JP4871186B2 - Wireless tag system and wireless tag ID information update method - Google Patents

Description

  The present invention relates to a wireless tag system and a wireless tag ID information updating method for preventing the privacy of a user carrying a wireless tag from being infringed by information output from the wireless tag.

In recent years, a system has been proposed in which a parent or guardian at home or work can watch the state of a child or student (also referred to as a schoolchild) attending a school or a cram school using a wireless tag (for example, Patent Document 1). reference). In such a system, a device with a monitoring camera is installed on a schoolchildren's school road, and the schoolchildren are provided with a wireless tag capable of wireless communication with the device. When the schoolchild passes the vicinity of the device when going to and from school, the tag ID is received from the wireless tag possessed by the schoolchild, and the position information and video information of the schoolchild are provided to the guardian.
Japanese Unexamined Patent Publication No. 2007-42009 (page 5-13, FIG. 1)

However, in the system as described above, when the tag ID information is illegally obtained by a third party, the position information of the wireless tag (that is, the position information of the schoolchild, etc.) is illegally tracked by the third party, and the user's Privacy may be infringed. Therefore, conventionally, as a method for protecting the user's privacy, a method for encrypting the user's personal information is known. For example, a method has been proposed in which personal information of a user is encrypted by using an encryption procedure for generating a code indicating an apparently different value that can be decoded into the same code (see, for example, Patent Document 2). In addition, a method has been proposed in which the personal information of a user is concealed from a third party by using an encryption procedure for generating different codes specifying the same identifier so that the identifier appears to be variable (for example, patents). Reference 3).
JP 2004-362201 (pages 7-12, FIG. 2) JP 2004-317764 A (page 5-11, FIG. 3)

  However, the encryption procedure for generating a code indicating an apparently different value that can be decoded into the same code as in Patent Document 2 is a special encryption method called re-encryption. This leads to an increase in the cost of the tag reader device, and there is a problem that real time encryption (ID update) is difficult due to a large amount of calculation. Further, in the technique as in Patent Document 3, it is necessary for the RFID tag device itself to hold secret information such as a secret key, and to implement both random number generation and an encryption algorithm. Become.

  In a monitoring system for managing the location of a carrier of a wireless tag device, it is necessary to distribute the wireless tag to a large number of people to be watched, and it is also necessary to arrange a large number of wireless tag reader devices in the monitoring region Therefore, it is desired to provide a system that protects the privacy of the wireless tag carrier with a low cost and simple configuration.

  The present invention has been made to solve the above-described conventional problems, and can prevent unauthorized tracking of the RFID tag device with a low-cost and simple configuration, thereby protecting the privacy of the RFID tag user. An object of the present invention is to provide a wireless tag system that can be protected.

  The wireless tag system of the present invention includes a wireless tag device and a wireless tag reader device capable of wireless communication with the wireless tag device, wherein the wireless tag device includes ID information of the wireless tag device, and the wireless tag device. Using storage means for storing transmission output information indicating the output intensity of the transmission signal to the tag reader apparatus, transmission output control means for controlling the output intensity of the transmission signal, and ID update information received from the wireless tag reader apparatus ID update means for performing an ID update process for updating the ID information, wherein the wireless tag reader device has an output intensity of the transmission signal based on the transmission output information received from the wireless tag device. A transmission strength determination means for determining whether the communication level or the short-distance communication level, and when it is determined that the level is a long-distance communication level An output reduction request means for transmitting a reduction request signal for reducing the output intensity of the transmission signal to the RFID tag device, and an ID update process in the RFID tag device when it is determined that the level is a near field communication level An update information generating unit that generates the ID update information used in the configuration, and an update information transmitting unit that transmits the generated ID update information to the wireless tag device. .

  With this configuration, when the RFID tag device enters the communication area of the telecommunications level, the output intensity of the transmission signal is controlled to decrease from the telecommunications level to the near field communication level. When the wireless tag device further approaches the communication area of the near field communication level, the ID information of the wireless tag device is updated. That is, every time the wireless tag device approaches the wireless tag reader device, the ID information (old ID information) of the wireless tag device is converted into another ID information (new ID information). Therefore, even if the ID information of the wireless tag device is wiretapped by a third party, the ID information of the wireless tag device is updated one after another, so that illegal tracking of the ID information can be prevented. it can. Thereby, the privacy of the RFID tag user can be protected. Also, the ID update information is transmitted only when the wireless tag device approaches the wireless tag reader device. Therefore, even if the ID information of the wireless tag device is wiretapped by a third party, the risk of ID update information being wiretapped by a third party can be reduced, and safety is improved.

  In the wireless tag system of the present invention, the wireless tag reader device includes reception strength determination means for determining whether the strength of the received signal received from the wireless tag device is equal to or higher than a predetermined threshold strength, The output reduction request means has a configuration for transmitting the reduction request signal to the wireless tag device when it is determined that the strength of the received signal from the wireless tag device is equal to or higher than the threshold strength.

  With this configuration, when the RFID tag device enters the communication area of the telecommunications level and further approaches until the intensity of the received signal from the RFID tag device exceeds the threshold strength, the transmission signal of the RFID tag device Control is performed so that the output intensity decreases. Thereby, it is possible to control the output intensity of the transmission signal with respect to the wireless tag device having a high probability of approaching the wireless tag reader device until entering the communication area of the near field communication level.

  The wireless tag system according to the present invention further includes a timer device that measures a duration in which the output intensity of the transmission signal is at a near field communication level, and the transmission output control means of the wireless tag device has the predetermined duration. When the threshold time is exceeded, the output intensity of the transmission signal is returned to the telecommunications level.

  With this configuration, the output intensity of the transmission signal of the RFID tag device is returned to the telecommunications level after a predetermined threshold time has elapsed after being switched to the near field communication level. Thereby, the wireless tag device can resume communication at the telecommunication level at an appropriate timing.

  In the wireless tag system of the present invention, a plurality of the wireless tag reader devices arranged include identification signal transmission means for transmitting a unique identification signal to each, and the transmission output control means of the wireless tag device is a single wireless signal. After receiving the identification signal of the tag reader device, when the identification signal of another wireless tag reader device is received, the output intensity of the transmission signal is returned to the telecommunications level.

  With this configuration, the output intensity of the transmission signal of the wireless tag device is long-range when receiving the identification number of another wireless tag reader device after receiving the identification number of a certain wireless tag reader device and switching to the near field communication level. Returned to communication level. Thereby, the wireless tag device can resume communication at the telecommunication level at an appropriate timing.

  In the wireless tag system of the present invention, the wireless tag device receives an updated signal indicating that the ID update information has been received from the wireless tag reader device and the ID update information has been updated. An updated signal transmission means for transmitting to the wireless tag reader device of the transmission source, and the update information transmission means of the wireless tag reader device receives the updated signal from the wireless tag device; The transmission is stopped.

  With this configuration, when the wireless tag device receives ID update information from a certain wireless tag reader device and updates the ID information, the wireless tag device transmits an updated signal to the wireless tag reader device. When receiving the updated signal from the wireless tag device, the wireless tag reader device stops transmitting the ID update information to the wireless tag device. Thereby, unnecessary transmission of the ID update information can be prevented.

  Further, in the wireless tag system of the present invention, the wireless tag reader device reduces the output intensity of a transmission signal to the wireless tag device when transmitting the ID update information to the wireless tag device. It has the structure provided with the means.

  With this configuration, by performing output control that reduces the output intensity of the transmission signal of the wireless tag reader device, it is possible to reduce the risk of ID update information being wiretapped by a third party, and the safety is further improved.

  The wireless tag system of the present invention includes a center device capable of communicating with the wireless tag reader device via a network, and the wireless tag reader device includes ID information of the wireless tag device and the ID information in the wireless tag device. Network update means for transmitting the ID update information used for updating to the center device, and the center device associates the ID information received from the wireless tag reader device with each wireless tag device. ID information management means for recording and updating the ID information recorded in the recording means by performing the same ID update processing as the wireless tag apparatus using the ID update information received from the wireless tag reader apparatus It has the composition provided with.

  With this configuration, in the center device, the ID information received from the wireless tag reader device is recorded for each wireless tag device, and the same ID update processing as that of the wireless tag device is performed using the ID update information received from the wireless tag device. . As a result, the ID information of the wireless tag device can be collectively managed by the center device.

  In the wireless tag system of the present invention, the ID information management means of the center device has a configuration for recording update history information of the ID information together with the ID information.

  With this configuration, when searching for a wireless tag device, it is possible to search using not only current ID information but also an update history of ID information. For example, when there is a communication failure between a wireless tag device and a wireless tag reader device, the ID information recorded in the center device may be updated even though the ID information of the wireless tag device has not been updated. is there. Even in such a case, the wireless tag device can be found using old ID information (for example, initial ID information or previous ID information).

  A wireless tag device of the present invention is a wireless tag device used in the above-described wireless tag system, and the wireless tag device indicates ID information of the wireless tag device and output intensity of a transmission signal to the wireless tag reader device. Storage means for storing transmission output information, transmission output control means for controlling the output intensity of the transmission signal to be reduced in response to a reduction request signal received from the wireless tag reader, and the received from the wireless tag reader device And an ID update means for updating the ID information using ID update information.

  According to this configuration as well, it is possible to prevent unauthorized tracking of the RFID tag device, and to protect the privacy of the RFID tag user. In addition, the risk of ID update information being wiretapped by a third party can be reduced, and safety is improved.

  The wireless tag reader device of the present invention is a wireless tag reader device used in the above wireless tag system, and the wireless tag reader device includes transmission output information indicating an output intensity of a transmission signal from the wireless tag device to the wireless tag reader device. Based on the transmission strength determination means for determining whether the output intensity of the transmission signal is a telecommunications level or a near field communication level, and when determined to be a telecommunications level, Output reduction request means for transmitting a reduction request signal for reducing the output intensity of the transmission signal to the wireless tag device, and ID update processing performed by the wireless tag device when it is determined that the level is a short-range communication level Update information generation means for generating the ID update information used for the update, and an update information transmission for transmitting the generated ID update information to the wireless tag device. And it has a configuration including a means.

  According to this configuration as well, it is possible to prevent unauthorized tracking of the RFID tag device, and to protect the privacy of the RFID tag user. In addition, the risk of ID update information being wiretapped by a third party can be reduced, and safety is improved.

  The center device of the present invention is a center device used in the above-described wireless tag system, and the center device records the ID information of the wireless tag device received from the wireless tag reader device in association with each wireless tag device. Using the ID update information received from the wireless tag reader device, the same ID update processing as the ID information update processing performed in the wireless tag device is performed to update the ID information recorded in the recording means It has a configuration provided with ID information management means.

  Also with this configuration, it is possible to prevent unauthorized tracking of the RFID tag device in the same manner as described above, thereby protecting the privacy of the RFID tag carrier. In addition, the risk of ID update information being wiretapped by a third party can be reduced, and safety is improved.

  The wireless tag ID information update method of the present invention is a wireless tag ID information update method used in the above wireless tag system, wherein the output intensity of the transmission signal from the wireless tag device to the wireless tag reader device is at the level for telecommunication. It is determined whether the level is for short-range communication, and when it is determined that the level is for long-distance communication, control is performed to reduce the output intensity of the transmission signal, and the level is for short-range communication. When it is determined, ID update information is generated, and the ID information of the RFID tag device is updated using the ID update information.

  Also by this method, it is possible to prevent unauthorized tracking of the RFID tag device in the same manner as described above, and the privacy of the RFID tag user can be protected. In addition, the risk of ID update information being wiretapped by a third party can be reduced, and safety is improved.

  According to the present invention, a transmission output control unit is provided in a wireless tag device, and a transmission strength determination unit, an output reduction request unit, an update information generation unit, and an update information transmission unit are provided in a wireless tag reader device. It is possible to provide a wireless tag system that can prevent a person from being illegally tracked and protect the privacy of the wireless tag device carrier.

  Hereinafter, a wireless tag system according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a case of a schoolchild watching system or the like in which a guardian at home or work can watch the state of schoolchildren (persons to watch over) attending a school or a cram school is illustrated.

(First embodiment)
A wireless tag system according to a first embodiment will be described with reference to FIGS. Here, an outline of the overall configuration of the system will be described first. FIG. 1 is a block diagram showing the configuration of the wireless tag system of the present embodiment. As shown in FIG. 1, the wireless tag system 1 includes a wireless tag device 2, a wireless tag reader device 3 (also simply referred to as a tag reader device 3), and a center device 4. The wireless tag device 2 is a device such as an IC card having a wireless IC tag, such as a student ID card or a private school student ID card, or a mobile terminal such as a mobile phone or a PDA, and is owned by a schoolchild who is a person to be watched over. A tag reader device 3 capable of wireless communication with the wireless tag device 2 is installed along a school road for school children. For example, the tag reader device 3 is installed at an intersection in the middle of a school road, a side of a road, a school gate, an entrance, or the like. The tag reader device 3 may include a monitoring camera (not shown) and may have a function of shooting a monitoring video around a schoolchild who is a watching target. The center device 4 can communicate with the tag reader device 3 via a network.

  In the example of FIG. 1, for convenience of explanation, three wireless tag devices 2 (wireless tag devices A, B, and C), three tag reader devices 3 (tag reader devices A, B, and C), 1 Although two center devices 4 are illustrated, the numbers of the wireless tag device 2, the tag reader device 3, and the center device 4 are not limited thereto. In FIG. 1, the detailed configuration of only the wireless tag device A among the three wireless tag devices 2 is illustrated, and the detailed configuration of the other wireless tag devices B and C is omitted. Similarly, of the three tag reader devices 3, only the tag reader device A is illustrated in detail, and the other tag reader devices B and C are not illustrated in detail.

  Next, each configuration of the wireless tag system 1 will be described in detail. First, the configuration of the wireless tag device 2 will be described. As shown in FIG. 1, the wireless tag device 2 includes a wireless communication unit 5 that performs wireless communication with the tag reader device 3, and a power supply unit 6 that supplies power to the wireless communication unit 5 and the like. That is, the wireless tag device 2 is an active tag or a semi-passive tag. When the wireless tag device 2 is an active tag, the wireless tag device 2 outputs a transmission signal periodically (for example, every minute) using a power source. When the wireless tag device 2 is a semi-passive tag, the wireless tag device 2 outputs a transmission signal using a power supply when receiving a search signal from the tag reader device 3.

  The wireless tag device 2 also includes an output control unit 7 that controls the output intensity of the transmission signal to the tag reader device 3 and a transmission output flag storage unit 8 that stores a transmission output flag indicating the output intensity of the transmission signal. . The transmission output of the wireless tag device 2 is set to a telecommunications level described later as an initial state. That is, it can be said that the telecommunications level is a normal output level.

  The transmission output is controlled in two stages, a telecommunications level and a near field communication level. For example, when wireless communication is performed at the level for long-distance communication, the communicable distance between the wireless tag device 2 and the tag reader device 3 is about 100 m, and when wireless communication is performed at the level for short-range communication, wireless communication is performed. The communicable distance between the tag device 2 and the tag reader device 3 is about 3 m. There are two transmission output flags: “large” indicating the level for long-distance communication and “small” indicating the level for short-range communication. That is, it can be said that the telecommunications level is a high output level (or a maximum output level). It can also be said that the near field communication level is a low output level (or a minimum output level).

  The wireless tag device 2 includes a tag ID storage unit 9 that stores a tag ID for identifying the wireless tag device 2 and a tag ID update unit 10 that performs a process of updating the tag ID. The tag ID is transmitted from the wireless tag device 2 to the tag reader device 3 together with the transmission output flag. The tag ID update unit 10 performs processing for converting the current tag ID (old tag ID) into the next tag ID (new tag ID) using a random number described later (see FIG. 3). Here, the tag ID corresponds to the ID information of the present invention, and the transmission output flag corresponds to the transmission output information of the present invention. The tag ID storage unit 9 and the transmission output flag storage unit 8 correspond to the storage means of the present invention.

As an ID conversion rule used in the ID update processing of the present embodiment, for example, a method of applying a predetermined hash function F to a combination (XOR, OR, concatenation, etc.) of a current tag ID and a random number is used. Yes, but not limited to this, excludes the method of encrypting the tag ID itself with a random encryption algorithm with a predetermined encryption algorithm, the method of encrypting the tag ID using another numerical value derived from the random number, etc. is not.
The wireless tag device 2 may use a plurality of ID conversion rules. In that case, the wireless tag device 2 transmits the identifier of the function used for the ID update process to the tag reader device 3. Alternatively, the tag reader device 3 indicates an identifier of a function used for the ID conversion process.

  Next, the configuration of the tag reader device 3 will be described. As illustrated in FIG. 1, the tag reader device 3 includes a wireless communication unit 11 that performs wireless communication with the wireless tag device 2 and a reception tag ID storage unit 12 that stores a tag ID received from the wireless tag device 2. . The tag reader device 3 includes a network communication unit 13 (NW communication unit 13) that communicates with the center device 4 via a network. The network communication unit 13 transmits the tag ID received from the wireless tag device 2 and the random number transmitted to the wireless tag device 2 to the center device 4. Here, the network communication unit 13 corresponds to the network transmission means of the present invention.

  In the tag reader device 3, based on the transmission output flag received from the wireless tag device 2, the output intensity when the wireless tag device 2 transmits a transmission signal is a long-distance communication level or a short-distance communication level. A transmission strength determination unit 14 is provided. The transmission strength determination unit 14 determines whether the output strength when the wireless tag device 2 transmits the transmission signal is “high” or “small”, not the signal strength when the transmission signal from the wireless tag device 2 is received. It is determined whether it is. Here, the transmission strength determination unit 14 corresponds to the transmission strength determination means of the present invention.

  The tag reader device 3 includes a reception strength determination unit 15 that determines whether the strength of the reception signal received from the wireless tag device 2 is equal to or higher than a predetermined threshold. The reception intensity determination unit 15 determines whether the intensity of the received signal actually received is large or small with reference to a predetermined threshold. This determination may determine that the strength of the received signal is high if it is at least once or more than the threshold, and may determine that the strength of the received signal is large if it is equal to or more than the threshold multiple times. This determination is also called RSSI (Received Signal Strength Indicator) determination. Therefore, it can be said that the reception strength determination unit 15 is an RSSI determination unit. Here, the threshold corresponds to the threshold strength of the present invention, and the reception strength determination unit 15 corresponds to the reception strength determination means of the present invention.

  For example, when there is an obstacle between the wireless tag device 2 and the tag reader device 3, the transmission signal from the wireless tag device 2 is transmitted to the tag reader even though the transmission intensity of the transmission signal is “high”. The reception intensity when the device 3 receives is reduced. In this case, the transmission strength determination unit 14 determines that the output strength of the transmission signal is “high”, and the reception strength determination unit 15 determines that the strength of the reception signal is less than the threshold value.

  Further, the tag reader device 3 reduces the transmission output to reduce the output strength of the transmission signal when the output strength of the transmission signal from the wireless tag device 2 is “high” and the strength of the reception signal is equal to or higher than the threshold value. A tag output control instruction unit 16 that transmits an instruction to the wireless tag device 2 is provided. Here, the transmission output reduction instruction corresponds to the reduction request signal of the present invention, and the tag output control instruction unit 16 corresponds to the output reduction request means of the present invention.

  For example, when the wireless tag device 2 enters an area within 100 m from the tag reader device 3, the transmission signal from the wireless tag device 2 can be received, and the transmission output is “large” based on the transmission output flag. It is determined that there is. However, when the wireless tag device 2 is considerably far from the tag reader device 3 (for example, when it is separated by 50 m or more), it is determined that the intensity of the received signal is less than the threshold value, and no transmission output reduction instruction is sent. When the wireless tag device 2 approaches the tag reader device 3 (for example, when the wireless tag device 2 approaches 10 m or less), the received signal strength becomes equal to or greater than the threshold value, and a transmission output reduction instruction is sent.

  The tag reader device 3 includes a random number generation unit 17 that generates a random number used for updating the tag ID each time when the output intensity of the transmission signal from the wireless tag device 2 is “low”. In the wireless tag device 2, a calculation process using the random number is performed to update the tag ID (convert from the current tag ID to the next tag ID). Here, the random number corresponds to the ID update information, and the random number generation unit 17 corresponds to the update information generation unit.

  The tag reader device 3 also includes a reader output control unit 18 that controls the output intensity of the transmission signal to the wireless tag device 2. The reader output control unit 18 reduces the transmission output when a random number is transmitted to the wireless tag device 2. When a random number is to be transmitted to the wireless tag device 2, the wireless tag device 2 is approaching the tag reader device 3 to such a short distance (for example, an area within 3 m) that communication is possible even with the transmission output “small”. Therefore, the reader output control unit 18 performs control so that the transmission output is reduced to a level at which short-distance (for example, 3 m) communication is possible. Here, the reader output control unit 18 corresponds to the reader transmission output control means of the present invention.

  Next, the configuration of the center device 4 will be described. As shown in FIG. 1, the center device 4 receives a network communication unit 19 (NW communication unit 19) that communicates with the tag reader device 3 via a network and records data received from the tag reader device 3 as reception history data. A history storage unit 20 is provided.

  FIG. 2 is a diagram illustrating an example of reception history data. As shown in FIG. 2, the reception history storage unit 20 includes a time at which the tag reader device 3 receives a transmission signal from the wireless tag device 2, a tag reader ID of the tag reader device 3, and the tag reader device 3 as a wireless tag device. The received tag ID received from 2 and the information of the random number transmitted from the tag reader device 3 to the wireless tag device 2 are recorded.

For example, in FIG. 2, the tag reader device A detects the wireless tag device A (old tag ID: T-ID _A (n)) at 16:00:30 on February 1, 2007, and generates a random number R (n). After the transmission and the tag ID is updated by the wireless tag device A, the tag reader device B detects the wireless tag device A (new tag ID: T-ID _A (n + 1)) at 16:05:40. In this example, a random number R (n + 1) is transmitted.

  Further, the center device 4 relates to a user ID management table 21 that stores information related to a user (for example, a child to be watched) who owns the wireless tag device, a tag ID management table 22 that stores information related to the tag ID, and a tag reader. A tag reader ID management table 23 for storing information is provided.

  FIG. 3 is a diagram illustrating an example of data recorded in the user ID management table 21. As shown in FIG. 3, the user ID management table 21 includes a user ID for identifying a user, the name of the user, a password dedicated to the user, and an initial tag ID of the wireless tag device 2 assigned to the user. (Tag ID assigned to the wireless tag device 2 at the time of shipment or sale) is recorded.

  FIG. 4 is a diagram illustrating an example of data recorded in the tag ID management table 22. As shown in FIG. 4, the tag ID management table 22 includes data such as an initial tag ID, a current tag ID (old tag ID), and a next tag ID (new tag ID) for each wireless tag device 2. Is recorded. In the tag ID management table 22, a process of updating the current tag ID (old tag ID) to the next tag ID (new tag ID) using the random number received from the tag reader device 3 is performed. That is, in the tag ID management table 22, the same update process as the ID update process performed in the wireless tag device 2 is performed. That is, the new tag ID recorded in the center device 4 and the new tag ID of the wireless tag device 2 are managed to be the same. The tag ID management table 22 records not only the tag ID (new tag ID) after the ID update but also the previous tag ID (old tag ID). That is, tag ID update history information is recorded. Here, the tag ID management table 22 corresponds to the ID information management means of the present invention.

  FIG. 5 is a diagram illustrating an example of data recorded in the tag reader ID management table 23. As shown in FIG. 5, the tag reader ID management table 23 records data such as the tag reader ID of the tag reader device 3, the latitude and longitude of the installation position of the tag reader device 3, and the address of the installation position of the tag reader device 3. ing. When the tag reader device 3 detects the wireless tag device 2 possessed by the child who is the person to be watched, based on the data of the tag reader ID management table 23, the installation position of the tag reader device 3 (that is, the current status of the child) Position). Further, by combining the tag reader ID, reception tag ID and random number information stored in the reception history storage unit 20 with the tag ID update history information stored in the tag reader ID management table 23, the position history of the child is sequentially obtained. It is also possible to save it in a form that can be referred to by parents of children.

  In addition, at the timing when the random number is transmitted from the tag reader device 3 to the wireless tag device 2 (that is, the timing when the user of the wireless tag device 2 approaches the tag reader device 3), or before and after the timing, By photographing with a monitoring camera (not shown) provided, it is possible to photograph the situation of a wireless tag device carrier such as a child approaching the vicinity of the tag reader device. In this case, the image taken by the tag reader device 3 is transmitted to the center device 4 together with the received tag ID information and stored in the center device 4, so that the child's guardian and the like are notified to the child's guardian. At the same time, a photographed image can be provided.

  The operation of the RFID tag system 1 configured as described above will be described with reference to FIGS. Here, when a child possessing a wireless tag device 2 (for example, a wireless tag device A) passes near a tag reader device 3 (for example, a tag reader device A) installed on a school road, the tag ID of the wireless tag device 2 A description will be given centering on the operation when is updated.

  First, the operation of the entire system of the wireless tag system 1 of the present embodiment will be described. FIG. 6 is a sequence diagram showing an overall operation flow of the wireless tag system 1 according to the present embodiment. As shown in FIG. 6, the tag ID and the transmission output flag “large” are transmitted from the wireless tag device 2. When the tag reader device 3 receives the tag ID and the transmission output flag “large”, the tag reader device 3 performs transmission intensity determination (S101) and reception intensity determination (S102). At this time, for example, when the child is considerably away from the tag reader device 3, it is determined that the transmission intensity is “high”, but the reception intensity is less than the threshold. In that case, no signal is transmitted from the tag reader device 3 to the wireless tag device 2. When the child further approaches the tag reader device 3, when the transmission strength determination (S103) and the reception strength determination (S104) are performed, it is determined that the transmission strength is “high” and the reception strength is equal to or greater than the threshold. Then, a transmission output decrease instruction is transmitted from the tag reader device 3 to the wireless tag device 2.

  When the wireless tag device 2 receives the transmission output reduction instruction, the wireless tag device 2 reduces the transmission output to the near field communication level (S105). A tag ID and a transmission output flag “small” are transmitted from the wireless tag device 2. When the tag reader device 3 receives the tag ID and the transmission output flag “small”, the tag reader device 3 performs transmission intensity determination (S106). If it is determined that the transmission intensity is “low”, random number generation (S107) is performed and control for reducing the reader transmission output is performed (S108). Then, a random number is transmitted from the tag reader device 3 to the wireless tag device 2, and a tag reader ID, a tag ID, and a random number are transmitted from the tag reader device 3 to the center device 4.

When the wireless tag device 2 receives the random number, the wireless tag device 2 updates the tag ID (S109). For example, the tag ID of the radio tag device 2 is updated from _{T-ID A (n) T} -ID A into (n + 1). When the center device 4 receives the tag reader ID, the tag ID, and the random number, the center device 4 updates the reception history data (S110) and the tag ID management table 22 (S111).

  Then, a process for returning the transmission output of the wireless tag device 2 to the level for telecommunications is performed (S112), and a process for returning the transmission output of the tag reader device 3 to the original strength is performed (S113).

  Next, the operation of each component of the wireless tag system 1 will be described. FIG. 7 is a flowchart showing an operation flow of the wireless tag device 2. As shown in FIG. 7, the wireless tag device 2 periodically transmits a tag ID and a transmission output flag “Large” (S120), and receives a transmission output lowering instruction from the tag reader device 3 (S121). The level is reduced to the near field communication level (S122).

  Thereafter, the wireless tag device 2 periodically transmits a tag ID and a transmission output flag “small” (S123), and receives a random number from the tag reader device 3 (S124), and updates the tag ID (S125). Then, the transmission output of the wireless tag device 2 is returned to the telecommunications level (S126).

  FIG. 8 is a flowchart showing an operation flow of the tag reader device 3. As shown in FIG. 8, when the tag reader device 3 receives the tag ID and the transmission output flag from the wireless tag device 2 (S130), the tag reader device 3 determines whether or not the transmission output flag is “large” (S131). If it is determined that the transmission output flag is “large”, it is determined whether or not the reception intensity is greater than or equal to a threshold value (S132). If it is determined that the reception intensity is greater than or equal to the threshold value, a transmission output decrease instruction is transmitted to the wireless tag device 2 (S133).

  On the other hand, if it is determined that the transmission output flag is “small”, a process for generating a random number is performed (S134), and output control for reducing the transmission output of the tag reader device 3 is performed (S135). Then, a random number is transmitted to the wireless tag device 2 (S136), and a reception ID report is performed by transmitting the tag reader ID, the tag ID, and the random number to the center device 4 (S137). Then, the transmission output of the tag reader device 3 is returned to the original output level (S138).

  FIG. 9 is a flowchart showing an operation flow of the center device 4. As shown in FIG. 9, when the center device 4 receives a reception ID report (tag reader ID, tag ID, random number) from the tag reader device 3 (S140), the reception history of the tag reader ID, tag ID, and random number as one record is received. Data is updated (S141).

  Then, the received tag ID (old tag ID) and a random number are used to perform the same calculation process as the calculation performed in the wireless tag device 2 to obtain the next tag ID (new tag ID) by calculation (S142). The tag ID management table 22 is updated (S143).

  According to the wireless tag system 1 of the first embodiment as described above, the output control unit 7 is provided in the wireless tag device 2, and the transmission strength determination unit 14, the tag output control instruction unit 16, and the random number generation unit 17 are connected to the tag reader device. By providing the wireless tag device 2, it is possible to prevent the carrier of the wireless tag device 2 from being illegally tracked and to protect the privacy of the wireless tag device carrier.

  That is, in the present embodiment, when the wireless tag device 2 enters a communication area of a telecommunications level (for example, an area within 100 m from the tag reader device 3), the output intensity of the transmission signal is close to the telecommunications level. Switch to distance communication level. When the wireless tag device 2 further approaches the communication area (for example, an area within 3 m) at the near field communication level, the tag ID of the wireless tag device 2 is updated. That is, each time the wireless tag device 2 approaches the tag reader device 3, the tag ID (old tag ID) of the wireless tag device 2 is converted to another tag ID (new tag ID). Therefore, even if the tag ID of the wireless tag device 2 is wiretapped by a third party, the tag ID of the wireless tag device 2 is updated one after another. be able to. Thereby, the privacy of the RFID tag user can be protected. Further, random numbers are transmitted only when the wireless tag device 2 approaches the tag reader device 3. Therefore, even if the tag ID of the wireless tag device 2 is wiretapped by a third party, the risk that the random number is wiretapped by the third party can be reduced, and safety is improved.

  For example, even when the tag ID is updated, if the tag ID and the random number are eavesdropped in pairs, the updated tag ID may be estimated. In the present embodiment, by controlling the output of the transmission signal of the wireless tag device 2, random numbers are transmitted only when the wireless tag device 2 approaches the tag reader device 3. Therefore, even if the tag ID of the wireless tag device 2 is wiretapped by a third party, the risk that the random number is wiretapped by the third party in pairs with the tag ID can be reduced, and safety is improved. To do.

  Further, in the present embodiment, after the RFID tag device 2 enters the communication area of the telecommunications level, until the strength of the received signal from the RFID tag device 2 becomes the threshold strength or more (for example, within 10 m) The output intensity of the transmission signal of the wireless tag device 2 is controlled to decrease when approaching. Thereby, it is possible to control the output intensity of the transmission signal for the wireless tag device 2 that has a high probability of approaching the tag reader device 3 until entering the communication area of the near field communication level.

  Moreover, in this Embodiment, the output control which reduces the output intensity of the transmission signal of the tag reader apparatus 3 can reduce the risk that a random number will be wiretapped by a third party, and the safety will be further improved. .

  In the present embodiment, the center device 4 records the tag ID received from the tag reader device 3 for each wireless tag device 2 and uses the same ID as the wireless tag device 2 using the random number received from the wireless tag device 2. Update processing is performed. As a result, the tag IDs of the wireless tag device 2 can be collectively managed by the center device 4. Therefore, the child's guardian can easily acquire the child's position information and video information simply by accessing the center device 4.

  Further, in the present embodiment, when searching for the wireless tag device 2, it is possible to search using not only the current tag ID but also the update history of the tag ID. For example, when there is a communication failure between the wireless tag device 2 and the tag reader device 3, the tag ID recorded in the center device 4 is updated even though the tag ID of the wireless tag device 2 is not updated. Sometimes. Even in such a case, the wireless tag device 2 can be found using the old tag ID (for example, the initial tag ID or the previous tag ID).

(Second Embodiment)
Next, a wireless tag system according to the second embodiment will be described with reference to FIGS. Here, the points different from the first embodiment will be mainly described. Unless otherwise mentioned here, the configuration of the second embodiment is the same as that of the first embodiment.

  FIG. 10 is a block diagram showing the configuration of the wireless tag system of this embodiment. As shown in FIG. 10, in the present embodiment, the wireless tag device 2 includes a time measuring unit 24. The time measuring unit 24 starts measuring time when the output intensity of the transmission signal from the wireless tag device 2 is switched from the long-distance communication level to the short-distance communication level, and the output intensity of the transmission signal is Measure the duration when the level is near field communication. The time measuring unit 24 has a so-called timer function and corresponds to the timer device of the present invention.

  Then, the output control unit 7 of the wireless tag device 2 returns the transmission output of the wireless tag device 2 to the long-distance communication level when the duration measured by the time measuring unit 24 has exceeded a predetermined timeout time. Thus, it is configured to perform timer control.

  The operation of the wireless tag system 1 configured as described above will be described with reference to FIGS. 11 and 12. Here, the operation when the timer control of the transmission output of the wireless tag device 2 is performed will be mainly described. Operations not particularly mentioned here are the same as those in the first embodiment.

  FIG. 11 is a sequence diagram showing an overall operation flow of the wireless tag system 1 according to the present embodiment. As shown in FIG. 11, when the tag ID and the transmission output flag are transmitted from the wireless tag device 2 and the tag reader device 3 receives the tag ID and the transmission output flag, the transmission strength determination (S201) and the reception strength determination (S202). ) Is performed. Similarly to the first embodiment, when a transmission output decrease instruction is transmitted from the tag reader device 3 and the wireless tag device 2 receives the transmission output decrease instruction, the wireless tag device 2 sets the transmission output to the near field communication level. Decrease (S203).

  When the transmission output of the wireless tag device 2 is switched from the long-distance communication level to the short-distance communication level, the time measurement unit 24 of the wireless tag device 2 is activated and starts measuring the duration of the short-distance communication level. (S204). Thereafter, when a predetermined timeout time elapses (S205), the transmission output of the wireless tag device 2 returns to the telecommunications level (S206).

  FIG. 12 is a flowchart showing an operation flow of the wireless tag device 2. As shown in FIG. 12, the wireless tag device 2 periodically transmits a tag ID and a transmission output flag “Large” (S210), and receives a transmission output lowering instruction from the tag reader device 3 (S211). The level is reduced to the near field communication level (S212). When the transmission output of the wireless tag device 2 is reduced, the time measuring unit 24 of the wireless tag device 2 is activated and starts measuring the duration of the near field communication level (S213). Then, the wireless tag device 2 periodically transmits the tag ID and the transmission output flag “small” (S214).

  When the wireless tag device 2 succeeds in communication with the tag reader device 3, even if the timeout time has not elapsed (S215), a random number is received from the tag reader device 3 (S216), and the tag ID is updated (S217). ). Then, the transmission output of the wireless tag device 2 is returned to the telecommunications level (S218). On the other hand, even if the RFID tag device 2 fails to communicate with the tag reader device 3, when the timeout time elapses (S215), the transmission output of the RFID tag device 2 is returned to the level for long-distance communication (S218).

  The wireless tag system 1 according to the second embodiment can provide the same operational effects as those of the first embodiment.

  In the present embodiment, after the output intensity of the transmission signal of the wireless tag device 2 is switched to the near field communication level, it returns to the far field communication level when a predetermined time-out period elapses. Thereby, the wireless tag device 2 can resume communication at the telecommunication level at an appropriate timing.

  For example, in the present embodiment, even when the wireless tag device 2 fails to communicate with the tag reader device 3, the time measuring unit 24 of the wireless tag device 2 measures a predetermined timeout time. When the time-out period elapses, the transmission output of the wireless tag device 2 is automatically returned to the telecommunications level.

(Third embodiment)
Next, a wireless tag system according to a third embodiment will be described with reference to FIGS. Here, the points different from the first embodiment will be mainly described. Unless otherwise mentioned here, the configuration of the third embodiment is the same as that of the first embodiment.

  FIG. 13 is a block diagram showing a configuration of the wireless tag system of the present embodiment. As shown in FIG. 13, in the present embodiment, the tag reader device 3 includes a time measuring unit 25 and a tag output management unit 26, and the center device 4 includes a tag output management unit 27. The time measurement unit 25 starts measuring time from when the transmission output decrease instruction is transmitted to the wireless tag device 2, and measures the duration when the output intensity of the transmission signal is at the near field communication level. The time measuring unit 25 has a so-called timer function and corresponds to the timer device of the present invention.

  Further, the tag output management units 26 and 27 of the tag reader device 3 and the center device 4 register the tag ID of the wireless tag device 2 instructed to reduce the transmission output. Specifically, the tag ID of the wireless tag device 2 to which the transmission output reduction instruction is transmitted is registered, and the tag ID of the wireless tag device 2 to which the output return instruction is transmitted is registered and deleted.

  The operation of the wireless tag system 1 configured as described above will be described with reference to FIG. Here, the operation when the timer control of the transmission output of the wireless tag device 2 is performed will be mainly described. Operations not particularly mentioned here are the same as those in the first embodiment.

  FIG. 14 is a sequence diagram showing an overall operation flow of the wireless tag system 1 of the present embodiment. As shown in FIG. 14, when the tag ID and the transmission output flag are transmitted from the wireless tag device 2, and the tag reader device 3 (for example, the tag reader device A) receives the tag ID and the transmission output flag, the transmission strength determination (S301). And reception strength determination (S302) is performed. Similarly to the first embodiment, when a transmission output decrease instruction is transmitted from the tag reader device 3 and the wireless tag device 2 receives the transmission output decrease instruction, the wireless tag device 2 sets the transmission output to the near field communication level. Decrease (S303).

  When the transmission output reduction instruction is transmitted to the wireless tag device 2, the time measuring unit 25 of the tag reader device 3 is activated to start measuring the duration of the near field communication level, and the tag ID of the wireless tag device 2 is assigned to the tag reader. Registration is performed in the tag output management unit 26 of the device 3 (S304). Thereafter, when the wireless tag device 2 fails to communicate with the tag reader device 3 and a predetermined timeout time elapses (S305), a timeout notification indicating that is transmitted from the tag reader device 3 to the center device 4, and the wireless tag The tag ID of the device 2 is registered in the tag output management unit 27 of the center device 4 (S306).

  Then, the center device 4 transmits a time-out notification for notifying (broadcasting) that the wireless tag device 2 has timed out to all the tag reader devices 3. The tag reader device 3 (for example, tag reader device B) that has received the time-out notification transmits an output return instruction by transmitting a beacon signal to the wireless tag device 2. When receiving the output return instruction from the tag reader device 3, the wireless tag device 2 returns the transmission output of the wireless tag device 2 to the level for long-distance communication (S307).

  The wireless tag device 2 transmits a tag ID and a transmission output flag to the tag reader device 3 (tag reader device B), and the tag reader device 3 that has received the tag ID uses the tag ID as an output return notification. Send to. When the center device 4 receives the output return notification, the tag ID of the wireless tag device 2 is registered and deleted from the tag output management unit 27 of the center device 4 (S308).

  Thereafter, the center device 4 transmits an output return notification for notifying that the wireless tag device 2 has returned to the output to all the tag reader devices 3. The original tag reader device 3 (tag reader device A) that has received the output return notification registers and deletes the tag ID of the wireless tag device 2 from the tag output management unit 26 of the tag reader device 3 (S309).

  The wireless tag system 1 according to the third embodiment can provide the same operational effects as those of the first embodiment.

  In the present embodiment, after the output intensity of the transmission signal of the wireless tag device 2 is switched to the near field communication level, it returns to the far field communication level when a predetermined time-out period elapses. Thereby, the wireless tag device 2 can resume communication at the telecommunication level at an appropriate timing.

  For example, in the present embodiment, even when the wireless tag device 2 fails to communicate with the tag reader device 3, the time measuring unit 25 of the tag reader device 3 measures a predetermined timeout time. When the time-out period elapses, an output return instruction is transmitted from one of the tag reader devices 3 to the wireless tag device 2, and the transmission output of the wireless tag device 2 is returned to the telecommunications level.

(Fourth embodiment)
Next, a wireless tag system according to a fourth embodiment will be described with reference to FIGS. 15 and 16. Here, the points different from the first embodiment will be mainly described. Unless otherwise mentioned here, the configuration of the fourth embodiment is the same as that of the first embodiment.

  FIG. 15 is a block diagram showing a configuration of the wireless tag system of this embodiment. As shown in FIG. 15, in the present embodiment, the center device 4 includes a time measurement unit 28 and a tag output management unit 29, and the tag reader device 3 includes a tag output management unit 30. The time measuring unit 28 starts measuring time from when the transmission output reduction instruction is transmitted to the wireless tag device 2, and measures the duration when the output intensity of the transmission signal is at the near field communication level. The time measuring unit 28 has a so-called timer function, and corresponds to the timer device of the present invention.

  Further, the tag output management units 29 and 30 of the tag reader device 3 and the center device 4 register the tag ID of the wireless tag device 2 instructed to reduce the transmission output. Specifically, the tag ID of the wireless tag device 2 to which the transmission output reduction instruction is transmitted is registered, and the tag ID of the wireless tag device 2 to which the output return instruction is transmitted is registered and deleted.

  The operation of the wireless tag system 1 configured as described above will be described with reference to FIG. Here, the operation when the timer control of the transmission output of the wireless tag device 2 is performed will be mainly described. Operations not particularly mentioned here are the same as those in the first embodiment.

  FIG. 16 is a sequence diagram showing an overall operation flow of the wireless tag system 1 of the present embodiment. As shown in FIG. 16, when the tag ID and the transmission output flag are transmitted from the wireless tag device 2 and the tag reader device 3 (for example, the tag reader device A) receives the tag ID and the transmission output flag, the transmission strength determination (S401). And reception strength determination (S402) is performed. Similarly to the first embodiment, when a transmission output decrease instruction is transmitted from the tag reader device 3 and the wireless tag device 2 receives the transmission output decrease instruction, the wireless tag device 2 sets the transmission output to the near field communication level. Decrease (S403).

  When a transmission output reduction instruction is transmitted from the tag reader device 3 to the wireless tag device 2, the tag IC of the wireless tag device 2 is transmitted from the tag reader device 3 to the center device 4 as an output reduction tag notification. Then, the tag ID of the wireless tag device 2 is registered in the tag output management unit 29 of the center device 4, and the time measuring unit 28 of the center device 4 is activated to start measuring the duration of the near field communication level. (S404). Thereafter, when the wireless tag device 2 fails to communicate with the tag reader device 3 (tag reader device A) and a predetermined time-out time elapses (S405), a time-out notification indicating that is transmitted to all the tag reader devices 3. .

  The tag reader device 3 that has received the time-out notification transmits an output return instruction by transmitting a beacon signal to the wireless tag device 2. When the tag reader device 3 (for example, the tag reader device B) succeeds in communication with the wireless tag device 2 and the wireless tag device 2 receives an output return instruction, the transmission output of the wireless tag device 2 returns to the level for telecommunications. (S406).

  The wireless tag device 2 transmits a tag ID and a transmission output flag to the tag reader device 3 (tag reader device B), and the tag reader device 3 that has received the tag ID uses the tag ID as an output return notification. Send to. When the center device 4 receives the output return notification, the tag ID of the wireless tag device 2 is registered and deleted from the tag output management unit 29 of the center device 4 (S407). The tag IC of the wireless tag device 2 is transmitted from the center device 4 to all the tag reader devices 3 as an output return notification.

  The wireless tag system 1 of the fourth embodiment can provide the same operational effects as those of the first embodiment.

  In the present embodiment, after the output intensity of the transmission signal of the wireless tag device 2 is switched to the near field communication level, it returns to the far field communication level when a predetermined time-out period elapses. Thereby, the wireless tag device 2 can resume communication at the telecommunication level at an appropriate timing.

  For example, in the present embodiment, even when the wireless tag device 2 fails to communicate with the tag reader device 3, the time measurement unit 28 of the center device 4 measures a predetermined timeout time. When the time-out period elapses, an output return instruction is transmitted to the RFID tag device 2 via any one of the tag reader devices 3, and the transmission output of the RFID tag device 2 is returned to the telecommunications level.

(Fifth embodiment)
Next, a wireless tag system according to a fifth embodiment will be described with reference to FIGS. Here, the points different from the first embodiment will be mainly described. Unless otherwise mentioned here, the configuration of the fifth embodiment is the same as that of the first embodiment.

  FIG. 17 is a block diagram showing a configuration of the wireless tag system of this embodiment. As shown in FIG. 17, in the present embodiment, the RFID tag device 2 includes a reader ID determination unit 31, and the tag reader device 3 includes a beacon generation unit 32. The beacon generator 32 is configured to generate a beacon signal including the tag reader ID and transmit the beacon signal to the wireless tag device 2. Here, the beacon signal including the tag reader ID corresponds to the identification signal of the present invention, and the beacon generation unit 32 corresponds to the identification signal transmission unit of the present invention.

  The reader ID determination unit 31 is configured to determine whether or not a beacon signal has been received from the same tag reader device 3 by comparing the tag reader IDs included in the beacon signal.

  The operation of the wireless tag system 1 configured as described above will be described with reference to FIGS. 18 and 19. Here, the operation when the return control of the transmission output of the wireless tag device 2 is performed will be mainly described. Operations not particularly mentioned here are the same as those in the first embodiment.

  FIG. 18 is a sequence diagram showing an overall operation flow of the wireless tag system 1 of the present embodiment. As shown in FIG. 18, first, a beacon signal is transmitted from the tag reader device 3 to the wireless tag device 2, and a tag reader ID (for example, tag reader ID of the tag reader device A) is notified by the beacon signal.

  Then, in the same manner as in the first embodiment, when the tag ID and the transmission output flag are transmitted from the wireless tag device 2 and the tag reader device 3 receives the tag ID and the transmission output flag, the transmission strength determination (S501). And reception strength determination (S502) is performed. Thereafter, in the same manner as in the first embodiment, when a transmission output decrease instruction is transmitted from the tag reader device 3 and the wireless tag device 2 receives the transmission output decrease instruction, the wireless tag device 2 uses the transmission output for short-range communication. The level is lowered (S503).

  When the wireless tag device 2 receives the transmission output reduction instruction from the tag reader device 3 (tag reader device A), the tag reader ID of the tag reader device 3 is stored as the instruction reader ID.

  Thereafter, when the user carrying the wireless tag device 2 moves, the wireless tag device 2 receives a beacon signal from another tag reader device 3 (for example, tag reader device B). That is, the tag reader ID (for example, the tag reader ID of the tag reader device B) is notified by the beacon signal. The wireless tag device 2 compares the received tag reader ID with the stored instruction reader ID (S505). If the received tag reader ID is different from the stored instruction reader ID, the transmission output of the wireless tag device 2 is set to a long distance. The communication level is restored (S506).

  FIG. 19 is a flowchart showing an operation flow of the wireless tag device 2. As shown in FIG. 12, upon receiving the reader ID notification from the tag reader device 3 (S510), the wireless tag device 2 transmits a tag ID and a transmission output flag “Large” (S511). When a transmission output reduction instruction is received from the tag reader device 3 (S512), the transmission output is reduced to the near field communication level (S513). When the transmission output of the wireless tag device 2 is reduced, the tag reader ID that transmitted the output reduction instruction is stored as the instruction reader ID (S514).

  Thereafter, when a reader ID notification is received from the tag reader device 3 (S515), it is determined whether or not the received tag reader ID matches the stored instruction reader ID (S516). When the wireless tag device 2 has successfully communicated with the tag reader device 3, the received tag reader ID matches the stored instruction reader ID. In that case, a random number is received from the tag reader device 3 (S517), and the tag ID is updated (S518). Then, the transmission output of the wireless tag device 2 is returned to the telecommunications level (S519).

  On the other hand, even if the user holding the wireless tag device 2 leaves the tag reader device 3 (tag reader device A) and the wireless tag device 2 fails to communicate with the tag reader device 3, other tag reader devices 3 ( The tag reader device B) may be approached and communication with the tag reader device 3 may be successful. In that case, the received tag reader ID does not match the stored instruction reader ID. In this embodiment, in such a case, the transmission output of the wireless tag device 2 is returned to the level for long-distance communication (S519).

  The wireless tag system 1 of the fifth embodiment can provide the same operational effects as those of the first embodiment.

  In the present embodiment, after the tag reader ID of a certain tag reader device 3 (tag reader device A) is received and the output intensity of the transmission signal of the wireless tag device 2 is switched to the near field communication level, another tag reader device 3 is used. When the tag reader ID of (tag reader device B) is received, the level is returned to the telecommunications level. Thereby, the wireless tag device 2 can resume communication at the telecommunication level at an appropriate timing.

(Sixth embodiment)
Next, a wireless tag system according to the sixth embodiment will be described with reference to FIGS. 20 and 21. FIG. Here, the points different from the first embodiment will be mainly described. Unless otherwise mentioned here, the configuration of the sixth embodiment is the same as that of the first embodiment.

  FIG. 20 is a block diagram showing a configuration of the wireless tag system of this embodiment. As shown in FIG. 20, in the present embodiment, the wireless tag device 2 includes an update flag management unit 33 and a reader ID determination unit 34, and the tag reader device 3 includes an update flag determination unit 35. The update flag management unit 33 manages an update flag indicating that the random number is received from the tag reader device 3 and the tag ID is updated. Specifically, the update flag “0” is transmitted to the tag reader device 3 when the tag ID is not updated, and the update flag “1” is transmitted to the tag reader device 3 when the tag ID is updated. Has been. Here, the update flag corresponds to the updated signal of the present invention, and the update flag management unit 33 corresponds to the updated signal transmission unit of the present invention.

  The reader ID determination unit 34 of the wireless tag device 2 receives the tag reader ID from the tag reader device 3, and determines whether the received tag reader ID and the tag reader device 3 that has received the random number are the same. The update flag management unit 33 is configured to return the update flag to “0” when it is determined that the received tag reader ID is different from the tag reader device 3 that has received the random number.

  The update flag determination unit 35 of the tag reader device 3 determines whether the update flag received from the wireless tag device 2 is “0” or “1”. When it is determined that the received update flag is “0”, the tag reader device 3 generates a random number and transmits the random number to the wireless tag device 2. When it is determined that the received update flag is “1”, the tag reader device 3 stops generating random numbers, and the random numbers are not transmitted to the wireless tag device 2.

  The operation of the RFID tag system 1 configured as described above will be described with reference to FIG. Here, the operation when the random number generation is controlled by the tag reader device 3 will be mainly described. Operations not particularly mentioned here are the same as those in the first embodiment.

  FIG. 21 is a sequence diagram showing an overall operation flow of the wireless tag system 1 according to the present embodiment. As shown in FIG. 21, first, the tag ID and the transmission output flag “large” are transmitted from the wireless tag device 2. When the tag reader device 3 (for example, the tag reader device A) receives the tag ID and the transmission output flag, transmission strength determination (S601) and reception strength determination (S602) are performed. Similarly to the first embodiment, when a transmission output decrease instruction is transmitted from the tag reader device 3 and the wireless tag device 2 receives the transmission output decrease instruction, the wireless tag device 2 sets the transmission output to the near field communication level. Decrease (S203). In this case, the tag reader ID is transmitted from the tag reader device 3 together with the transmission output decrease instruction.

  When the transmission output of the wireless tag device 2 is lowered, the tag ID, the transmission output flag “small”, and the update flag “0” are transmitted from the wireless tag device 2 to the tag reader device 3. Then, the update flag determination is performed in the tag reader device 3 (S604). In this case, since the update flag is “0”, a random number is generated in the tag reader device 3 (S605), and the random number and the tag reader ID are transmitted to the wireless tag device 2.

  Upon receiving the random number and the tag reader ID, the wireless tag device 2 updates the tag ID using the random number (S606). Then, the update flag management unit 33 changes the update flag from “0” to “1”, and the reader ID determination unit 34 stores the tag reader ID (S607).

  Thereafter, the updated tag ID (new tag ID), the transmission output flag “small”, and the update flag “1” are transmitted from the wireless tag device 2 to the tag reader device 3. Then, the update flag determination is performed in the tag reader device 3 (S608). In this case, since the update flag is “1”, generation of a random number is stopped in the tag reader device 3, and the random number is not transmitted to the wireless tag device 2. That is, only the tag reader ID is transmitted to the wireless tag device 2.

  The wireless tag device 2 performs reader ID determination for comparing the received tag reader ID with the stored tag reader ID (S609). In this case, since the received tag reader ID and the stored tag reader ID are determined to be the same, the update flag remains “1”.

  Thereafter, when the user carrying the wireless tag device 2 moves and approaches another tag reader device 3 (for example, tag reader device B), the updated tag ID (new tag ID), the transmission output flag “small”, and the update flag “1” is transmitted from the wireless tag device 2 to the tag reader device 3. Then, the update flag determination is performed in the tag reader device 3 (S610). In this case, since the update flag is “1”, the tag reader device 3 does not generate a random number, and the random number is not transmitted to the wireless tag device 2. That is, only the tag reader ID is transmitted to the wireless tag device 2.

  The wireless tag device 2 performs reader ID determination for comparing the received tag reader ID with the stored tag reader ID (S611). In this case, since it is determined that the received tag reader ID and the stored tag reader ID are different from each other, the update flag is returned from “1” to “0” (S612), and the transmission output of the wireless tag device 2 is changed. Processing to return to the distance communication level is performed (S613).

  The wireless tag system 1 according to the sixth embodiment can provide the same operational effects as those of the first embodiment.

  In the present embodiment, upon receiving a random number from a certain tag reader device 3 and updating the tag ID, the wireless tag device 2 transmits an update flag to the tag reader device 3. When the tag reader device 3 receives the update flag from the wireless tag device 2, the tag reader device 3 stops transmitting random numbers to the wireless tag device 2. Thereby, unnecessary transmission of random numbers can be prevented.

  For example, when the user who owns the wireless tag device 2 stays in the vicinity of the tag reader device 3 for a while, the wireless tag device 2 receives a random number from the tag reader device 3 and updates the tag ID. ing. In such a case, unnecessary transmission of random numbers from the same tag reader device 3 can be prevented.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  For example, in the above description, the transmission output control is performed in two stages and the transmission output flag has two “large” and “small”, but the scope of the present invention is limited to this. Instead, transmission output control may be performed in three or more stages, and the transmission output flag may be three or more according to the number of stages.

  As described above, the RFID tag system according to the present invention can prevent the carrier of the RFID tag device from being illegally tracked and has the effect of protecting the privacy of the RFID tag carrier. However, it is useful as a monitoring system for school children and elderly people using a wireless tag, a location management system, an action monitoring system, and the like.

Block diagram of the wireless tag system of the first embodiment The figure which shows an example of reception history data The figure which shows an example of a user ID management table The figure which shows an example of a tag ID management table The figure which shows an example of a tag reader ID management table Sequence diagram for explaining the operation of the wireless tag system of the first embodiment Flow diagram for explaining the operation of the wireless tag device Flow diagram for explaining the operation of the tag reader device Flow diagram for explaining the operation of the center unit Block diagram of the wireless tag system of the second embodiment Sequence diagram for explaining the operation of the wireless tag system of the second embodiment Flow diagram for explaining the operation of the wireless tag device Block diagram of the wireless tag system of the third embodiment Sequence diagram for explaining the operation of the wireless tag system of the third embodiment Block diagram of the wireless tag system of the fourth embodiment Sequence diagram for explaining the operation of the RFID tag system of the fourth embodiment Block diagram of a wireless tag system according to a fifth embodiment Sequence diagram for explaining the operation of the RFID tag system of the fifth embodiment Flow diagram for explaining the operation of the wireless tag device The block diagram of the radio | wireless tag system of 6th Embodiment Sequence diagram for explaining the operation of the wireless tag system of the sixth embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wireless tag system 2 Wireless tag apparatus 3 Tag reader apparatus 4 Center apparatus 7 Output control part 9 Tag ID storage part 10 Tag ID update part 11 Wireless communication part 13 Network communication part 14 Transmission intensity determination part 15 Reception intensity determination part 16 Tag output control Instruction unit 17 Random number generation unit 18 Reader output control unit 20 Reception history storage unit 22 Tag ID management table 24 Time measurement unit 25 Time measurement unit 28 Time measurement unit 32 Beacon generation unit 33 Update flag management unit

Claims (12)

In a wireless tag system comprising a wireless tag device and a wireless tag reader device capable of wireless communication with the wireless tag device,
The wireless tag device is:
Storage means for storing ID information of the wireless tag device and transmission output information indicating an output intensity of a transmission signal to the wireless tag reader device;
Transmission output control means for controlling the output intensity of the transmission signal;
ID update means for performing an ID update process for updating the ID information using the ID update information received from the wireless tag reader device;
With
The wireless tag reader device
Based on the transmission output information received from the wireless tag device, transmission intensity determination means for determining whether the output intensity of the transmission signal is a telecommunications level or a near field communication level;
An output reduction request means for transmitting a reduction request signal for reducing the output intensity of the transmission signal to the wireless tag device when it is determined that the level is for telecommunications;
An update information generating means for generating the ID update information used for the ID update process in the RFID tag device when it is determined that the level is a near field communication;
Update information transmitting means for transmitting the generated ID update information to the wireless tag device;
A wireless tag system comprising: The wireless tag reader device includes reception strength determination means for determining whether the strength of a received signal received from the wireless tag device is equal to or higher than a predetermined threshold strength,
The output reduction requesting unit transmits the reduction request signal to the wireless tag device when it is determined that the strength of the received signal from the wireless tag device is equal to or higher than the threshold strength. Item 4. The wireless tag system according to Item 1. A timer device for measuring a duration in which the output intensity of the transmission signal is at a near field communication level;
The transmission output control means of the wireless tag device returns the output intensity of the transmission signal to a telecommunications level when the duration exceeds a predetermined threshold time. The wireless tag system according to claim 2. The wireless tag reader device includes an identification signal transmitting means for transmitting an identification signal unique to the wireless tag reader device,
When the transmission output control means of the wireless tag device receives the identification signal of one wireless tag reader device and then receives the identification signal of another wireless tag reader device, the output intensity of the transmission signal is set to the level for telecommunications. The wireless tag system according to claim 1, wherein the wireless tag system is returned. The wireless tag device receives an ID update information from the wireless tag reader device and transmits an updated signal indicating that the ID information has been updated to the wireless tag reader device that is the transmission source of the ID update information. A signal transmission means,
The update information transmitting means of the wireless tag reader device stops transmitting the ID update information when receiving the updated signal from the wireless tag device. The wireless tag system according to any one of the above.   The wireless tag reader device includes reader transmission output control means for reducing an output intensity of a transmission signal to the wireless tag device when transmitting the ID update information to the wireless tag device. The wireless tag system according to any one of claims 1 to 5. A center device capable of communicating with the wireless tag reader device via a network;
The wireless tag reader device
Network transmission means for transmitting the ID information of the wireless tag device and the ID update information used for updating the ID information in the wireless tag device to the center device,
The center device is
The ID information received from the wireless tag reader device is recorded corresponding to each wireless tag device, and the same ID update processing as the wireless tag device is performed using the ID update information received from the wireless tag reader device. 7. The RFID tag system according to claim 1, further comprising ID information management means for performing the update and updating the ID information recorded in the recording means.   8. The RFID tag system according to claim 7, wherein the ID information management means of the center device records update history information of the ID information together with the ID information. A wireless tag device used in the wireless tag system according to claim 1,
The wireless tag device is:
Storage means for storing ID information of the wireless tag device and transmission output information indicating an output intensity of a transmission signal to the wireless tag reader device;
A transmission output control means for controlling to reduce the output intensity of the transmission signal in response to a reduction request signal received from the wireless tag reader;
ID update means for updating the ID information using the ID update information received from the wireless tag reader device;
A wireless tag device comprising: A wireless tag reader device used in the wireless tag system according to claim 1,
The wireless tag reader device
Based on transmission output information indicating the output intensity of the transmission signal from the wireless tag device to the wireless tag reader device, it is determined whether the output intensity of the transmission signal is a level for long-distance communication or a level for short-range communication. Transmission strength determination means;
An output reduction request means for transmitting a reduction request signal for reducing the output intensity of the transmission signal to the wireless tag device when it is determined that the level is for telecommunications;
An update information generating means for generating the ID update information used in the ID update process performed by the wireless tag device when it is determined that the level is a near field communication;
Update information transmitting means for transmitting the generated ID update information to the wireless tag device;
A wireless tag reader device comprising: A center device used in the wireless tag system according to claim 7,
The center device is
ID information of the wireless tag device received from the wireless tag reader device is recorded corresponding to each wireless tag device, and ID information updating performed in the wireless tag device is performed using the ID update information received from the wireless tag reader device. A center device comprising ID information management means for performing the same ID update processing as the processing and updating the ID information recorded in the recording means. A wireless tag ID information update method used in the wireless tag system according to claim 1,
Determining whether the output intensity of the transmission signal from the wireless tag device to the wireless tag reader device is a level for long-distance communication or a level for short-range communication;
When it is determined that the level is for telecommunications, control to reduce the output intensity of the transmission signal,
When it is determined that the level is near field communication, ID update information is generated, and the ID information of the RFID tag device is updated using the ID update information. Method.