JP4665874B2 - Wireless device and program - Google Patents

Description

  The present invention confirms the presence of each other by performing wireless transmission and reception periodically or irregularly between the wireless key and the main body side device, and when the wireless key and the main body side device exceed a predetermined communication range, The present invention relates to a wireless device that can be used for an authentication device that restricts the function of a side device.

  In recent years, security systems have been put into practical use in which an operation lock of an electronic device such as a mobile phone or a personal computer is wirelessly controlled in consideration of security.

  As one form of such a security system, in order to prevent the mobile phone from being stolen, a user of the mobile phone possesses an identification signal transmitter in the form of a card, and the mobile phone and the identification signal transmitter are previously connected. There is a mobile phone that can be used when a predetermined identification code is communicated with each other and the identification code is confirmed by both parties (see, for example, Patent Document 1).

In Patent Document 1 of this wireless two-way communication system, a device (hereinafter referred to as an authentication device) mounted on the main body side such as an electronic device is periodically issued from a portable device (hereinafter referred to as a wireless key). It is described that the authentication ID is received and collated with the ID stored in the authentication device.
JP 2004-143806 A

  In the conventional configuration, the M-sequence signal transmitted every second is demodulated, and it is determined whether or not the authentication ID included in the M-sequence signal matches the ID stored in the authentication device. In order to perform verification of the authentication ID, the data length of the M-sequence signal cannot be shortened, and although there is no special description in Patent Document 1, in general, in order to accurately demodulate the M-sequence signal, the M-sequence signal A preamble signal having a predetermined length is required before the sequence signal.

  For this reason, there is a problem that the transmission time cannot be shortened and the current consumption cannot be reduced.

  The present invention solves the above-described conventional problems. For example, it can extend the battery life of a wireless key, a mobile phone, or the like without losing an electronic device such as a mobile phone or impairing a theft prevention function (security function). An object of the present invention is to provide a wireless device and a program thereof.

  The wireless device A is composed of a wireless device A and a wireless device B, and the wireless device A wirelessly transmits a signal including a first identification signal at a predetermined cycle, and from the first identification signal at a cycle that is an integral multiple of the predetermined cycle. A signal including a second identification signal having a long number of bits is wirelessly transmitted, and the wireless device B transmits a signal including the first identification signal and a signal including the second identification signal transmitted by the wireless device A. A wireless device that performs a reception operation in synchronization with each other, wherein the wireless device B performs a reception level check for a predetermined time at a reception timing of a signal including the first identification signal, and the reception level during the predetermined time It is a wireless device that considers that a signal including the first identification signal has been received when the signal becomes equal to or higher than a predetermined level.

  Since it is not necessary to demodulate the signal including the first identification signal and perform ID collation, the preamble signal and the first identification signal can be shortened, so that current consumption can be reduced.

  By using the wireless device and the program of the present invention, the power consumption of the wireless device A and the wireless device B can be reduced, for example, the battery life and misplacement of the wireless key and the convenience of preventing theft can be achieved.

  1st invention is comprised with the radio | wireless machine A and the radio | wireless machine B, and the said radio | wireless machine A carries out the radio transmission of the signal containing the 1st identification signal with a predetermined period, and the said period is the integer multiple of the said predetermined period. Wirelessly transmitting a signal including a second identification signal having a longer number of bits than the first identification signal, and the wireless device B transmits the signal including the first identification signal transmitted by the wireless device A and the second A wireless device that performs a reception operation in synchronization with a signal including an identification signal, wherein the wireless device B performs a reception level check for a predetermined time at a reception timing of the signal including the first identification signal, and the predetermined time A wireless device that considers that a signal including the first identification signal has been received when the reception level becomes equal to or higher than a predetermined level.

  Since it is not necessary to demodulate the signal including the first identification signal and perform ID collation, the preamble signal and the first identification signal can be shortened, so that current consumption can be reduced.

  According to a second aspect of the invention, the wireless device B performs a reception level check for a predetermined time at a reception timing of the signal including the first identification signal, and when the reception level becomes a predetermined level or more, It is a wireless device that suspends reception assuming that a signal including an identification signal has been received, and suspends reception assuming that a signal including the first identification signal has not been received when the predetermined time has elapsed.

  And since it is not necessary to demodulate the signal including the first identification signal and perform ID collation as in the first invention, the preamble signal and the first identification signal can be shortened, so that current consumption can be reduced. Become.

  According to a third aspect of the present invention, the signal including the first or second identification signal transmitted by the wireless device A is a signal for the wireless device A and the wireless device B to perform mutual authentication, The wireless device B outputs a signal that restricts the function of the device connected to the wireless device B when it is determined that the signal including the first identification signal has not been received under a predetermined condition. Device.

  For example, the battery life and misplacement of the wireless key can be made compatible with the convenience of preventing theft.

  According to a fourth aspect of the present invention, a hysteresis is provided between the predetermined level after outputting a signal for limiting the function of the device and the predetermined level when a signal for limiting the function of the device is not output. Wireless device.

  By providing the hysteresis, it is possible to prevent the fluttering that the function restriction is applied for a short time.

According to a fifth aspect of the present invention, there is provided a program for causing a computer to realize at least a part of the wireless devices according to the first to fourth aspects of the invention. Since it is a program, at least a part of the present invention can be realized with simple hardware by cooperating hardware resources such as an electric / information device and a computer. In addition, the program can be distributed / updated and installed easily by recording on a recording medium or distributing the program using a communication line.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram of a radio apparatus according to the first embodiment of the present invention.

  1 is a first antenna, 2 is a radio A, 3 is a first transmission / reception means, 4 is a first time control means, 5 is a first authentication means, 6 is a second antenna, 7 Is a radio B, 8 is a second transmission / reception means, 9 is a second time control means, and 10 is a second authentication means. Reference numeral 11 denotes a mobile phone connected to a wireless device.

  The wireless device A is a wireless key, for example, and is carried by the user of the mobile phone 11. Then, when the reception level of the radio wave from the wireless device A becomes weak, the wireless device B restricts the use of the mobile phone 11. In FIG. 1, the mobile phone 11 and the wireless device B are shown separately, but the wireless device B is often built in the mobile phone 11.

  2 and 3 show communication sequences between the wireless device A (2) and the wireless device B (7). FIG. 2 shows a communication sequence in search mode, and FIG. 3 shows a communication sequence in authentication mode.

  The search mode is a mode in which the wireless device A and the wireless device B confirm each other's existence and shift to the authentication mode.

  The authentication mode is a mode in which the wireless device A and the wireless device B regularly communicate with each other in time synchronization to confirm the existence of the other party. The presence of the other party is confirmed in the authentication mode, and the wireless device B does not restrict the use of the mobile phone 11 while receiving radio waves from the wireless device A at a predetermined reception level or higher.

  The search mode communication sequence will be described with reference to FIG.

  Radio A periodically transmits a search signal 12. The time interval for transmitting the search signal 12 is, for example, every 2 seconds. The search signal 12 includes an identification code indicating the wireless device A.

  When receiving the search signal 12, the wireless device B transmits a search response 13 to the wireless device A. Then, an initial authentication sequence 101 including exchange of identification signals between the wireless devices A and B is executed. After confirming the presence of each other in the initial authentication sequence 101, the mode shifts to the authentication mode of FIG.

  In shifting to the authentication mode in FIG. 3, the wireless devices A and B start the timer T <b> 1 from the end timing of the initial authentication sequence 101.

  Next, a communication sequence in the authentication mode of FIG. 3 will be described.

  The wireless device A transmits a simple ID signal 20 that is a signal including the first identification signal when the timer T1 is an integer multiple of 4 seconds. The wireless device B performs reception at the timing of the simple ID signal 20 and measures the reception level.

  If the reception level is less than or equal to a predetermined value, the counter built in the second authentication means 10 constituting the wireless device B is incremented assuming that the distance from the wireless device A is more than the predetermined distance. When the counter reaches a predetermined count, a function restriction signal is output to the mobile phone 11.

  If the reception level is equal to or higher than a predetermined level, the counter is cleared. That is, when the reception level of the simple ID from the wireless device A every 4 seconds is continuously below the predetermined level and reaches the predetermined number of times, the use restriction signal is output.

  When the timer T1 reaches 32 seconds, the wireless device A transmits a request signal 21 that is a signal including the second identification signal. When the timer T1 reaches 32 seconds, the wireless device B also starts reception and receives the request signal 21. Then, the wireless device B creates and transmits a challenge signal 22 using a random number generator.

  The wireless device A starts the timer T1 again at the timing when the request signal 21 is transmitted. When the challenge signal 22 is received, it is determined that authentication has been established, and a pause state is entered.

  When the wireless device A cannot receive the challenge signal, it retransmits the request signal 23 after T2 from the timing of transmitting the request signal 21, and starts the timer T1 again at the timing of transmitting the request signal 23.

  If the retransmission of the challenge signal 24 cannot be received, the request signal 25 is retransmitted after T3 from the transmission timing of the request signal 23, and the timer T1 is started again at the transmission timing of the request signal 25. A retransmission of the challenge signal 26 is received.

  When the challenge signal 26 cannot be received, the search signal 27 is transmitted after T4 from the timing of transmitting the request signal 24, and the search mode is entered.

  On the other hand, the wireless device B measures the error between the internal clock of the wireless device A and the internal clock of the wireless device B at the timing when the request signal 21 is received. Then, the timer T1 is started again.

  Here, a time error between the timer T1 of the wireless device A and the timer T1 of the wireless device B will be considered. When the absolute accuracy of the timepiece is ± 100 ppm, the relative error between the timepieces of the wireless device A and the wireless device B is ± 200 ppm. Therefore, a relative error of ± 6.4 msec (assuming ΔT) occurs at 32 seconds.

  Therefore, when receiving the first request signal 25 that has shifted from the search mode to the authentication mode, the reception is performed 6.4 ms before the timer T1 of the radio B indicates 32 seconds in consideration of the relative error ± 6.4 ms. Need to start. Then, by receiving the request signal 25, the relative error ΔT with the wireless device A can be measured.

  When the relative error ΔT is measured, the reception timing of the next 32 seconds is a time obtained by correcting ΔT from the 32 seconds indicated by the timer T1.

In the example of FIG. 3, a value obtained by subtracting ΔT from 32 seconds is the reception timing of the next 32 seconds. Since the simple ID 20 is transmitted every 4 seconds, the correction of the reception timing of the simple ID 20 subtracts ΔT × n / 8 from the value of the timer T1. n is the nth reception timing of the simple ID 20. And the time error ΔT with the timer T1 of the wireless device A is measured at the reception timing of the next 32 seconds,
Add to the previous ΔT. The above-described correction is performed using ΔT as a result of the addition. Thereafter, this correction process is repeated.

  By performing the above correction process, the reception timing of the subsequent simple ID 20 (signal including the first identification signal) and the reception of the request signal 21 (signal including the second identification signal) every 32 seconds or the response signal 18 described later are received. The timing can be matched with the transmission timing of the wireless device A without relative error.

  Actually, reception is performed at a reception timing described later in consideration of a measurement error and a relative error due to a temperature change for 32 seconds. Eliminating the relative error between the timepiece of the wireless device A and the timepiece of the wireless device B can minimize the reception time of the simple ID 20 and greatly contribute to the reduction of current consumption.

  Since there may be retransmission from the wireless device A, reception starts at the timing when the request signal 23 is transmitted.

  When the request signal 23 is received, the challenge signal 24 is retransmitted, the clock error of the radio A and the radio B is measured at the timing when the request signal 23 is received, and the timer T1 is started again. Since there may be retransmission from the wireless device A, reception starts at the timing when the request signal 25 is transmitted.

  When the request signal 25 is received, the challenge signal 26 is retransmitted, the clock error of the radio A and the radio B is measured at the timing when the request signal 25 is received, and the timer T1 is started again. Then, reception starts at the timing when the wireless device A transmits the search signal 27, and it is confirmed whether the search signal 27 is present.

  If there is no search signal, it is determined that the wireless device A has received any of the challenge signals 22, 24, and 26, and authentication is established, and the wireless communication device A enters a sleep state.

  If the search signal 27 is received, the search mode is entered. When the search signal 27 is received even though any of the challenge signals 22, 24, 26 is transmitted, the function restriction output is not immediately output to the mobile phone 11 even when the search mode is entered.

  A function restriction signal is output when the sequence of FIG. 2 is not established with the wireless device A within a predetermined time after shifting to the search mode.

  When the authentication is established without shifting to the search mode, the wireless device A transmits the simple ID 20 at the timing when the timer T1 is an integral multiple of 4 seconds.

  The sequence shown in FIG. 3 is repeated. In the next 32 seconds, the response signal 18 and the confirmation signal 19 shown in FIG. 2 are exchanged instead of the exchange of the request signal 21 and the challenge signal 22. In the next 32 seconds, the request signal 21 and the challenge signal 22 are exchanged again.

  FIG. 4 shows transmission / reception timings of the wireless devices A and B in the search mode of FIG. The reception timing will be described with reference to FIG.

  (1) transmits the search signal 12 every T5 at the transmission timing of the wireless device A. T5 is 2 seconds as an example.

(2) is the reception timing of the wireless device B, and continues reception for the period T5 + α every T6.
T6 is, for example, 10 seconds, and α is 10 milliseconds.

  (3) is an enlarged view of the reception timing of the wireless device B of (2). As shown in (3), the reception of the wireless device B in the T5 + α period is intermittent reception.

  FIG. 5 is a diagram showing a telegram structure of the search signal 12 transmitted by the wireless device A and the reception timing of the wireless device B in the T5 + α period. In FIG. 5, (1) is a telegram structure of the search signal 12, and (2) is a reception timing of the wireless device B.

  The search signal 12 includes a preamble, a frame synchronization signal, and data. The data is a so-called identification code.

  The wireless device B performs intermittent reception that is in a reception state only for T11 every T7.

  A reception level check is performed to determine whether or not there is a search signal 12 during the reception period T11. If the result of the reception level check is a predetermined level or less, reception is interrupted. If it is above a predetermined level, reception continues.

  T11 is a very short time, for example, 200 μsec. T7 is determined by the preamble length of the search signal 12.

  In this way, the wireless device B receives intermittently at intervals shorter than the duration of the preamble, so that the wireless device B always has at least one reception timing during the preamble period of the search signal 12, and is received during the preamble period. The level check can be performed and reception can be continued, so that the frame synchronization signal and data following the preamble can be received.

  In FIG. 5, the current when the radio B is receiving is 12 mA, and the base current when receiving is OFF is 2 mA. The base current is the operating current of the microcomputer.

  As described above, by making the preamble of the search signal 12 longer, the radio B can be intermittently received, and when the search signal 12 cannot be received continuously, the current consumption of the radio B is greatly reduced. it can. Then, the wireless device B performs intermittent reception every T6 for the period T5 + α.

  FIG. 6 shows a message structure and reception timing in a search mode with a search response 13 or lower.

  (1) is a message structure transmitted from the transmission side, and (2) is a reception timing on the reception side.

  Hereinafter, an example in which the search response 13 is received will be described.

  When the wireless device B receives the search signal 12, a search response 13 is transmitted. The timing at which the search response 13 is transmitted is promised in advance by the wireless device A and the wireless device B. Radio A starts reception with a delay of T8 from the timing at which search response 13 is transmitted.

  The search response 13 does not always return. If the wireless device B does not exist nearby, it will not return. Therefore, it is important from the viewpoint of current reduction that the wireless device A immediately stops receiving when there is no search response 13.

By configuring to start reception in the middle of the preamble of the search response 13, the wireless device A performs a reception level check in a short time T11 similarly to that shown in FIG. it can. Also, variations in reception timing and transmission timing can be absorbed.

  As described in the search response 13, the same applies to a message used in the intended authentication sequence 101. The timing of transmission / reception of messages below the search response 13 is determined in advance by the wireless device A and the wireless device B. That is, transmission / reception is performed in a time-synchronized state. Therefore, it can be configured to start reception from the middle of the preamble.

  FIG. 7 shows the message structure and the reception timing of the request signal 21 and the challenge signal 22 which are authentication communication sequences in the authentication mode of FIG.

  In FIG. 7, (1) is a message structure of the request signal 21 or the challenge signal 22 transmitted from the transmission side. (2) is a reception timing on the reception side.

  The preamble is set to the minimum number of bits necessary for receiving synchronization. Therefore, since reception is not possible if reception is set to start in the middle of the preamble, reception is started before request signal 21 or challenge signal 22 is transmitted T9, and request signal 21 or challenge signal 22 is transmitted. wait.

  T9 is, for example, 1 ms. The next 32-second response signal 18 and confirmation signal 19 also have the reception timing shown in FIG.

  The search signal 27 is the same as the search signal 12 in FIG. 2 and has the telegram structure shown in FIG. In order to confirm the presence / absence of a retransmission signal, the wireless device B always performs reception as described above.

  Retransmission uses the reception timing shown in FIG. As a result, the presence / absence of a retransmission signal can be detected in a short time, and if there is no retransmission signal, reception can be interrupted immediately, leading to a reduction in current.

  The part of the present invention in the operation of the present embodiment described above will be described in more detail below.

  FIG. 8 shows the message structure and reception timing of the simple ID 20 in the authentication mode shown in FIG. (1) is the message structure of the simple ID 20 transmitted from the wireless device A, and (2) is the reception timing of the wireless device B.

  In the simple ID 20 shown in FIG. 8, the data is the first identification signal, for example, 8 bits. In addition, the data of the message | telegram structure shown in FIG. 7 (1) is a 2nd identification signal, and is set to the integer multiple of 8 bits. The second identification signal is included in the request signal 21 shown in FIG.

  The reception of the simple ID 20 in the wireless device B only checks the reception level. The reception level check period is performed before and after the simple ID 20 is transmitted. That is, reception starts before T10 when the simple ID 20 is transmitted. This is because the reception level check is always performed including the period during which the simple ID is transmitted even if there is a time error caused by the clock error between the wireless device A and the wireless device B or the processing variation of the transmission / reception timing.

  As described above, if the reception level is equal to or lower than the predetermined level as a result of the reception level check, it is incorporated in the second authentication means 10 constituting the wireless device B assuming that the distance from the wireless device A is more than the predetermined distance. Increment the counter. When the counter reaches a predetermined count, a function restriction signal is output to the mobile phone 11.

  If the reception level is equal to or higher than the predetermined level, it is assumed that the simple ID 20 has been received and the counter is cleared. That is, when the reception level of the simple ID from the wireless device A every 4 seconds is continuously below the predetermined level and reaches the predetermined number of times, a use restriction signal is output. If the reception level is above the predetermined level, the simple ID 20 It is assumed that the message has been received and usage restrictions are not applied.

  As described above, since it is not necessary to demodulate the received signal and it is only necessary to check the reception level, the preamble of the simple ID 20 and the first identification signal need only have a length necessary for checking the reception level. That is, the signal length of the simple ID 20 can be extremely shortened compared to the preamble of the request signal 21 and the second identification signal, which need to be demodulated every 32 seconds to verify the ID.

  As a method for checking the reception level of the simple ID 20, as described above, the reception level is checked for a predetermined time including before and after the transmission of the simple ID in consideration of a clock error and the like, and the maximum value of the reception level The reception level may be a check level, or may be a reception level in which an average value or a median value is checked.

  Rather than checking the reception level for a predetermined time, it is assumed that the simple ID 20 has been received when the reception level exceeds the predetermined level, the reception is terminated, the counter is cleared, and the predetermined time has elapsed. Even if the reception level does not exceed a predetermined level, it may be assumed that the simple ID 20 has not been received, the reception is terminated, and the counter is incremented.

  FIG. 9 shows a flowchart showing the operation of the above wireless device B. The operation of the wireless device B will be described again with reference to FIG.

  In process S51 following the standby state S50, it is determined whether it is time to receive the simple ID 20. And if it is NO, it will return to standby state S50 again. If YES, in step S52, a timer for counting a predetermined time set in consideration of a clock error and the like is started and a reception level check is started.

  In step S53, it is determined whether the reception level is equal to or higher than the predetermined level. If the reception level is higher than the predetermined level, the reception level check is immediately interrupted (step S59), and the counter is cleared in step S60. In step S61, the function restriction output is turned off, and the process returns to the standby state 50.

  On the other hand, if the reception level is equal to or lower than the predetermined level in process S53, it is determined in process S54 whether or not the predetermined time has elapsed, and if the predetermined time has not elapsed, the process returns to process S53.

  If the predetermined time has elapsed, the reception level check is terminated in step S55, and the counter is incremented in step S56. In step S57, it is determined whether or not the count value of the counter has reached a predetermined number. If the counter value has reached the predetermined number, the function restriction output is turned on in step S58, and the process returns to the standby state S50.

  On the other hand, when the count value of the counter does not reach the predetermined number in the process S57, the process returns to the standby state S50.

Two levels may be provided as the predetermined level. That is, when it is assumed that the simple ID has been received and the function restriction output is not performed, for example, -9 is set as a predetermined level.
5 dBm. When it is assumed that the simple ID has not been received and the function restriction output is performed, for example, the predetermined level is set to −92 dBm.

  By giving hysteresis to the predetermined level in this way, it is possible to prevent fluttering that the function limit output is not output each time the simple ID 20 is received.

  The first transmission / reception means 3 and the second transmission / reception means 8 in FIG. 1 perform wireless transmission / reception. The first time control 4 and the second time control means 9 control transmission and reception timing. The first authentication unit 5 and the second authentication unit 10 determine whether authentication communication is established or whether to output a function restriction signal.

  In addition, the numerical value demonstrated by the said embodiment is an example for demonstrating, and is not limited to this.

  1 described in this embodiment uses hardware resources such as a CPU (or microcomputer), a RAM, a ROM, a storage / recording device, an electric / information device including an I / O, a computer, a server, and the like. You may implement in the form of the program made to cooperate. In the form of a program, new functions can be easily distributed / updated and installed by recording them on a recording medium such as magnetic media or optical media or distributing them using a communication line such as the Internet.

  As described above, the present invention can provide, for example, an electronic device that can achieve both the battery life and misplacement of the wireless key and the convenience of preventing theft. In addition, it can be used in a wireless device that requires low power consumption.

The block diagram of the radio | wireless apparatus in embodiment of this invention Communication sequence diagram in search mode of wireless device in an embodiment of the present invention Communication sequence diagram in authentication mode of wireless device in the embodiment of the present invention Transmission / reception timing chart of wireless device A and wireless device B in the search mode of the wireless device in the embodiment of the present invention Telegram structure and reception timing diagram of search signal of wireless device according to embodiment of present invention Message structure and reception timing chart of search mode of wireless device in embodiment of the present invention Message structure and reception timing chart of search mode of wireless device in embodiment of the present invention Message structure and reception timing diagram of simple ID of wireless device in the embodiment of the present invention Flowchart in the embodiment of the present invention

Explanation of symbols

1 First antenna 2 Radio A
3 First transmission / reception means 4 First time control means 5 First authentication means 6 Second antenna 7 Radio B
8 Second transmission / reception means 9 Second time control means 10 Second authentication means 11 Mobile phone

Claims (2)

It consists of radio A and radio B,
The wireless device A wirelessly transmits a signal including a first identification signal at a predetermined cycle in an authentication mode that is a mode for performing mutual authentication, and is longer than the first identification signal at a cycle that is an integral multiple of the predetermined cycle. Wirelessly transmitting a signal including the second identification signal of the number of bits,
The wireless device B is a wireless device that performs a receiving operation in synchronization with a signal including the first identification signal and a signal including the second identification signal transmitted by the wireless device A in the authentication mode. ,
The radio B is
When a signal including the second identification signal is received, it is demodulated to check the ID and the reception level is confirmed. If the reception level is equal to or lower than a predetermined level, the function of the device connected to the radio B is limited. Output a signal to
When a signal including the first identification signal is received, the reception level is confirmed, the number of times that the reception level becomes a predetermined level or less is counted, and when the number reaches the predetermined value, the radio B is connected. A wireless device that outputs a signal that restricts the function of the device. A program for causing a computer to realize at least a part of the wireless device according to claim 1 .

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