Terminal apparatus carrying out communications after authentication, a communication system, and a communication method

An acquiring unit acquires the positional information. A first request unit requests an authentication station to perform authentication by using the positional information acquired by the acquiring unit. When the authentication station grants authentication for a request from the first request unit, a communication processing unit carries out communications using a first radio communication system. When authentication required for carrying out the communications using the first radio communication system is not performed in the communication processing unit, a second request unit requests another terminal apparatus to perform authentication by using a second radio communication system, whose transmission distance is shorter than the first radio communication system.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2014-154717, filed on Jul. 30, 2014, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a communication technology, and it particularly relates to a terminal apparatus carrying out communications after authentication, a communication system, and a communication method.

2. Description of the Related Art

User authentication is carried out for the purpose of ensuring the security of a network. For example, when it is verified that a user is located within a predetermined distance, based on user authentication information for each user and the GPS (Global Positioning System) information indicating the location of a user, this user is authenticated (see Reference (1) in the following Related Art List, for instance).

RELATED ART LIST

(1) Japanese Unexamined Patent Application Publication 2012-123487.

The security improves when only terminal apparatuses located within a predetermined rage are authenticated. However, every terminal apparatus has to move within the predetermined range in order to be authenticated and this is inconvenient for users.

SUMMARY

In order to resolve the foregoing problems, a terminal apparatus according to one embodiment includes: an acquiring unit that acquires positional information; a first request unit that requests an authentication station to perform authentication by using the positional information acquired by the acquiring unit; a communication unit that carries out communication using a first radio communication system, when a request from the first request unit has been authenticated by the authentication station; and a second request unit that requests another terminal apparatus to perform authentication by using a second radio communication system, whose transmission distance is shorter than the first radio communication system, when authentication required for carrying out the communication using the first radio communication system is not performed in the communication unit.

Another embodiment relates to a communication system. The communication system includes: a first terminal apparatus that requests authentication using acquired positional information; an authentication station that permits the first terminal apparatus to carry out communication using a first radio communication system, in response to a request sent from the first terminal apparatus, when the first terminal apparatus has been authenticated based on the positional information; and a second terminal apparatus for which the communication using the first radio communication system is not authenticated. The second terminal apparatus requests the first terminal apparatus to perform authentication by using a second radio communication system, whose transmission distance is shorter than the first radio communication system.

Still another embodiment relates to a communication method. The communication method includes: acquiring positional information; requesting an authentication station to perform authentication by using the positional information; carrying out communication using a first radio communication system, when an authentication request has been authenticated by the authentication station; and requesting another terminal apparatus to perform authentication by using a second radio communication system, whose transmission distance is shorter than the first radio communication system, when authentication required for carrying out the communication using the first radio communication system is not performed.

Still another embodiment relates also to a communication method. The communication method includes: requesting, by a first terminal apparatus, authentication by using positional information acquired; permitting, by an authentication station, the first terminal apparatus to carry out communication using a first radio communication system, in response to a request sent from the first terminal apparatus, when the first terminal apparatus has been authenticated based on the positional information; and requesting, by a second terminal apparatus, the first terminal apparatus to perform authentication by using a second radio communication system, whose transmission distance is shorter than the first radio communication system, when authentication required for carrying out the communication using the first radio communication system is not performed.

Optional combinations of the aforementioned constituting elements, and implementations of the invention in the form of methods, apparatuses, systems, recording media, computer programs and so forth may also be practiced as additional modes.

DETAILED DESCRIPTION

The invention will now be described by reference to the preferred embodiments. This does not intend to limit the scope, but to exemplify the invention.

First Exemplary Embodiment

The present invention will be outlined before it is explained in detail. A first exemplary embodiment relates to a communication system including a plurality of base station apparatuses connected to a network, a plurality of terminal apparatuses connected to each of the plurality of base station apparatuses, and an authentication station connected to the network. An example of the communication system is a wireless system for business or commercial use (hereinafter referred to as “business-use wireless system” also). In the business-use wireless system, a group is formed by a plurality of terminal apparatuses. A base station apparatus allots an uplink channel and an uplink channel to a group. Under such circumstances, one terminal apparatus (hereinafter referred to as a “transmitter”) in the group transmits a signal through the uplink channel, and another terminal apparatus (hereinafter referred to as a “receiver”) in the group receives the signal through the downlink. A base station apparatus, which differs from the base station apparatus to which the transmitter is connected, is also allotted a downlink channel for this group. Thus a receiver connected to this different base station apparatus can also receive the signal. Further, the similar processing is carried out to another group but no communication is carried out between different groups.

In order to ensure the security of the communication, authentication for terminal apparatuses used is required. For example, a terminal apparatus acquires its own positional information before the communication is started, and transmits an authentication request while the positional information is being attached to the authentication request. If the authentication request reaches the authentication station by way of a base station and then the positional information lies within a predetermined area, the authentication station authenticates this terminal apparatus (namely, grants authentication for this terminal apparatus). Once the terminal apparatus is authenticated, the terminal apparatus participates in a group and carries out communications. The authentication is granted only when the terminal apparatus is located within the area. Thus a terminal apparatus located in an unexpected position fails to be authenticated, thereby improving the security. If, on the other hand, the terminal apparatus is located in a position where the positional information cannot be acquired, authentication cannot be granted. In this case, the communication cannot be carried out, thereby reducing user convenience.

In order to cope with this, the terminal apparatuses according to the present embodiment are compatible with a short-range communication system that is different from the business-use communication system. In contrast to the short-range communication system, the business-use wireless system is said to be a long-distance communication system. A terminal apparatus, which has failed to acquire the positional information, broadcasts an authentication request using the short-range communication system, instead of transmitting the authentication request to the authentication station. If another terminal apparatus, which has received this authentication request, has already been authenticated by the authentication station, the other terminal apparatus acts on behalf of the authentication station (namely, the other terminal apparatus is used in substitution for the authentication station) and grants the authentication request. As a result, the terminal apparatus, which had failed to acquire the positional information, also participates in the group and communicates with other terminal apparatuses and so forth in the group.

FIG. 1shows a structure of a communication system100according to a first exemplary embodiment. The communication system100includes a first terminal apparatus10aand a second terminal apparatus10b, which are generically referred to as “terminal apparatus10” or “terminal apparatuses10”, a base station apparatus12, a network14, and an authentication station16. The first terminal apparatus10aincludes a first antenna20afor use with long-distance communications (hereinafter referred to as a “first long-distance communication antenna20a”), a first antenna22afor use with short-range communications (hereinafter referred to as a “first short-range communication antenna22a”), and a first antenna24afor use with GPS (global positioning system) (hereinafter referred to as a “first GPS antenna24a”). Similarly, the second terminal apparatus10bincludes a second long-distance communication antenna20b, a second short-range communication antenna22b, and a second GPS antenna24b. Here, the first long-distance communication antenna20aand the second long-distance communication antenna20bare generically referred to as “long-distance communication antenna20” or “long-distance communication antennas20”. Also, the first short-range communication antenna22aand the second short-range communication antenna22bare generically referred to as “short-range communication antenna22” or “short-range communication antennas22”. Also, the first GPS antenna24aand the second GPS antenna24bare generically referred to as “GPS antenna24” or “GPS antennas24”. An area18is formed around the base station apparatus12.

The base station apparatus12can set a plurality of channels, and allocates each channel to a group. Known art may be used for channels. Here, for example, a plurality of channels are multiplexed by TDMA (Time-Division Multiple Access)/FDD (Frequency-Division Duplexing). For example, the base station apparatus12can set channel1(Ch1) and channel3(Ch3) to channel6(Ch6) as downlink channels and can set channel2(Ch2) and channel7(Ch7) to channel10(Ch10) as uplink channels. Here, Ch1is used for a downlink control channel, and Ch2is used for an uplink control channel. Also, Ch3and Ch7are allocated to the same group as a single combination. The same is applied to Ch4to Ch6as well as Ch8to Ch10.

The base station apparatus12is connected to not-shown other terminal apparatuses10via the network14. Although other base station apparatuses12set the channels similarly, the number of channels that can be set may differ for each base station apparatus12or those channels may be commonly used. Assume herein that Ch1and Ch2are commonly used for all base station apparatuses12as the downlink control channel and the uplink control channel, respectively. Also, a plurality of frequency channels may be used for each of the downlink channel and the uplink channel.

A terminal apparatus10is a radio terminal that can communicate with other terminal apparatuses (not shown) via the base station apparatus12. Assume herein that the communications mean voice communications (telephone calls) between terminal apparatuses10. Note that data communications may be carried out. When the terminal apparatus10moves toward and then approaches the base station apparatus12, the terminal apparatus10requests the base station apparatus12to register the position of the terminal apparatus10. At this time, the registration of a group to be used is also required. These requests are contained in the uplink control channel of Ch2and are transmitted in a random access. The base station apparatus12registers terminal apparatuses10for each group in response to the request.

When a call is placed by a terminal apparatus10, the terminal apparatus10transmits an uplink control channel signal containing the call originating request, through Ch2. The base station apparatus12, which has received the uplink control channel signal, regards this terminal apparatus12as a transmitter and allocates a channel to the group to which the transmitter belongs. Here, the channel or channels is/are generic or collective terms for downlink channels and uplink channels. The base station apparatus12requests the other base station apparatuses12to allocate a channel to the group, via the network14. The other base station apparatuses12verify whether or not the group is registered, in response to the request. If the group is registered, the other base station apparatuses12assigns a channel to the group.

The base station apparatus12and the other base station apparatuses12transmit the downlink control channel signal, which contain the information on the allocated channel, to the terminal apparatus10. The receiver and the transmitter, which are the rest of the terminal apparatuses10included in the group, receive the downlink control channel signal so as to recognize the allocated channel. The transmitter transmits the signal to the base station apparatus12through the allocated uplink channel. This signal contains a digitized audio signal. If the receiver is included in the group to which the transmitter belongs, the base station apparatus12transmits the signal to the receiver through the allocated downlink channel. Also, the base station apparatus12transmits the received signal to the other base station apparatuses12. The other base station apparatuses12transmit the signal to the receiver through the allocated channel. The receiver reproduces the audio signal based on the received signal and then outputs the reproduced audio signal from a speaker.

In this manner, a plurality of groups each including a plurality of terminal apparatuses10are formed. Also, a plurality of base station apparatuses12each allocates a channel to each group. As a result, one terminal apparatus10included in a group, to which the channel has been allocated, communicates with the rest of the terminal apparatuses10belonging to this same group.

Among a plurality of terminal apparatuses10belonging to the same group, the transmitter and the receiver may exchange their functions (namely, the transmitter may function as the receiver, and the receiver may function as the transmitter). If a signal to be transmitted is generated in a terminal apparatus10that has operated as the receiver, this terminal apparatus10transmits the uplink control channel signal containing the call originating request, as described above. Thereby, this terminal apparatus10, which has operated as the receiver so far, now switches its function to a transmitter. Also, the terminal apparatus10, which operates as the transmitter, now switches its function back to the receiver when the transmission of the signal has been completed. When a call is generated, such a group call uses a single combination of channels of each base station apparatus12. Thus, if the terminal apparatus10included in the same group is registered in a plurality of base station apparatuses12, one call uses channels the number of which is equal to the number of the plurality of base station apparatuses12. The above-described processing is carried out for each group.

Prior to such a communication processing, an authentication processing may be performed between the terminal apparatus10and the authentication station16. The authentication processing may be carried out by the base station apparatus12, instead of by the authentication station16. The first terminal apparatus10aacquires information on a position, where the first terminal apparatus10ais located (hereinafter this information will be referred to as “positional information”), by receiving signals sent from not-shown GPS satellites via the first GPS antenna24a. The first terminal apparatus10agenerates an authentication request signal containing the positional information and transmits the authentication request to the base station apparatus12from the first long-distance communication antenna20a. Specifically, the first terminal apparatus10arequests authentication by using the acquired positional information.

The authentication station16is connected to the base station apparatus12via the network14and receives the authentication request sent from the terminal apparatus10. The authentication station16performs authentication processing on the first terminal apparatus10a, based on the positional information, in response to the authentication request sent from the first terminal apparatus10a. The authentication station16specifies beforehand the area18that can be validated. If the positional information contained in the authentication request is within the area18, the authentication station16authenticates the first terminal apparatus10a. If, on the other hand, the positional information is not within the area18, the authentication is not granted for the first terminal apparatus10a.FIG. 1corresponds to the former case where the authentication is granted for the first terminal apparatus10a. If the authentication is granted, the authentication station16transmits an authentication response signal indicating that the authentication has been granted, to the first terminal apparatus10avia the network14and the base station apparatus12. This corresponds to permitting the first terminal apparatus10ato communicate using the long-distance communication system. An uplink control channel is used for the transmission of the authentication request, whereas a downlink control channel is used for the transmission of the authentication response.

The second terminal apparatus10bis configured similarly to the first terminal apparatus10a. However, the second terminal apparatus10bcannot receive signals sent from the GPS satellites via the second GPS antenna24band therefore cannot acquire the positional information. For this reason, the second terminal apparatus10bcannot transmit an authentication request containing the positional information, to the authentication station16. Thus, the authentication required for the communication using the long-distance communication system is not granted for the second terminal apparatus10b. On the other hand, the second terminal apparatus10bbroadcasts the authentication request via the second short-range communication antenna22b. The authentication request broadcast by the second terminal apparatus10bdoes not contain the positional information. This corresponds to requesting other terminal apparatuses10to perform authentication by using the short-range communication system, whose transmission distance is shorter than the long-distance communication system.

In the case ofFIG. 1, the first terminal apparatus10areceives the authentication request from the second terminal apparatus10bvia the first short-range communication antenna22a. Since the first terminal apparatus10ahas been authenticated by the authentication station16, the first terminal apparatus10aacts on behalf of the authentication station16and performs authentication processing on the second terminal apparatus10b. Assume herein that the first terminal apparatus10aauthenticates the second terminal apparatus10b. If the authentication is granted, the first terminal apparatus10atransmits an authentication response signal indicating the approval of the authentication, to the second terminal apparatus10bvia the first short-range communication antenna22a. This corresponds to permitting the second terminal apparatus10bto communicate using the long-distance communication system.

FIG. 2shows a structure of a terminal apparatus10. The terminal apparatus10includes a long-distance communication antenna20, a short-range communication antenna22, a GPS antenna24, a long-distance communication unit30, a short-range communication unit32, an authentication processing unit34, a communication processing unit36, an acquiring unit38, and a storage40. The authentication processing unit34includes a first request unit50, a first response unit52, a second request unit54, a second response unit56, a receiving unit58, and a granting unit60.

The acquiring unit38receives signals from not-shown GPS satellites via the GPS antenna24. The acquiring unit38acquires positional information, based on the received signals. Known art may be used for the acquisition of the positional information and therefore the description thereof is omitted here. If the positional information has been acquired, the acquiring unit38outputs the positional information to the first request unit50. If, on the other hand, the acquisition of the positional information has failed, the acquiring unit38outputs the fact about the failure to the second request unit54.

If the positional information has been acquired by the acquiring unit38, the first request unit50receives the positional information fed from the acquiring unit38. The first request unit50generates an authentication request so that the positional information acquired by the acquiring unit38can be contained in the authentication request. The request signal is a signal with which to request the authentication station16to perform authentication. The first request unit50outputs the authentication request to the long-distance communication unit30.

The long-distance communication unit30carries out a communication processing corresponding to the aforementioned business-use wireless system. As described above, for clarification by comparison with the short-range communication system, there may be cases where the business-use wireless system is here called a long-distance communication system. The long-distance communication unit30receives the authentication request fed from the first request unit50and then transmits the authentication request to the base station apparatus12via the long-distance communication antenna20. The base station apparatus12outputs the received authentication request to the authentication station16where the authentication processing is performed as described above. If the positional information is within the area18, the authentication station16authenticates the terminal apparatus10and transmits an authentication response corresponding to the authentication of the terminal apparatus10.

The first response unit52receives the authentication response from the authentication station16and the base station apparatus12via the long-distance communication unit30. If the authentication response indicates that the authentication is granted, the first response unit52instructs the communication processing unit36to carry out communications. If the authentication response indicates that the authentication is not granted, the first response unit52terminates the processing. The storage40stores the result of the authentication. If instructions are received from the first response unit52, the communication processing unit36carries out communications using the long-distance communication system, via the long-distance communication unit30. The communication carried out here is assumed to be a group call.

If acquiring the positional information by the acquiring unit38has failed, the second request unit54is notified of the failure from the acquiring unit38. This corresponds to the case where the authentication required for the communication using the long-distance communication system is not granted in the communication processing unit36. The second request unit54generates an authentication request. This authentication request does not contain the positional information. The second request unit54outputs the authentication request to the short-range communication unit32.

The short-range communication unit32carries out a communication processing corresponding to the short-range communication system. An example of the short-range communication system is Bluetooth (registered trademark). The short-range communication unit32receives an authentication request fed from the second request unit54and broadcasts the authentication request from the short-range communication antenna22. This corresponds to requesting other terminal apparatuses10to perform authentication by using the short-range communication system, whose transmission distance is shorter than the long-distance communication system. The processing carried out by other terminal apparatuses will be discussed later.

The second response unit56receives an authentication response fed from another terminal apparatus10, via the short-range communication unit32. If the authentication response indicates that the authentication is granted, the second response unit56instructs the communication processing unit36to carry out communications. If the authentication response indicates that the authentication is not granted, the second response unit56terminates the processing. If instructions fed from the second response unit56are received, the communication processing unit36carries out communications using the long-distance communication system, via the long-distance communication unit30. The communication carried out here is assumed to be a group call.

The authentication request sent from this terminal apparatus10is receive by the other terminal apparatus10. The receiving unit58and the granting unit60in the other terminal apparatus10carry out the following processings. The receiving unit58receives the authentication request sent from the terminal apparatus10, via the short-range communication unit32. As the receiving unit58receives the authentication request, the granting unit60references the storage40and thereby verifies whether or not authentication has already been granted by the authentication station16. If the authentication is granted, the granting unit60, which now acts on behalf of the authentication station16, authenticates the terminal apparatus10. If the authentication is not done, the granting unit60does not grant authentication. The granting unit60generates an authentication response containing the authentication result, and transmits the authentication response to the terminal apparatus10via the short-range communication unit32.

These structural components may be implemented hardwarewise by elements such as a CPU, memory and other LSIs of an arbitrary computer, and softwarewise by memory-loaded programs or the like. Depicted herein are functional blocks implemented by cooperation of hardware and software. Therefore, it will be obvious to those skilled in the art that the functional blocks may be implemented by a variety of manners including hardware only, software only or a combination of both.

Operations of the communication system100configured as above are now explained.FIG. 3is a sequence diagram showing a communication procedure carried out by the communication system100. The signals sent from the GPS satellites are received by the first terminal apparatus10a(S10). The first terminal apparatus10aacquires positional information (S12). The first terminal apparatus10atransmits an authentication request, which contains the positional information, to the authentication station16(S14). The authentication station16performs authentication (S16). The authentication station16transmits an authentication response indicating that the authentication is successful, to the first terminal apparatus10a(S18). The first terminal apparatus10acarries out communications (S20). The signals sent from the GPS satellites are not received by the second terminal apparatus10b(S22). The second terminal apparatus10bfails to acquire the positional information (S24). The second terminal apparatus10btransmits an authentication request to the first terminal apparatus10a(S26). The first terminal apparatus10aperforms authentication (S28). The first terminal apparatus10atransmits an authentication response indicating that the authentication is successful, to the second terminal apparatus10b(S30). The second terminal apparatus10bcarries out communications (S32).

FIG. 4is a flowchart showing an authentication request procedure carried out by the terminal apparatus10. If the acquiring unit38has acquired the positional information (Y of S50), the first request unit50transmits an authentication request using the long-distance communication (S52). If the acquiring unit38does not acquire the positional information (N of S50), the second request unit54transmits an authentication request using the short-range communication (S54).

FIG. 5is a flowchart showing an authentication response procedure carried out by the authentication station16. The authentication request is received (S70). If the positional information is within the area (Y of S72), the authentication proves successful (S74). If the positional information is not within the area (N of S72), the authentication is unsuccessful (S76). The authentication station16conveys the authentication result by an authentication response (S78).

FIG. 6is a flowchart showing an authentication response procedure carried out by the terminal apparatus10. The receiving unit58receives an authentication request (S90). If the authentication has already been approved (Y of S92), the granting unit60grants authentication (S94). If the authentication has not been approved (N of S92), the granting unit60does not grant authentication (S96). The granting unit60conveys the authentication result by an authentication response (S98).

FIG. 7is a flowchart showing a communication procedure carried out by the terminal apparatus10. The first response unit52or the second response unit56receives the authentication response (S110). If the authentication is granted (Y of S112), the communication processing unit36carries out communications (S114). If the authentication is not granted (N of S112), the processing is terminated.

By employing the first exemplary embodiment, when a terminal apparatus does not acquire the positional information, this terminal apparatus asks another terminal apparatus, which has already been authenticated, to perform authentication, so that the user's convenience can be enhanced while the security is being ensured. Also, the short-range communication system is used when this terminal requests the other terminal apparatus to perform authentication, so that the authentication can be done if these two terminal apparatuses are located close to each other. Also, since the authentication is executed if these terminal apparatuses are located close to each other, the security can be enhanced. Also, since the authentication request using the short-range system is not transmitted if the positional information has been acquired, an increase in the traffic can be suppressed. Also, since the terminal apparatus, which has already been authenticated by the authentication station, acts on behalf of the authentication station and performs authentication, the reliability of authentication can be kept intact.

Second Exemplary Embodiment

A description is now given of a second exemplary embodiment. Similar to the first exemplary embodiment, the second exemplary embodiment relates also to a communication system in which authentication is performed based on the positional information. In the first exemplary embodiment, the authentication is performed by the other terminal apparatus. On the other hand, the other terminal apparatus in the second exemplary embodiment does not perform authentication but, instead, carries out a processing to assist the authentication performed by the authentication station. A communication system100and a terminal apparatus10according to the second exemplary embodiment are of similar types to those shown inFIG. 1andFIG. 2, respectively. A description is given herein centering around features different from the first exemplary embodiment.

The first terminal apparatus10aofFIG. 1requests authentication by using the acquired positional information. If the positional information contained in the authentication request is within the area18, the authentication station16authenticates the first terminal apparatus10a. If authentication is granted, the authentication station16transmits an authentication response signal indicating that the authentication has been granted, to the first terminal apparatus10avia the network14and the base station apparatus12. Here, the authentication station16has an authentication code contained in an authentication response. The authentication code is information with which to verify that authentication has been granted by the authentication station16. Upon receiving the authentication response, the first terminal apparatus10astores the authentication code.

The second terminal apparatus10b, which cannot acquire the positional information, now broadcasts an authentication request via the second short-range communication antenna22b. The first terminal apparatus10areceives the authentication request sent from the second terminal apparatus10b, via the first short-range communication antenna22a. The first terminal apparatus10a, which has stored the authentication code sent from the authentication station16, generates an authentication response containing the authentication code. The first terminal apparatus10atransmits the authentication response to the second terminal apparatus10bvia the first short-range communication antenna22a. Upon receiving the authentication response, the second terminal apparatus10bextracts the authentication code from the authentication response.

The second terminal apparatus10bgenerates an authentication request containing the authentication code and transmits the authentication request to the base station apparatus12from the second long-distance communication antenna20b. In response to the authentication request sent from the second terminal apparatus10b, the authentication station16performs authentication processing on the second terminal apparatus10b, based on the authentication code. If the received authentication code is the same as the authentication code that has already been outputted, the authentication station authenticates the second terminal apparatus10b. If, on the other hand, the received authentication code is not the same, the authentication is not granted for the second terminal apparatus10b. If the authentication is granted, the authentication station16transmits an authentication response signal indicating that the authentication has been granted, to the second terminal apparatus10bvia the network14and the base station apparatus12.

The first response unit52ofFIG. 2receives the authentication response from the authentication station16and the base station apparatus12via the long-distance communication unit30. If the authentication response indicates that the authentication is granted, the first response unit52instructs the communication processing unit36to carry out communications. Also, the storage40stores the authentication code contained in the authentication response. If instructions fed from the first response unit52are received, the communication processing unit36carries out communications using the long-distance communication system, via the long-distance communication unit30.

If the acquiring unit38has failed to acquire the positional information, the second request unit54generates an authentication request and outputs the authentication request to the short-range communication unit32. The short-range communication unit32receives the authentication request fed from the second request unit54and then broadcasts the authentication request from the short-range communication antenna22. A processing, carried out by another terminal apparatus10, corresponding to this processing will be discussed later. The second response unit56receives an authentication response sent from the other terminal apparatus10, via the short-range communication unit32. The authentication response contains an authentication code. The storage40stores the authentication code. The first request unit50generates an authentication request so that, instead of the positional information, the authentication code stored in the storage40can be contained in the authentication request. The first request unit50outputs the authentication request to the long-distance communication unit30. The long-distance communication unit30receives the authentication request fed from the first request unit50and then transmits the authentication request to the base station apparatus12via the long-distance communication antenna20.

The base station apparatus12outputs the received authentication request to the authentication station16, and the authentication station16performs authentication processing. If the authentication code contained in the authentication request is the same as the authentication code that has already been outputted, the authentication station16authenticates the terminal apparatus10and transmits an authentication response reflecting this result. The first response unit52receives the authentication request from the authentication station16and the base station apparatus12via the long-distance communication unit30. If the authentication response indicates that the authentication is granted, the first response unit52instructs the communication processing unit36to carry out communications. If instructions fed from the first response unit52are received, the communication processing unit36carries out communications using the long-distance communication system, via the long-distance communication unit30.

The authentication request sent from this terminal apparatus10is received by another terminal apparatus10. The receiving unit58and the granting unit60in the other terminal apparatus10carries out the following processing. Here, the other terminal apparatus10has already been authenticated by the authentication station16and has received the authentication code sent from the authentication station16. The receiving unit58receives the authentication request sent from the terminal apparatus10, via the short-range communication unit32. As the receiving unit58receives the authentication request, the granting unit60generates the authentication response, which contains the authentication code, stored in the storage40and then transmits the authentication response to the terminal apparatus10via the short-range communication unit32.

FIG. 8is a sequence diagram showing a communication procedure carried out by the communication system100according to the second exemplary embodiment. The signals sent from the GPS satellites are received by the first terminal apparatus10a(S130). The first terminal apparatus10aacquires positional information (S132). The first terminal apparatus10atransmits an authentication request, which contains the positional information, to the authentication station16(S134). The authentication station16performs authentication (S136). The authentication station16transmits an authentication response, which indicates that the authentication is successful and which contains an authentication code, to the first terminal apparatus10a(S138). The first terminal apparatus10astores the authentication code (S140) and carries out communications (S142). The signals sent from the GPS satellites are not received by the second terminal apparatus10b(S144). The second terminal apparatus10bfails to acquire the positional information (S146).

The second terminal apparatus10btransmits an authentication request to the first terminal apparatus10a(S148). The first terminal apparatus10aextracts the authentication code (S150). The first terminal apparatus10atransmits an authentication response containing the authentication code, to the second terminal apparatus10b(S152). The second terminal apparatus10btransmits an authentication request containing the authentication code, to the authentication station16(S154). The authentication station16performs authentication (S156). The authentication station16transmits an authentication response indicating that the authentication is successful, to the second terminal apparatus10b(S158). The second terminal apparatus10bcarries out communications (S160).

FIG. 9is a flowchart showing an authentication request procedure carried out by a terminal apparatus10according to the second exemplary embodiment. If the acquiring unit38has acquired the positional information (Y of S180), the first request unit50transmits an authentication request using the long-distance communication (S182). If the acquiring unit38does not acquire the positional information (N of S180), the second request unit54transmits an authentication request using the short-range communication (S184). If the second response unit56has received an authentication response containing the authentication code (Y of S186), the first request unit50transmits an authentication request (authentication code) using the long-distance communication (S188). If the second response unit56does not receive the authentication response containing the authentication code (N of S186), Step S188is skipped.

FIG. 10is a flowchart showing an authentication response procedure carried out by the authentication station16according to the second exemplary embodiment. An authentication request is received (S200). If the positional information is within the area (Y of S202), the authentication code is extracted (S204). If the positional information is not within the area (note here that included is the case where no positional information is contained in the authentication request) (N of S202) and if the authentication codes match (Y of S206), the authentication proves successful (S208). If the authentication codes do not match (note also here that included is the case where no positional information is contained in the authentication request) (N of S206), the authentication is unsuccessful (S210). The authentication station16conveys the authentication result by the authentication response (S212).

FIG. 11is a flowchart showing an authentication response procedure carried out by a terminal apparatus10according to the second exemplary embodiment. The receiving unit58receives an authentication request (S230). If the authentication has already been approved (Y of S232), the granting unit60extracts the authentication code (S234). If the authentication has not been approved (N of S232), the granting unit60does not grant authentication (S236). The granting unit60conveys the authentication result by an authentication response (S238).

FIG. 12is a flowchart showing a communication procedure carried out by a terminal apparatus10according to the second exemplary embodiment. The authentication response is received by the first response unit52(S250). If the authentication is granted (Y of S252) and if the authentication code is contained in the authentication response (Y of S254), the storage40stores the authentication code (S256). If the authentication code is not contained in the authentication response (N of S254), Step S256is skipped. The communication processing unit36carries out communications (S258). If the authentication is not granted (N of S252), Steps S254to S258are skipped.

By employing the second exemplary embodiment, the terminal apparatus transmits the authentication code and then the authentication station performs authentication based on the authentication code, so that the security can be ensured. Also, since the terminal apparatus transmits the authentication code, the user's convenience can be enhanced.

Third Exemplary Embodiment

A description is now given of a third exemplary embodiment. Similar to the first and second exemplary embodiments, the third exemplary embodiment relates also to a communication system in which authentication is performed based on the positional information. In the above-described first and second exemplary embodiments, the authentication request is broadcast to other terminal apparatuses using the short-range communication system if the positional information cannot be acquired. In the third exemplary embodiment, a description is now given of a case where after the positional information is acquired and an authentication request is transmitted to the authentication station, the authentication is not granted by the authentication station. A communication system100according to the third exemplary embodiment is of a similar type to that shown inFIG. 2. A description is given herein centering around features different from the first and second exemplary embodiments.

FIG. 13shows a structure of a communication system100according to the third exemplary embodiment. In comparison withFIG. 1, the second terminal apparatus10bshown inFIG. 13is located outside the area18. The second terminal apparatus10breceives signals sent from the GPS satellites.

The second terminal apparatus10breceives the signals sent from the satellites, via the second GPS antenna24band thereby acquires the positional information. The second terminal apparatus10bgenerates an authentication request signal containing the positional information, and transmits the authentication request signal to the base station apparatus12from the second long-distance communication antenna20b. The authentication station16performs authentication processing on the second terminal apparatus10b, based on the positional information, in response to the authentication request sent from the second terminal apparatus10b. Since the positional information is not within the area18, the authentication is not granted for the second terminal apparatus10b. The authentication station16transmits an authentication response signal indicating that the authentication is not granted, to the second terminal apparatus10bvia the network14and the base station apparatus12.

The second terminal apparatus10bbroadcasts the authentication request via the second short-range communication antenna22b. The first terminal apparatus10areceives the authentication request from the second terminal apparatus10bvia the first short-range communication antenna22a. Since the first terminal apparatus10ahas been authenticated by the authentication station16, the first terminal apparatus10aacts on behalf of the authentication station16and performs authentication processing on the second terminal apparatus10b. Assume herein that the first terminal apparatus10aauthenticates the second terminal apparatus10b. The first terminal apparatus10atransmits an authentication response signal indicating that the authentication has been granted, to the second terminal apparatus10bvia the first short-range communication antenna22a. The second terminal apparatus10bcarries out communications using the long-distance communication system.

The first response unit52ofFIG. 2receives the authentication response from the authentication station16and the base station apparatus12via the long-distance communication unit30. If the authentication response indicates that the authentication is not granted, the execution of the subsequent processing is outputted to the second request unit54. The second request unit54generates an authentication request in response to the processing done by the first response unit52. The second request unit54outputs the authentication request to the short-range communication unit32. Specifically, when the request from the first request unit50is not authenticated by the authentication station16, the second request unit54requests another terminal apparatus10to perform authentication by using the short-range communication system. The short-range communication unit32receives the authentication request fed from the second request unit54and then broadcasts the authentication request from the short-range communication antenna22.

The second response unit56receives the authentication response sent from the other terminal apparatus10, via the short-range communication unit32. If the authentication response indicates that the authentication is granted, the second response unit56instructs the communication processing unit36to carry out communications. If the authentication response indicates that the authentication is not granted, the second response unit56terminates the processing. If instructions are received from the second response unit56, the communication processing unit36carries out communications using the long-distance communication system, via the long-distance communication unit30.

The receiving unit58and the granting unit60carry out processings in the other terminal apparatus10that has received the authentication request using the short-range communication system. The receiving unit58receives the authentication request sent from the terminal apparatus10, via the short-range communication unit32. As the receiving unit58receives the authentication request, the granting unit60references the storage40and thereby verifies whether or not authentication has already been granted by the authentication station16. If the authentication is granted, the granting unit60, which now acts on behalf of the authentication station16, authenticates the terminal apparatus10. If the authentication is not done, the granting unit60does not grant authentication. The granting unit60generates an authentication response containing the authentication result, and transmits the authentication response to the terminal apparatus10via the short-range communication unit32.

FIG. 14is a sequence diagram showing a communication procedure carried out by the communication system100according to the third exemplary embodiment. Signals sent from the GPS satellites are received by the first terminal apparatus10a(S270). The first terminal apparatus10aacquires positional information (S272). The first terminal apparatus10atransmits an authentication request containing the positional information, to the authentication station16(S274). The authentication station16determines that the authentication is successful (S276). The authentication station16transmits an authentication response indicating that the authentication is successful, to the first terminal apparatus10a(S278). The first terminal apparatus10acarries out communications (S280).

Signals sent from the GPS satellites are received by the second terminal apparatus10b(S282). The second terminal apparatus10bacquires positional information (S284). The second terminal apparatus10btransmits an authentication request containing the positional information, to the authentication station16(S286). The authentication station16determines that the authentication is not successful (S288). The authentication station16transmits an authentication response indicating that the authentication is not successful, to the second terminal apparatus10b(S290). The second terminal apparatus10btransmits an authentication request to the first terminal apparatus10a(S292). The first terminal apparatus10adetermines that the authentication is successful (S294). The first terminal apparatus10atransmits an authentication response indicating that the authentication is successful, to the second terminal apparatus10b(S296). The second terminal apparatus10bcarries out communications (S298).

FIG. 15is a flowchart showing an authentication request procedure carried out by a terminal apparatus10according to the third exemplary embodiment. If the acquiring unit38has acquired the positional information (Y of S310), the first request unit50transmits an authentication request using the long-distance communication (S312). If the authentication failure is received (Y of S314), the second request unit54transmits an authentication request using the short-range communication (S316). If the authentication failure is not received (N of S314), Step S316is skipped. If the acquiring unit38does not acquire the positional information (N of S310), the second request unit54transmits an authentication request using the short-range communication (S316).

By employing the third exemplary embodiment, the authentication is not granted for terminal apparatuses not located within the area, so that only terminal apparatuses located within the area can be authenticated. Also, since only the terminal apparatuses located within the area are authenticated, the security can be ensured. Also, even if a terminal apparatus is not located within the area but if it is located at a distance, where the short-range communication is enabled, from another terminal apparatus that has already been authenticated, the authentication is granted. Thus, the security based on this policy can be ensured. Also, since even if the terminal apparatus is not located within the area but located at a short-range communication enabled distance from the other terminal apparatus that has already been authenticated, the authentication is granted, so that the user's convenience can be enhanced.

The present invention has been described based on the exemplary embodiments. The exemplary embodiments are intended to be illustrative only, and it is understood by those skilled in the art that various modifications to constituting elements and processes as well as arbitrary combinations thereof could be developed and that such modifications and combinations are also within the scope.

In the first to third exemplary embodiments, the long-distance communication system is a business-use wireless system. However, this should not be considered as limiting and, for example, the long-distance communication system may be a mobile phone system or the like, instead of the business-use wireless system. In other words, the long-distance communication system may be any communication system as long as the transmission distance is longer than the short-range communication system. By employing this modification, the degree of freedom in configuring the communication system100, namely the structural flexibility of the communication system100, can be enhanced.

In the third exemplary embodiment, the second terminal apparatus10bperforms authentication on the first terminal apparatus10a, as with the first exemplary embodiment. However, this should not be considered as limiting and, for example, the second terminal apparatus10bmay transmit the authentication code, instead, as in the second exemplary embodiment. The subsequent processing may also be carried out similarly to the second exemplary embodiment. By employing this modification, the advantageous effects similar to those of the second exemplary embodiment can be achieved.