Patent Publication Number: US-9907091-B2

Title: Communication device, control method, and program

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/564,913, filed Aug. 2, 2012, which claims priority from Japanese Patent No. JP 2011-176492, filed in the Japanese Patent Office on Aug. 12, 2011 the disclosure of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present technology relates to communication devices, control methods, and programs. In particular, the present technology relates to a communication device, a control method, and a program that are capable of quickly establishing a communication. 
     NFC (near-field communication) standards have been available for wireless communication. In NFC devices that support the NFC standards, each terminal may have therein multiple communication targets (hereinafter may be referred to as “targets”). 
     The present applicant has previously proposed an NFC device including multiple secure elements that serve as targets and a front end that is shared by the secure elements and that performs near-field communication with an external device, such as a reader. During startup, the front end in the NFC device allots different time slots for communications to the multiple secure elements (see, for example, Japanese Unexamined Patent Application Publication No. 2011-49778). 
     As illustrated in  FIG. 1 , two systems, i.e., a single-response system and a multi-response system, are available for near-field communication performed between a reader and a contactless wireless chip (a CLE (contactless front end), which may also be referred to as a “front end” hereinafter) for performing near field wireless communication. 
     In the single-response system, since the front end sends back a single polling response in response to polling from the reader, the reader performs processing on a target corresponding to the polling response. Accordingly, the single-response system has an advantage in that it can be implemented without provision of a special circuit, but has a drawback in that a target correctness rate (i.e., the probability of being able to sending a response from a target desired by the reader back to the reader; hereinafter may simply be referred to as a “correctness rate”) is reduced compared to the multi-response system. 
     On the other hand, in the multi-response system, the front end sends back multiple poling responses in response to polling from the reader. Thus, the reader, when it supports multi-response reception, performs processing on a target corresponding to a desired polling response selected from the multiple polling responses. Thus, in the multi-response system, a special circuit for sending back the responses at once is provided in the front end to thereby complicate the implementation, but the correctness rate can be increased compared to the single-response system. 
     SUMMARY 
     As illustrated in  FIG. 2 , with the front end having the function of the multi-response system, for example, if only two time slots are available when it is desired to send back three polling responses, no polling responses can be sent back at once because of the insufficient number of slots. Thus, in the multi-response system, when the number of slots is large, all the polling responses can be sent back, but when the reader performs polling with a small TSN (time slot number), such as TSN=0 or 1, there are cases in which the number of slots is insufficient and not all polling responses can be sent back. 
     In addition, for an existing device that does not support the multi-response system, in order to employ the multi-response system, a special circuit is typically installed as the special circuit to be provided in the front end. 
     One NFC reader operation standard defines operation specifications stating that the reader performs a polling operation twice and an operation of a P2P (peer-to-peer) application is allowed when a response to one of the two polling operations is received from the P2P application. It is preferable to provide a technology that supports the operation specifications. 
     In view of the foregoing situation, it is desirable to provide a technology that supports the above-described reader operation specifications and that ensures that a target desired by the reader is selected to allow for quick establishment of a communication, without implementation of a special circuit in the front end. 
     According to an embodiment of the present technology, there is provided a communication device. The communication device includes: targets that are each configured to execute predetermined processing; and a front end that is configured to select, from the targets, a confirmed target with which an external device is to communicate and that is configured to perform near-field communication with the external device. The front end is configured to select, during transmission of a command for selecting at least one candidate of the confirmed target, a predetermined one of the targets once every two times as a transmission destination of the command. 
     The front end may be configured to broadcast, upon receiving a polling command from the external device, the polling command to the targets other than the predetermined target. 
     The predetermined target may be a P2P (peer-to-peer) application. 
     Of the targets, the targets other than the predetermined target may include at least one of a secure element and a UICC (universal integrated circuit card). 
     The front end may be configured to confirm the target with which the external device is to communicate, out of the at least one target selected as the at least one confirmed-target candidate, as the confirmed target. 
     The front end may be configured to confirm the confirmed-target candidate as the confirmed target when an identifier of the target selected as the confirmed-target candidate, the identifier being obtained from the target, and an identifier included in a command transmitted by the external device match each other. 
     The front end may be configured to confirm the confirmed-target candidate as the confirmed target when a command for confirming, as the confirmed target, the target selected as the confirmed-target candidate is received from the external device. 
     The front end may be configured to release, on a basis of a predetermined target release condition, the confirmed target from the target with which the external device is to communicate. 
     The front end may be configured to release, after the near-field communication with the external device is disconnected, the confirmed target upon receiving a polling command from the external device. 
     The front end may be configured to release the confirmed target when a command for terminating a communication between the external device and the confirmed target is received from the external device. 
     The communication device may be an independent device or may be an internal block included in one device. 
     According to an embodiment of the present technology, there is provided a control method or program corresponding to the above-described communication device according to the embodiment of the present technology. 
     In the communication device, the control method, and the program according to the embodiment of the present technology, a confirmed target with which an external device is to communicate is selected from targets that each execute predetermined processing and near-field communication is performed with the external device. During transmission of a command for selecting at least one candidate of the confirmed target, a predetermined one of the targets is selected once every two times as a transmission destination of the command. 
     According to the embodiment of the present technology, a communication can be quickly established. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a near-field communication system; 
         FIG. 2  illustrates an example of polling parameters and response conditions in a multi-response system; 
         FIG. 3  illustrates an exemplary configuration of an NFC device; 
         FIG. 4  illustrates an exemplary detailed configuration of a CLF; 
         FIG. 5  is a flowchart illustrating routing processing; 
         FIG. 6  is a diagram illustrating candidate transition in a simple rotation system; 
         FIG. 7  is a diagram illustrating candidate transition in a simple rotation system including a skip function; 
         FIG. 8  is a diagram illustrating candidate transition in a P2P-main rotation system including a skip function; 
         FIG. 9  is a sequence diagram illustrating broadcast transmission; 
         FIG. 10  is a diagram illustrating candidate transition when the broadcast transmission is incorporated into the P2P-main rotation system including the skip function; 
         FIG. 11  is a flowchart illustrating a flow of candidate selection processing; 
         FIG. 12  is a sequence diagram illustrating IDm comparison system; 
         FIG. 13  is a flowchart illustrating a flow of confirmation processing using an IDm comparison system; 
         FIG. 14  is a sequence diagram illustrating an ATR_REQ reception system; 
         FIG. 15  is a flowchart illustrating a flow of confirmation processing using the ATR_REQ reception system; 
         FIG. 16  is a diagram illustrating release of a target when an RF signal is lost; 
         FIG. 17  is a sequence diagram illustrating a case in which an RF signal is lost and is then restored; 
         FIG. 18  is a flowchart illustrating a flow of release processing; 
         FIG. 19  is diagram illustrating state transition in routing; 
         FIG. 20  is a sequence diagram illustrating use case 1; 
         FIG. 21  is a sequence diagram illustrating use case 2; 
         FIG. 22  is a sequence diagram illustrating use case 3; 
         FIG. 23  is a diagram illustrating candidate transition in an extended version of the P2P-main rotation system including the skip function; and 
         FIG. 24  is a diagram illustrating an exemplary configuration of a computer. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present technology will be described below with reference to the accompanying drawings. 
     [Exemplary Configuration of NFC Device] 
       FIG. 3  illustrates an exemplary configuration of an NFC device. 
     An NFC device  11  is configured as, for example, a mobile phone, an IC (integrated circuit) card, a mobile information terminal, or a personal computer. For example, using a carrier with a frequency of 13.56 MHz in an ISM (Industry Science Medical) band, the NFC device  11  performs a near-field communication with an external device, such as an NFC reader  12 , over a distance of several tens of centimeters or less (including a case in which they are in contact with each other). 
     The NFC device  11  includes a CLF  31 , an ESE  32 , a DH  33 , and a UICC  34 . The CLF  31  is coupled with the ESE  32 , the DH  33 , and the UICC  34 , which serve as targets, through corresponding lines to allow communication with each other. 
     The CLF (contactless front end)  31  is coupled to an antenna, provided in the NEC device  11 , to perform a near-field communication with the NFC reader  12 . In response to a command transmitted from the NFC reader  12 , the CLF  31  selects one of the targets which is desired by the NFC reader  12  and performs control so as to allow communication with the NFC reader  12 . 
     The CLF  31  has therein a memory  31 A in which various types of data are stored as appropriate. 
     The ESE (embedded secure element)  32  is a secure element that achieves a security function in NFC applications for electronic payment, electronic tickets, entry control, and so on. 
     The DH (device host)  33  controls the operations of the individual elements in the NFC device  11 . The DH  33  executes a P2P (peer-to-peer) application  41 . The DH  33  can execute one or multiple P2P applications  41 . 
     The UICC (universal integrated circuit card)  34  is implemented by, for example, a SIM (subscriber identity module) card. The UICC  34  executes an NFC application to realize, for example, an electronic payment function. 
     Thus, the ESE  32 , the UICC  34 , and the P2P application  41  each perform predetermined processing and serve a target with which the NFC reader  12  is to communicate. In other words, the targets include devices, such as the ESE  32  and the UICC  34 , and applications, such as the P2P application  41 . 
     The NEC device  11  is configured as described above. 
     [Detailed Exemplary Configuration of CLF] 
       FIG. 4  illustrates a detailed exemplary configuration of the CLF  31  illustrated in  FIG. 3 . 
     The CLF  31  includes a candidate selecting section  101 , a confirming section  102 , a releasing section  103 , and a wireless-communication controlling section  104 . 
     In accordance with a predetermined rule, the candidate selection section  101  performs candidate selection processing for selecting a candidate of a target with which the NFC reader  12  is to communicate (the candidate may hereinafter be referred to as a “target candidate”). As a result of the candidate selection processing, one or multiple targets are selected as one or more target candidates. 
     In accordance with a predetermined rule, the confirming section  102  performs confirmation processing for confirming the target selected as a target candidate by the candidate selection processing. As a result of the confirmation processing, the target with which the NFC reader  12  is to communicate is confirmed (this target is hereinafter referred to as a “confirmed target”) out of the target(s) selected as the target candidate(s). 
     In accordance with a predetermined rule, the releasing section  103  performs release processing for releasing the target confirmed by the confirmation processing. As a result of the release processing, the confirmed target is released from the communication target of the NFC reader  12 . 
     The wireless-communication controlling section  104  performs processing for controlling a near-field communication with the NFC reader  12 . 
     The CLF  31  is configured as described above. 
     [Routing Processing] 
     Next, routing processing executed by the CLF  31  will be described with reference to a flowchart illustrated in  FIG. 5 . 
     In step S 1 , the candidate selecting section  101  performs candidate selection processing. In the candidate selection processing, one or more targets are selected from multiple targets as one or more target candidates. 
     Details of the candidate selection processing are described below with reference to  FIGS. 6 to 11 . 
     In step S 2 , the confirming section  102  performs confirmation processing. In the confirmation processing, a confirmed target that serves as the communication target of the NFC reader  12  is confirmed out of the one or more targets selected as the target candidate(s). 
     Details of the confirmation processing are described below with reference to  FIGS. 12 to 15 . 
     In step S 3 , the releasing section  103  performs release processing. In the release processing, the confirmed target is released from the communication target of the NFC reader  12 . That is, the confirmed target once confirmed as the communication target of the NFC reader  12  remains as the communication target until the release processing is performed to release the confirmed target from the communication target. 
     Details of the release processing are described below with reference to  FIGS. 16 to 18 . Also, some standards do not define the release processing, and when such a standard is employed, the processing in step S 3  may be omitted. 
     The description of the routing processing has been described thus far. 
     According to the above-described routing processing, one or more target candidates are selected from multiple targets and the confirmed target that serves as the communication target of the NFC reader  12  is confirmed out of the selected one or more candidates. A communication is performed between the confirmed target, confirmed as the communication target, and the NFC reader  12  until the confirmed target is released. 
     [Candidate Selection Processing] 
     Next, candidate selection processing corresponding to step S 1  illustrated in  FIG. 5  will be described with reference to  FIGS. 6 to 11 . 
     Now, four systems, i.e., a fixed target system, a simple rotation system, a simple rotation system including a skip function, and a P2P-main rotation system including a skip function, will be described with respect to the candidate selection processing. 
     The fixed target system is a system in which a default target is selected unless another target is particularly selected by an application. 
     When the fixed target system is employed, there is an advantage in that the implementation is quite simple, but there is a disadvantage in that the correctness rate of the target-candidate selection is reduced. For example, when the target is fixed to the ESE  32 , applications, such as the P2P application  41  and the UICC  34 , are not operable unless a user performs pre-setting. 
     The simple rotation system is a system in which the target candidate is sequentially changed to select the target. That is, each time the CLF  31  is polled by the NFC reader  12 , the CLF  31  selects a different target candidate and transmits a response received from the selected target. 
     More specifically, as illustrated in  FIG. 6 , the ESE  32  is selected as a target candidate in response to a first polling operation and then rotation is performed each time a polling operation is performed, so that the UICC  34 , the P2P application  41 , and the ESE  32  are sequentially selected as target candidates. 
     When the simple rotation system is employed, there is an advantage in that the implementation is simple, but there is a disadvantage in that the correctness rate of the target-candidate selection does not increase, since there are cases in which a retry of polling is repeated in order to select a desired target. 
     The rotation system including the skip function is a system in which a function for skipping a target determined to be excluded and selecting a next target as a target candidate is further added to the above-described simple rotation system. That is, each time the CLF  31  is polled by the NFC reader  12 , the CLF  31  checks polling parameters of the polling to thereby determine a target to be excluded. Then, when one target is determined to be a target candidate to be excluded, the CLF  31  skips the target to be excluded and selects a next target as a target candidate. 
     More specifically, for example, when a polling parameter SC (system code) is not “FFFF” or when a polling parameter RC (request code) is “1”, the polling is not for the P2P application  41  and thus the CLF  31  switches the target candidate from the UICC  34  to the ESE  32 , as illustrated in  FIG. 7 . That is, while the next target candidate after the UICC  34  is supposed to be the P2P application  41  in the above-described simple rotation, the P2P application  41  is skipped and the target candidate is forcibly switched to the ESE  32 . 
     When the simple rotation system including the skip function is employed, not only can the implementation be realized with a simple scheme equivalent to that of the above-described simple rotation system, but the correctness rate of the target-candidate selection can also be improved by identifying a target to be excluded according to a predetermined rule and deselecting the identified target. 
     The P2P-main rotation system including the skip function is a system in which the above-described simple rotation including the skip function is performed with the P2P application  41  being the rotation center. 
     More specifically, as illustrated in  FIG. 8 , the rotation is performed, for example, in the order of the P2P application  41 , the ESE  32 , the P2P application  41 , the UICC  34 , and the P2P application  41 , with the P2P application  41  being the rotation center. One NFC reader operation standard defines operation specifications stating that the NFC reader  12  performs a polling operation twice and a P2P operation is allowed when a response to one of the two polling operations is received from the P2P application  41 . In order to support the operation specifications, the rotation in this example is adapted so that a response from the P2P application  41  is sent back once every two times. 
     With this arrangement, since the P2P application  41  among the P2P application  41 , the ESE  32 , and the UICC  34  is selected once every two times, it is ensured that the NFC reader  12  performs an operation on the P2P application  41 . For example, when the polling is not for the P2P application  41 , the P2P application  41  is skipped in the rotation and the target candidate is forcibly switched to the ESE  32  or the UICC  34 , as in the above-described rotation system including the skip function. 
     Although a case in which the P2P application  41  is selected as a target candidate once every two times has been described in the example of  FIG. 8 , any target other than the P2P application  41  may also be selected as a target candidate once every two times in accordance with an operational rule for the NFC reader  12 . That is, one of three or more targets may be selected as a target candidate once every two times, so as to ensure that the NFC reader  12  can select a desired target to quickly establish a communication. 
     When the P2P-main rotation system including the skip function is employed, not only can the implementation be realized with a simple scheme equivalent to that of the above-described simple rotation system, but the correctness rate of the target-candidate selection can also be improved. Since a predetermine target is selected with higher priority in accordance with an operational rule for the NFC reader  12 , it is also possible to achieve a match with the operation of the NFC reader  12 . 
     The CLF  31  can also send a polling command, received from the NFC reader  12 , to one target by unicasting or to multiple targets by broadcasting. 
     In the unicast, a polling command is sent to only one target currently selected as a target candidate. Thus, the unicast transmission achieves a simple implementation, but does not contribute to an improvement in the correctness rate of the target-candidate selection. 
     In the broadcast, on the other hand, a polling command is sent to multiple targets, regardless of whether the targets are selected as target candidates. 
     More specifically, for example, when the ESE  32  is a target candidate and the NFC reader  12  transmits a polling command designating the SC for the UICC  34 , the CLF  31  broadcasts a polling command to both of the ESE  32  and the UICC  34 , as illustrated in  FIG. 9 . As a result, since no response is received from the ESE  32  and a response is received from the UICC  34 , the CLF  31  can switch the target candidate from the ESE  32  to the UICC  34  to send a response back to the NFC reader  12 . That is, when the broadcast transmission is performed, the implementation is complicated compared to the unicast transmission but a significant improvement in the correctness rate of target-candidate selection can be expected. 
       FIG. 10  is a diagram illustrating target candidate transition when the broadcast transmission described above and illustrated in  FIG. 9  is incorporated into the P2P-main rotation system including the skip function described above and illustrated in  FIG. 8 . 
     As described above, in the P2P-main rotation system including the skip function, the rotation is performed, for example, in the order of the P2P application  41 , the ESE  32 , the P2P application  41 , the UICC  34 , and the P2P application  41 , with the P2P  41  application being the rotation center. In contrast, when the broadcast transmission is incorporated, the target candidate changes from the P2P application  41  to the ESE  32  or the UICC  34  in response to a response to the broadcast transmission. 
     For example, after the target candidate changes in the order of the P2P application  41 , the ESE  32 , and the P2P application  41 , the polling command is broadcast and, when no response is received from the UICC  34  and a response is received from the ESE  32 , the ESE  32 , not the UICC  34 , is selected as a target candidate. After the target candidate changes in the order of the P2P application  41 , the UICC  34 , and the P2P application  41 , a polling command is broadcast and, when a response is received from the UICC  34  and no response is received from the ESE  32 , the UICC  34 , not the ESE  32 , is selected as a target candidate and the target candidate is changed to the P2P application  41 . 
     That is, when the broadcast transmission is incorporated into the P2P-main rotation system including the skip function, the rotation is performed, for example, in the order of the P2P application  41 , the ESE  32 , the P2P application  41 , the ESE  32 , the P2P application  41 , the UICC  34 , the P2P application  41 , the UICC  34 , and the P2P application  41 , with the P2P application  41  being the rotation center. 
     Not only is the target-candidate selection performed so that one of three or more targets is selected once every two times, but also the broadcast transmission is performed as described above, thus making is possible to further improve the correctness rate of the target other than the target selected once every two times. This can ensure that the NFC reader  12  selects a desired target to establish a communication. 
     Next, a flow of candidate selection processing corresponding to step S 1  in  FIG. 5 , the candidate selection processing being executed by the candidate selecting section  101 , will be described with reference to a flowchart illustrated in  FIG. 11 . 
       FIG. 11  illustrates candidate selection processing using the P2P-main rotation system including the skip function, this candidate selection processing being the most efficient candidate selection processing. 
     In step S 21 , the candidate selecting section  101  performs initial setting. In the initial setting, for example, a variable i is set to 0 or 1, depending on whether or not the rotation is to be started at the P2P application  41 . 
     In step S 22 , the candidate selecting section  101  controls the wireless-communication controlling section  104  to determine whether or not a polling command is received from the NFC reader  12 . When it is determined in step S 22  that a polling command is received, the process proceeds to step S 23 . 
     In step S 23 , on the basis of polling parameters included in the polling command received from the NFC reader  12 , the candidate selecting section  101  determines whether or not the P2P application  41  is excluded from the target candidate. In this case, for example, when the polling parameter SC is “FFFF” or the polling parameter RC is “1”, the polling is not for the P2P application  41 , as described above. 
     Although an example in which the P2P application  41  is excluded from the target candidate has been described above, any target other than the P2P application  41  may be excluded in accordance with the polling parameters. 
     When it is determined in step S 23  that the P2P application  41  is excluded from the target candidate, the process proceeds to step S 24 . In step S 24 , the candidate selecting section  101  selects the target other than the P2P application  41  as a target candidate. In this case, for example, the ESE  32  or the UICC  34  is selected as a target candidate. 
     On the other hand, when it is determined in step S 23  that the P2P application  41  is a target of a target candidate, the process proceeds to step S 25 . In step S 25 , the candidate selecting section  101  determines whether or not the value of the variable i is an even number. 
     When it is determined in step S 25  that the value of the variable i is an even number, the process proceeds to step S 26 . In step S 26 , the candidate selecting section  101  selects the P2P application  41  as a target candidate. 
     On the other hand, when it is determined in step S 25  that the value of the variable i is an odd number, the process proceeds to step S 24 . In step S 24 , the candidate selecting section  101  selects the target other than the P2P application  41  as a target candidate. In this case, for example, the ESE  32  or the UICC  34  is selected as a target candidate. In this case, as described above with reference to  FIG. 9 , it is possible to improve the correctness rate of target-candidate selection by broadcasting a polling command to the ESE  32  and the UICC  34 . 
     Upon completion of step S 24  or S 26 , the process proceeds to step S 27 . In step S 27 , the candidate selecting section  101  increments the value of the variable i by 1. As a result, in next determination processing in step S 25 , the even number and the odd number are reversed and thus an opposite result is obtained in the determination. That is, when the P2P application  41  is selected as a target candidate most recently, the target other than the P2P application  41  is selected in the next selection. Conversely, when the target other than the P2P application  41  is selected most recently, the P2P application  41  is selected as a target candidate in the next selection. 
     After completion of the processing in step S 27 , the process proceeds to step S 28  in which the candidate selecting section  101  determines whether or not the selection of the target candidate is completed. 
     When it is determined in step S 28  that the selection of the target candidate is not completed, the process returns to step S 22  and the above-described processing is repeated. That is, the processing in step S 22  to S 28  is repeated until it is determined that the selection of the target candidate is completed (Yes in step S 28 ), so that the P2P application  41  is selected as a target candidate once every two times. However, for example, when the polling is not for the P2P application  41 , the ESE  32  or the UICC  34  is forcibly selected as a target candidate, as described above. 
     When it is determined in step S 28  that the selection of the target candidate is completed, the candidate selection processing illustrated in  FIG. 11  ends. 
     As described above, when the P2P-main rotation system including the skip function is employed to perform the candidate selection processing, not only can the implementation be realized with a simple scheme comparable to that of the above-described simple rotation system, but the correctness rate of the target-candidate selection can also be improved. 
     Since a predetermine target, such as the P2P application  41 , is selected with higher priority in accordance with an operational rule for the NFC reader  12 , it is possible to achieve a match with the operation of the NFC reader  12 . In addition, since a polling command is broadcast to multiple targets other than a predetermined target, the correctness rate of the target-candidate selection can be significantly improved. 
     [Confirmation Processing] 
     Next, confirmation processing corresponding to step S 2  illustrated in  FIG. 5  will be described with reference to  FIGS. 12 to 15 . 
     Two systems, i.e., an IDm comparison system and an ATR_REQ reception system, will now be described as exemplary systems for the confirmation processing. 
     The IDm comparison system is a system in which, when the NFC reader  12  performs a polling operation on the CLF  31  multiple times in the single-response system, the CLF  31  sends back a different polling response in response to each polling operation by using an IDm (a manufacture ID, which is unique ID of an IC chip), to thereby make a response in a pseudo manner. 
     More specifically, as illustrated in  FIG. 12 , the CLF  31  performs the candidate selection processing in response to a polling command from the NFC reader  12 . When receiving a response from the UICC  34 , the CLF  31  obtains the IDm of the UICC  34  and stores the IDm in the memory  31 A. As a result, the UICC  34  is kept as a target candidate. The CLF  31  then transmits a polling response including the IDm of the UICC  34  back to the NFC reader  12 . 
     Subsequently, when a different polling command is transmitted from the NFC reader  12 , the CLF  31  performs the candidate selection processing. When receiving a response from the ESE  32 , the CLF  31  obtains the IDm of the ESE  32  and stores the IDm in the memory  31 A. As a result, the ESE  32  is added as a candidate, so that the UICC  34  and the ESE  32  are selected as target candidates. The CLF  31  then transmits a polling response including the IDm of the ESE  32  back to the NFC reader  12 . 
     Thereafter, when a non-polling command, such as a request service, is transmitted from the NFC reader  12 , the CLF  31  compares the IDm included in the received command with each IDm stored in the memory  31 A and confirms, as a confirmed target that serves as the communication target, the target candidate having a matched IDm. For example, when the IDm of the ESE  32  is included in the request service from the NFC reader  12 , the CLF  31  confirms the ESE  32  as a confirmed target and transmits the request service to the ESE  32 . 
     When the IDm comparison processing is employed, the processing for obtaining and comparing the IDm and so on are added, but the correctness rate of the target can be improved with respect to the NFC reader  12  that transmits a polling command to the CLF  31  multiple times. However, before the target candidate is confirmed, any command that does not include an IDm is not receivable. 
     Next, a flow of the confirmation processing using the IDm comparison system, the confirmation processing being executed by the confirming section  102 , will be described with reference to a flowchart illustrated in  FIG. 13 . 
     In step S 41 , the confirming section  102  determines whether or not a target candidate is selected in the candidate selection processing. When it is determined in step S 41  that a target candidate is selected, the process proceeds to step S 42 . 
     In step S 42 , the confirming section  102  obtains the IDm of the selected target candidate. In step S 43 , the confirming section  102  stores the IDm in the memory  31 A. 
     Upon completion of the processing in step S 43 , the process proceeds to step S 44  in which the confirming section  102  controls the wireless-communication controlling section  104  to determine whether or not a non-polling command is received from the NFC reader  12 . 
     When it is determined in step S 44  that a non-polling command is not received, the process returns to step S 41  and the above-described processing is repeated. That is, the processing in steps S 41  to S 44  is repeated, and when a target candidate is selected, the IDm of the selected target is stored in the memory  31 A. 
     On the other hand, when it is determined in step S 44  that a non-polling command is received, the process proceeds to step S 45 . In step S 45 , the confirming section  102  compares the IDm included in the non-polling-command from the NFC reader  12  with each IDm stored in the memory  31 A. In step S 46 , the confirming section  102  determines whether or not the IDm included in the command matches any IDm stored in the memory  31 A. 
     When it is determined in step S 46  that the IDm included in the command matches any IDm stored in the memory  31 A, the process proceeds to step S 47 . In step S 47 , the confirming section  102  confirms, as a confirmed target, a target candidate whose IDm matches any IDm stored in the memory  31 A. For example, when the IDm of the ESE  32  is stored in the memory  31 A and is also included in the request service from the NFC reader  12 , the ESE  32  is determined as a confirmed target. 
     On the other hand, when it is determined in step S 46  that the IDm does not match, step S 47  is skipped. In this case, since no communication target is confirmed, the candidate selection processing is continued. Even when the communication with the NFC reader  12  continues, the CLF  31  does not make a response and stays in the same state, since no route has been established. Thereafter, when the communication between the NFC reader  12  and the CLF  31  is disconnected, the target candidate is reset and thus the processing is restarted from the polling by the NEC reader  12 . That is, after the communication with the NFC reader  12  is disconnected, the NFC reader  12  performs polling again. 
     When a confirmed target is confirmed (in step S 47 ) or when it is determined that the IDm does not match (No in step S 46 ), the confirmation processing in  FIG. 13  ends. 
     When the confirmation processing is performed using the IDm comparison system, the correctness rate of the target can be improved with respect to the NFC reader  12  that transmits a polling command to the CLF  31  multiple times. 
     The ATR_REQ reception system is a system in which, when a correct ATR_REQ (attribute request) is received in the multi-response system or the single-response system after a response indicating the P2P application  41  is sent back to the NFC reader  12 , an ATR_RES is sent back and a confirmed target is determined. 
     More specifically, as illustrated in  FIG. 14 , in response to a polling command from the NFC reader  12 , the CLF  31  performs the candidate selection processing and sends back a polling response of the P2P application  41 . As a result, the P2P application  41  is kept as a target candidate. 
     Subsequently, when a different polling command is transmitted from the NFC reader  12 , the CLF  31  performs the candidate selection processing. When receiving a response from the ESE  32 , the CLF  31  obtains the IDm of the ESE  32  and stores the IDm in the memory  31 A. As a result, the ESE  32  is added as a candidate, so that the P2P application  41  and the ESE  32  are selected as target candidates. The CLF  31  then transmits a polling response including the IDm of the ESE  32  back to the NFC reader  12 . 
     Thereafter, when an ATR_REQ is transmitted from the NFC reader  12 , the CLF  31  confirms the P2P application  41  as a confirmed target and sends an ATR_RES back to the NFC reader  12 . 
     In response to the ATR_REQ from the NFC reader  12 , the CLF  31  confirms the P2P application  41  as a confirmed target. In this case, the IDm comparison for the target confirmation is not performed and a target is confirmed upon reception of a correct ATR_REQ. 
     Next, a flow of the confirmation processing using the ATR_REQ reception system, the confirmation processing being executed by the confirming section  102 , will be described with reference to a flowchart illustrated in  FIG. 15 . 
     In steps S 61  to S 63 , the confirming section  102  obtains the IDm of the selected target candidate and stores the IDm in the memory  31 A, as in steps S 41  to S 43  illustrated in  FIG. 13 . 
     In step S 64 , the confirming section  102  controls the wireless-communication controlling section  104  to determine whether or not an ATR_REQ is received from the NFC reader  12 . 
     When it is determined in step S 64  that no ATR_REQ is received, the process returns to step S 61  and the above-described processing is repeated. That is, the processing in steps S 61  to S 64  is repeated, and when a target candidate is selected, the IDm of the selected target is stored in the memory  31 A. 
     On the other hand, when it is determined in step S 64  that an ATR_REQ is received, the process proceeds to step S 65 . In step S 65 , the confirming section  102  confirms the P2P application  41  as a confirmed target. 
     When the P2P application  41  is confirmed as a communication target, the confirmation processing in  FIG. 15  ends. 
     As described above, when the confirmation processing is performed using the ATR_REQ reception system, the correctness rate of the target can be improved with respect to the NEC reader  12  that transmits a polling command to the CLF  31  multiple times. 
     For example, when a FALP (FeliCa Ad-hoc Link Protocol) is implemented on the DH  33 , the confirming section  102  monitors a propose ad-hoc command transmitted from a FALP-specific NFC reader  12  and can forcibly confirm a FALP target as a confirmed target upon receiving the propose ad-hoc command. That is, the confirming section  102  monitors a command transmitted from the NFC reader  12 , and upon receiving the predetermined command, the confirming section  102  forcibly confirms, as a confirmed target, a predetermined target corresponding to the received command. 
     [Release Processing] 
     Next, release processing will be described with reference to  FIGS. 16 to 18 . 
     Five systems, i.e., a forced-termination system, an RF-loss release system, a polling-reception release system, an RLS_REQ-reception release system, and a DSL_REQ-reception release system, will now be described as exemplary systems for the release processing. 
     The forced-termination system is a system in which, when an application executed by the DH  33  is terminated by a user operation, the DH  33  forcibly releases the confirmed target. 
     The RF-loss release system is a system in which, when a near-field communication between the NFC reader  12  and the CLF  31  is disconnected and an RF (radio frequency) signal is lost, the confirmed target is released. 
     In the RF-loss release system, when on/off chattering of an RE signal occurs, unexpected loss of the RF signal may cause releasing of the communication target, resulting in user inconvenience. More specifically, when a carrier is detected at the end of polling during a near-field communication between the NEC reader  12  and the CLF  31 , as illustrated in  FIG. 16 , an RF signal is turned on for a moment and then the communication partner enters a listen mode and the RF signal is turned off. The detection of the turn-off of the RF signal and the release of the confirmed target at this point is not preferable in terms of the processing. 
     As illustrated in  FIG. 17 , if an RF signal is lost during a near-field communication between the NFC reader  12  and the CLF  31  and the release processing is performed, when the near-field communication between the NFC reader  12  and the CLF  31  is restored later on, with which target the communication is to be performed is unclear for the CLF  31  since the confirmed target has been released. 
     Accordingly, in the polling-reception release system, in order to enable the reconnection after the loss of the RF signal, the confirmed target is not released at the time of the loss of the RF signal, and instead, after the loss of the RF signal, the confirmed target is released at the time of reception of a next polling command from the NFC reader  12 . When the command received after the loss of the RF signal is not a polling command, processing for a route before the loss of the RF signal, i.e., processing for the same target as the target before the loss of the RF signal is maintained. 
     In the polling-reception release system, it is possible to enable the reconnection after the loss of the RF signal. When the polling-reception release system is employed, there is an advantage in that a simple configuration can be provided since no special circuit is provided for the implementation. 
     The RLS_REQ-reception release system is a system using an RLS_REQ, which is a command that the NFC reader  12  transmits to completely stop a near-field communication with the CLF  31 . Thus, in this system, upon reception of the RLS_REQ, the confirmed target is released. In this case, when the P2P application  41  is confirmed as the confirmed target and the RLS_REQ is received, the CLF  31  releases the P2P application  41  from the confirmed target. 
     The DSL_REQ-reception release system is a system using a DSL_REQ, which is a command that the NFC reader  12  transmits to deselect (i.e., deactivate) the target. In this system, upon reception of the DSL_REQ, the confirmed target is released. In this case, when the P2P application  41  is confirmed as the confirmed target and the DSL_REQ is received, the CLF  31  releases the P2P application  41  from the confirmed target. 
     Any target release condition other than the above-described five systems may also be used to release the target. One example of such a target release condition is reception of a command, such as a device reset command for resetting the NFC device  11 , defined by various standards. 
     Next, a flow of release processing executed by the releasing section  103  will be described with reference to a flowchart illustrated in  FIG. 18 . 
     In step S 81 , the releasing section  103  determines whether or not a target release condition that is a predetermined condition for releasing a confirmed target occurs. 
     Examples of the target release condition include reception of a polling command after loss of an RF signal in the polling-reception release system, reception of the RLS_REQ in the RLS_REQ-reception release system, and reception of the DSL_REQ in the DSL_REQ-reception release system. When such a release condition occurs, the process proceeds to step S 82 . 
     In step S 82 , the releasing section  103  releases the confirmed target confirmed as the communication target, such as the P2P application  41 . 
     When the confirmed target is released, the release processing illustrated in  FIG. 18  ends. 
     As described above, when the release processing is performed using the polling-reception release system, the RLS_REQ-reception release system, or the DSL_REQ-reception release system, for example, it is possible to enable the reconnection after loss of an RF signal. 
     [Routing State Transition] 
       FIG. 19  illustrates routing state transition. 
     In  FIG. 19 , an “unselected” state represents a state in which no target candidate is selected. A “selected” state represents a state in which a target candidate is selected after a polling command is received from the NFC reader  12 . In the “selected” state, when a communication is disconnected and an RF signal is lost or when a predetermined command is received, the state changes to the “unselected” state. 
     A “P2P confirmed” state represents a state in which the ATR_REQ is received from the NFC reader  12  in the “selected state” and the P2P application  41  is confirmed as a confirmed target. In the “P2P confirmed” state, when an RF signal is lost or when the command RLS_REQ or DSL_REQ is received from the NFC reader  12  or when a DEACTIVATE_CMD, which is a command for requesting a forced-termination of wireless communication processing, is received from the DH  33  for controlling the CLF  31 , the state changes to the “unselected” state. 
     A “confirmed” state represents a state in which a polling command and a command other than the ATR_REQ are received from the NFC reader  12  in the “selected” state and a target other than the P2P application  41  is confirmed as a confirmed target. When a predetermined command is received in the “confirmed state”, the state changes to the “unselected” state. When the communication is disconnected and an RF signal is lost in the “confirmed” state, the state changes to a “retry standby” state. 
     The “retry standby” state represents a state in which a retry is waited for since an RF signal is lost in the “confirmed” state. For example, when an NFC-F command, other than a polling command, is received after restoration of an RF signal in the “retry standby” state, the state changes to the “confirmed” state. When a polling command is received in the “retry standby” state, the state changes to the “selected” state. 
     As described above, in the routing processing, the state changes to one of the “unselected” state, the “selected” state, the “P2P confirmed” state, the “confirmed” state, and the “retry standby” state, so that one or more target candidates are selected from the multiple targets and a confirmed target is then confirmed. A communication is performed between the confirmed target and the NFC reader  12  until the confirmed target is released. 
     [Examples of Use Cases] 
     Use cases 1 to 3 will be described next as specific examples of the above-described routing processing.  FIG. 20  is a sequence diagram illustrating use case 1. 
     Use case 1 is one example of a case in which the NFC reader  12  is a P2P-application-specific reader and the rotation for the target-candidate selection is started at the P2P application  41 . 
     As illustrated in  FIG. 20 , when a polling command is transmitted from the P2P-application-specific NFC reader  12 , the candidate selecting section  101  in the CLF  31  selects the P2P application  41  as a target candidate and transmits a polling response thereof back to the NFC reader  12 . 
     Next, when a polling command is transmitted from the NFC reader  12 , the candidate selecting section  101  broadcasts the polling command. The broadcast polling command is received by the ESE  32  and the UICC  34  and responses thereof are sent back to the CLF  31 . 
     In response to the responses from the ESE  32  and the UICC  34 , the candidate selecting section  101  selects the ESE  32  as a target candidate and transmits a polling response thereof back to the NFC reader  12 . As a result, the P2P application  41  and the ESE  32  are selected as target candidates. 
     Subsequently, when a command ATR_REQ is transmitted from the NEC reader  12 , the confirming section  102  in the CLF  31  confirms the P2P application  41  as a confirmed target and sends back a command ATR_RES. As a result, the P2P-application-specific NFC reader  12  and the P2P application  41  perform predetermined P2P transaction processing via the CLF  31 . 
     Subsequently, when the P2P transaction processing is completed and a command DSL_REQ is transmitted from the NFC reader  12 , the releasing section  103  in the CLF  31  releases the P2P application  41  from the confirmed target and sends back a command DSL RES. Thereafter, when a polling command is transmitted from the NEC reader  12  again, the above-described processing is repeated and the P2P application  41  is selected as a target candidate. 
     As described above, in use case 1, at the stage when the P2P application  41  and the ESE  32  are selected as target candidates in response to the polling performed by the NFC reader  12 , the P2P application  41  is confirmed as a confirmed target and the P2P transaction processing is performed. When the P2P application  41  is released from the confirmed target after the P2P transaction processing is completed, the polling by the NFC reader  12  is resumed and the P2P application  41  and the UICC  34  are selected as target candidates. 
     That is, in use case 1, the P2P-main rotation system including the skip function is used for the target-candidate selection and the targets are selected, for example, in the order of the P2P application  41 , the ESE  32 , the P2P application  41 , and the UICC  34 , so that the P2P application  41  is selected once every two times. 
       FIG. 21  is a sequence diagram illustrating use case 2. 
     Use case 2 is one example of a case in which the NFC reader  12  is a P2P-application-specific reader and the rotation for the target-candidate selection is started at the ESE  32 . 
     As illustrated in  FIG. 21 , when a polling command is transmitted from the P2P-application-specific NFC reader  12 , the candidate selecting section  101  in the CLF  31  broadcasts the polling command. The broadcast polling command is received by the ESE  32  and the UICC  34  and responses thereof are sent back to the CLF  31 . 
     In response to the responses from the ESE  32  and the UICC  34 , the candidate selecting section  101  selects the ESE  32  as a target candidate and transmits a polling response thereof back to the NFC reader  12 . 
     Next, when a polling command is transmitted from the NFC reader  12 , the candidate selecting section  101  selects the P2P application  41  as a target candidate and transmits a polling response thereof back to the NFC reader  12 . As a result, the ESE  32  and the P2P application  41  are selected as target candidates. 
     Subsequently, when a command ATR_REQ is transmitted from the NFC reader  12 , the P2P application  41  is confirmed as a confirmed target. Thus, predetermined P2P transaction processing is performed between the P2P-application-specific NFC reader  12  and the P2P application  41 . Upon completion of the P2P transaction processing, a command DSL_REQ is transmitted from the NFC reader  12  and the P2P application  41  is released from the confirmed target. 
     Next, when a polling command is transmitted from the NFC reader  12 , the candidate selecting section  101  broadcasts the polling command and the ESE  32  and the UICC  34  receives the polling command. The UICC  34  is then selected as a target candidate, and a polling response thereof is transmitted back to the NFC reader  12 . Thereafter, the P2P application  41  is added as a target candidate and the above-described processing is repeated. 
     As described above, in use case 2, at the stage when the ESE  32  and the P2P application  41  are selected as target candidates in response to the polling performed by the NFC reader  12 , the P2P application  41  is confirmed as a confirmed target and the P2P transaction processing is performed. When the P2P application  41  is released from the confirmed target after the P2P transaction processing is completed, the polling by the NFC reader  12  is resumed and the UICC  34  and the P2P application  41  are selected as target candidates. 
     That is, in use case 2, the P2P-main rotation system including the skip function is used for the target-candidate selection and the targets are selected, for example, in the order of the ESE  32 , the P2P application  41 , the UICC  34 , and the P2P application  41 , so that the P2P application  41  is selected once every two times. 
       FIG. 22  is a sequence diagram illustrating use case 3. 
     Use case 3 is an example of a case in which the NFC reader  12  is an ESE-specific reader and the rotation for the target-candidate selection is started at the P2P application  41 . 
     As illustrated in  FIG. 22 , when a polling command is transmitted from the ESE-specific NFC reader  12 , the candidate selecting section  101  checks the polling parameters in the polling command. Upon determining that the polling is not for the P2P application  41 , the candidate selecting section  101  switches the target candidate from the P2P application  41  to the ESE  32 . The candidate selecting section  101  in the CLF  31  then broadcasts the polling command. 
     The broadcast polling command is received by the ESE  32  and the UICC  34 . At this point, when a response is received from the ESE  32  and no response is received from the UICC  34 , the candidate selecting section  101  selects the ESE as a target candidate and transmits a polling response thereof back to the NFC reader  12 . In this case, the IDm of the ESE  32  selected as a target candidate is stored in the memory  31 A. 
     Subsequently, when a non-polling command, such as a request service, is transmitted from the NFC reader  12 , the confirming section  102  compares the IDm included in the received command with each IDm stored in the memory  31 A. The confirming section  102  confirms the ESE  32  having a matched IDm as a confirmed target and transmits the request service to the ESE  32 . When the ESE  32  sends back a response to the request service, the response is then transmitted to the NFC reader  12 . As a result, the ESE-specific NFC reader  12  and the ESE  32  perform predetermined ESE transaction processing via the CLF  31 . 
     Thereafter, when an RF signal is lost, the release processing is not performed and the confirmed target is maintained until a predetermined target release condition is satisfied. 
     When a polling command is transmitted from the NFC reader  12  again, the ESE  32  is released from the confirmed target. The candidate selecting section  101  also checks the polling parameters in the polling command. Upon determining that the polling is not for the P2P application  41 , the candidate selecting section  101  switches the target candidate from the P2P application  41  to the UICC  34 . When the candidate selecting section  101  broadcasts the polling command, the polling command is received by the ESE  32  and the UICC  34  and a response is sent back from only the ESE  32 . Thus, the candidate selecting section  101  selects the ESE  32  as a target candidate and transmits a polling response thereof back to the NFC reader  12 . 
     Subsequently, when a request service is transmitted from the NFC reader  12 , the confirming section  102  performs IDm comparison to confirm the ESE  32  having a matched IDm as a confirmed target and sends the request service to the ESE  32 . A response from the ESE  32  is also transmitted to the NFC reader  12 . As a result, the ESE-specific NFC reader  12  and the ESE  32  perform predetermined ESE transaction processing via the CLF  31 . 
     As described above, in use case 3, the P2P-main rotation system including the skip function is used for the target-candidate selection. That is, polling parameters are checked at the stage when a target candidate is selected in response to the polling performed by the NFC reader  12 , and the ESE  32  or the UICC  34  is selected as a target candidate since the polling condition does not correspond to the P2P application  41 . Thereafter, a polling command is broadcast, the ESE  32  that sends back a response is confirmed as a confirmed target, and then ESE transaction processing is performed. 
     When an RF signal is lost, the confirmed target is also maintained until a predetermined target release condition is satisfied. Thus, the processing can be maintained when a near-field communication between the NFC reader  12  and the CLF  31  is restored. 
     While the ESE-specific reader has been described in the example of  FIG. 22 , an operation for a UICC-specific reader is basically the same as the operation for the ESE-specific reader and thus a description of the operation of the UICC-specific reader is omitted herein. 
     When the P2P-main rotation system including the skip function is employed as described above, one of three or more targets can be selected as a target candidate once every two times. This can ensure that the NFC reader  12  selects a desired target to quickly establish a communication. 
     In addition, the use of the single-response system can ensure that the NFC reader  12  selects a desired target to quickly establish a communication, without implementation of a special circuit in the CLF (front end)  31 . 
     [Extension of P2P-main rotation System Including Skip Function] 
       FIG. 23  is a diagram illustrating target candidate transition for an extended version of the P2P-main rotation system including the skip function. 
     In the extended version of the P2P-main rotation system including the skip function, the rotation includes a T3T (type 3 tag) emulation implemented on the DH  33 , in addition to the ESE  32 , the UICC  34 , and the P2P application  41  described above with reference to  FIG. 8 . In this rotation system, the basic rotation is also the same as the rotation illustrated in  FIG. 8 , so that the P2P application  41  among the P2P application  41 , the ESE  32 , the UICC  34 , and the T3T, which serve as targets, is selected once every two times. 
     More specifically, for example, as illustrated in  FIG. 23 , the rotation is performed in the order of the P2P application  41 , the ESE  32 , the P2P application  41 , the UICC  34 , and the P2P application  41 , the T3T, and the P2P application  41 , with the P2P application  41  being the rotation center. For example, when the polling is not for the P2P application  41 , the P2P application  41  is skipped in the rotation and the target candidate is forcibly switched to the ESE  32 , the UICC  34 , or the T3T, as in the case described above. 
     Thus, even when the number of targets other than the P2P application  41  increases, the rotation is performed with the P2P application  41  being the rotation center and the P2P application  41  is selected once every two times. This ensures that the NFC reader  12  performs an operation on the P2P application  41 . 
     [Computer to which Present Technology is Applied] 
     The above-described series of processing may be realized by hardware or software. When the series of processing is realized by software, a program provided by the software may be installed to a general-purpose computer. 
       FIG. 24  illustrates an exemplary configuration of one example of a computer to which a program for executing the above-described series of processing is installed. 
     The program may also be pre-recorded to a storage section  208 , such as a hard disk, and/or a ROM (read only memory)  202 , which are built into a computer  200 . 
     Alternatively, the program may be temporarily or permanently stored (recorded) on a removable media  211 , such as a flexible disk, a CD-ROM (compact disc-read only memory), an MO (magneto optical) disk, a DVD (digital versatile disc), a magnetic disk, or a semiconductor memory. Such a removable media  211  may be supplied as the so-called “packaged software”. 
     Not only is the program installed from the removable media  211  as described above to the computer  200 , but also the program may be installed by transferring the program from a download side to the computer  200  through wireless communication via an artificial satellite for digital satellite broadcast or through wired communication over a network, such as a LAN (local area network) or the Internet. In this case, the computer  200  uses a communication section  209  to receive the program transferred in such a manner and can install the program in the storage section  208 . 
     The computer  200  has a CPU (central processing unit)  201  therein. An input/output interface  205  is connected to the CPU  201  through a bus  204 . The computer  200  is provided with an input section  206  including a keyboard, a mouse, a microphone, and so on. For example, when a user operates the input section  206  to input an instruction via the input/output interface  205 , the CPU  201  executes a program stored in the ROM  202 . Alternatively, the CPU  201  loads a program in a RAM (random access memory)  203  and executes the loaded program. Examples of the program include a program pre-stored in the storage section  208 ; a program transferred through a satellite or network, received by the communication section  209 , and installed in the storage section  208 ; and a program read from the removable media  211 , inserted into a drive  210 , and installed in the storage section  208 . With this configuration, the CPU  201  performs the processing according to the flowcharts described above and the processing realized by the configurations described above and illustrated in the block diagrams. For example, the CPU  201  causes a result of the processing to be output from an output section  207 , to be transmitted from the communication section  209 , or to be recorded to the storage section  208  via the input/output interface  205 , as appropriate. The output section  207  includes an LCD (liquid crystal display), a speaker, and so on. 
     Herein, processing steps describing the program for causing the computer  200  to perform various types of processing may or may not be time-sequentially performed according to the sequence illustrated in the flowcharts, and also include processing that is executed in parallel or individually (e.g., parallel processing or object-based processing). 
     The program may also be processed by a single computer or may be processed by multiple computers in a distributed manner. In addition, the program may be transferred to a remote computer for execution. 
     Embodiments of the present technology are not limited to the above-described embodiment and various changes and modifications can be made thereto without departing from the spirit and scope of the present technology. 
     In addition, the present technology may be configured as described below. 
     (1) A communication device, including: 
     targets that are each configured to execute predetermined processing; and 
     a front end that is configured to select, from the targets, a confirmed target with which an external device is to communicate and that is configured to perform near-field communication with the external device, 
     wherein the front end is configured to select, during transmission of a command for selecting at least one candidate of the confirmed target, a predetermined one of the targets once every two times as a transmission destination of the command. 
     (2) The communication device according to (1), wherein the front end is configured to broadcast, upon receiving a polling command from the external device, the polling command to the targets other than the predetermined target. 
     (3) The communication device according to (1) or (2), wherein the predetermined target is a P2P (peer-to-peer) application. 
     (4) The communication device according to (3), wherein, of the targets, the targets other than the predetermined target include at least one of a secure element and a UICC (universal integrated circuit card). 
     (5) The communication device according to one of (1) to (4), wherein the front end is configured to confirm the target with which the external device is to communicate, out of the at least one target selected as the at least one confirmed-target candidate, as the confirmed target. 
     (6) The communication device according to (5), wherein the front end is configured to confirm the confirmed-target candidate as the confirmed target when an identifier of the target selected as the confirmed-target candidate, the identifier being obtained from the target, and an identifier included in a command transmitted by the external device match each other. 
     (7) The communication device according (5), wherein the front end is configured to confirm the confirmed-target candidate as the confirmed target when a command for confirming, as the confirmed target, the target selected as the confirmed-target candidate is received from the external device. 
     (8) The communication device according to one of (5) to (7), wherein, the front end is configured to release, on the basis of a predetermined target release condition, the confirmed target from the target with which the external device is to communicate. 
     (9) The communication device according to (8), wherein, the front end is configured to release, after the near-field communication with the external device is disconnected, the confirmed target upon receiving a polling command from the external device. 
     (10) The communication device according to (8), wherein the front end is configured to release the confirmed target when a command for terminating a communication between the external device and the confirmed target is received from the external device. 
     (11) A control method for a communication device including targets that each execute predetermined processing and a front end that selects, from the targets, a confirmed target with which an external device is to communicate and that performs near-field communication with the external device, the control method including: 
     causing the front end to select, during transmission of a command for selecting at least one candidate of the confirmed target, a predetermined one of the targets once every two times as a transmission destination of the command. 
     (12) A program for controlling a communication device including targets that each execute predetermined processing and a front end that selects, from the targets, a confirmed target with which an external device is to communicate and that performs near-field communication with the external device, the program causing a computer for the communication device to execute processing including: 
     selecting, during transmission of a command for selecting at least one candidate of the confirmed target, a predetermined one of the targets once every two times as a transmission destination of the command. 
     The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2011-176492 filed in the Japan Patent Office on Aug. 12, 2011, the entire contents of which are hereby incorporated by reference. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.