JP2010206437A - Information processing apparatus and method, program, and information processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably detect a plurality of IC cards. <P>SOLUTION: Each of IC cards generates a random number RND, and updates the number of waits of polling R based on the value. Each of the IC cards counts the number of receptions of the polling whenever the polling is transmitted from a reader/writer, and if the number of waits of the polling R becomes equal to the number of receptions of the polling K by the reader/writer, the IC card transmits a response to the reader/writer for the first time. When transmitting a response to the reader/writer, each of the IC cards generates a random number RND again and updates the number of waits of the polling R based on the new random number RND. This method can be applied to an information processing apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information processing apparatus and method, a program, and an information processing system, and more particularly, to an information processing apparatus and method, a program, and an information processing system that can accurately detect a plurality of IC cards.

  As a system for performing proximity communication, for example, an IC (Integrated Circuit) card system is widely known. In the IC card system, the reader / writer tries to detect an IC card held over itself or an IC card emulation device having a plurality of functions. Hereinafter, not only the right IC card but also an IC card emulation device having a plurality of functions are simply referred to as an IC card. The reader / writer transmits a control signal (hereinafter referred to as polling) for detecting the IC card. The IC card transmits a response to polling from the reader / writer. The reader / writer can detect the IC card by receiving this response.

  As described above, for example, the following standard exists as a communication standard for performing proximity communication that transmits polling at the time of detection. That is, there are standards called TYPE-A and TYPE-B defined by ISO / IEC (International Organization for Standardization / International Electrotechnical Commission) 14443. There is also a standard called JIS (Japanese Industrial Standards) X 6319-4. In proximity communication according to these standards, polling is repeatedly transmitted in a short time in order to improve the detection capability and reduce power consumption of IC cards of different communication systems.

  JIS X 6319-4 stipulates a method (hereinafter referred to as the time slot method) in which a time slot is provided in communication processing for a plurality of IC cards, and the polling transmission timing is intentionally shifted between IC cards. ing. In the time slot method, a plurality of transmission timings (time slots) are provided in time in one polling transmission process. As a result, signal transmission timing is dispersed, so that occurrence of signal collision can be suppressed (see, for example, Patent Document 1).

JP 2004-215225 A

  However, there is a reader / writer that operates with only one time slot in order to shorten the repetition time of polling by the time slot method. When a plurality of IC cards are held over such a reader / writer, responses from the IC cards are simultaneously transmitted to the reader / writer. As a result, there is a high possibility that the responses from each IC card will collide, and it will be difficult for the reader / writer to correctly detect each IC card.

  The present invention has been made in view of such a situation, and makes it possible to accurately detect a plurality of IC cards.

  An information processing apparatus according to an aspect of the present invention includes a communication unit that receives polling from another information processing apparatus that communicates using a time slot and transmits a response to the polling to the other information processing apparatus, When another information processing apparatus uses one time slot, while the number of polls received by the communication unit is less than a threshold, the communication unit prohibits the transmission of the response, and the number of polls Control means for performing communication control for permitting transmission of the response by the communication means when the value coincides with the threshold value.

  The control unit further repeats updating the threshold value and performing the communication control using the updated threshold value each time the previous response is transmitted from the communication unit.

  The control unit further generates a random number after the response is transmitted from the communication unit, and updates the threshold using the random number.

  The other information processing apparatus is configured as a reader / writer, and the information processing apparatus is configured as an IC (Integrated Circuit) card.

  An information processing method and program according to one aspect of the present invention are a method and program corresponding to the information processing apparatus according to one aspect of the present invention described above.

  In the information processing apparatus, method, and program according to one aspect of the present invention, polling from another information processing apparatus that communicates using a time slot is received, and a response to the polling is transmitted to the other information processing apparatus. When the other information processing apparatus uses one time slot by the information processing apparatus provided with the communication means or the computer that controls the information processing apparatus, the number of times of polling received by the communication means is less than a threshold value. The transmission of the response by the communication unit is prohibited, and the transmission of the response by the communication unit is permitted when the number of polling matches the threshold value.

  An information processing system according to one aspect of the present invention is a system including one or more information processing apparatuses corresponding to the information processing apparatus according to one aspect of the present invention described above.

  In the information processing system according to one aspect of the present invention, the first information processing apparatus communicates with another information processing apparatus using a time slot, and polling is transmitted to detect the other information processing apparatus. The polling from the first information processing apparatus is received by the second information processing apparatus, and a response to the polling is transmitted to the first information processing apparatus. When a time slot is used, transmission of the response is prohibited while the number of polls received is less than a threshold, and transmission of the response is permitted when the number of polls matches the threshold. .

  As described above, according to the present invention, a plurality of IC cards can be accurately detected.

It is a figure explaining the communication system as one Embodiment of the information processing system to which this invention is applied. 2 is a diagram illustrating a configuration example of an IC card 12. FIG. It is a flowchart explaining an example of the response transmission process performed by the IC card 12 side among response transmission processes. It is a figure for demonstrating a series of flows of the response transmission process by IC card 12-1. It is a flowchart explaining an example of the relationship of mutual processing between each of the reader / writer 11 and two IC cards 12-1 and 12-2. It is a block diagram which shows the hardware structural example of the information processing apparatus with which this invention is applied.

<1. Outline of the present invention>

  First, the outline of the present invention will be described in order to facilitate understanding of the present invention.

  When the designated value of the time slot for polling by the reader / writer is specified as 0 and there is one reply slot, the response from each IC card collides when a plurality of IC cards are held over the reader / writer at the same time. There is a case.

  In order to avoid a collision in such a case, in the present invention, each IC card does not immediately set a response transmission timing every time a polling is received as in the prior art. It waits for the reception of polling of an integer value of 1 or more. This number R is hereinafter referred to as polling wait number R. That is, each time the IC card receives polling from the reader / writer, it counts the number K of polling receptions. Each IC card transmits a response to the reader / writer when the polling waiting count R and the polling reception count K match.

  Since it is necessary to prevent collision of responses of a plurality of IC cards on the reader / writer side, the polling waiting count R used by each IC card needs to have a different value at any timing. For this reason, each IC card updates the setting of the polling waiting count R every time a response is transmitted, for example, at an appropriate timing. The update method itself is not particularly limited, and, for example, a numerical value variable unit that changes a numerical value using a cyclic code or the like or changes a numerical value by generating a random number is provided. A method of setting or updating the polling waiting frequency R using the numerical value generated by the numerical value variable unit can also be employed. For example, in the present embodiment, which will be described later, a technique is employed in which a random number is generated and the polling waiting count R is set or updated using the random number.

  Hereinafter, a series of processes on the IC card side, that is, each IC card sets a polling waiting frequency R, and transmits a response when the polling waiting frequency R matches the polling reception frequency K. The series of processes up to is referred to as a response transmission process.

  Even when a plurality of IC cards perform proximity communication with the reader / writer, each IC card can respond to the reader / writer at random by repeatedly executing the response transmission process. As a result, it becomes possible to suppress the possibility of collision of responses by a plurality of IC cards, so that the reader / writer can accurately detect each IC card.

<2. Embodiment of the Invention>

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

[Communication system to which the present invention is applied]

  FIG. 1 is a diagram for explaining a communication system as an embodiment of an information processing system to which the present invention is applied.

  The communication system in the example of FIG. 1 includes a reader / writer 11 and IC cards 12-1 to 12-N (N is a natural number of 1 or more).

  Hereinafter, when it is not necessary to individually distinguish the IC cards 12-1 to 12-N, they are collectively referred to as an IC card 12.

  Between the reader / writer 11 and the IC card 12, non-contact data transmission / reception is performed using electromagnetic waves.

  In this embodiment, JIS X 6319-4 or NFCIP (Near Field Communication Interface and Protocol) -1 is adopted as the communication method. However, the communication method is not particularly limited as long as the method adopts the time slot method.

  When the IC card 12 is held close to the reader / writer 11 or the like, the reader / writer 11 radiates electromagnetic waves to start communication processing with the IC card 12.

[Configuration example of IC card]

  FIG. 2 is a diagram illustrating a configuration example of the IC card 12.

  In the example of FIG. 2, the IC card 12 includes an IC chip module 21 and an antenna 22. The IC chip module 21 is provided with an ASK (Amplitude Shift Keying) modulation / demodulation unit 31 and a BPSK (Binary Phase Shift Keying) modulation / demodulation unit 32. The IC chip module 21 is also provided with a CPU (Central Processing Unit) 33 and an EEPROM (Electrically Erasable and Programmable Read Only Memory) 34.

  The ASK modulation / demodulation unit 31 detects and demodulates the modulated wave (ASK modulated wave) input via the antenna 22. The ASK modulation / demodulation unit 31 supplies the demodulated data to the BPSK modulation / demodulation unit 32. The BPSK modulation / demodulation unit 32 performs BPSK demodulation (Manchester code decoding) of the data supplied from the ASK modulation / demodulation unit 31, and obtains data obtained as a result (for example, polling from the reader / writer 11 in FIG. 1 in this example). Supply to CPU33.

  The CPU 33 executes a predetermined process based on the data supplied from the BPSK modulation / demodulation unit 32. For example, the CPU 33 executes a response transmission process described later.

  The EEPROM 34 is a nonvolatile memory. Even after the IC card 12 ends communication with the reader / writer 11 of FIG. 1 and the power supply is stopped, the EEPROM 34 can continue to store data.

  On the other hand, when transmitting data (for example, response to polling in this example) from the IC card 12 to the reader / writer 11 of FIG. 1, the CPU 33 reads the target data from the EEPROM 34 and supplies it to the BPSK modulation / demodulation unit 32. . The BPSK modulation / demodulation unit 32 BPSK modulates the data supplied from the CPU 33 and supplies the modulated data to the ASK modulation / demodulation unit 31. The ASK modulation / demodulation unit 31 executes, for example, on / off control for a predetermined switching element (not shown) corresponding to the data supplied from the BPSK modulation / demodulation unit 32. The on / off control refers to control in which the state of the switching element is changed from the on state to the off state or from the off state to the on state at a predetermined timing.

  When the switching element is in the on state, a predetermined load is connected in parallel to the antenna 22, and when it is in the off state, the connection is disconnected. Therefore, the load on the antenna 22 varies as the ASK modulation / demodulation unit 31 performs on / off control for the switching element. In this manner, the ASK modulation / demodulation unit 31 ASK modulates the modulated wave received via the antenna 22 by changing the load of the antenna 22, and the modulated wave is transmitted via the antenna 22 to the FIG. To the antenna on the reader / writer 11 side.

  In other words, when the reader / writer 11 receives data from the IC card 12, that is, when the IC card 12 transmits predetermined data, the reader / writer 11 outputs a modulated wave (carrier) with the maximum amplitude of the modulated wave being constant. To do. The modulated wave (carrier) output from the reader / writer is ASK modulated (load modulated) due to the load variation of the antenna 22 of the IC card 12.

  Some IC cards 12 are equipped with a battery as a power source. In this case, power is supplied from this battery to each part of the IC card 12. However, in the present embodiment, it is assumed that the power supply method to each part of the IC card 12 is as follows, for example. That is, the IC card 12 of the present embodiment has an LC circuit composed of an antenna 22 serving as a coil and a capacitor (not shown). In this LC circuit, one of the electromagnetic waves radiated from the antenna on the reader / writer 11 side. The part is converted into an electrical signal. Furthermore, in the IC card 12 of the present embodiment, envelope detection is performed by rectifying and smoothing the electrical signal (modulated wave). The resulting signal is supplied to a voltage regulator (not shown) and stabilized, and the resulting DC voltage signal (the resulting power) is supplied to each part of the IC card 12.

  The configuration of the IC card 12 is not limited to the example of FIG. 2, and it is sufficient if it has a configuration capable of communicating various information including polling and its response with the reader / writer 11. For example, the non-contact IC card 12 may be composed of an IC in which components including an antenna are stored in one chip.

  Further, the shape of the IC card 12 may not be a card shape. That is, the IC card 12 is a name used for convenience of explanation, and intends the function as described above or described later. For example, there is a Felica chip (registered trademark) that provides the same function as the IC card 12. That is, for example, if a Felica chip is mounted on a portable terminal, the portable terminal can be used as the non-contact IC card 12.

  Various information is transmitted and received between the reader / writer 11 configured as described above and the IC card 12 using electromagnetic waves as a medium. Hereinafter, an example of the response transmission process among such transmission / reception processes will be described with reference to the flowcharts of FIGS.

[Response transmission process]

  FIG. 3 is a flowchart for explaining an example of a response transmission process executed on the IC card 12 side in the response transmission process.

  FIGS. 4 and 5 are flowcharts for explaining an example of the mutual processing relationship between the reader / writer 11 and the IC card 12.

  That is, FIG. 4 is a diagram for explaining a series of response transmission processing by the IC card 12-1 performed when the polling waiting count R = 1. FIG. 5 is a diagram for explaining the mutual processing relationship between the reader / writer 11 and a plurality of IC cards (IC card 12-1 and IC card 12-2).

  Hereinafter, the response transmission process performed by the CPU 33 will be described with reference to FIG. The mutual processing relationship between the reader / writer 11 and the IC card 12 can be understood by referring to the corresponding steps in FIGS.

  The first process of the response transmission process shown in FIG. 3 starts when power is supplied from the reader / writer 11 to the IC card 12. Note that the second and subsequent times are executed at the timing after the previous response transmission process is completed in principle.

  In step S1 of the response transmission process of FIG. 3, the CPU 33 generates a random number RND, initializes CNT = 0, and sets R = RNDmod3. Here, CNT indicates a counter value (hereinafter referred to as a polling counter value) that counts the number K of polling receptions (more precisely, K-1 up to the previous time). R indicates the number of polling wait times. Therefore, in the example of FIG. 3, a value obtained by dividing the random number RND by 3 is set as the polling waiting count R. That is, if the range that the random number RND can take is 1 to 3, the polling waiting count R is set to any value from 0 to 2.

  In step S <b> 2, the CPU 33 determines whether or not polling from the reader / writer 11 has been received.

  Unless the polling from the reader / writer 11 is received, it is determined as NO in Step S2, and the process returns to Step S2, and the subsequent processes are repeated. That is, until the polling from the reader / writer 11 is received, the determination process in step S2 is repeated.

  Thereafter, when polling from the reader / writer 11 is received, it is determined as YES in Step S2, and the process proceeds to Step S3.

  In step S3, the CPU 33 determines whether or not the designated value of the time slot is 0. That is, the CPU 33 determines whether or not the number of reply slots for polling by the reader / writer 11 is specified as 1.

  When the designated value of the time slot is 0, that is, when the number of reply slots used by the reader / writer 11 is 1, it is determined as YES in Step S3, and the process proceeds to Step S4. However, a series of processes after step S4 will be described later.

  On the other hand, when the designated value of the time slot is other than 0, that is, when the number of reply slots used by the reader / writer 11 is plural, it is determined as NO in step S3, and the process proceeds to step S6. Proceed to

  In step S <b> 6, the CPU 33 transmits a response to the reader / writer 11. That is, the case where the designated value of the time slot is not 0 means that the number of reply slots used by the reader / writer 11 is plural as described above. In such a case, on the reader / writer 11 side, the possibility of a response collision between the plurality of IC cards 12 is reduced. Therefore, the CPU 33 immediately transmits a response to the first polling from the reader / writer 11.

  In this way, when the designated value of the time slot is not 0, the response transmission process is also finished when the process of step S6 is finished.

  On the other hand, the case where the designated value of the time slot is 0 means that the number of reply slots used by the reader / writer 11 is one. In such a case, on the reader / writer 11 side, there is a high possibility that a response collision will occur between the plurality of IC cards 12. Therefore, in such a case, the CPU 33 determines NO in step S3, and determines whether or not R = <CNT in step S4. That is, the CPU 33 determines whether or not the polling counter value CNT is equal to or greater than the polling waiting number R.

  If R = <CNT, that is, if the polling counter value CNT is smaller than the polling waiting count R, it is determined as NO in step S4, and the process proceeds to step S5.

  In step S5, the CPU 33 increments the polling counter value CNT by 1 (CNT = CNT + 1). Thereafter, the process returns to step S2, and the subsequent processes are repeated. That is, by repeating the processing from step S2 to step S5, every time polling is received, the polling counter value CNT indicating the number of times of polling reception K (more precisely, K-1 up to the previous time) is counted up. To go. During this time, no response is sent. When the polling reception count K matches the polling wait count R, that is, when the relationship of R = <CNT is satisfied, it is determined as YES in step S4, and the process proceeds to step S6. . In step S <b> 6, the CPU 33 transmits a response to the reader / writer 11. As a result, the response transmission process ends.

  Thus, the polling counter value CNT (more precisely, CNT-1) used in the response transmission process can be grasped as a kind of threshold value. When grasped in this way, it can be seen that the response transmission process is an example of the following process. That is, response transmission processing is an example of processing in which response transmission is prohibited while the polling reception count K is less than the threshold, and response transmission is permitted when the polling reception count K matches the threshold. .

  The CPU 33 transmits a response to the reader / writer 11 (step S6), and when the response transmission process is terminated, a new response transmission process is executed again. That is, the CPU 33 generates a new random number RND, and updates the polling waiting count R based on the new random number RND (see step S1). Then, the CPU 11 again waits for transmission of polling from the reader / writer 11 (see processing after step S2).

[Relationship between reader / writer and IC card]

  Hereinafter, the response transmission process will be described with reference to FIGS. 4 and 5 from the viewpoint of mutual processing between the reader / writer 11 and the IC card 12. Hereinafter, processing on the reader / writer 11 side with respect to response transmission processing by the IC card 12 is referred to as polling transmission processing.

  FIG. 4 shows, from the left, a flowchart for explaining an example of the polling transmission process of the reader / writer 11 and a flowchart for explaining an example of the response transmission process of the IC card 12-1. In addition, the arrow which connects between both has shown the flow of information.

  When the response transmission process is started, the IC card 12-1 generates a new random number RND, and sets or updates the polling waiting count R based on the new random number RND. For example, in the example of FIG. 4, since the random number RND = 1 is generated, the polling waiting count R is set to 1 or updated.

  In step S21, the reader / writer 11 transmits polling.

  In this case, when receiving the polling, the IC card 12-1 determines YES in step S2, and advances the process to step S3. In step S3, the CPU 33 determines whether or not the designated value of the time slot is 0.

  Here, it is assumed that the number of reply slots for polling by the reader / writer 11 is designated as 1. That is, it is assumed that the specified value is 0. In this case, it is determined as YES in Step S3, and the process proceeds to Step S4.

  At this stage, since the polling counter value CNT is still at the initial value 0 and the polling waiting count R = 1, it is determined NO in the process of step S4, and the polling counter value is determined in the process of step S5. It is updated to CNT = 1 (CNT = CNT + 1).

  Thereafter, the process returns to step S2, and the determination process of step S2 is repeated until the next polling is received, and the response transmission process of the IC card 12-1 enters a standby state.

  Since the reader / writer 11 has not yet detected the IC card 12-1, the reader / writer 11 transmits polling again in step S21.

  In this case, when receiving the second polling, the IC card 12-1 determines YES in step S2, and advances the process to step S3. In step S3, the CPU 33 determines whether or not the designated value of the time slot is 0.

  Here, since the specified value is 0 as described above, it is determined as YES in Step S3, and the process proceeds to Step S4.

  At this stage, since the polling counter value CNT = 1 and the polling waiting count R = 1, it is determined YES in the process of step S4, and the process proceeds to step S6.

  In step S <b> 6, the IC card 12-1 transmits a response to the reader / writer 11. Thus, the IC card 12-1 transmits a response to polling to the reader / writer 11 only when the polling counter value CNT and the polling waiting count R match. As a result, the response transmission process ends.

  On the other hand, in step S22, the reader / writer 11 receives a response from the IC card 12-1. As a result, the reader / writer 11 can detect the IC card 12-1, and thus ends the polling transmission process.

  The specific example of the response transmission process has been described above with reference to FIG. Furthermore, another specific example of response processing will be described below with reference to FIG.

[Relationship between reader / writer and multiple IC cards]

  FIG. 5 is a flowchart for explaining an example of the mutual processing relationship between the reader / writer 11 and the two IC cards 12-1 and 12-2.

  FIG. 5 illustrates, from the left, a flowchart for explaining an example of polling transmission processing of the reader / writer 11 and a flowchart for explaining an example of response transmission processing of each of the IC cards 12-1 and 12-2. . In addition, the arrow which connects between each has shown the flow of information.

  For example, when the user simultaneously holds two IC cards 12-1 and 12-2 in a wallet or the like and brings the wallet or the like closer to the reader / writer 11, the process according to the flowchart of FIG.

  When the response transmission process is started, the IC card 12-1 generates a random number RND in step S1, and sets or updates the polling waiting count R based on the new random number RND. For example, in the example of FIG. 5, since the random number RND = 0 is generated, the polling wait count R is set to 0 or updated.

  Similarly, when the response transmission process is started, the IC card 12-2 generates a random number RND in step S1, and sets or updates the polling waiting count R based on the new random number RND. For example, in the example of FIG. 5, since the random number RND = 0 is generated, the polling wait count R is set to 0 or updated.

  In step S21 of the polling transmission process, the reader / writer 11 transmits polling. Here, it is assumed that the number of reply slots for polling by the reader / writer 11 is designated as 1. That is, it is assumed that the specified value is 0.

  At this stage, in both the IC cards 12-1 and 12-2, the polling counter value CNT is still at the initial value 0, and the polling waiting count R = 0. Therefore, each of the IC cards 12-1 and 12-2 is determined as NO in the process of step S4 of the response transmission process. In step S6, the IC cards 12-1 and 12-2 transmit responses to the reader / writer 11, respectively.

  In this case, since there is only one reply slot, the responses of the IC cards 12-1 and 12-2 in response to polling from the reader / writer 11 will collide. As a result, the reader / writer 11 cannot correctly detect both the IC cards 12-1 and 12-2. Thus, if the random numbers RND generated by the IC cards 12-1 and 12-2 happen to be the same, a collision of responses will occur as in the conventional case.

  In such a case, each of the IC cards 12-1 and 12-2 executes the response transmission process again. That is, in step S1, the IC card 12-1 generates a new random number RND, and updates the polling waiting count R based on the new random number RND. For example, since a new random number RND = 1 is generated here, the polling waiting count R is updated from 0 to 1.

  On the other hand, in step S1, the IC card 12-2 also generates a new random number RND and updates the polling waiting count R based on the new random number RND. For example, since a new random number RND = 3 is generated here, the polling waiting count R is updated from 0 to 3.

  As described above, it is assumed that the random numbers RND generated by the IC cards 12-1 and 12-2 have different values this time, and as a result, the polling waiting count R is set to a different count.

  In this case, the reader / writer 11 has not yet detected the IC cards 12-1 and 12-2, and therefore transmits the polling again in step S21.

  At this stage, the IC card 12-1 has a polling counter value CNT = 0 and a polling waiting count R = 1. Accordingly, it is determined NO in step S4 of the response transmission process of the IC card 12-1, and the polling counter value CNT = 1 is updated in the process of step S5 (CNT = CNT + 1). Thereafter, until the polling from the reader / writer 11 is received again, the response transmission process of the IC card 12-1 is in a standby state.

  On the other hand, at this stage, the IC card 12-2 has the polling counter value CNT = 0 and the polling waiting count R = 3. Therefore, it is determined NO in step S4 of the response transmission process of the IC card 12-2, and the polling counter value CNT = 1 is updated in the process of step S5 (CNT = CNT + 1). Thereafter, until the polling from the reader / writer 11 is received again, the response transmission process of the IC card 12-2 is in a standby state.

  Thus, even at this stage, since no response is transmitted from either of the IC cards 12-1 and 12-2, the reader / writer 11 has not yet detected the IC cards 12-1 and 12-2. . Therefore, the reader / writer 11 transmits polling again in step S21.

  At this stage, the IC card 12-1 has the polling counter value CNT = 1 and the polling waiting count R = 1. The polling counter value CNT matches the polling wait count R. Therefore, the IC card 12-1 determines YES in the process of step S4, and transmits a response to the reader / writer 11 in the process of step S6. As a result, the response transmission process ends, and a new response transmission process is executed again. That is, in step S1, the IC card 12-1 generates a new random number RND, and updates the polling waiting count R based on the new random number RND. For example, since a new random number RND = 2 is generated here, the polling waiting count R is updated from 1 to 2.

  In this case, the reader / writer 11 receives the response of the IC card 12-1 in step S22. As a result, the reader / writer 11 detects the IC card 12-1.

  On the other hand, at this stage, the IC card 12-2 has the polling counter value CNT = 1 and the polling waiting count R = 3. Therefore, it is determined NO in step S4 of the response transmission process of the IC card 12-2, and the polling counter value CNT = 2 is updated in the process of step S5 (CNT = CNT + 1). Thereafter, until the polling from the reader / writer 11 is received, the response transmission process of the IC card 12-1 is in a standby state.

  Thus, the reader / writer 11 was able to detect the IC card 12-1 because the reader / writer 11 was able to receive the response of the IC card 12-1. However, since the IC card 12-2 cannot be detected, the reader / writer 11 transmits polling again in step S21.

  At this stage, the IC card 12-1 has a polling counter value CNT = 0 and a polling waiting count R = 2. Therefore, the IC card 12-1 determines NO in the process of step S4, and updates the polling counter value CNT = 1 in the process of step S5 (CNT = CNT + 1). Thereafter, the response transmission process of the IC card 12-1 is in a standby state until polling from the reader / writer 11 is received.

  On the other hand, at this stage, the IC card 12-2 has the polling counter value CNT = 2 and the polling waiting count R = 3. Therefore, the IC card 12-2 determines NO in the process of step S4, and updates the polling counter value CNT = 3 in the process of step S5 (CNT = CNT + 1). Thereafter, until polling from the reader / writer 11 is received, the response transmission process of the IC card 12-2 is in a standby state.

  Since no response is transmitted from either of the IC cards 12-1 and 12-2, the reader / writer 11 has not yet detected the IC cards 12-1 and 12-2. Therefore, the reader / writer 11 transmits polling again in step S21.

  At this stage, the IC card 12-1 has the polling counter value CNT = 1 and the polling waiting count R = 2. Therefore, the IC card 12-1 determines NO in the process of step S4, and updates the polling counter value CNT = 2 in the process of step S5 (CNT = CNT + 1). Thereafter, the response transmission process of the IC card 12-1 is in a standby state until polling from the reader / writer 11 is received.

  On the other hand, at this stage, the IC card 12-2 has the polling counter value CNT = 3 and the polling waiting count R = 3. The polling counter value CNT matches the polling wait count R. Therefore, the IC card 12-1 determines YES in the process of step S4, and transmits a response to the reader / writer 11 in the process of step S6. As a result, the response transmission process ends, and a new response transmission process is executed again. That is, in step S1, the IC card 12-2 generates a new random number RND, and updates the polling waiting count R based on the new random number RND. For example, since a new random number RND = 1 is generated here, the polling waiting count R is updated from 3 to 1.

  In this case, the reader / writer 11 receives the response of the IC card 12-2 in step S22. As a result, the reader / writer 11 detects the IC card 12-2.

  The response transmission process of the IC card 12 has been described above with reference to FIGS.

  Thus, even when a plurality of IC cards 12 perform proximity communication with the reader / writer 11, each IC card 12 can transmit a response to the reader / writer 11 at random. Thereby, on the reader / writer 11 side, the possibility of a collision of responses between the IC cards 12 can be reduced. As a result, the reader / writer 11 can accurately detect each IC card 12.

  As described above, the information processing system configured as shown in FIG. 1, that is, the communication system including the reader / writer 11 and the IC card 12 has been described as an embodiment of the information processing system to which the present invention is applied. However, the present invention can be widely applied not only to the information processing system shown in FIG. The components of such an information processing system are not particularly limited. For example, the present invention can be applied not only to the above-described IC card 12 but also to various communication devices such as a PDA (Personal Digital Assistant), a personal computer, and a mobile phone.

[Application of the present invention to a program]

  By the way, the series of processes described above can be executed by hardware, but can also be executed by software.

  In this case, for example, a personal computer shown in FIG. 6 may be employed as at least a part of the information processing apparatus described above.

  In FIG. 6, a CPU (Central Processing Unit) 101 executes various processes according to a program recorded in a ROM (Read Only Memory) 102. Alternatively, various processes are executed according to a program loaded from a storage unit 108 to a RAM (Random Access Memory) 103. The RAM 103 also appropriately stores data necessary for the CPU 101 to execute various processes.

  The CPU 101, ROM 102, and RAM 103 are connected to each other via a bus 104. An input / output interface 105 is also connected to the bus 104.

  The input / output interface 105 is connected to an input unit 106 such as a keyboard and a mouse and an output unit 107 such as a display. Further, a storage unit 108 composed of a hard disk or the like and a communication unit 109 composed of a modem, a terminal adapter, etc. are connected. The communication unit 109 controls communication performed with other devices (not shown) via a network including the Internet.

  A drive 110 is connected to the input / output interface 105 as necessary, and a removable medium 111 made of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is appropriately attached. Then, the computer program read from them is installed in the storage unit 108 as necessary.

  When a series of processing is executed by software, a program constituting the software executes various functions by installing a computer incorporated in dedicated hardware or various programs. For example, a general-purpose personal computer is installed from a network or a recording medium.

  As shown in FIG. 6, the recording medium including such a program is distributed to provide a program to the user separately from the apparatus main body, and a magnetic disk (including a floppy disk) on which the program is recorded. , Removable media (package media) consisting of optical disks (including CD-ROM (compact disk-read only memory), DVD (digital versatile disk)), magneto-optical disks (including MD (mini-disk)), or semiconductor memory ) 111 as well as a ROM 102 on which a program is recorded and a hard disk included in the storage unit 108 provided to the user in a state of being incorporated in the apparatus main body in advance.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the order, but is not necessarily performed in chronological order, either in parallel or individually. The process to be executed is also included.

  11 Reader / Writer, 12 IC Card, 21 IC Chip Module, 31 ASK Modulation / Demodulation Unit, 32 BPSK Modulation / Demodulation Unit, 33 CPU, 34 EEPROM, 101 CPU, 102 ROM, 103 RAM, 108 Storage Unit, 111 Removable Media

Claims (7)

A communication unit that receives polling from another information processing apparatus that communicates using a time slot and transmits a response to the polling to the other information processing apparatus;
When the other information processing apparatus uses one time slot, while the number of polls received by the communication unit is less than a threshold, the transmission of the response by the communication unit is prohibited, and the polling An information processing apparatus comprising: a control unit that performs communication control that permits transmission of the response by the communication unit when the number of times matches the threshold value. The control means includes
Furthermore, every time the previous response is transmitted from the communication means,
Updating the threshold and performing the communication control using the updated threshold;
The information processing apparatus according to claim 1. The information processing apparatus according to claim 2, wherein the control unit further generates a random number after the response is transmitted from the communication unit, and updates the threshold using the random number. The other information processing apparatus is configured as a reader / writer,
The information processing apparatus according to claim 1, wherein the information processing apparatus is configured as an IC (Integrated Circuit) card. An information processing apparatus including a communication unit that receives polling from another information processing apparatus that communicates using a time slot and transmits a response to the polling to the other information processing apparatus,
When the other information processing apparatus uses one time slot, while the number of polls received by the communication unit is less than a threshold, the transmission of the response by the communication unit is prohibited, and the polling An information processing method including a step of permitting transmission of the response by the communication means when the number of times coincides with the threshold value. A computer that controls the information processing apparatus including a communication unit that receives polling from another information processing apparatus that communicates using a time slot and transmits a response to the polling to the other information processing apparatus.
When the other information processing apparatus uses one time slot, while the number of polls received by the communication unit is less than a threshold, the transmission of the response by the communication unit is prohibited, and the polling A program for executing a control process including a step of permitting transmission of the response by the communication means when the number of times coincides with the threshold value. A first information processing apparatus that communicates with another information processing apparatus using a time slot and transmits polling to detect the other information processing apparatus;
Communication means for receiving polling from the first information processing apparatus and transmitting a response to the polling to the first information processing apparatus;
When the first information processing apparatus uses one time slot, while the number of polls received by the communication unit is less than a threshold value, the transmission of the response by the communication unit is prohibited, and the polling is performed. A second information processing apparatus, comprising: a control unit that performs communication control that permits transmission of the response by the communication unit when the number of times matches the threshold value.

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