JP4394024B2 - Wireless tag and interrogator - Google Patents

Description

The present invention relates to a radio tag and an interrogator capable of frequency conversion.
The present invention is a wireless tag, particularly a wireless tag having a form that receives and reacts to a signal from the outside, and most of the technology is related to a passive RFID (: Radio Frequency Identification) that does not have a battery. In addition, even in the case of an active RFID with a built-in battery, those having a receiving function such as carrier sense fall under this technical field.

Currently, the number of radios that can be used by a wireless tag varies depending on the radio wave administration in each country. Assuming that the wireless tag will be used in various places in daily life in the future, it is necessary to adjust the standard of the number of operating cycles between countries or to standardize the world.
"RF tag development and application II" Japan Automatic Recognition System Association, Chapters 5 and 7

As described above, assuming that the wireless tag will be used in various places in daily life in the future, it is necessary to adjust and standardize the standards and frequencies used in various countries or worldwide.
These viewpoints, that is, the radio frequency used for the wireless tag of each country and the standardization situation are taken up in Reference Document 1. In particular, the frequency of 860 to 960 MHz specified by ISO / IEC 18000-6 (p.58-59 in Reference 1) and ISO / IEC18000-7 (p.59-60) (433 MHz in the United States) Is specified in the Federal Communications Commission FCC 15.247) When focusing on the 400MHz band, it is said that the world is the world despite the fact that both are internationally ISM frequencies (references 2-1 and 2-2). In fact, even in major countries, there is a reality that cannot always be used for wireless tags (see Reference 3).
Therefore, at present, the wireless tag is replaced in response to such a complicated country difference, or at least the wireless tag attached to the imported product is removed in some cases (to stop radio waves) Need).

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wireless tag and an interrogator that eliminate the inconvenience of replacing the wireless tag depending on the area where it is used.

In order to achieve the above object, the present invention provides a wireless tag that, when receiving an activation command from an interrogator, transmits a wireless signal including a unique identifier of the wireless tag, Interrogator identification information is included, and the wireless tag authenticates the interrogator identification information in the received wireless signal and determines whether to transmit a wireless signal based on the authentication result. And

The invention of the present application is a wireless tag that transmits a wireless signal including a unique identifier of the wireless tag when receiving an activation command from the interrogator, and the wireless tag receives the query received together with the command from the interrogator. It has a file in which information that realizes the function of determining whether to transmit a radio signal by the code in the identification information of the device and a transmission / reception function unit having a communication function, and receives a command from the interrogator Based on the identification code in the received identification information, the file is referenced to determine whether or not to transmit a wireless signal, and when transmitting, the wireless signal is transmitted from the transmission / reception function unit. When not transmitting, the transmission / reception function unit stops transmission.

Further, the present invention, in the above-mentioned wireless tag, wherein the file is rewritable.

The invention of the present application is a wireless tag that transmits a wireless signal including a unique identifier of the wireless tag when receiving an activation command from the interrogator. The identification information of the interrogator that is output from the interrogator includes a code that specifies the region, and the region A that is sent together with the command from the interrogator When the identification information A including the identifying code is received, the wireless signal is transmitted at a frequency suitable for the region A, and the identification including the code identifying the region B transmitted together with a command from another interrogator When the information B is received, a radio signal is transmitted at a frequency suitable for the region B.

Further, the present invention relates to the above-mentioned wireless tag, the file includes not only the frequency but also the output of the transmission radio, the transmission / pause interval ratio (duty) of the radio wave, the modulation of the radio signal, corresponding to each region. The communication condition such as the method is written, and the transmission / reception function unit sets the communication condition so that the corresponding communication condition is set based on the code specifying the region included in the identification information received from the interrogator. It is characterized by changing.

The invention of the present application is a passive wireless tag having no battery, characterized in that it receives radio waves from an interrogator, supplies power, and slightly changes the frequency.

In addition, the present invention is a passive wireless tag having no battery, and when the frequency of the wireless signal transmitted from the interrogator is significantly different from the already set frequency, the wireless tag from the wireless tag The frequency is also changed according to the difference.

The invention of the present application is an active type wireless tag having a battery, which determines the identification information of the interrogator sent together with the command from the interrogator, and supplies the power from the battery built in itself for communication use. The frequency to be changed is greatly changed.

The present invention is an active type wireless tag having a battery,
The wireless output is increased regardless of the wireless output from the interrogator.

In addition, the present invention receives a preamble from the interrogator in addition to the command and the identification information of the interrogator. If the radio wave from the interrogator has a different frequency depending on the region at this stage, should a radio signal be output at this time? It is characterized by determining whether or not to transmit a radio signal at which frequency.

The invention of the present application is a wireless tag that transmits a wireless signal including a unique identifier of the wireless tag when receiving an activation command from the interrogator, and the wireless tag includes a transmission / reception right unit having a communication function and each A file in which regional judgment information is written, and the transmission medium of the command from the interrogator to the wireless tag and the identification information of the interrogator is not limited to radio waves, and the frequency of the radio waves transmitted from the wireless tag is Information indicating communication conditions such as more frequencies is stored in the file so as to be adapted.

The invention of the present application is an interrogator that activates a wireless tag and controls communication of the wireless tag, and transmits information to the wireless tag at a frequency commonly used in each region. Characterize

The invention of the present application is an interrogator that activates a radio tag and controls communication of the radio tag, and transmits information to the radio tag at a frequency commonly used in each region when activated. And after starting, the information containing a control command is transmitted by the frequency used in the area, It is characterized by the above-mentioned.

  As described above, according to the wireless tag of the present invention, the wireless tag itself authenticates and determines the difference depending on the area where the wireless tag is used by receiving the activation command and the identification information from the interrogator. As a result, it is possible to save the trouble and necessity of changing the wireless tag or removing the wireless tag used overseas.

In addition, according to the wireless tag of the present invention, the above determination of the difference depending on the region where the wireless tag is used is performed with reference to the information written in the file in the wireless tag. It is possible to deal with various conditions.
In particular, when this file can be rewritten, it can be handled by changing to new information during use.
Also, even if the amount of information that can be written to the file is small (in extreme cases, there is one way, that is, a condition that transmission is permitted under certain conditions, and transmission is not performed otherwise. The conditions are rewritten according to the operational status. Can work).

  On the contrary, when a plurality of conditions are stored in the file, it is possible to transmit radio waves such as frequencies suitable for both conditions. Assuming a wireless tag attached to a product with this condition, the same wireless tag can be used in both the export area of trade such as the production area and the import area of the consumption area. In other words, it is not necessary to remove the wireless tag used in the exporting country for the wireless tag attached to the product and reattach it in the importing country.

These multiple conditions are not only based on the radio frequency transmitted by the wireless tag, but also the output of the transmission radio, the transmission / pause interval ratio (duty) of the radio wave, the modulation of the radio signal, etc. It only has to be adapted to.
Even with a passive type wireless tag having no battery, the frequency can be changed somewhat (if it is in the range of several hundred kHz, an RF transmitter circuit can be realized by CMOS). Therefore, the present invention can also be applied to passive wireless tags that occupy most of the wireless tags.

  Further, according to the wireless tag of the present invention, the passive wireless tag receives the wireless signal (radio wave) from the interrogator and supplies and modulates the radio wave as electric power. Therefore, the wireless signal transmitted from the interrogator If the frequency is significantly different from the frequency set for the wireless tag, the frequency of the wireless signal transmitted from the wireless tag can also be changed according to the difference.

Moreover, in the active type wireless cog having the battery of the present invention, the identification information sent together with the command from the interrogator is only used as a material for judgment. Since power for transmission is supplied from a battery built in itself, it can be changed to a significantly different frequency, and it can be said that an active wireless tag is suitable for sufficiently covering the difference in frequency and the like.
In the active type wireless tag of the present invention, the transmission output is not related to the wireless output from the interrogator. Therefore, the active wireless tag can increase the wireless output to be transmitted.

  In the wireless tag of the present invention, the wireless tag receives a preamble in addition to the command and the identification information from the interrogator. At this stage, if the radio wave (wireless signal) from the interrogator has a different frequency depending on the region, it can be determined whether or not to output at this time, or at what frequency the radio wave is transmitted. That is, in the extreme case, the above identification information may be unnecessary, and in this case, the determination can be made based on the preamble frequency.

  For the command and identification information received by the RFID tag from the interrogator, use a signal based on a frequency that can be used in common with each country (region) (for example, the IMS band or a low frequency including a magnetic field, 125 kHz is shown in FIG. 2). The wireless tag reception function can be shared. In this case, the frequency of the radio signal transmitted from the radio tag must be adapted to the frequency used in each country, but there is a possibility that it can cope with more regions.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the configuration of an RFID system that converts the frequency between an interrogator (reader) and a wireless tag, to which the present invention is applied. In FIG. 1, the RFID system includes an interrogator 1 that activates and controls a wireless tag 2, a wireless tag 2, and a reader (receiver) 3. The wireless tag 2 is a wireless tag that sends a wireless signal including its own unique ID (identifier) to a reader (receiver) 3 when receiving an activation command from the interrogator 1.

  The wireless tag 2 communicates with a file 21 in which information for realizing a function for determining whether or not to transmit a wireless signal is transmitted by a code in the identification information of the interrogator 1 received together with an instruction from the interrogator 1. When receiving an instruction from the interrogator 1, it transmits a radio signal by referring to the file 21 on the basis of the identification code in the received identification information. When transmitting and receiving, the transmission / reception function unit 20 transmits a radio signal, and when not transmitting, the transmission / reception function unit 20 has a function of stopping transmission.

FIG. 1A shows a case where information for determining whether to transmit to the file 21 of the wireless tag 2 is fixedly written so that it can be used only in a specific area.
Various wireless frequencies are used in the wireless tag. Here, a wireless frequency in the 400 MHz band is assumed as an example. In the case of Japan, a start-up command is transmitted from the interrogator to the wireless tag 2 at a radio frequency of 429 MHz. A unique ID (identifier) of the interrogator 1 is added to this activation command. The identification information includes a region code.
The regional code here does not have to be special. There is already an EPC (Electronic Product Code (see Reference 4)) as an ID code system to be attached to the wireless tag 2.

  The frequency that can be used for the wireless tag varies depending on the country (region) in each major country (region). The 400 MHz band radio frequency is regulated by FCC15 in the US, and 433 MHz is to be used as the ISM frequency in Europe. Therefore, the frequency of 429 MHz is only in Japan. The wireless tag 2 recognizes that the region code in the identification information of the interrogator 1 sent from the interrogator 1 is Japan, and refers to the information on Japan stored in the file 21. According to the referred result, the wireless tag 2 can transmit its own identifier at a wireless frequency of 429 MHz.

  Here, if the file 21 in the wireless tag 2 is rewritable, the amount of information written in the file 21 can be reduced. That is, the minimum information such as Japan and others. In the above example, information on Japan, the United States, and Europe is written, and the United States (as defined in FCC15) receives a start signal of 429 MHz shown in FIG. 1A and transmits a response signal of 429 MHz, for example. And Europe (433 MHz as ISM frequency), and conditions that do not fall into these three regions (simply, if there is nothing in Japan, the US and Europe, it does not transmit).

  However, for example, information is written in a file such as Japanese information and other information (including the United States and Europe, not transmitted). If this wireless tag is operated in Japan, it will work properly. In addition, if you move to a location other than Japan, you can deal with it by rewriting the information in accordance with the radio wave administration of the destination country and the other cases (no transmission).

Radio signals (radio waves) transmitted from the wireless tag 2 to the reader 3 are different in each country (Japan, USA, Europe, etc.). This difference is not only in the usable frequency, but also in radio output, duty (transmission / stop ratio), and modulation method. For example, the wireless output is different such as 50 nW, 500 μVA, and 1100 mW.
In addition, the duty may be 100% that is always allowed to be transmitted, and in most cases it may be 10% that can be transmitted only in a limited time ratio when the transmission is stopped. As modulation methods, there are a digital amplitude modulation (ASK: Amplitude Shift Keying) method, a digital phase modulation (PSK) method, a digital frequency modulation (FSK: Frequency Shift Keying) method, and the like. FIG. 6 shows signal waveforms of the above digital modulation systems.

The use in each region common: possible frequency to start controlling the wireless tag 2 from the interrogator 1 with the signal by (low frequency including IMS band or magnetic For example) can also be envisaged. An example of this is shown in FIG. In Figure 2, cites 125KHz as available-frequency use in each region common. This low frequency signal can be used in the US and Europe as well as Japan. For this purpose, the response by radio waves from the wireless tag 2 to the reader 3 is determined by using the area code included in the ID (identification information) transmitted together with the command from the interrogator 1 to start the wireless tag 2 and the like. , Under conditions such as the frequency that suits the region. This correspondence is also performed by the transmission / reception function unit 20 with reference to the information in the file.

Next, the configuration of the RFID system and its operation sequence are shown in FIG.
An additional description is given of a case where a radio signal is transmitted from the interrogator 1 to the wireless tag 2 using a frequency such as an IMS band that can be commonly used in each country as shown in FIG.
In FIG. 3A, transmission from the interrogator 1 to the wireless tag 2 is performed at a low frequency of 125 kHz. This low frequency can be commonly used in each country (region). The transmission signal from the interrogator 1 to the wireless tag 2 includes a country (region) code.

The wireless tag 2 identifies this country (region) code, and if it is Japan, transmits it at a frequency of 426 MHz. In the case of the United States, transmission is performed at 433 MHz defined in FCC 15, and in Europe, transmission is performed using the IMS standard even at the same 433 MHz.
In this way, several operation sequences (FIGS. 3B, 3C, and 3D) can be assumed as cases where the interrogator 1 starts transmission to the wireless tag 2 at a frequency common to each country.

  The simplest operation sequence among the operation sequences of the RFID system (FIG. 3A) is shown in FIG. In this operation sequence, the interrogator 1 transmits a command such as activation of a wireless tag to the wireless tag 2 in a frequency band common to each country (step 100). The wireless tag 2 receives the country (region) code together with this command, reads out communication conditions such as a frequency matching the country (region) code from the file 21, and transmits the wireless tag 2 under the read communication conditions ( Step 101).

  Next, FIG. 3C shows an operation sequence for improving the reliability of the frequency conversion of the wireless tag by the country (region) code. The interrogator 1 is similar to the operation sequence of FIG. 3B described above, and the interrogator 1 transmits to the wireless tag 2 using a frequency band common to each country (region) (step 200). In this transmission, the country code is included, and based on this, the wireless tag 2 transmits to the reader 3 a preparation completion signal which means that the wireless tag 2 can be transmitted at the corresponding frequency (step 201). ). The reader 3 that has received this preparation completion signal notifies the interrogator 1 of the reception result of this signal. Here, as shown in FIG. 3A, the interrogator 1 and the reader 3 may be connected by a signal (communication) cable or may be connected to a network and communicated if they have different configurations. It's okay to be able to. Alternatively, although it is different from the configuration shown in FIG. 3A, there may be a case in which the interrogator 1 and the reader 3 are integrated (equipped with an interrogator and a reader).

In response to this notification, the interrogator 1 transmits again a control command instructing transmission of the wireless tag 2 in a frequency band common to each country (step 202). The wireless tag 2 transmits a signal responding to the request such as the control command (step 203).
As described above, mutual information (a country (region) code from the interrogator 1 and a ready signal at a frequency corresponding to the country (region) from the interrogator 1) is exchanged between the interrogator 1 and the wireless tag 2. As a result, the reliability of the frequency conversion operation in the wireless tag 2 can be improved.

Furthermore, the reliability can be further improved only by changing a part of the operation sequence shown in FIG. This operation sequence is shown in FIG. In the operation sequence shown in FIG. 3C described above, the changed part is an operation after the wireless tag 2 transmits a preparation completion signal to the reader and the reader notifies the interrogator. That is, steps 300 and 301 in FIG. 3D are the same as steps 200 and 201 in FIG.
In FIG. 3D, the interrogator 1 uses a different frequency in each region and transmits a command to activate the wireless tag 2 (step 302), and the wireless tag 2 transmits by this command (step 303).

  In this way, if the activation command uses a different frequency in each region, the certainty is increased in operation than the activation command using the frequency commonly used in each country. The wireless tag 2 needs to have a reception function corresponding to a frequency common to each country and a reception function of a different frequency in each country. However, in this technology, the wireless tag originally has a transmission function of a different frequency in each country. . Therefore, the implementation of the reception function that is different in each region can share many configurations with the transmission function.

  Next, signals transmitted by the interrogator 1 (or the reader 3) and the wireless tag 2 are shown in FIG. Many wireless tags include a passive wireless tag having no battery and an active wireless tag having a battery. FIG. 4 (a) shows the case of a passive type wireless tag, and FIG. 4 (b) shows the case of an active type wireless tag.

The left side of FIG. 4A shows the relationship between radio output and frequency in the case of a passive radio tag. The wireless output from the wireless tag 2 to the reader 3 is transmitted from the interrogator 1 to the left and right (plus or minus the same frequency) around the wireless output transmitted from the interrogator 1 to the wireless tag 2. This frequency shift can be realized by a CMOS circuit if it is several tens kHz, that is, several hundred kHz or less.
Regarding the strength of the wireless output, the wireless output from the wireless tag 2 to the reader 3 is weaker than the wireless output transmitted from the interrogator 1 to the wireless tag 2. This is because the wireless tag 2 receives the wireless output transmitted from the interrogator 1 and is driven by this power.

On the right side of FIG. 4A, the wireless output of the wireless signal transmitted from the interrogator 1 and the wireless signal transmitted from the wireless tag 2 in the case of a passive wireless tag is shown on the time axis.
The wireless output transmitted from the interrogator 1 to the wireless tag 2 is a wireless output for supplying power to the wireless tag 2 after commands such as preamble and activation, ID (identification information) of the interrogator 1 in order of time passage. . Here, the ID of the interrogator 1 is indicated as “ID_Reader” in FIG. It should be noted that the ID of the interrogator 1 is generally different from the ID of the wireless tag 2.

The preamble can determine the frequency and modulation method, etc., read the following command and the ID (identification information) of the interrogator 1, and in particular determine the region where the wireless tag 2 is used by the region code included in the ID (identification information). to decide.
Here, the ID ( identification information) may indicate a more detailed location in addition to the area code, or may be defined as in the EPC (Electronic Product Code) standard (see Reference 4). good.
The wireless tag 2 transmits its own wireless output while receiving the wireless output from the interrogator 1 according to the determination result based on the difference in the country (region).
The wireless output on the time axis shown on the right side of FIG. 4 (a) assumes the operation sequence of FIG. 3 (b).
In the case of the operation sequence of FIG. 3C, a preparation completion signal is transmitted at the portion where the wireless tag 2 on the right side of FIG. In response to the command, the wireless tag 2 transmits a signal responding to the request.
Further, in the case of the operation sequence of FIG. 3D, the interrogator 1 and the wireless tag 2 on the time axis on the right side of FIG. 4A are transmitted as in the operation sequence of FIG. The difference is that, on the left side of FIG. 4A, the frequency when the interrogator 1 transmits a control command or the like after the wireless tag 2 transmits a preparation completion signal is the frequency common to each country in which the preamble was first transmitted. It is a different point. This point is not shown on the left side of FIG.

On the other hand, the left side of FIG. 4B shows the relationship between the wireless output and the frequency in the case of the active wireless tag.
The wireless output from the wireless tag 2 to the reader 3 can also be transmitted to a position away from the wireless output from the wireless output transmitted from the interrogator 1 to the wireless tag 2. Of course, the same frequency may be used. In this case, the preamble or ID from the unrelated tag 2 is different (ID of the interrogator is identification information, and ID of the wireless tag is an identifier).

Thus, the wireless output signal transmitted from the interrogator 1 to the wireless tag 2 and the wireless output signal from the wireless tag 2 to the reader 3 are identified.
As for the strength of the wireless output, it is possible to increase the wireless output from the wireless tag to the reader with respect to the wireless output transmitted from the interrogator to the wireless tag. This is because the wireless tag is equipped with a battery and is driven by this power.

The right side of FIG. 4B shows the wireless output on the time axis for the wireless signal transmitted from the interrogator 1 and the wireless signal transmitted from the wireless tag 2 in the case of the active wireless tag.
As in the case of the passive wireless tag described with reference to the right side of FIG. 4 (a), the wireless output transmitted from the interrogator 1 to the wireless tag 2 includes instructions such as a preamble and a start-up and an interrogator in order of time. 1 (identification information). Unlike the case of passive wireless tags, wireless output for supplying power to the subsequent wireless tags is unnecessary.

The frequency and modulation method can be determined by the preamble described above, the subsequent instruction and the ID (identification information) of the interrogator 1 are read, and this wireless dada 2 is used by the country (region) code included in the ID (identification information). Determine the country (region) to be used. This correspondence is also the same as in the case of a passive wireless tag.
According to the determination result based on the difference in the above country (region), the wireless tag 2 transmits its own wireless output using the power of the equipped battery. For this reason, even when the activation command for the wireless tag 2 is repeatedly transmitted from the interrogator 1, the frequency is greatly different, so that the wireless tag 2 can be transmitted. Therefore, when the interrogator 1 handles a plurality of wireless tags 2, there are few troubles.

FIG. 5 is a diagram conceptually showing the point (essence) of the present invention.
The point (essence) of the present invention is conceptually shown in the upper part of FIG. The ID (identification information) of the interrogator is included in the radio signal transmitted from the interrogator. The wireless tag authenticates the ID (identification information) of the interrogator included in this wireless signal. It is the essence of the present invention that the wireless tag is provided with a function for determining whether or not to output the wireless output of the wireless tag itself as a result of the authentication and for dealing with it.

When the essential features of the present invention are applied to traffic, the following can be achieved.
The car is equipped with a reader and an interrogator. According to the current radio wave law, 426 MHz is used for domestic vehicles and 433 MHz is used for European and American vehicles (however, when the frequency of 433 MHz is opened in Japan, the wireless tag itself can be used as described above).
Therefore, wireless tags are attached to bicycles, electric carts, pedestrians, and other cars and motorcycles.

  At this time, the ID (identification information and identifier) includes the color and type of those bicycles, electric carts and pedestrians, as well as other cars and motorcycles (in the case of cars, motorcycles, bicycles, electric carts, etc.) Contains information. When the two approach each other, an ID (identification information) is transmitted between the interrogator and the wireless tag, recognizing that the two have approached a short distance (the wireless output can be received), and then the wireless An ID (identification information) is sent from the tag to the reader, and a warning (danger) is given to what kind of thing (bicycle, electric cart, pedestrian, motorcycle, another car) and what features are approaching. Can do.

In addition to the frequency, duty (transmission / stop ratio), and modulation method already described in the explanation of FIG. There are CSMA in the standard, hopping, transmission timing, etc.
CSMA (Carrier Sense Multiple Access / Collision Avoidance Method) is a method for preventing collision of radio signals, and there is a standard that requires the wireless tag to have this function. Hopping mainly refers to frequency hopping and FH (Frequency Hopping).
Further, as described above, there is EPC (see Reference 4) as an ID code system attached to a wireless tag.

[Reference 1] Supervised by the Japan Automatic Recognition System Association, “Development and Application of RF Tags II 2004.05.30 First Issue, CM Publishing, ISBN: 4-88231-446-0
pp.49-63, Chapter 5 ISO Progress Status Section 3 "Things" Management RF Tag 3.6 ISO / IEC 1 8000-6, 3.7
ISO / IEC 18000-7, pp.74-80, Chapter 7 New Frequency of Electronic Tags Section 3 Availability of New Frequency 3.2 (1) 800 / 900MHz, (2) 433MHz
[Reference 2-1]
Tadahiko Hirano, “Radio Law on Automatic Recognition Systems that Anyone can Know [4th] Understanding 2.4GHz Band Wireless Systems”, Barcode, pp.51-59, 2002.7.
http://www.jaisa.or.jp/about/pdfs/denpa0207.pdf
[Reference 2-2]
Tadahiko Hirano, “Radio Law on Automatic Recognition Systems that Anyone can Know [6th] International Standardization Trends and ISM Bands for RFID Systems”, Barcode, pp. 56-58, 2002.10.
http://www.jaisa.or.jp/about/pdfs/denpa0210.pdf
[Reference 3]
Nine points of RFID introduction learned from experimental data (final round -1), (final round -2)
The frequency that can be used differs depending on the country
http://itpro.nikkeibp.co.jp/free/NBY/RFID/20041018/1/
http://itpro.nikkeibp.co.jp/free/NBY/RFID/20041018/2/
[Reference 4] Shunichiro Suenaga ・ ・ Two Flows of Practical Use of RPID "UNISYS TECHNOLOGY REVIEW 78th, AUG 2003, pp. (229) 59- (237) 67
http://www.unisys.co.jp/tec_info/tr78/7806.pdf
Section 5.1 EPC proposed by AUTO-ID Center

Explanatory drawing which shows a structure and operation | movement of the RFID system which converts the frequency between an interrogator (reader) and a wireless tag. Explanatory drawing which shows the structure and operation | movement of an RFID system in the case of carrying out start control of the wireless tag from an interrogator using the signal by the frequency which can be used in common with each area. The figure which shows the structure and operation | movement sequence of an RFID system which performs frequency conversion operation | movement. Explanatory drawing which shows the signal which an interrogator (or leader) and a wireless tag transmit. Explanatory drawing which shows notionally the essence of this invention. The figure which shows the waveform of various digital modulation waves.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Interrogator, 2 ... Wireless tag, 3 ... Reader, 20 ... Transmission / reception function part, 21 ... File

Claims (7)

When receiving an activation command from the interrogator, the wireless tag transmits a wireless signal including its own unique identifier,
The interrogator instruction includes identification information of the interrogator, and the wireless tag authenticates the identification information of the interrogator in the received wireless signal and transmits a wireless signal based on the authentication result. A wireless tag characterized by determining whether or not. When receiving an activation command from the interrogator, the wireless tag transmits a wireless signal including its own unique identifier,
The wireless tag is a transmission / reception device having a communication function and a file in which information for realizing a function of determining whether to transmit a wireless signal is transmitted according to a code in the identification information of the interrogator received together with an instruction from the interrogator Having a functional part,
When receiving an instruction from the interrogator, based on the identification code in the identification information of the interrogator received together, determine whether or not to transmit a radio signal by referring to the file, A wireless tag, wherein a wireless signal is transmitted from the transmission / reception function unit and transmission is stopped by the transmission / reception function unit when not transmitted.   The wireless tag according to claim 2, wherein the file is rewritable. When receiving an activation command from the interrogator, the wireless tag transmits a wireless signal including its own unique identifier,
The identification information of the interrogator that has a transmission / reception function part having a communication function and a file in which the judgment information of each area is written, and includes a code for specifying the area,
When receiving the identification information A including the code specifying the area A sent together with a command from a certain interrogator, a radio signal is transmitted at a frequency suitable for the area A,
In addition, when the identification information B including the code specifying the area B sent together with the command from another interrogator is received, a radio signal is transmitted at a frequency suitable for the area B. tag. In the file, communication conditions are written corresponding to each region,
5. The transmission / reception function unit changes communication condition settings so that the communication condition is satisfied based on a code specifying the region included in the identification information received from the interrogator. The described wireless tag.   Receives a preamble other than the command from the interrogator and the identification information of the interrogator, and outputs a radio signal when the preamble is received if the radio wave from the interrogator has a different frequency depending on the region when the preamble is received. A wireless tag characterized by determining whether or not to transmit or at which frequency a wireless signal is transmitted. An interrogator that activates a wireless tag and controls communication of the wireless tag,
An interrogator characterized in that, when activated, information is transmitted at a frequency commonly used in each area, and information including a control command is transmitted at a frequency used in that area after activation. .

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