JP2006025360A - Wireless network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless network system capable of preventing various kinds of information from being carried out of a network. <P>SOLUTION: The wireless network system 100 comprises an access point 10 and radio units 20, 30, 40, 50, 60. The access point 10 measures a communication distance with each of the radio units 20, 30, 40, 50, 60 utilizing a period of time during which communication is not performed in a radio communication space 70, and determines contents of a communication service to be permitted for each of the radio units 20, 30, 40, 50, 60 in accordance with the measured communication distance. Furthermore, the access point 10 determines the contents of the communication service to be permitted for each of the radio units 20, 30, 40, 50, 60 in accordance with whether or not terminal intrinsic information of each of the radio units 20, 30, 40, 50, 60 is registered or not. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radio network system, and more particularly to a radio network system capable of changing the contents of a communication service according to the communication distance between two communication terminals.

  In a conventional wireless LAN (Local Area Network) system, a CDMA (Code Division Multiple Access) method is used as a physical layer protocol, and a CSMA / CA (Carrier Sense) is used as a medium access control method in a data link layer. Multiple Access with Collation Avidance) is used.

  This CSMA / CA method is a method for avoiding a communication collision by constantly monitoring whether another communication terminal is transmitting a packet and whether a packet addressed to itself is being transmitted (non-transmission). Patent Document 1). That is, each communication terminal transmits data after confirming that the network is continuously available for a predetermined time or more.

Thus, in the conventional wireless LAN system, data communication is performed using the CSMA / CA method.
By Koizumi, “All of Data Communication with Illustrations”, Nihon Jitsugyo Publishing Co., Ltd., November 20, 1999, p. 272

  However, the conventional wireless LAN system has a problem that information transmitted and received in the system is eavesdropped.

  That is, in the conventional wireless LAN system, each communication terminal can receive all communication services regardless of the communication distance between the two communication terminals. Assuming a wireless LAN system in which a plurality of communication terminals are connected to a certain access point, the access point provides all communication services to the plurality of communication terminals. That is, the access point provides all communication services to each communication terminal regardless of the communication distance with each communication terminal.

  Therefore, a communication terminal having a long communication distance from the access point is provided with the same communication service as a communication terminal having a short communication distance from the access point, and should be provided only to a communication terminal having a short communication distance from the access point. There is a problem that information is wiretapped by a communication terminal having a long communication distance from the access point.

  Also, a communication terminal whose communication distance from the access point changes, that is, a moving communication terminal, a communication terminal whose communication distance to the access point hardly changes, that is, a communication terminal which remains in a substantially constant place. There is a problem that the same communication service is provided, and information that should be provided only to a communication terminal originally staying in a certain place is taken out of the network by the moving communication terminal.

  Such a problem also occurs between a registered communication terminal and an unregistered communication terminal.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a wireless network system capable of suppressing taking out of various information outside the network.

  According to the present invention, the wireless network system includes n (n is a natural number of 1 or more) wireless devices and a relay station. The relay station measures a communication distance with each of the n wireless devices, and determines a communication service permitted to the n wireless devices according to the measured communication distance.

  Preferably, the relay station holds a plurality of communication services associated with a plurality of communication distances, and changes the contents of the communication services stepwise according to the measured communication distance.

  Preferably, the relay station prohibits all communication services for wireless devices existing outside a certain communication distance.

  Preferably, the relay station determines a communication service according to the communication distance for a wireless device that exists within a certain communication distance.

  Preferably, the relay station limits the content of the communication service as the communication distance becomes longer.

  Preferably, the fixed communication distance is determined according to the content of the communication service.

  Preferably, the relay station changes the communication service based on the communication distance history information.

  Preferably, the relay station determines a communication service for the n wireless devices according to the history information and the registration / non-registration of the n wireless devices.

  Preferably, the relay station is between a first timing that completes transmission of data to each of the n radio devices and a second timing that starts receiving data from each of the n radio devices. The total time is measured, and the communication distance to each of the n wireless devices is determined based on the measured total time and the response time of each of the n wireless devices received from each of the n wireless devices. decide.

  In the wireless network system according to the present invention, the relay station measures a communication distance with each of the n wireless devices, and determines a communication service permitted to the n wireless devices according to the measured communication distance. For example, when the measured communication distance is within a certain communication distance, the relay station permits all communication services or relatively many communication services to the wireless device, and the communication distance is outside the certain communication distance. The relay station prohibits or restricts communication services to relatively few communication services.

  Therefore, according to the present invention, it is possible to suppress various information acquired via the relay station from being taken out of the network.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic block diagram of a radio network system according to an embodiment of the present invention. The wireless network system 100 includes an access point 10 and wireless devices 20, 30, 40, 50 and 60. The access point 10 and the wireless devices 20, 30, 40, 50, 60 are arranged in the wireless communication space 70, and the access point 10 performs wireless communication with the wireless devices 20, 30, 40, 50, 60 by the CSMA / CA method. Do.

  The access point 10 is connected to the registration terminal 80 via the wired LAN 1, and is connected to a web server, a mail server, and the like via the wired LAN 1 and the communication service LAN 2. The access point 10 receives the registration information of the wireless devices 20, 30, 40, 50, 60 from the registration terminal 80 via the wired LAN 1, and registers the received registration information in its storage unit.

  The access point 10 uses, for example, an IFS (Interframe Space), which is a period during which communication is not performed in the wireless communication space 70, to transmit data at a carrier frequency of 2.4 GHz through the wireless communication space 70, for example. To the wireless devices 30, 40, 50, 60). Then, the access point 10 receives data from the wireless device 20 (or the wireless devices 30, 40, 50, 60) at the timing when the transmission of data to the wireless device 20 (or the wireless devices 30, 40, 50, 60) is completed. The time between the start of data reception is measured, and the wireless communication is performed by a method described later based on the measured time and the response time of the wireless device 20 (or the wireless devices 30, 40, 50, 60). The communication distance with the device 20 (or the wireless devices 30, 40, 50, 60) is determined.

  When the access point 10 measures the communication distance with the wireless device 20 (or the wireless devices 30, 40, 50, 60), the wireless device 20, 30, 40, 50, The content of the communication service permitted to 60 is determined.

  The wireless device 20 (or the wireless devices 30, 40, 50, 60) receives data from the access point 10 via the wireless communication space 70, and from data reception completion to data transmission according to the data reception completion. The response time is measured, and the measured response time is transmitted to the access point 10 via the wireless communication space 70.

  In addition, the wireless device 20 (or the wireless devices 30, 40, 50, 60) receives a communication service permitted from the access point 10 via the access point 10. That is, if the wireless device 20 (or the wireless devices 30, 40, 50, 60) is permitted a normal communication service in the wireless LAN, the wireless device 20 receives the normal communication service via the access point 10, and the web. If only access to the server is permitted, only access to the web server through the access point 10 is performed.

  FIG. 2 is a schematic block diagram showing the configuration of the access point 10 shown in FIG. The access point 10 includes an antenna 101, a transmission / reception switching unit 102, a transmission unit 103, a reception unit 104, a distance measurement unit 105, a response control unit 106, a distance history storage unit 107, and a terminal specific information storage unit 108. A terminal registration operation unit 109 and an external interface unit 110.

  The antenna 101 receives data from the wireless device 20 (or wireless devices 30, 40, 50, 60) via the wireless communication space 70 and outputs the data to the transmission / reception switching unit 102, and data from the transmission / reception switching unit 102. Are transmitted to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70.

  The transmission / reception switching unit 102 is connected to the transmission unit 103 or the reception unit 104 in accordance with control from the response control unit 106. The transmission / reception switching unit 102 is connected to the reception unit 104 when the access point 10 receives data or the like from the wireless device 20 (or the wireless devices 30, 40, 50, 60), and receives the data received from the antenna 101. The data is output to the receiving unit 104. The transmission / reception switching unit 102 is connected to the transmission unit 103 when the access point 10 transmits data or the like to the wireless device 20 (or the wireless devices 30, 40, 50, 60), and the data received from the transmission unit 103. Is given to the antenna 101.

  The transmission unit 103 performs transmission system processing such as modulation and amplification on the data received from the response control unit 106, and wirelessly transmits the data subjected to the transmission system processing via the transmission / reception switching unit 102 and the antenna 101. Transmit to device 20 (or wireless device 30, 30, 40, 50, 60). In addition, when the transmission unit 103 measures the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60), the data is transmitted to the wireless device 20 (or the wireless devices 30, 30, 40, 60). 50, 60), a signal DTF indicating the end of data transmission is generated and output to the distance measuring unit 105.

  The receiving unit 104 performs reception processing such as amplification and demodulation on the data received from the transmission / reception switching unit 102 and outputs the data subjected to the reception processing to the response control unit 106. In addition, the reception unit 104 measures the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the antenna 101 and the transmission / reception switching unit 102. When reception of data from the wireless devices 30, 40, 50, 60) is started, a signal DETS indicating the start of reception is generated and output to the distance measuring unit 105. Furthermore, the receiving unit 104 detects the response time of the wireless device 20 (or the wireless devices 30, 40, 50, 60) included in the data received from the wireless device 20 (or the wireless devices 30, 40, 50, 60). And output to the distance measuring unit 105.

  The distance measurement unit 105 measures the time between the timing at which the signal DTF is received from the transmission unit 103 and the timing at which the signal DETS is received from the reception unit 104, and the measured time and the wireless device 20 (or the wireless device) (30, 40, 50, 60) and the response time of the wireless device 20 (or the wireless devices 30, 40, 50, 60) are determined by a method described later. Then, the distance measurement unit 105 outputs the determined communication distance to the response control unit 106 or stores it in the distance history storage unit 107.

  The response control unit 106 accesses the access point 10 based on a MAC (Media Access Control) address stored in the terminal specific information storage unit 108 (wireless devices 20, 30, 40, 50, 60). Whether or not the wireless device is a registered wireless device, and the content of the communication service permitted to the wireless device is determined according to the determination result.

  The response control unit 106 reads the communication distance (or communication distance history) stored in the distance history storage unit 107 and accesses the access point 10 according to the read communication distance (or communication distance history). The content of the communication service permitted to the wireless device that has been received is determined.

  Further, the response control unit 106 relays various types of information between the wireless devices 20, 30, 40, 50, 60 and the web server, mail server, and the like via the external interface unit 110.

  Furthermore, the response control unit 106 controls the transmission unit 103 and the transmission / reception switching unit 102 so as to periodically measure the communication distance with each of the radio apparatuses 20, 30, 40, 50, 60 by a method described later.

  Further, the response control unit 106 receives the MAC address of the wireless device about to register the MAC address from the terminal registration operation unit 109, and measures the communication distance with the wireless device having the received MAC address. The transmission / reception switching unit 102 and the transmission unit 103 are controlled. Then, when the communication distance to the wireless device is measured, the response control unit 106 receives the measured communication distance from the distance measuring unit 105, and if the received communication distance is within a predetermined range, If signal ALW for permitting registration of the MAC address of the wireless device in terminal specific information storage unit 108 is output to terminal registration operation unit 109 and the communication distance received from distance measurement unit 105 is outside the predetermined range, Then, a signal IHB for prohibiting registration of the MAC address of the wireless device in terminal specific information storage section 108 is output to terminal registration operation section 109.

  The distance history storage unit 107 stores the communication distance from the distance measurement unit 105 in association with the MAC address from the terminal specific information storage unit 108. In addition, the distance history storage unit 107 is a communication distance for each wireless device 20 (or wireless device 30, 40, 50, 60) identified by the MAC address from the terminal specific information storage unit 108, that is, a communication distance. Is stored in association with the MAC address.

  Then, in response to a request from the response control unit 106, the distance history storage unit 107 transmits the communication distance or the communication distance history of each wireless device 20 (or the wireless devices 30, 40, 50, 60) to the response control unit 106. Output.

  The terminal specific information storage unit 108 stores the MAC address received from the terminal registration operation unit 109 as terminal specific information.

  The terminal registration operation unit 109 receives the registration request and MAC address of each wireless device 20 (or wireless device 30, 40, 50, 60) via the external interface unit 110 connected to the wired LAN 1, and receives the received MAC address. Is output to the response control unit 106.

  Then, when receiving the signal ALW permitting registration from the response control unit 106, the terminal registration operating unit 109 stores the MAC address received together with the registration request in the terminal specific information storage unit 108, and responds with a signal IHB prohibiting registration. When received from the control unit 106, a notification that registration is not performed is transmitted via the external interface unit 110 to the wireless device that has transmitted the registration request.

  The external interface unit 110 outputs the registration request received from the registration terminal 80 via the wired LAN 1 and the MAC address of the target wireless device to the terminal registration operation unit 109, as well as various types received from a web server, a mail server, and the like. Is output to the response control unit 106, and various information received from the response control unit 106 is transmitted to the web server, the mail server, and the like via the wired LAN 1 and the communication service LAN 2.

  FIG. 3 is a schematic block diagram showing the configuration of the wireless device 20 shown in FIG. The radio apparatus 20 includes an antenna 120, selectors 130 and 230, amplifiers 140 and 280, mixers 150 and 270, low-pass filters 160 and 260, a demodulator 170, a clock adjuster 180, and a carrier detector 190. A controller 200, a crystal oscillator 210, a clock generator 220, a 1 / N frequency divider 240, and a modulator 250.

  The antenna 120 receives a radio wave via the wireless communication space 70 and transmits the received radio wave to the selector 130. The antenna 120 transmits the radio wave from the selector 130 to the wireless communication space 70.

  The selector 130 includes terminals 131 and 132 and a switch 133. Terminal 131 is connected to the input of amplifier 140. Terminal 132 is connected to the output of amplifier 280. The switch 133 is connected to the antenna 120. The selector 130 connects the antenna 120 to the input of the amplifier 140 or the output of the amplifier 280 by switching the switch 133 between the terminal 131 and the terminal 132 based on the signal SLT 1 from the controller 200. More specifically, the selector 130 connects the switch 133 to the terminal 131 in response to the H (logic high) level signal SLT1 from the controller 200, and generates the L (logic low) level signal SLT1 from the controller 200. In response, the switch 133 is connected to the terminal 132.

  The amplifier 140 receives the received radio wave received by the antenna 120 via the selector 130, amplifies the received received radio wave, and outputs it to the mixer 150. The mixer 150 mixes the received radio wave from the amplifier 140 and the clock signal CLK_PAT from the clock adjuster 180 and outputs the mixed signal to the low-pass filter 160.

  The low pass filter 160 removes high frequency noise from the radio wave from the mixer 150 and outputs a baseband signal to the demodulator 170 and the carrier detector 190. Demodulator 170 detects a frequency shift signal of the baseband signal and outputs the detected frequency shift signal to clock adjuster 180. The demodulator 170 demodulates the baseband signal and outputs the demodulated data DATA to the controller 200.

  The clock adjuster 180 estimates the carrier frequency of the other party of communication according to the frequency shift signal from the demodulator 170, generates a clock signal CLK_PAT having the estimated carrier frequency, and outputs it to the mixer 150 and the selector 230 To do. The carrier detector 190 detects the end of data reception based on the baseband signal from the low-pass filter 160, generates a signal DETF indicating the end of data reception, and outputs the signal DETF to the controller 200.

  When the wireless device 20 receives data, the controller 200 generates an H level signal SLT1 and outputs the signal from the terminal SEL1 to the selector 130. When the wireless device 20 transmits data, the controller 200 generates an L level signal SLT1. To output to the selector 130 from the terminal SEL1.

  Further, the controller 200 generates an H level signal SLT2 when the wireless device 20 receives data and outputs the signal from the terminal SEL2 to the selector 230. When the wireless device 20 transmits data, the controller 200 generates an L level signal SLT2. Is output from the terminal SEL2 to the selector 230.

  Further, when the controller 200 receives the signal DETF from the carrier detector 190 at the terminal CDET, the frequency-divided clock signal from the 1 / N frequency divider 240 between the timing of receiving the signal DETF and the timing of outputting the data DATA. The response time of the wireless device 20 is measured by counting the number of components of CLK_B. Then, when measuring the response time, the controller 200 outputs data DATA including the response time from the terminal TDA to the modulator 250.

  Note that the timer 201 may be built in the controller 200, and the controller 200 may measure the response time from the timing of receiving the signal DETF to the timing of outputting the data DATA using the built-in timer 201.

  Furthermore, the controller 200 receives the data DATA from the demodulator 170 at the terminal RDA, and transmits the received data DATA to the personal computer via the terminal HOSTIF.

  The crystal oscillator 210 generates a predetermined periodic signal and outputs it to the clock generator 220. Clock generator 220 generates clock signal CLK_SEF based on the periodic signal from crystal oscillator 210, and outputs the generated clock signal CLK_SEF to selector 230.

  The selector 230 includes terminals 231 and 232 and a switch 233. The terminal 231 is connected to the clock adjuster 180. Terminal 232 is connected to clock generator 220. The switch 233 is connected to the 1 / N frequency divider 240 and the mixer 270. Upon receiving the H level signal SLT2 from the controller 200, the selector 230 connects the switch 233 to the terminal 231 and outputs the clock signal CLK_PAT from the clock adjuster 180 to the 1 / N frequency divider 240 and the mixer 270. . When the selector 230 receives the L level signal SLT2 from the controller 200, the selector 230 connects the switch 233 to the terminal 232, and outputs the clock signal CLK_SEF from the clock generator 220 to the 1 / N frequency divider 240 and the mixer 270. .

  The 1 / N divider 240 divides the clock signal CLK_PAT or CLK_SEF from the selector 230 by 1 / N and outputs the divided clock signal CLK_B to the controller 200.

  Modulator 250 modulates data from controller 200 (consisting of transmission data and response time) with a predetermined modulation frequency, and outputs the modulated data to low-pass filter 260. The low pass filter 260 converts the modulation data from the modulator 250 into a baseband signal and outputs it to the mixer 270.

  The mixer 270 mixes the baseband signal from the low-pass filter 260 and the clock signal CLK_PAT or CLK_SEF from the selector 230 and outputs the mixed signal to the amplifier 280. The amplifier 280 amplifies the output of the mixer 270 and outputs it to the selector 130.

  Note that the wireless devices 30, 40, 50, and 60 shown in FIG. 1 also have the same configuration as the wireless device 20 shown in FIG.

  FIG. 4 is a timing chart of transmission data and reception data. Hereinafter, a method for determining the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) will be described. In FIG. 4, the data DATT represents data that the access point 10 transmits to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70, and the data DARR is the wireless device 20 ( Alternatively, the wireless device 30, 40, 50, 60) represents data received from the access point 10 via the wireless communication space 70, and the data DART is the wireless device 20 (or the wireless device 30, 40, 50, 60) wirelessly. The data DATR represents data to be transmitted to the access point 10 via the communication space 70, and the data DATR is data that the access point 10 receives from the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70. Represents.

  In the CSMA / CA scheme, when the access point 10 transmits one packet PKT_n-1, the access point 10 receives an acknowledgment after a waiting time of SIFS (Short Interframe Space). Then, after receiving an affirmative response, the access point 10 transmits the next packet PKT_n after a waiting time of DIFS (Distributed Interframe Space) and a waiting time of BACK_OFF have elapsed.

  In the present invention, the access point 10 uses a period during which communication is not performed in the wireless communication space 70 such as SIFS and DIFS, and data is transmitted to and from the wireless device 20 (or the wireless devices 30, 40, 50, 60). The round-trip time is measured, and the wireless device 20 (or wireless devices 30, 40, 50, 60) is based on the measured round-trip time and the response time of the wireless device 20 (or wireless devices 30, 40, 50, 60). ) To determine the communication distance.

  The access point 10 starts to transmit the data DATT to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70, and at timing t1, which is the beginning of the SIFS period of the wireless communication space 70. The transmission of data DATT is terminated. Then, the wireless device 20 (or the wireless devices 30, 40, 50, 60) starts to receive the data DARR from the access point 10 via the wireless communication space 70, and the transmission end of the data DATT at the access point 10 is finished at the timing t2. Is transmitted to the wireless device 20 (or the wireless devices 30, 40, 50, 60). That is, the time during which data is propagated from the access point 10 to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70 is τ1.

  When the wireless device 20 (or the wireless devices 30, 40, 50, 60) finishes receiving the data DARR from the access point 10, it measures the response time Tresp by the method described above, and the timing when the measurement of the response time Tresp ends. At t3, transmission of data including the response time Tresp to the access point 10 is started via the wireless communication space 70. Then, the access point 10 starts to receive data including the response time Tresp from the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70, and the wireless device 20 (or the wireless device 30). , 40, 50, 60), the transmission start of the data DART is propagated to the access point 10 at timing t4. That is, the time during which data is propagated from the wireless device 20 (or the wireless devices 30, 40, 50, 60) to the access point 10 via the wireless communication space 70 is τ2.

  As described above, the distance measuring unit 105 of the access point 10 measures the time from the timing of receiving the signal DTF to the timing of receiving the signal DETS, that is, the total time Ttotal from the timing t1 to the timing t4. As a result, the following equation is established.

Ttotal = τ1 + Tresp + τ2 (1)
Since the response time Tresp is measured by the controller 200 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) as described above, τ1 + τ2 is obtained by subtracting the response time Tresp from the total time Ttotal. This τ1 + τ2 is a round-trip time during which data reciprocates between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60).

  Note that the response time Tresp measured in the wireless device 20 (or the wireless devices 30, 40, 50, 60) is transmitted to the access point 10, so that the distance measuring unit 105 of the access point 10 uses the equation (1). Based on this, the round trip time τ1 + τ2 can be easily calculated.

  When the wireless device 20 (or the wireless devices 30, 40, 50, 60) stops moving, the end of data transmission at the access point 10 is propagated to the wireless device 20 (or the wireless devices 30, 40, 50, 60). The propagation time τ1 is equal to the propagation time τ2 at which the start of data transmission in the wireless device 20 (or the wireless devices 30, 40, 50, 60) is propagated to the access point 10, so half of the round-trip time τ1 + τ2 (τ1 + τ2) / 2 is the data propagation time between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60).

  Therefore, the distance measuring unit 105 of the access point 10 multiplies the time (τ1 + τ2) / 2 by the speed of light c to communicate between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60). Determine the distance.

  Since the response time Tresp is a fixed value in each wireless device 20 (or the wireless devices 30, 40, 50, 60), the total time Ttotal is increased by the data propagation times τ1, τ2.

  Therefore, the present invention utilizes the fact that the total time Ttotal is increased by the data propagation times τ1, τ2 between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60). 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) are determined.

[Measurement of communication distance]
FIG. 5 is a flowchart for explaining the operation of determining the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60). When a series of operations is started, the response control unit 106 of the access point 10 transmits data for measuring the communication distance to the wireless device 20 (or the wireless devices 30, 40, 50, 60) to the wireless device 20 (or The transmission unit 103 is controlled to transmit to the wireless device 30, 40, 50, 60), and data is transmitted / received to transmit data from the transmission unit 103 to the wireless device 20 (or wireless device 30, 40, 50, 60). The switching unit 102 is controlled.

  The transmission unit 103 generates data for measuring the communication distance with the wireless device 20 (or the wireless devices 30, 40, 50, 60) according to control from the response control unit 106, and modulates the generated data. Amplified and output to the transmission / reception switching unit 102.

  The transmission / reception switching unit 102 transmits the data from the transmission unit 103 to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the antenna 101 according to the control from the response control unit 106. Thereby, transmission of data to the wireless device 20 (or the wireless devices 30, 40, 50, 60) is started (step S1).

  Thereafter, the data is transmitted to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70, and when the data transmission is completed at the access point 10 (step S2), the transmission unit 103 The signal DTF is generated and output to the distance measuring unit 105. Then, the distance measurement unit 105 starts time measurement according to the signal DTF from the transmission unit 103 (step S3).

  On the other hand, the controller 200 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) generates an H level signal SLT1 and outputs it to the selector 130, generates an H level signal SLT2, and selects the selector 230. Output to. Then, the selector 130 connects the switch 133 to the terminal 131 in accordance with the H level signal SLT1. The selector 230 connects the switch 233 to the terminal 231 in accordance with the H level signal SLT2.

  The data transmitted from the access point 10 is transmitted to the wireless device 20 (or the wireless devices 30, 40, 50, 60) via the wireless communication space 70. The antenna 120 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) supplies the data received via the wireless communication space 70 to the amplifier 140 via the selector 130. The amplifier 140 amplifies the data supplied from the selector 130 and outputs the amplified data to the mixer 150. The mixer 150 mixes the output of the amplifier 140 and the clock signal CLK_PAT from the clock adjuster 180 and outputs the mixed signal to the low-pass filter 160. That is, the mixer 150 outputs the baseband signal to the low-pass filter 160 in synchronization with the clock signal CLK_PAT. The low pass filter 160 removes high frequency noise from the output of the mixer 150 and outputs a baseband signal to the demodulator 170 and the carrier detector 190.

  Demodulator 170 detects a frequency shift signal of the baseband signal and outputs the detected frequency shift signal to clock adjuster 180. Demodulator 170 demodulates the baseband signal and outputs the demodulated data to controller 200. The clock adjuster 180 estimates the carrier frequency of the access point 10 according to the frequency shift signal from the demodulator 170, generates a clock signal CLK_PAT having the estimated carrier frequency, and outputs it to the mixer 150 and the selector 230. . Thereby, the radio | wireless apparatus 20 (or radio | wireless apparatus 30,40,50,60) receives data synchronizing with the clock signal produced | generated in the access point 10 which is a communication other party (step S4).

  Then, the carrier detector 190 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) detects the end of reception of the data DATA based on the baseband signal from the low-pass filter 160 (step S5). ), A signal DETF indicating that the reception of the data DATA has been completed is generated and output to the controller 200.

  Subsequently, the selector 230 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) outputs the clock signal CLK_PAT from the clock adjuster 180 to the 1 / N frequency divider 240 and the mixer 270. The 1 / N frequency divider 240 divides the clock signal CLK_PAT by 1 / N and outputs the divided clock signal CLK_B to the controller 200.

  Then, the controller 200 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) synchronizes with the timing when the signal DETF from the carrier detector 190 is received at the terminal CDET, and the divided clock signal received at the terminal MCLK. The counting of the number of components of CLK_B is started, and the response time Tresp from the timing of receiving the signal DETF to the timing of outputting the data DATA is measured (step S6).

  As described above, the radio device 20 (or the radio devices 30, 40, 50, 60) measures the response time Tresp based on the clock signal CLK_PAT having the carrier frequency of the access point 10 estimated by the clock adjuster 180.

  In step S6, the controller 200 may measure the response time Tresp from the timing of receiving the signal DETF to the timing of outputting the data DATA by the built-in timer 201.

  After that, the controller 200 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) generates the L level signal SLT1 and outputs it to the selector 130, and the selector 130 responds to the L level signal SLT1. Then, the switch 133 is connected to the terminal 132.

  When the measurement of the response time Tresp ends, the controller 200 of the wireless device 20 (or the wireless devices 30, 40, 50, 60) generates data DATA including the response time Tresp, and modulates the generated data DATA from the terminal TDA. Output to the device 250. Modulator 250 modulates data DATA with a predetermined modulation frequency, and low-pass filter 260 removes high-frequency noise from the modulated data and outputs a baseband signal to mixer 270. The mixer 270 mixes the baseband signal from the low-pass filter 260 and the clock signal CLK_PAT from the selector 230 and outputs the mixed signal to the amplifier 280. That is, the mixer 270 outputs the baseband signal to the amplifier 280 in synchronization with the clock signal CLK_PAT. The amplifier 280 amplifies the output of the mixer 270 and outputs it to the selector 130. The selector 130 transmits the output of the amplifier 280 via the antenna 120. As a result, transmission of data DATA from the wireless device 20 (or the wireless devices 30, 40, 50, 60) to the access point 10 is started (step S7).

  As described above, the wireless device 20 (or the wireless devices 30, 40, 50, 60) transmits / receives data DATA from the access point 10 in synchronization with the clock signal CLK_PAT having the same carrier frequency as the carrier frequency at the access point 10. .

  Thereafter, the antenna 101 of the access point 10 outputs the data received via the wireless communication space 70 to the transmission / reception switching unit 102, and the transmission / reception switching unit 102 outputs the data DATA from the antenna 101 to the reception unit 104.

  The receiving unit 104 receives data DATA from the transmission / reception switching unit 102. As a result, the access point 10 starts receiving data DATA from the wireless device 20 (or wireless devices 30, 40, 50, 60) (step S8). When receiving the data DATA from the wireless device 20 (or the wireless devices 30, 40, 50, 60), the receiving unit 104 generates a signal DETS and outputs the signal DETS to the distance measuring unit 105. The response time Tresp in the wireless device 20 (or the wireless devices 30, 40, 50, 60) is extracted by demodulation, and the extracted response time Tresp is output to the distance measuring unit 105.

  When the distance measurement unit 105 receives the signal DETS from the reception unit 104, the distance measurement unit 105 ends the time measurement (step S9) and detects the total time Ttotal. Then, the distance measuring unit 105 calculates a round trip time τ1 + τ2 by subtracting the response time Tresp from the detected total time Ttotal. Thereafter, the distance measuring unit 105 determines the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) by multiplying the half of the round-trip time τ1 + τ2 (τ1 + τ2) / 2 by the speed of light c. Then, the determined communication distance is output to the response control unit 106 or stored in the distance history storage unit 107.

  Thereby, a series of operations are completed.

  As described above, the wireless device 20 (or the wireless devices 30, 40, 50, 60) measures the response time Tresp based on the clock signal CLK_PAT having the carrier frequency of the access point 10 that is the communication partner (step S6). reference). Further, the wireless device 20 (or the wireless devices 30, 40, 50, 60) transmits and receives data from the access point 10 in synchronization with the clock signal CLK_PAT having the same carrier frequency as the carrier frequency at the access point 10 (step S4). , S7).

  Accordingly, the data reception end timing, the response time Tresp length, and the data transmission start timing in the wireless device 20 (or the wireless devices 30, 40, 50, 60) are synchronized with the clock signal generated in the access point 10. The access point 10 can accurately measure the total time Ttotal = τ1 + Tresp + τ2. As a result, the communication distance between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) can be accurately determined.

  Further, since the access point 10 receives the actually measured response time Tresp from the wireless device 20 (or the wireless devices 30, 40, 50, 60), the response time in each of the wireless devices 20, 30, 40, 50, 60. Even if Tresp is different, the communication distance with each of the wireless devices 20, 30, 40, 50, 60 can be accurately determined.

  In the above, communication between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) using SIFS (SIFS shown in FIG. 4) in the wireless LAN system using the CSMA_CA method. Although it has been described that the distance is measured, the present invention is not limited to this, and access is performed using a PIFS (Point Coordination Function IFS) or DIFS (DIFS shown in FIG. 4) longer than SIFS in the wireless LAN system using the CSMA_CA method. The communication distance between the point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) may be measured.

  As described above, the access point 10 receives the response time actually measured in the wireless device 20 (or wireless devices 30, 40, 50, 60) from the wireless device 20 (or wireless devices 30, 40, 50, 60). Since the communication distance is determined, the data DATA is transferred between the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) using DIFS, which is a period during which communication is not performed in the wireless communication space 70. The communication distance can be determined even if the data is transmitted / received.

  That is, as shown in FIG. 4, DIF_ is accompanied by BACK_OFF, and this BACK_OFF is variable. Therefore, if the response time in the wireless device 20 (or the wireless devices 30, 40, 50, 60) is not actually measured, the time length of the DIFS cannot be determined and the communication distance cannot be determined. Measures the response time in the wireless device 20 (or the wireless devices 30, 40, 50, 60), so that the access point 10 and the wireless device 20 (or wireless) can be used even when using DIFS with variable time length. The communication distance between the devices 30, 40, 50, 60) can be determined.

  Therefore, in the present invention, the access point 10 and the wireless device 20 (or the wireless devices 30, 40, 50, 60) are used regardless of which SIFS, PIFS, or DIFS is a period during which communication is not performed in the wireless communication space 70. ) Can be determined.

  In the above description, the wireless device 20 (or the wireless devices 30, 40, 50, 60) measures its own response time and transmits the measured response time to the access point 10, but in the present invention, The wireless device 20 (or the wireless devices 30, 40, 50, 60) is not limited to this, and does not have to measure its own response time and transmit it to the access point 10.

  In this case, the access point 10 regards the response time in the wireless device 20 (or the wireless devices 30, 40, 50, 60) as SIFS or PIFS that is not communicating in the wireless communication space 70, and calculates the round trip time τ1 + τ2. Based on the calculated round trip time τ1 + τ2, the communication distance to the wireless device 20 (or the wireless devices 30, 40, 50, 60) is determined by the method described above.

[Register device-specific information]
Each wireless device 20, 30, 40, 50, 60 registers the MAC address as its own unique information in the access point 10 via the registration terminal 80. In this case, each of the wireless devices 20, 30, 40, 50, 60 transmits a registration request including the MAC address MACadds to the registration terminal 80 by wireless communication. Then, the registration terminal 80 transmits a registration request for each wireless device 20, 30, 40, 50, 60 to the access point 10 via the wired LAN 1.

  Then, the external interface unit 110 of the access point 10 outputs the registration request received via the wired LAN 1 to the terminal registration operation unit 109. The terminal registration operation unit 109 extracts the MAC address MACadds from the registration request received from the external interface unit 110 and outputs the MAC address MACadds to the response control unit 106.

  When the response control unit 106 receives the MAC address MACadds from the terminal registration operation unit 109, the response control unit 106 sets the communication distance to the wireless device (any of the wireless devices 20, 30, 40, 50, 60) having the received MAC address MACadds. The transmitting unit 103 and the transmission / reception switching unit 102 are controlled to transmit data for measurement.

  Then, the distance measuring unit 105 measures the communication distance with the wireless device having the MAC address MACadds by the method described above, and outputs the measured communication distance to the response control unit 106. The response control unit 106 determines whether or not the communication distance received from the distance measurement unit 105 is within a certain communication distance. Then, when the communication distance received from the distance measurement unit 105 is within a certain communication distance, the response control unit 106 generates a signal ALW that permits registration and outputs the signal ALW to the terminal registration operation unit 109. When the communication distance received from is outside a certain communication distance, a signal IHB for prohibiting registration is generated and output to the terminal registration operation unit 109.

  Upon receiving the signal ALW from the response control unit 106, the terminal registration operation unit 109 stores the MAC address MACadds in the terminal specific information storage unit 108. As a result, the terminal-specific information of each wireless device 20, 30, 40, 50, 60 is registered in the access point 10.

  On the other hand, when the terminal registration operation unit 109 receives the signal IHB from the response control unit 106, the terminal registration operation unit 109 transmits a message indicating that the terminal specific information is not registered to the registration terminal 80 via the wired LAN 1 via the external interface unit 110. 80 transmits to the wireless devices 20, 30, 40, 50, 60 by wireless communication that the terminal specific information is not registered.

  Thereby, the registration operation of the terminal specific information ends.

  In this way, the access point 10 permits the registration of the MAC address MACadds as terminal-specific information when each wireless device 20, 30, 40, 50, 60 exists within a certain communication distance, and each wireless device 20, When 30, 40, 50, and 60 do not exist within a certain communication distance, registration of the MAC address MACadds as terminal specific information is prohibited.

  In the present invention, registration of terminal-specific information is permitted when each wireless device 20, 30, 40, 50, 60 exists at a short distance (for example, within several meters) from the access point 10. Is preferred.

[Contents restriction of communication service]
As will be described below, the response control unit 106 of the access point 10 sends the wireless devices 20, 30, 40, 50, 60 to each wireless device 20, 30, 40, 50, 60 according to the communication distance with the wireless devices 20, 30, 40, 50, 60. Restrict the contents of the permitted communication services.

[First restriction method]
FIG. 6 is a diagram for explaining a first restriction method for a communication service. When the wireless devices 20, 40, 50 exist within a certain communication distance R from the access point 10, and the wireless device 30 exists outside the certain communication distance R from the access point 10, the access point 10 All communication services such as access to the server, transfer of data or programs to other computers connected to the communication service LAN 2, and transmission / reception of encrypted data to / from other computers are provided to the wireless devices 20, 40, 50. Permit and prohibit all communication services such as access to the web server and the mail server for the wireless device 30.

  When all communication services are permitted for the radio apparatuses 20, 40, 50, the response control unit 106 sets all port numbers of http (Hyper Text Transfer Protocol), “110” of POP (Post Office Protocol) 3. "Port number", SMTP (Simple Mail Transfer Protocol) "25" port number, FTP (File Transfer Protocol) "21" port number, SSH (Secure Shell) "22" port number 103, and transmitted to the radio apparatuses 20, 40, 50 via the transmission / reception switching unit 102 and the antenna 101.

  http is a protocol for accessing a web server. POP and SMTP are means for transmitting and receiving information to and from the mail server. POP is used when receiving information from the mail server, and SMTP is used when transmitting information to the mail server. Accordingly, the wireless devices 20, 40, and 50 can transmit and receive information to and from the mail server by allowing both POP and SMTP.

  Further, FTP is a means for transferring a file to another computer connected to the communication service LAN2, and SSH encrypts data when transmitting / receiving data to / from another computer connected to the communication service LAN2. Is a protocol for transmitting and receiving data.

  When the response control unit 106 of the access point 10 receives an access request from the wireless devices 20, 40, 50 via the antenna 101, the transmission / reception switching unit 102, and the receiving unit 104, the wireless device 20 included in the access request. , 40, 50, and the communication distance corresponding to the extracted MAC address is read from the distance history storage unit 107. When the response control unit 106 confirms that the read communication distance is within a certain communication distance R, the response control unit 106 permits access to the above-described web server, mail server, and the like. The access request is transmitted to the web server, the mail server, etc. via the external interface unit 110 via the wired LAN 1 and the communication service LAN 2.

  On the other hand, when the response control unit 106 receives an access request from the wireless device 30 via the antenna 101, the transmission / reception switching unit 102, and the receiving unit 104, the response control unit 106 extracts the MAC address of the wireless device 30 included in the access request. The communication distance corresponding to the extracted MAC address is read from the distance history storage unit 107. Then, when the response control unit 106 confirms that the read communication distance is outside the fixed communication distance R, the response control unit 106 notifies the wireless communication via the transmission unit 103, the transmission / reception switching unit 102, and the antenna 101 that the access is prohibited. Transmit to device 30. That is, the access point 10 completely restricts the communication service of the wireless device 30.

  Thus, the access point 10 determines whether or not to limit the content of the communication service depending on whether or not the communication distance with the wireless device is within a certain communication distance R.

  When there are three wireless devices 20, 40, 50 within a certain communication distance R from the access point 10, the access point 10 communicates with the wireless devices 20, 40, 50 by communication distances r1 to r3 (<R). The contents of the communication service permitted to each wireless device 20, 40, 50 may be determined according to the above.

  Here, it is assumed that the mutual relationship between the distances r1 to r3 is r2> r3> r1. That is, it is assumed that the wireless device 40 is farthest from the access point 10, the wireless device 50 is next farthest from the access point 10, and the wireless device 20 is closest to the access point 10. .

  In this case, the access point 10 permits all communication services for accessing the web server, the mail server, etc. to the wireless device 20 that is closest to the wireless device 50, and then to the wireless device 50 that is next nearby. In this case, access to the web server by http, transmission / reception of information to / from the mail server by POP and SMTP, and file transfer by FTP are permitted. For the wireless device 40 that is farthest away, the port number of the web server Of these, only access to the port number “80” is permitted.

  Accordingly, when the response control unit 106 of the access point 10 receives an access request from the wireless device 20 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the access control unit 106 receives the access request via the external interface unit 110 and the wired LAN 1 and It transmits to the web server via the communication service LAN 2, transmits an access request to the mail server via the wired interface 1 and the communication service LAN 2 via the external interface unit 110, and transmits the access request to the wired LAN 1 and the communication service via the external interface unit 110. Send to other computers via LAN2. As a result, the wireless device 20 can acquire various types of information from the web server, can transmit and receive various types of information with the mail server, can transfer files to other computers, and can encrypt data with other computers. Can be sent and received.

  When the response control unit 106 of the access point 10 receives an access request from the wireless device 50 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the response control unit 106 receives the access request via the external interface unit 110 and the wired LAN 1 and It transmits to the web server via the communication service LAN 2, transmits an access request to the mail server via the wired interface 1 and the communication service LAN 2 via the external interface unit 110, and transmits the access request to the wired LAN 1 and the communication service via the external interface unit 110. Send to other computers via LAN2. As a result, the wireless device 50 can acquire various types of information from the web server, can transmit and receive various types of information with the mail server, and can transfer files to other computers.

  Further, when the response control unit 106 of the access point 10 receives an access request from the wireless device 40 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the access request is received via the external interface unit 110 via the wired LAN 1 and It transmits only to the port number “80” of the web server via the communication service LAN 2. As a result, the wireless device 40 can acquire only information existing in the port number “80” of the web server.

  As described above, the access point 10 permits each of the wireless devices 20, 40, and 50 depending on the communication distances r1 to r3 with respect to the plurality of wireless devices 20, 40, and 50 that exist within a certain communication distance R. Restrict communication services.

[Second restriction method]
FIG. 7 is a diagram for explaining the second restriction method of the communication service. The response control unit 106 of the access point 10 holds four constant communication distances R1 to R4 as the constant communication distance R. The fixed communication distances R1 to R4 have a relationship of R1 <R2 <R3 <R4, and are set according to the content of the communication service.

  For example, the communication distance R1 is set for a communication service that encrypts data using SSH and transmits / receives data to / from another computer, and the communication distance R2 is a communication service that transfers files to another computer using FTP. The communication distance R3 is set for a communication service that transmits / receives information to / from a mail server using POP and SMTP, and the communication distance R4 is a communication that acquires various types of information from a web server using http. Set for the service.

  And since the radio | wireless apparatus 20 exists in the shortest communication distance R1, the access point 10 permits the radio | wireless apparatus 20 the communication service which encrypts data using SSH and transmits / receives with another computer. . Further, since the wireless device 30 exists between the communication distance R1 and the communication distance R2, the access point 10 permits the wireless device 30 to use a communication service for transferring a file to another computer using FTP. . Furthermore, since the wireless device 40 exists between the communication distance R2 and the communication distance R3, the access point 10 permits the wireless device 40 to communicate with the mail server using POP and SMTP. To do. Further, since the wireless device 50 exists between the communication distance R3 and the communication distance R4, the access point 10 permits the wireless device 50 to use a communication service for acquiring various types of information from the web server using http. To do.

  Accordingly, when the response control unit 106 of the access point 10 receives an access request from the wireless device 20 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the response request is transmitted to the wired LAN 1 via the external interface unit 110. And transmitted to another computer via the communication service LAN 2. As a result, the wireless device 20 can transmit and receive data encrypted with other computers.

  When the response control unit 106 of the access point 10 receives an access request from the wireless device 30 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the response request is transmitted to the wired LAN 1 via the external interface unit 110. And transmitted to another computer via the communication service LAN 2. As a result, the wireless device 30 can transfer the file to another computer.

  Further, when the response control unit 106 of the access point 10 receives an access request from the wireless device 40 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the access request is received via the external interface unit 110 via the wired LAN 1. And to the mail server via the communication service LAN2. Thereby, the radio | wireless apparatus 40 can transmit / receive various information with a mail server.

  Further, when the response control unit 106 of the access point 10 receives the access request from the wireless device 50 via the antenna 101, the transmission / reception switching unit 102, and the reception unit 104, the access request is received via the external interface unit 110 via the wired LAN 1. And transmitted to the web server via the communication service LAN2. Thereby, the radio | wireless apparatus 50 can acquire information from a web server.

  As described above, the access point 10 sets a certain communication distance R1 to R4 according to the contents of the communication service, and the wireless devices 20, 30, 40, 50, and 60 exist within the set communication distance R1 to R4. The content of the communication service is restricted depending on whether or not to do so.

  That is, the access point 10 changes the content of the communication service in a stepwise manner according to the communication distance with each wireless device 20, 30, 40, 50, 60.

  The response control unit 106 corresponds to the plurality of communication distances R1 to R4, and includes a plurality of communication services (acquisition of information from the web server, transmission / reception with the mail server, transfer of files to other computers and encryption) When the access request is received from each wireless device 20, 30, 40, 50, 60, the wireless device 20, 30, 40, 50 is received from the access request. , 60 MAC addresses are extracted, the communication distance corresponding to the extracted MAC address is read from the distance history storage unit 107, and based on the correspondence between the plurality of communication distances R1 to R4 and the plurality of communication services that are held. To determine the communication service to be permitted.

[Third restriction method]
FIG. 8 is a conceptual diagram of the distance history stored in the distance history storage unit 107 shown in FIG. In the following description, it is assumed that all the communication distances shown in FIG. 8 are within a certain communication distance R.

  In FIG. 8, MAC addresses MACA1 to MACA4 represent the MAC addresses of the wireless devices 20, 30, 40, and 50, respectively.

  The distance measuring unit 105 of the access point 10 measures, for example, the communication distance with the wireless devices 20, 30, 40, 50 every hour by the method described above, and uses the measured communication distance as a distance history to store a distance history storage unit. It memorize | stores in 107.

  The distance history storage unit 107 stores the communication distance measured by the distance measurement unit 105 in association with the MAC addresses MACA1 to MACA4 of the wireless devices 20, 30, 40, 50, and 60 for each time.

  The response control unit 106 receives an access request from each of the wireless devices 20, 30, 40, 50 via the antenna 101, the transmission / reception switching unit 102 and the receiving unit 104, and includes a MAC address (MAC address) included in the received access request. Any one of MACA1 to MACA4) is extracted. Then, the response control unit 106 reads out the distance history corresponding to the same MAC address as the extracted MAC address from the distance history storage unit 107, and transmits the distance history to each wireless device 20, 30, 40, 50 based on the read distance history. Determine the content of the communication service to be allowed.

  Since the distance history corresponding to the MAC address MACA1 indicates that the wireless device 20 has hardly moved, the response control unit 106 provides all communication services such as access to the web server to the wireless device 20. to approve.

  Further, since the distance history corresponding to the MAC address MACA2 indicates that the wireless device 30 is moving away from the access point 10, the response control unit 106 allows the wireless device 30 only to access the web server. To do.

  Furthermore, since the distance history corresponding to the MAC address MACA3 indicates that the wireless device 40 is approaching the access point 10, the response control unit 106 accesses the wireless device 40 to the web server, the mail server. Access to and file transfer via FTP.

  Furthermore, since the distance history corresponding to the MAC address MACA4 indicates that the wireless device 50 is approaching or moving away from the access point 10, the response control unit 106 sends the wireless device 50 to the web server. Allow access to and mail servers.

  In this way, the response control unit 106 determines the content of the communication service permitted to each wireless device 20, 30, 40, 50 based on the distance history of each wireless device 20, 30, 40, 50.

  In the above example, the response control unit 106 determines the content of the communication service permitted to each wireless device 20, 30, 40, 50 according to the following criteria.

(1) All communication services are permitted to the radio apparatus 20 that has hardly moved, that is, the radio apparatus 20 whose communication distance from the access point 10 is almost constant.

(2) The content of the communication service is most restricted for the wireless device 30 moving away from the access point 10.

(3) A relatively large number of communication services are permitted for the wireless device 40 approaching the access point 10.

(4) The wireless device 5 approaching or moving away from the access point 10
For 0, relatively few communication services are allowed.

  The wireless device 20 staying in almost a certain place has the lowest possibility of taking out various information acquired via the access point 10 to the other and is most reliable. It is.

  In addition, the wireless device 30 that is moving away from the access point 10 has the highest possibility of bringing the information acquired via the access point 10 to others, so the content of the communication service is most limited.

  Further, the wireless device 40 approaching the access point 10 is less likely to take information acquired via the access point 10 to others, but it is unclear whether or not it will remain in a certain place, so there are relatively many. The communication service is allowed.

  Further, since the wireless device 50 that is approaching or moving away from the access point 10 is not sure whether the information acquired via the access point 10 is likely to be taken out or not, it is relatively less communication service. Is decided to allow.

  Such a criterion for determining the content of the communication service is one example, and in the present invention, the content of the communication service may be determined according to another criterion. For example, the content of the communication service may be determined based on the moving speed of each wireless device 20, 30, 40, 50, 60.

  In this case, a positive speed indicates that the wireless device is moving away from the access point 10, and a negative speed indicates that the wireless device is approaching the access point 10. For wireless devices approaching the access point 10 at the fastest speed, all communication services are permitted, and for wireless devices approaching the access point 10 at a speed slower than the fastest speed, For wireless devices that allow relatively many communication services and move away at the fastest speed, for wireless devices that restrict the communication service most and move away at a slower speed than the fastest speed, Allow relatively few communication services. In this case, the response control unit 106 calculates the moving speed of each wireless device 20, 30, 40, 50, 60 based on the communication distance history acquired from the distance history storage unit 107, and calculates the calculated moving speed. The contents of the communication service permitted to each wireless device 20, 30, 40, 50, 60 are determined by applying the above criteria.

  When determining the contents of the communication service based on the distance history, the communication service is based on the history of the communication distance in an arbitrary range from the time when each wireless device 20, 30, 40, 50, 60 accesses the access point 10. The contents of may be determined. In the example shown in FIG. 8, the content of the communication service is determined based on the history of the communication distance within 4 hours from the time when each wireless device 20, 30, 40, 50, 60 accesses the access point 10. , Communication distances within various fixed periods such as within 1 hour, within 1 week, within 1 month, and within 1 year from the time each wireless device 20, 30, 40, 50, 60 accessed the access point 10 The content of the communication service may be determined based on the history.

  When various fixed periods are set, it is necessary to set a time interval for measuring the communication distance between the access point 10 and each of the wireless devices 20, 30, 40, 50, 60 so as to conform to the set fixed period. is there.

[Fourth restriction method]
When the response control unit 106 receives an access request from each of the wireless devices 20, 30, 40, 50, 60 via the antenna 101, the transmission / reception switching unit 102 and the reception unit 104, the response control unit 106 includes a MAC address included in the received access request. Whether or not (any one of MAC addresses MACA1 to MACA5) is stored in the terminal specific information storage unit 108 is searched.

  When the MAC address is stored in the terminal specific information storage unit 108, the response control unit 106 permits all communication services to the wireless device that has transmitted the access request.

  In this case, the response control unit 106 also reads the communication distance from the distance history storage unit 107 based on the MAC address included in the access request, and transmits the access request even if the read communication distance is long. Even when the wireless device is away from the access point 10, all communication services are permitted.

  On the other hand, when the MAC address is not stored in the terminal specific information storage unit 108, the response control unit 106 prohibits all communication services for the wireless device that has transmitted the access request.

  Also in this case, the response control unit 106 reads the communication distance from the distance history storage unit 107 based on the MAC address included in the access request, and transmits the access request even if the read communication distance is short. Even when the wireless device is close to the access point 10, all communication services are prohibited.

  When the MAC address is not stored in the terminal specific information storage unit 108, the response control unit 106 may permit a part of communication services to the wireless device that has transmitted the access request. For example, the response control unit 106 may allow only access to the port number “80” in the web server.

  In this way, the response control unit 106 determines the content of the communication service based on whether or not the terminal specific information of the wireless device that has transmitted the access request is registered in the access point 10.

  When the content of the communication service is restricted by registration / non-registration of terminal specific information, is the communication distance between the access point 10 and each wireless device 20, 30, 40, 50, 60 within a certain communication distance R? It may or may not be determined.

  In the various restriction methods described above, the communication distance between the access point 10 and each wireless device 20, 30, 40, 50, 60 is within a certain communication distance, or each wireless device 20, 30, 40, 50. , 60 terminal specific information is registered in the access point 10, all communication services or a relatively large number of communication services are permitted to the wireless devices 20, 30, 40, 50, 60, and the communication distance is constant. If the communication distance is outside the communication distance or if the terminal-specific information is not registered in the access point 10, the communication service is prohibited or restricted to relatively few communication services.

  Therefore, it is possible to prevent various information acquired via the access point 10 from being taken out of the network.

  In the above description, various methods for restricting the contents of the communication service have been described. However, the present invention is not limited to the above-described method, and various information acquired via the access point 10 is not taken out of the network. As long as the content of the communication service is restricted as described above, any restriction method may be used.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a wireless network system that can suppress various information from being taken out of the network.

1 is a schematic block diagram of a wireless network system according to an embodiment of the present invention. It is a schematic block diagram which shows the structure of the access point shown in FIG. It is a schematic block diagram which shows the structure of the radio | wireless apparatus shown in FIG. It is a timing chart of transmission data and reception data. It is a flowchart for demonstrating the operation | movement which determines the communication distance between an access point and a radio | wireless apparatus. It is a figure for demonstrating the 1st restriction | limiting method of a communication service. It is a figure for demonstrating the 2nd restriction method of a communication service. FIG. 3 is a conceptual diagram of a distance history stored in a distance history storage unit shown in FIG. 2.

Explanation of symbols

  10 access point, 20, 30, 40, 50, 60 wireless device, 70 wireless communication space, 100 wireless network system, 101, 120 antenna, 102 transmission / reception switching unit, 103 transmission unit, 104 reception unit, 105 distance measurement unit, 106 Response control unit 107 Distance history storage unit 108 Terminal specific information storage unit 109 Terminal registration operation unit 110 External interface unit 130/230 Selector 131/132/231/232 terminal 133/233 switch 140 280 amplifier, 150, 270 mixer, 160, 260 low pass filter, 170 demodulator, 180 clock adjuster, 190 carrier detector, 200 controller, 201 timer, 210 crystal oscillator, 220 clock generator, 240 1 / N divider , 50 modulator.

Claims (9)

n (n is a natural number of 1 or more) wireless devices;
A wireless network system comprising: a relay station that measures a communication distance with each of the n radio devices and determines a communication service permitted to the n radio devices according to the measured communication distance.   The said relay station hold | maintains the some communication service matched with the some communication distance, The content of the said communication service is changed in steps according to the said measured communication distance. Wireless network system.   The wireless network system according to claim 1, wherein the relay station prohibits all communication services for wireless devices existing outside a certain communication distance.   The wireless network system according to claim 1, wherein the relay station determines the communication service according to the communication distance for a wireless device existing within a certain communication distance.   The wireless network system according to claim 4, wherein the relay station limits the content of the communication service as the communication distance increases.   The wireless network system according to any one of claims 3 to 5, wherein the fixed communication distance is determined according to a content of the communication service.   The wireless network system according to claim 1, wherein the relay station changes the communication service based on history information of the communication distance.   The radio network system according to claim 7, wherein the relay station determines a communication service for the n radio devices in accordance with the history information and registration / non-registration of the n radio devices.   The relay station between a first timing for completing transmission of data to each of the n radio devices and a second timing for starting reception of the data from each of the n radio devices Each of the n wireless devices based on the measured total time and the response time of each of the n wireless devices received from each of the n wireless devices. The wireless network system according to any one of claims 1 to 8, wherein a communication distance is determined.

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