminal device 3 communicates. Transmits an inquiry signal to the mobile terminal device in ST11. The inquiry signal is an inquiry addressed to an unspecified number of mobile terminal devices including the identification information of the own station. If the mobile terminal device is not present in the surrounding area, it is determined that there is no response in ST12, and the process returns to the transmission of the inquiry signal in ST11.

On the other hand, the portable terminal device is in the reception waiting state in ST31, and when it is determined in ST32 that the inquiry signal is received, the wireless P that makes the inquiry in ST33.
A response including the identification information of the OS terminal device 3 and the identification information of its own station is transmitted. When receiving the inquiry signal, the mobile terminal device synchronizes the transmission / reception timing with the wireless POS terminal device and establishes a communication link. Depending on the communication method used at this time, wireless signals may be further exchanged in order to synchronize the transmission / reception timing.

When the wireless POS terminal device 3 determines in ST12 that there is a response, the wireless POS terminal device 3 transmits a request for minimizing the transmission power to the portable terminal device that responded in ST13.
Upon receiving the request for minimizing the transmission power in ST34, the mobile terminal device transmits the transmission power setting means 225 in ST35.
Transmits a command for minimizing the transmission power to the transmission power control unit 209, and the transmission power control unit 209 sets the transmission output of the transmission unit 207 to be the minimum. Also, the transmission power setting unit 2
25 transmits the set value to the transmission power acquisition means 226, the transmission power acquisition means 226 acquires the transmission power from the set value, and transmits the acquired transmission power value to the transmission data creation means 224.

Minimizing the transmission power in this way is as follows.
This has the effect of avoiding communication with a mobile terminal device that is far from the wireless POS terminal device, and can reduce malicious interception by narrowing the range in which the mobile terminal device can receive information transmitted. Further, there is an effect of suppressing the power consumption of the mobile terminal device.

After that, the mobile terminal device creates and transmits a response including the transmission power value received by the transmission data creation means 224 from the transmission power acquisition means 226 in ST36. The wireless POS terminal 3 waits for a response after transmitting the request for minimizing the transmission power, and determines in ST14 whether the response has been received. When the response cannot be received even after the elapse of a certain time or more, it is determined that the mobile terminal device that has transmitted the request for minimizing the transmission power is not within the communication range, and the process returns to ST11.

When a response is received from the portable terminal device with the minimum transmission power, the received signal strength display unit 105 displays the RS signal.
The SI value is input to the reception power acquisition means 121, acquires the reception power, and is transmitted to the distance estimation means 123. In addition, the received wireless signal is input to the reception data acquisition unit 122 as digital data, and the reception data acquisition unit 122 acquires the transmission power of the mobile terminal device included in the received data and transmits it to the distance estimation unit 123. And ST1
The distance is estimated from the transmission power and the reception power of the mobile terminal device received in 5.

The power transmitted from the mobile terminal device is set to Pt.
(DBm), the power received by the wireless POS terminal 3 is Pi (dBm), and the wavelength of the radio wave is λ (m), the distance D between the mobile terminal and the wireless POS terminal 3 is D.
(M) is

[Equation 1] Becomes As an example, the power transmitted from the mobile terminal device is 0 dBm, and the power received by the wireless POS terminal device is -30.
If the dBm is used and the radio frequency is 2.45 GHz, the distance between the mobile terminal device and the wireless POS terminal device 3 is 0.3.
It can be estimated to be 08 m. Further, by using the above formula (1), it is possible to estimate the distance even when there are mobile terminal devices having different transmission powers.

When the distance is estimated in this way, S
It is determined whether the distance estimated at T16 is within the threshold.
Since the arrangement of the wireless POS terminal devices and the queues for waiting are different between the supermarket and the convenience store, the distance threshold differs depending on the usage pattern of the wireless POS terminal devices. For example, in a supermarket, the distance threshold is set to 0.5 m, and if the distance between the wireless POS terminal device 3 and the mobile terminal device is within the threshold value, a timer for transmitting to the mobile terminal device waiting in ST17. Disable interrupts. If the distance between the wireless POS terminal device 3 and the mobile terminal device exceeds the threshold value, the process proceeds to A1 in FIG.

After that, the wireless POS terminal device 3 determines ST1.
In step 8, a communication start signal for notifying communication start is transmitted to the mobile terminal device, and in step ST19, communication is performed. On the other hand, the mobile terminal device determines in ST37 whether communication is started, and if a communication start signal is received, starts communication in ST38. If the communication start signal is not received, the process proceeds to B1 in FIG.

In this way, the wireless POS terminal device 3 communicates in ST19, the portable terminal device communicates in ST38, and exchanges information. This allows
The wireless POS terminal device can limit one mobile terminal device within the communication range from a plurality of mobile terminal devices.

As in the portable terminal device 2 owned by a person waiting in line in FIG.
Regarding the mobile terminal device that will approach the terminal device 3,
Even if it is determined that the distance is far and communication is not performed, it is more efficient to keep the communication link with the mobile terminal device established.

When the portable terminal device receives the inquiry signal, it synchronizes the transmission / reception timing with the wireless POS terminal device 3 and establishes a communication link. However, like the portable terminal device 2, the wireless POS terminal device 3 is immediately connected. The mobile terminal device that is likely to come close to is put in a standby state with the communication link established.

The transmission power value and the response transmitted from the portable terminal device in ST36 are received by the POS terminal device 3, and S
When it is determined that the distance is longer than the threshold value at T16,
Then, in ST20, it is determined whether or not the distance is within the standby range that is the second threshold value. The waiting range in this case can be thought of as the distance lined up waiting for settlement,
For example, the distance from the POS terminal device 3 may be within 1.5 m. The result of ST15 may be used to estimate the distance.

When it is determined that the mobile terminal device is out of the standby range, the POS terminal device 3 determines that it does not communicate with the mobile terminal device, and the process returns to ST11. At this time, the mobile terminal device does not receive the communication start signal in ST37 and does not receive the standby signal in ST39 even after a lapse of a certain time, and therefore returns to ST31.

When the wireless POS terminal device 3 determines that the portable terminal device is within the standby range, the ST
At 21, a standby signal is transmitted to the mobile terminal device. When the portable terminal device receives the standby signal in ST39, the portable terminal device waits for reception while maintaining the synchronization of the transmission / reception timing in ST40.

After transmitting the standby signal, the wireless POS terminal device 3 periodically communicates with the portable terminal device in order to maintain synchronization of transmission / reception timing and to confirm the distance. ST2
The timer interrupt is set so that transmission can be performed after a certain period of time for the mobile terminal device that has been put on standby in step 2, and ST1
Return to 1. This timer generates a timer interrupt after a set time and shifts to a timer interrupt.

Next, in order to search for another portable terminal device, S
The inquiry signal is transmitted at T11. When the POS terminal device 3 finds a mobile terminal device that performs communication after the mobile terminal device that has been put on standby, it prohibits timer interruption to the mobile terminal device that is on standby in ST17, and ST1
After the communication of 9 is completed, the timer interrupt inhibition to the standby mobile terminal device may be released.

As a result, when the wireless POS terminal device 3 and the mobile terminal device are communicating with each other, the wireless POS terminal device 3 does not perform transmission / reception with the mobile terminal device in the standby state, and can efficiently perform communication. You can

If a timer interrupt occurs while the wireless POS terminal 3 is searching for a portable terminal, ST2
In 3, the transmission power request is transmitted to the mobile terminal device in the standby state. Since the mobile terminal device has already minimized the transmission power, it is not necessary to send a command to minimize the transmission power here. It should be noted that there is no problem even if an instruction for minimizing the transmission power is included in the transmission.

Upon reception of the transmission power request in ST41, the mobile terminal device on standby transmits the transmission power value in ST42 and returns to ST37. On the other hand, the wireless POS terminal device 3
Receives the transmission power value in ST24, and at this time RSS
I value is also read. Then, in ST25, the transmission power value and RS
The distance is estimated from the SI value. Distance estimation method is ST1
It is the same as the case of 5. Then, when it is determined in ST26 that the distance is within the threshold value, the process returns to ST17 to communicate with the mobile terminal device. When it is determined in ST26 that the distance is outside the threshold value, the process returns to ST20 and it is determined whether the mobile terminal device is within the standby range.

By doing so, the person who owns the portable terminal device is waiting for the settlement in front of the POS terminal device 3, the portable terminal device is in the standby state, and the transmission / reception timing with the POS terminal device 3 is changed. If they are synchronized, when the person's turn is reached and the POS terminal is approached, P
It is possible to perform wireless communication with the OS terminal device 3.

Further, the POS terminal device 3 displays whether the mobile terminal device may communicate at the start of communication with the mobile terminal device, and allows the owner of the mobile terminal device to judge whether communication is possible. The connection of the mobile terminal device with which the POS terminal device communicates can be ensured.

Further, in the portable terminal device, keeping the receiving state always increases the power consumption. Therefore, normally, the power supply of the wireless section is stopped, and the person who owns the portable terminal device has the POS terminal device. If the power is supplied to the wireless unit near the terminal, the number of mobile terminal devices that the POS terminal device receives in response to the inquiry signal decreases, and the connection with the target mobile terminal device is performed more reliably. be able to.

In this embodiment, the case where the inquiry signal is transmitted from the POS terminal device has been described, but the present invention is not limited to this, and it may be transmitted from the portable terminal device. That is, when the person who owns the mobile terminal device makes a turn to communicate with the POS terminal device, by operating the mobile terminal device, an inquiry signal is transmitted to the POS terminal device. When the POS terminal device receives the inquiry signal, the POS terminal device may respond and send a request for minimizing the transmission output of the mobile terminal device.

In this embodiment, the POS terminal device receives the transmission power from the mobile terminal device and estimates the distance from the mobile terminal device. However, the transmission power from the POS terminal device to the mobile terminal device is further estimated. Information including information is transmitted, the mobile terminal device receives the information, the mobile terminal device estimates the distance from the POS terminal device from the received power and the transmission power information at this time, and the estimated distance is used as the POS terminal device. Then, the POS terminal device may determine whether or not it is the distance for communication from the distance estimated by itself and the distance received from the mobile terminal device (second embodiment). The system configuration is the same as that of the first embodiment described above. The difference from the first embodiment is that the mobile terminal device transmits a reference signal. The reference signal is composed of data including the identification information of the device that transmits and the information that can identify the reference signal, and is a wireless signal that transmits with the same transmission power regardless of which mobile terminal device transmits. For example, the transmission power of the reference signal may be defined as 0 dBm in advance.

The hardware structure of the wireless POS terminal is the same as that of the first embodiment, but the means for estimating the distance is different. When the antenna 101 receives a radio signal that is a reference signal, the reception unit 103 and the reception data conversion unit 104 transmit the reception data, which has been converted into digital data, to the reception data acquisition unit 122, which is the reference signal. If it is determined that the reference signal has been received, the distance estimation means 123 is informed that the reference signal has been received.
3 acquires the transmission power corresponding to the reference signal.

When the reference signal is being received, the receiving unit 10
The reception power acquisition means 121 acquires the reception power from 3 through the reception signal strength display unit 105. Received power acquisition means 12
The received power obtained in 1 is transmitted to the distance estimation means 123. The distance estimation means 123 estimates the distance to the mobile terminal device that transmitted the reference signal from the transmission power of the reference signal and the reception power when the reference signal is received.

The hardware configuration of the mobile terminal device is the same as that of the first embodiment, but the difference is that the reference signal is transmitted. When transmitting the reference signal, the transmission power setting means 225 transmits at the transmission power corresponding to the reference signal, so that the transmission power of the transmission unit 207 is set via the transmission power control unit 209.

The transmission power setting means 225 informs the transmission power acquisition means 226 that it is a reference signal, and the transmission power acquisition means 226 informs the transmission data creation means 224 that the reference signal is transmitted. The transmission data creation means 224 creates reference signal data including identification information of its own station and information capable of identifying that it is a reference signal. The reference signal data passes through the transmission data conversion unit 208 and the transmission unit 207 and the antenna 2
01 is transmitted as a reference signal.

FIG. 8 is a flow chart showing the exchange of signals between the wireless POS terminal device and the portable terminal device when the wireless POS terminal device 3 determines the portable terminal device with which the wireless POS terminal device 3 communicates. Transmits an inquiry signal to the mobile terminal device in ST51. The inquiry signal is an inquiry addressed to an unspecified number of mobile terminal devices including the identification information of the own station. When the mobile terminal device is not present in the surroundings, it is determined that there is no response in the determination of the response in ST52, and the process returns to the transmission of the inquiry signal in ST51.

On the other hand, the portable terminal device is in the reception waiting state in ST71, and when it is determined that the inquiry signal is received in ST72, the wireless P that has made the inquiry in ST73.
A response including the identification information of the OS terminal device 3 and the identification information of its own station is transmitted. When receiving the inquiry signal, the mobile terminal device synchronizes the transmission / reception timing with the wireless POS terminal device and establishes a communication link. Depending on the communication method used at this time, wireless signals may be further exchanged in order to synchronize the transmission / reception timing.

When the wireless POS terminal device 3 determines that there is a response in ST52, it transmits a reference signal transmission request to the portable terminal device that responded in ST53. The reference signal includes the identification information of the transmission destination, the identification information of the transmission source, and the identification information notifying that it is the reference signal, and the transmission power is defined in advance. When the mobile terminal device receives the reference signal transmission request in ST74, the wireless communication control unit 206 sets the transmission power control unit 209 in ST75 so that the transmission is performed with the transmission power specified as the transmission power of the reference signal. Then, the transmitter 207 is set.

After that, the reference signal is transmitted in ST76. The wireless POS terminal device 3 is waiting to receive the reference signal, and determines in ST54 whether the reference signal has been received.
When the reference signal cannot be received even after a lapse of a certain time or more, it is determined that the mobile terminal device that transmitted the reference signal request is not within the communication range, and the process returns to ST51.

When the reference signal is received, the RSSI value is input from the received signal strength display unit 205 to the reception power acquisition means 221, the reception power is acquired, and it is transmitted to the distance estimation means 223. Since the transmission power of the reference signal is known in advance, the distance is estimated in ST55 from the transmission power of the reference signal and the received power of the received mobile terminal device.

The transmission power of the reference signal is Pt (dBm), and the power received by the wireless POS terminal 3 is Pi (dB).
m) and the wavelength of the radio wave is λ (m), the distance D (m) between the mobile terminal device and the wireless POS terminal device 3 can be calculated by using the above-mentioned equation (1).

When the distance is estimated in this way, S
It is determined whether the distance estimated at T56 is within the threshold.
If the distance between the wireless POS terminal device 3 and the mobile terminal device is within the threshold, the timer interrupt for transmitting to the mobile terminal device waiting in ST57 is prohibited. In addition, wireless P
If the distance between the OS terminal device 3 and the mobile terminal device exceeds the threshold value, the process proceeds to C1 in FIG.

After that, the wireless POS terminal device 3 determines ST5.
At 8, a communication start signal for notifying the start of communication is transmitted to the mobile terminal device, and at ST59, communication is performed. On the other hand, the mobile terminal device determines in ST77 whether communication is started, and if a communication start signal is received, starts communication in ST78. If the communication start signal is not received, the process proceeds to D1 in FIG.

In this way, the wireless POS terminal device 3 communicates in ST59, the portable terminal device communicates in ST78, and exchanges information.

As in the portable terminal device 2 owned by a person waiting in line in FIG.
Regarding the mobile terminal device that will approach the terminal device 3,
The communication link with the mobile terminal device remains established.

When the POS terminal device 3 receives the reference signal transmitted from the portable terminal device in ST76 and determines that the distance is longer than the threshold value in ST56, the process proceeds to C1 of FIG. 9 and to ST60. It is determined whether or not the distance is within the waiting range which is the second threshold value.

When it is determined that the mobile terminal device is out of the standby range, the POS terminal device 3 determines that it does not communicate with the mobile terminal device, and the process returns to ST51. At this time, the mobile terminal device does not receive the communication start signal in ST77 and does not receive the standby signal in ST79 even after a lapse of a certain time, and therefore returns to ST71.

If the wireless POS terminal device 3 determines that the portable terminal device is within the standby range, the ST
At 61, a standby signal is transmitted to the mobile terminal device. When the portable terminal device receives the standby signal in ST79, the portable terminal device waits for reception while maintaining the synchronization of the transmission / reception timing in ST80.

After transmitting the standby signal, the wireless POS terminal device 3 periodically communicates with the portable terminal device in order to maintain synchronization of transmission / reception timing and to confirm the distance. ST6
The timer interrupt is set so that transmission can be performed after a certain period of time for the mobile terminal device that has been put on standby in step 2, and ST6
Return to 1. This timer generates a timer interrupt after a set time and shifts to a timer interrupt.

Next, in order to search for another portable terminal device, S
An inquiry signal is transmitted at T51. When the POS terminal device 3 finds a mobile terminal device with which communication is to be performed after the mobile terminal device that has been put on standby, the POS terminal device 3 prohibits timer interruption to the mobile terminal device on standby in ST57, and ST5
After the communication of 9 is completed, the timer interrupt inhibition to the standby mobile terminal device may be released.

As a result, when the wireless POS terminal device 3 and the portable terminal device are communicating, the wireless POS terminal device 3 does not transmit / receive to / from the waiting portable terminal device, and the efficient communication is performed. You can

If a timer interrupt occurs while the wireless POS terminal 3 is searching for a portable terminal, ST6
At 3, the reference signal transmission request is transmitted to the mobile terminal device on standby. Upon receiving the reference signal transmission request in ST81, the mobile terminal device transmits the reference signal in ST82, and S
Return to T77.

Since the mobile terminal device on standby has already been set to the transmission power for transmitting the reference signal, it is not necessary to set the transmission power after receiving the reference signal transmission request.
There is no problem even if the transmission power for transmitting the reference signal is reset.

The wireless POS terminal device 3 also acquires the reception power when receiving the reference signal in ST64. Then, in ST65, the distance is estimated from the transmission power and the reception power. The distance estimation method is the same as in ST55. Then, when it is determined in ST66 that the distance is within the threshold value, the process returns to ST57, and communication with the mobile terminal device is performed. When it is determined in ST66 that the distance is out of the threshold value, the process returns to ST60 to determine whether the mobile terminal device is within the standby range.

By doing so, the person who owns the portable terminal device is waiting for settlement in front of the wireless POS terminal device 3, the portable terminal device is in the standby state, and the wireless POS device is in the standby state.
If the transmission / reception timing with the terminal device 3 is synchronized, when the person approaches and comes close to the wireless POS terminal device, wireless communication with the POS terminal device 3 can be performed immediately.

The inquiry signal may be transmitted from the mobile terminal device. That is, when the person who owns the mobile terminal device makes a turn to communicate with the wireless POS terminal device, by operating the mobile terminal device, an inquiry signal is transmitted to the POS terminal device. Upon receiving the inquiry signal, the wireless POS terminal device responds by sending a reference signal transmission request to the mobile terminal device.

In each of the embodiments described above, one wireless POS terminal device is used, but the number is not limited to this, and a plurality of wireless POS terminal devices may be used. When there are a plurality of wireless POS terminal devices, the POS terminal device may be set so as not to respond to the inquiry signal of another POS terminal device. That is, the identification information of the POS terminal device is known at the time of installation, and if the identification signal of the POS terminal device is included in the inquiry signal, it is possible not to respond to the inquiry signals of other POS terminal devices. Become. Thereby, unnecessary communication between the POS terminal devices can be eliminated.

Further, in the first embodiment, the response signal transmitted from the mobile terminal device to the POS terminal device with the minimum transmission power, and in the second embodiment transmitted from the mobile terminal device to the POS terminal device. Alternatively, the POS terminal device may receive the signal, read the RSSI value each time the signal is received, and determine whether the distance is within the threshold value based on the results of the plurality of times.

That is, (Pi-P in the above equation (1)
t) (dB) as the amount of power attenuation in the wireless section,
FIG. 10 shows the relationship with the distance. In this relationship, the distance does not change significantly even if the attenuation changes by about 10 dB near the POS terminal, but the distance changes by 1 m or more at a position about 3 m away from the POS terminal when the attenuation changes by about 5 dB. It is shown that. From this, it may be determined that the communication range is within the range when the variation in the distance obtained from the results of reading the transmission output value and the RSSI value a plurality of times is small.

In each of the embodiments described above,
The first wireless communication device is a mobile terminal device, the second wireless communication device is a wireless POS terminal device, and the present invention is applied to a wireless POS system. However, the present invention is not limited to this. .

[0093]

As described above in detail, according to the first to eighth aspects of the invention, the wireless communication device performs wireless communication by specifying the wireless communication device to communicate with from a large number of unspecified wireless communication devices. In this case, it is possible to provide a wireless communication method capable of performing wireless communication without troublesome work.

According to the invention of claims 9 to 12, when the wireless communication device specifies a wireless communication device to communicate with from a large number of unspecified wireless communication devices and performs wireless communication,
A wireless communication system that can perform wireless communication without troublesome work can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a wireless POS terminal device according to the same embodiment.

3 is a block diagram showing a configuration of a wireless communication control unit of the wireless POS terminal device in FIG.

FIG. 4 is a block diagram showing a configuration of a mobile terminal device according to the same embodiment.

5 is a block diagram showing a configuration of a wireless communication control unit of the mobile terminal device in FIG.

FIG. 6 is a diagram illustrating a wireless P when a wireless POS terminal device determines a mobile terminal device to communicate with in the embodiment.
The flowchart which shows the exchange of the signal between an OS terminal device and a portable terminal device.

FIG. 7 shows a wireless P when a wireless POS terminal device determines a mobile terminal device with which the wireless POS terminal device communicates in the same embodiment.
The flowchart which shows the exchange of the signal between an OS terminal device and a portable terminal device.

FIG. 8 is a flowchart showing the exchange of signals between the wireless POS terminal device and the portable terminal device when the wireless POS terminal device determines the portable terminal device with which the wireless POS terminal device communicates according to another embodiment of the present invention.

FIG. 9 is a diagram illustrating a wireless P when the wireless POS terminal device determines a mobile terminal device to communicate with in the same embodiment.
The flowchart which shows the exchange of the signal between an OS terminal device and a portable terminal device.

FIG. 10 is a graph showing the relationship between power attenuation and distance.

[Explanation of symbols]

1, 2 ... Mobile terminal device (first wireless communication device) 3 ... Wireless POS terminal device (second wireless communication device) 100, 200 ... Wireless unit 106, 206 ... Wireless communication control unit 121, 221 ... Received power acquisition means 122, 222 ... Received data acquisition means 123, 223 ... Distance estimating means 124, 224 ... Transmission data creating means 125, 225 ... Transmission power setting means 126, 226 ... Transmission power acquisition means

Claims (12)

[Claims] 1. A wireless signal including transmission power information is transmitted from a first wireless communication device to a second wireless communication device, and the second wireless communication device receives the wireless signal and receives received power information. Is calculated, and the distance to the first wireless communication device is calculated from the acquired reception power information and the transmission power information of the wireless signal, and if the calculated distance is within a predetermined value, the first wireless A wireless communication method comprising performing wireless communication with a communication device. 2. The first wireless communication device transmits the wireless signal by including the transmission power information set when transmitting the wireless signal in the wireless signal, and the second wireless communication device acquires the received power information. The wireless communication method according to claim 1, wherein the distance to the first wireless communication device is calculated from the transmission power information included in the wireless signal. 3. The second wireless communication apparatus transmits a wireless signal including transmission power designation information to the first wireless communication apparatus, and the first wireless communication apparatus transmits the transmission power included in the wireless signal. The transmission power is set based on the designation information of the second transmission power, and the transmission power is included in the wireless signal as the transmission power information.
The wireless communication method according to claim 2, wherein the wireless communication method is transmitted to the wireless communication device. 4. The wireless communication according to claim 3, wherein the transmission power designation information transmitted from the second wireless communication device to the first wireless communication device is designation information for minimizing the transmission power. Method. 5. An inquiry signal is transmitted from the first or second wireless communication device to the second or first wireless communication device, and the first or second wireless communication device is transmitted from the second or first wireless communication device. The second wireless communication device transmits a wireless signal including transmission power designation information to the first wireless communication device after transmitting a response signal to the wireless communication device to confirm the other party. The wireless communication method according to claim 3. 6. The first wireless communication device transmits a reference signal having a fixed transmission power as a wireless signal, and the second wireless communication device transmits the reference signal.
2. The wireless communication method according to claim 1, wherein the wireless communication device calculates the distance from the first wireless communication device from the acquired received power information and the transmission power of the reference signal. 7. The first or second wireless communication device transmits an inquiry signal to the second or first wireless communication device, and the second or first wireless communication device transmits the first or second wireless communication device. After confirming the other party by transmitting a response signal to the wireless communication device to the inquiry signal, the second wireless communication device transmits a request signal of a reference signal to the first wireless communication device, and the first wireless communication device. 7. The wireless communication method according to claim 6, wherein the device transmits the reference signal based on the request signal. 8. The first wireless communication device is a portable terminal device and the second wireless communication device is a master station, and when the calculated distance to the portable terminal device exceeds a predetermined value, the master station carries the portable device. 8. The standby signal is transmitted to a terminal device, and when the portable terminal device receives the standby signal, the portable terminal device enters a reception standby state while maintaining synchronization of transmission / reception timing with the master station. Wireless communication method. 9. A wireless communication system in which wireless communication is performed between a first wireless communication device and a second wireless communication device, wherein the second wireless communication device is transmitted from the first wireless communication device. The first wireless communication based on an acquisition unit that receives a wireless signal including transmission power information and acquires the reception power of the wireless signal, and the reception power acquired by the acquisition unit and the transmission power information included in the wireless signal. A wireless communication comprising: a calculating unit that calculates a distance to the device; and a wireless communication unit that wirelessly communicates with the first wireless communication device when the distance calculated by the calculating unit is within a predetermined value. system. 10. A wireless communication system for performing wireless communication between a first wireless communication device and a second wireless communication device, wherein the first wireless communication device has a setting means for setting its own transmission power. 10. The wireless communication system according to claim 9, further comprising: a transmitting unit that transmits a wireless signal including the transmission power information set by the setting unit. 11. A wireless communication system in which wireless communication is performed between a first wireless communication device and a second wireless communication device, wherein the second wireless communication device is transmitted from the first wireless communication device. The first wireless communication device based on an acquisition unit that receives a reference signal that acquires the reference signal and a reception power that is acquired by the acquisition unit, and transmission power information that is preset for the reference signal. And a wireless communication means for performing wireless communication with the first wireless communication device when the distance calculated by the calculating means is within a predetermined value. . 12. A wireless communication system in which wireless communication is performed between a first wireless communication device and a second wireless communication device, wherein the first wireless communication device transmits to the second wireless communication device. 12. The radio according to claim 11, further comprising: setting means for setting the transmission power of the reference signal to a preset transmission power; and transmission means for transmitting the reference signal with the transmission power set by the setting means. Communications system.