Abstract:
A radio communication device including: a processor configured to: perform wireless communications using at least one of a first radio access network and a second radio access network, the first radio access network configured to be used when a communication quality of the first radio access network is higher than a threshold value, the second radio access network configured to be used when a communication quality of the first radio access network is equal to or lower than the threshold value, and fix a radio access network for communicating with a specified network, when the processor starts the wireless communications using the first radio access network and the processor detects that a blocking of specified communications is set to the radio communication device, to the first radio access network until the wireless communications of specified times are finished using the first radio access network.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2015-175995, filed on Sep. 7, 2015, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiments discussed herein are related to a radio communication device, a radio communication method, and a radio communication program. 
       BACKGROUND 
       [0003]    A mobile terminal such as a smartphone includes a communication measure that couples to a mobile phone line such as the long term evolution (LTE) or the 3rd generation (3G) and a communication measure that couples to a wireless local area network (LAN) such as the wireless fidelity (Wi-Fi). 
         [0004]    Normally, under an environment in which both the mobile phone line and the wireless LAN can be coupled, the mobile terminal couples to the wireless LAN, which has higher priority. When the wireless LAN becomes out of range, the mobile terminal makes switching to the mobile phone line and carries out communications. Among mobile terminals of recent years are terminals in which a link aggregation function of carrying out communications by simultaneously using both the mobile phone line and the wireless LAN is implemented. For example, while being carrying out communications relating to an application A by using a mobile phone line, a mobile terminal carries out communications relating to an application B by using a wireless LAN. 
       CITATION LIST 
     Patent Documents 
       [0005]    [Patent Document 1] Japanese Laid-open Patent Publication No. 2008-136150 
         [0006]    [Patent Document 2] Japanese Laid-open Patent Publication No. 2011-166251 
       SUMMARY 
       [0007]    According to an aspect of the embodiment, a radio communication device includes a first radio interface configured to wirelessly coupled to a first wireless station via a first radio access network, the first wireless station coupled to a specified network, a second radio interface configured to wirelessly coupled to a second wireless station via a second radio access network, the second wireless station coupled to the specified network, and a processor configured to: perform wireless communications using at least one of the first radio access network and the second radio access network, the first radio access network configured to be used when a communication quality of the first radio access network is higher than a threshold value, the second radio access network configured to be used when a communication quality of the first radio access network is equal to or lower than the threshold value, and fix a radio access network for communicating with the specified network, when the processor starts the wireless communications using the first radio access network and the processor detects that a blocking of specified communications is set to the radio communication device, to the first radio access network until the wireless communications of specified times are finished using the first radio access network. 
         [0008]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0009]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is a diagram exemplifying a configuration of a communication system; 
           [0011]      FIG. 2  is a diagram exemplifying a functional block configuration of a mobile terminal according to an embodiment; 
           [0012]      FIG. 3  is a diagram exemplifying authentication processing by a web authentication system; 
           [0013]      FIG. 4  is a diagram exemplifying an authentication screen of a website of web authentication; 
           [0014]      FIG. 5  is a diagram explaining a request for web authentication due to change of a subnet; 
           [0015]      FIGS. 6A and 6B  are diagrams exemplifying success and failure in web authentication processing by a simultaneous communication function; 
           [0016]      FIG. 7  is a sequence diagram exemplifying a case in which web authentication fails in simultaneous communications; 
           [0017]      FIG. 8  is a diagram exemplifying a display screen of a website that notifies that a mobile terminal is subjected to access limitation; 
           [0018]      FIG. 9  is a diagram explaining redirection for web authentication and redirection due to access limitation; 
           [0019]      FIGS. 10A and 10B  are diagrams exemplifying an operation flow of web authentication processing according to an embodiment; 
           [0020]      FIGS. 11A and 11B  are diagrams exemplifying a flow of communications in a web authentication processing according to the embodiment; and 
           [0021]      FIG. 12  is a diagram exemplifying a hardware configuration of a computer for implementing a mobile terminal according to an embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0022]    However, in the above-described technique, if the line is automatically switched in execution of web authentication that is user authentication for using a web service, the web authentication fails. 
         [0023]    For example, mobile terminals of recent years simultaneously use the Wi-Fi and a mobile phone line and carry out web access by distributing data to the Wi-Fi and the mobile phone line. Such a mobile terminal accesses a web server by using the Wi-Fi and acquires an authentication screen for using a web service from the web server. Thereafter, due to the deterioration of the quality of the Wi-Fi, the mobile terminal returns a response of authentication information to the web server by using the LTE. In this case, the web server determines that this response is web access by new communication, and transmits an authentication screen to the mobile terminal again. 
         [0024]    As above, if the line at the time of the request for web authentication and the line at the time of the response are different, retransmission of the authentication screen is carried out and authentication processing is not started although the authentication request and the authentication response are transmitted from the same mobile terminal. 
         [0025]    Techniques to be disclosed are made in view of the above and intend to provide a radio communication device, a radio communication method, and a radio communication program that can suppress failure in authentication processing. 
         [0026]    Several embodiments will be described in detail below with reference to the drawings. Elements that correspond in plural drawings are given the same numeral. 
         [0027]    In recent years, for example, the wireless LAN has been used also in public networks for suppression of overuse of the data amount of packet communications on the mobile phone line and for increase in the speed of the packet communications. 
         [0028]      FIG. 1  is a diagram exemplifying a configuration of a communication system  100 . For example, the communication system  100  includes plural servers  101 , a mobile phone line (may be referred to as a mobile phone access network)  102 , a wireless LAN line (may be referred to as a wireless LAN access network)  103 , and a mobile terminal  104 . The servers  101  may be computers that provide services and data to clients for example. Furthermore, for example, the servers  101  include an authentication server  111  for carrying out authentication to give permission to use the wireless LAN line  103  to the mobile terminal  104 , a first server  112  that returns a given error to be described later, and a second server  113  that notifies that the mobile terminal  104  is subjected to access limitation. 
         [0029]    The mobile phone line  102  may be a communication line of a cellular system provided by a mobile phone operator or the like for example. The mobile phone line  102  includes a base station (may be referred to as a second wireless station)  121  and a relay device  122  for example. The mobile phone line  102  may be the LTE or the 3G for example. The mobile terminal  104  couples to the base station  121  and carries out communications by the mobile phone line  102  through the base station  121  for example. 
         [0030]    Furthermore, the wireless LAN line  103  includes access points (APs) (may be referred to as a first wireless station)  131  and gateways  132  for example. The wireless LAN line  103  may be the Wi-Fi or the worldwide interoperability for microwave access (WiMAX) (registered trademark) for example. The mobile terminal  104  couples to the access point  131  and carries out communications by the wireless LAN line  103  through the access point  131  for example. 
         [0031]    The mobile terminal  104  may be a mobile phone, a smartphone, a tablet terminal, a notebook personal computer (PC), or the like for example. 
         [0032]      FIG. 2  is a diagram exemplifying a functional block configuration of the mobile terminal  104  according to the embodiment. The mobile terminal  104  includes a control unit  200 , a storing unit  210 , and a communication unit  220  for example. The control unit  200  includes functional units such as a changing unit  201  and a fixing unit  202  for example. The storing unit  210  of the mobile terminal  104  stores information on first quality and second quality that are determination criteria of the communication quality to be described later, and so, forth, for example. The communication unit  220  includes a first radio interface  221  and a second radio interface  222  for example. The first radio interface  221  may be radio communication equipment used for coupling to the wireless LAN line  103  for example. The second radio interface  222  may be radio communication equipment used for coupling to the mobile phone line  102  for example. Details of these respective functional units and details of information stored in the storing unit  210  will be described later. 
         [0033]      FIG. 3  is a diagram exemplifying authentication processing by a web authentication system. At the access points  131  of the wireless LAN line  103  of a public network, the web authentication system is used for authentication of the user for example. As illustrated in  FIG. 3 , suppose that, in web authentication, the mobile terminal  104  couples to the access point  131  (( 1 ) of  FIG. 3 ) and then carries out communications by a browser (( 2 ) of  FIG. 3 ). In this case, the gateway  132  checks whether or not the mobile terminal  104  that carries out communications has been already authenticated (( 3 ) of  FIG. 3 ). Then, if the mobile terminal  104  that carries out communications has not yet been authenticated, the gateway  132  carries out redirection of the coupling destination of the communications to the authentication server  111  (( 4 ) of  FIG. 3 ). As a result, the mobile terminal  104  couples to a website of the web authentication provided by the authentication server  111  (( 5 ) of  FIG. 3 ).  FIG. 4  is a diagram exemplifying an authentication screen of a website of the web authentication. Then, when the user inputs an identification (ID) and a password on the authentication screen by using the mobile terminal  104  and transmits the ID and the password to the authentication server  111 , the authentication server  111  executes authentication processing. If the authentication of the user succeeds in the authentication server  111 , the gateway  132  treats the mobile terminal  104  as a terminal that has been authenticated and permits the subsequent communications (( 6 ) of  FIG. 3 ). For example, in the web authentication, authentication of the mobile terminal  104  is carried out in the above-described manner. The processing of the web authentication may be executed through an application such as a browser operated through execution of a program by the control unit  200  of the mobile terminal  104  for example. Furthermore, communications via the mobile phone line  102  and the wireless LAN line  103  by the control unit  200  of the mobile terminal  104 , which will be described later, may be carried out through an application such as a browser for example. 
         [0034]    Furthermore, in recent years, a subscriber identity module (SIM) authentication system has been used as another example of authentication of the user in the wireless LAN line  103 . The SIM authentication system is a system in which automatic authentication is carried out by the SIM card. In the SIM authentication system, authentication of a user is completed on the basis of information read from a SIM card at the time of a coupling to the access point  131 . Thus, the user does not have to input an ID, a password, and so forth. However, in the present circumstances, the mobile terminal  104  that does not support the SIM authentication still remains. Therefore, the access point  131  of the web authentication system and the access point  131  that can use both the web authentication system and the SIM authentication system are used. Furthermore, for example, even with the mobile terminal  104  that supports the SIM authentication system, once authentication processing is executed by the web authentication system, authentication processing by the web authentication system is executed in a coupling to the access point  131  that provides only web authentication. 
         [0035]    Moreover, in the web authentication, an authentication system is constructed for each one local area network system. Therefore, authentication is requested again when the local area changes.  FIG. 5  is a diagram explaining request for authentication due to change of a subnet. For example, suppose that the mobile terminal  104  has succeeded in authentication and been already authenticated at the access point  131  in an access point group belonging to a certain subnet (( 1 ) of  FIG. 5 ). Also in this case, when the mobile terminal  104  moves to a different local area and the subnet of the Internet protocol (IP) address changes, authentication is requested again by the gateway  132  of a local area network system that constructs a different subnet (( 2 ) of  FIG. 5 ). Then, the mobile terminal  104  becomes the state in which communications by the wireless LAN line  103  are not permitted until authentication is completed in the local area network system that constructs the different subnet. As one example, when a user moves by train in commuting, even when the user couples to the access point  131  at a station at which the user boards a train and authentication has been completed once, web authentication is requested again if the user links to the access point  131  belonging to another local area at a station in the middle of the movement. Many opportunities of using the web authentication when using the wireless LAN line  103  as above still exist. 
         [0036]    Furthermore, in the web authentication, the authentication processing comes not to progress even when the communication quality of the wireless LAN line  103  is favorable in some cases. For example, if plural mobile terminals  104  couple to the access point  131  at one time, the communication resources between the access point  131  and the mobile terminals  104  often become insufficient. Alternatively, if plural mobile terminals  104  couple to the access point  131 , a load is imposed on the authentication server  111  and the authentication processing comes not to progress in some cases. As a result, for example, even in the situation in which the communication quality of a wireless LAN is favorable and communications can be carried out by the wireless LAN as long as authentication is completed, the authentication does not proceed and it is difficult to use the wireless LAN line  103  in some cases. Furthermore, in this case, it is difficult for the user to distinguish whether the authentication stops due to the deterioration of the communication quality of the wireless LAN or the authentication stops due to congestion and the user turns off the wireless LAN line  103  in some cases. As a result, for example, the situation occurs in which the wireless LAN line  103  is not used although trouble is taken to set the access point  131  in order to offload packets of the mobile phone line  102 . 
         [0037]    It is conceivable that the mobile terminal  104  is equipped with a simultaneous communication function of carrying out simultaneous communications with the mobile phone line  102  and, the wireless LAN line  103  in order to suppress inaccessibility to the server  101  due to communication failure of the wireless LAN line  103 . In this case, the control unit  200  of the mobile terminal  104  determines whether or not the communication quality of the wireless LAN line  103  is higher than a determination criterion for example. Then, for example, if the communication quality of the wireless LAN line  103  is higher than the determination criterion, the control unit  200  controls the first radio interface  221  to carry out communications by the wireless LAN line  103 . Furthermore, for example, if the communication quality of the wireless LAN line  103  decreases to the determination criterion or lower, the control unit  200  does not carry out communications by the wireless LAN line  103  even when linking to the access point  131 , and controls the second radio interface  222  to carry out communications by the mobile phone line  102 . Therefore, the user can access the server  101  by the mobile phone line  102  even when the wireless LAN line  103  involves communication failure. 
         [0038]    However, if the mobile terminal  104  is equipped with the function of simultaneous communications with the mobile phone line  102  and the wireless LAN line  103 , the simultaneous communication function distributes communications to the mobile phone line  102  in the middle of web authentication and the web authentication fails in some cases. 
         [0039]      FIGS. 6A and 6B  are diagrams exemplifying success and failure in web authentication processing by a simultaneous communication function.  FIG. 6A  is a diagram exemplifying the case in which web authentication succeeds. In  FIG. 6A , for example, a user couples to the wireless LAN line  103  by the mobile terminal  104  and gets web authentication done when boarding a train at a station, and thereafter couples to the general server  101  by simultaneous communications with the mobile phone line  102  and the wireless LAN ine  103 . After the train departs, the communication quality of the wireless LAN line  103  deteriorates and the mobile terminal  104  carries out communications by the mobile phone line  102 . When arriving at a different station and coupling to the access point  131  of the wireless LAN line  103  belonging to a different subnet, the user of the mobile terminal  104  carries out web authentication again by the wireless LAN line  103 . Then, if the authentication succeeds, it becomes possible to couple to the general server  101  by simultaneous communications with the mobile phone line  102  and the wireless LAN line  103  from then on. 
         [0040]    On the other hand,  FIG. 6B  is a diagram exemplifying the case in which web authentication fails. Also in  FIG. 6B , communications are carried out similarly to  FIG. 6A  until the mobile terminal  104  carries out communications via the mobile phone line  102  after train departure. Subsequently, when arriving at a different station and coupling to the access point  131  of the wireless LAN line  103  belonging to a different subnet, the user of the mobile terminal  104  carries out web authentication again in the wireless LAN line  103 . However, if the simultaneous communication function distributes communications to the mobile phone line  102  in this authentication processing, the authentication fails because it is difficult to access the authentication server  111  from the mobile phone line  102 , so that the web authentication is not completed to the last. As a result, simultaneous communications are difficult and communications by the mobile phone line  102  are carried out. 
         [0041]    With reference to  FIG. 7 , the case in which web authentication fails in simultaneous communications with the mobile phone line  102  and the wireless LAN line  103  will be described in more detail.  FIG. 7  is a sequence diagram exemplifying the case in which web authentication fails in simultaneous communications with the mobile phone line  102  and the wireless LAN line  103 . 
         [0042]    In  FIG. 7 , the control unit  200  of the mobile terminal  104  couples to the access point  131  of the wireless LAN line  103  and transmits a hypertext transfer protocol (HTTP) request toward the server  101  that provides a website desired to be coupled through a browser for example (S 701 ). When receiving, the HTTP request, the gateway  132  of the wireless LAN line  103  determines whether or not the mobile terminal  104  as the transmission source of the received HTTP request, has been authenticated. Then, if the mobile terminal  104  has not yet been authenticated, the gateway  132  returns, to the mobile terminal  104 , an instruction to carry out redirection to an authentication site provided by the authentication server  111  ( 5702 ). When receiving the instruction of the redirection, the mobile terminal  104  transmits an HTTP request toward the authentication site provided by the authentication server  111  (S 703 ), and the gateway  132  transmits the HTTP request to the authentication server  111  (S 704 ). When receiving the HTTP request, the authentication server  111  returns an HTTP response to the gateway  132  ( 5705 ), and the gateway  132  of the wireless LAN line  103  returns the HTTP response to the mobile terminal  104  ( 5706 ). As a result, for example, the authentication screen of  FIG. 4  is displayed on the display screen of a display device included in the mobile terminal  104 . 
         [0043]    Subsequently, the user of the mobile terminal  104  inputs an ID and a password to the authentication screen and transmits the ID and the password toward the authentication server  111 . However, for example if the simultaneous communication function of the mobile terminal  104  distributes communications to use the mobile phone line  102  at this time ( 5707 ), it is difficult to access the authentication server  111  from the mobile phone line  102  ( 5708 ) and thus the web authentication is not completed. As a result, the mobile terminal  104  does not receive a response from the authentication server  111  and the authentication processing stops. Thus, for example, the display screen of the display device included in the mobile terminal  104  becomes the state in which the display freezes. 
         [0044]    For this reason, it is desired to provide a technique of controlling the distribution of communications to suppress communications by the mobile phone line  102  in web authentication. 
         [0045]    For example, it is conceivable that access to a first server  112  that is set, to return an error is attempted by the wireless LAN line  103  and whether or not web authentication is being currently carried out is determined from the response to the access in order to suppress communications by the mobile phone line  102  in web authentication. As the first server  112 , a server that is set to return “204 NO Content,” which indicates that the response entity to be returned does not exist, among HTTP status codes when being accessed can be used for example. For example, when the mobile terminal  104  attempts to access such a first server  112  by the wireless LAN line  103 , an error of “204 NO Content” is returned as a response to the request from the server if the access can be made. However, for example if the gateway  132  determines that the mobile terminal  104  is a terminal that has not been authenticated when the mobile terminal  104  couples to the wireless LAN line  103 , the gateway  132  carries out redirection and forcibly changes the coupling destination to the authentication server  111 . Therefore, success (for example, 200 OK of an HTTP status code) is returned from the authentication server  111 . 
         [0046]    Therefore, for example, the mobile terminal  104  can determine whether or not authentication is being carried out from the result of an attempt to access the first server  112  set to return a given error by the wireless LAN line  103 . Furthermore, for example, suppose that success (for example, 200 OK of an HTTP status code) is returned as the result of an attempt to access the first server  112  by the mobile terminal  104  by the wireless LAN line  103 . In this case, the mobile terminal  104  determines that web authentication is being carried out, and fixes communications to the wireless LAN line  103  until the web authentication is completed and carries out control so as not to use the mobile phone line  102 . This allows the mobile terminal  104  to properly complete the web authentication. For example, when the web authentication is completed, the response when access to the first server  112  is attempted by the wireless LAN line  103  becomes the error of “204 NO Content” Therefore, the mobile terminal  104  can determine that the authentication has been completed if the response is the error of “204 NO content” when the mobile terminal  104  attempts to access the first server  112  by the wireless LAN line  103 . 
         [0047]    Furthermore, for example, also in the case of web authentication at a hotel or an airport, processing of web authentication by redirection occurs in a coupling to the access point  131  and therefore whether or not web authentication is being carried out can be determined by the above-described processing. 
         [0048]    However, access limitation (may be referred to as a blocking of specified communications) is set in the mobile terminal  104  or the SIM in some cases. For example, in the mobile terminal  104  or the SIM that is for professional use or is used by a minor, access limitation is set in order to suppress the user from accessing an undesirable website. Furthermore, when the mobile terminal  104  on which the access limitation is set or the mobile terminal  104  equipped with the SIM attempts to access an unpermitted website, the mobile terminal  104  is redirected to the second server  113  that notifies that the mobile terminal  104  is subjected to the access limitation for example.  FIG. 8  is a diagram exemplifying a display screen of a website provided by the second server  113  that notifies that the mobile terminal  104  is subjected to the access limitation. 
         [0049]      FIG. 9  is a diagram explaining redirection for authentication and redirection due to access limitation. When the mobile terminal  104  couples to the access point  131  (( 1 ) of  FIG. 9 ), first the mobile terminal  104  attempts to access a website of the first server  112  set to return a given error (( 2 ) of  FIG. 9 ). When receiving the request from the mobile terminal  104 , the gateway  132  checks whether or not the mobile terminal  104  has been authenticated and whether or not the mobile terminal  104  is a terminal of the object of the access limitation (( 3 ) of  FIG. 9 ). Then, if the mobile terminal  104  is a terminal of the object of the access limitation, the gateway  132  carries out redirection of the coupling destination to the second server  113 , which notifies the access limitation. As a result, the second server  113 , which notifies the access limitation, returns success in, the access (for example, 200 OK of an HTTP status code) to the mobile terminal  104  (( 4 ) of  FIG. 9 ). Furthermore, if the mobile terminal  104  has not been authenticated, the gateway  132  carries out redirection of the coupling destination to the authentication server  111 . As a result, the authentication server  111  returns success in the access (for example 200 OK of an HTTP status code) to the mobile terminal  104  (( 5 ) of  FIG. 9 ). For this reason, for example although the mobile terminal  104  accesses the first server  112  set to return the given error and determines whether or not authentication is being currently carried out from a response to this access, it is difficult to distinguish whether redirection is carried out for authentication or redirection is carried out due to the access limitation. Therefore, a technique that can distinguish the redirection for authentication and the redirection due to access limitation is desired. An exemplary embodiment will be described below with reference to  FIG. 10 , and  FIGS. 11A and 11B . 
       Embodiment 
       [0050]    In the exemplary embodiment, the control unit  200  of the mobile terminal  104  attempts to access the first server  112  set to return the given error via the mobile phone line  102 . Here, if access limitation exists, the access limitation is imposed even with the mobile phone line  102  and redirection is carried out to the second server  113 , which provides the website that notifies that the mobile terminal  104  is subjected to the access limitation. As a result, the second server  113 , which provides the website that notifies that the mobile terminal  104  is subjected to the access limitation, returns success (for example, 200 OK of an HTTP status code) to the mobile terminal  104 . 
         [0051]    On the other hand, if access limitation does not exist, when the control unit  200  of the mobile terminal  104  attempts to access the first server  112  by the mobile phone line  102 , the access to the first server  112  succeeds because redirection to the authentication server  111  does not occur from the mobile phone line  102 . As a result, the first server  112  returns the given error response (for example, error of “204 NO content” as an HTTP status code) to the mobile terminal  104 . 
         [0052]    Therefore, the control unit  200  of the mobile terminal  104  can determine (or detect) whether or not the self-terminal is subjected to the access limitation from the response to the attempt to access the first server  112  set to return the given error via the mobile phone line  102 . Furthermore, if the self-terminal is not subjected to the access limitation, the control unit  200  can determine whether or not web authentication is being carried out from the response to an attempt to access the first server  112  set to return the given error via the wireless LAN line  103  in the above-described manner. 
         [0053]    On the other hand, if the self-terminal is subjected to the access limitation, the mobile terminal  104  is subjected to redirection due to the access limitation although attempting to access the first server  112  set to return the given error. Thus, it is difficult to determine whether or not web authentication is being currently carried out from the response. For this reason, for example, by executing the following processing, the control unit  200  of the mobile terminal  104  suppresses a situation in which the mobile phone line  102  is used in authentication by the wireless LAN line  103  and the web authentication fails. 
         [0054]    First, if the self-terminal is subjected to the access limitation, the control unit  200  sets the determination criterion of the communication quality for determining whether or not to select the wireless LAN line  103  by the simultaneous communication function to second quality higher than first quality for the normal state when coupling to the access point  131 . Then, if the communication quality of the wireless LAN line  103  is lower than the second quality, the control unit  200  does not use the wireless LAN line  103  and carries out communications by the mobile phone line  102  even when linking to the access point  131  of the wireless LAN line  103 . The purpose of this is to avoid failure in web authentication attributed to the communication quality if the communication quality in the wireless LAN line  103  is low. 
         [0055]    Furthermore, if the communication quality of the wireless LAN line  103  is higher than the second quality, the control unit  200  of the mobile terminal  104  starts communications by the wireless LAN line  103 . Thereafter, the control unit  200  fixes communications to the wireless LAN line  103  until data communications of a given number of times of communication coupling (for example, a given number of continuous sockets) are carried out (or finished), and carries out control so as not to cause data to flow to the mobile phone line  102  and completes the web authentication processing in the interim. Then, after the data communications of the given number of times of communication coupling are carried out, the control unit  200  returns the determination criterion to the first quality and carries out switching to simultaneous communications of the mobile phone line  102  and the wireless LAN line  103 . 
         [0056]    The communication quality may include the received radio wave intensity (for example, dBm) and the link speed (for example, bps) between the coupled access point  131  and the mobile terminal  104  for example. That is to say, for example if the determination criterion of the communication quality is set to the first quality, the control unit  200  may select the wireless LAN line  103  if the received radio wave intensity is higher than a first threshold and the link speed is higher than a first link speed. Furthermore, if the determination criterion of the communication quality is changed to the second quality, the control unit  200  may select the wireless LAN line  103  if the received radio wave intensity is higher than a second threshold and the link speed is higher than a second link speed for example. The second threshold is a value higher than the first threshold and the second link speed is a link speed higher than the first link speed. 
         [0057]    Furthermore, the web authentication processing is executed through an application such as a browser for example. For this reason, the count of the given number of times of communication coupling may be carried out by counting the communication coupling by the application such as a browser that executes the web authentication processing from communications carried out in the mobile terminal  104  for example. 
         [0058]    As described above, when the mobile terminal  104  is subjected to the access limitation, if the communication quality of the wireless LAN line  103  is, sufficiently favorable, the control unit  200  of the mobile terminal  104  fixes communications to the wireless LAN line  103  and causes data to flow to the wireless LAN line  103  during the given number of times of communication coupling and completes the web authentication processing in the interim. This can suppress a situation in which the mobile phone line  102  is used in authentication by the wireless LAN line  103  and the web authentication fails. 
         [0059]      FIG. 10  is a diagram exemplifying an operation flow of the web authentication processing executed by the control unit  200  of the mobile terminal  104  according to the embodiment. The control unit  200  of the mobile terminal  104  may start the operation flow of  FIG. 10  when the first radio interface  221  for coupling to the wireless LAN line  103  is turned on in the mobile terminal  104  for example. 
         [0060]    In a step  1001  (hereinafter, step will be described as “S” and the step  1001  will be represented as S 1001  for example), the control unit  200  of the mobile terminal  104  determines whether or not the mobile terminal  104  has newly coupled to the access point  131  of a web authentication system. If the mobile terminal  104  has not newly coupled to the access point  131  of the web authentication system (NO in S 1001 ), the flow repeats S 1001 . On the other hand, if the mobile terminal  104  has newly coupled to the access point  131  of the web authentication system (YES in S 1001 ), the flow proceeds to S 1002 . 
         [0061]    In S 1002 , the control unit  200  of the mobile terminal  104  determines whether or not the coupled access point  131  is an access point used in the wireless LAN line  103  in which access limitation can be set. For example, the service set identifier (SSID) set in the access point  131  of the wireless LAN line  103  provided by a mobile phone operator is settled. Thus, the control unit  200  of the mobile terminal  104  may determine, from the SSID, whether or not the access point  131  is an access point point used in the wireless LAN line  103  in which access limitation can be set. 
         [0062]    If the access point  131  is an access point used in the wireless LAN line  103  in which access limitation can be set (YES in S 1002 ), the flow proceeds to S 1003 . In S 1003 , the control unit  200  of the mobile terminal  104  attempts to access the first server  112  set to return a given error (for example, 204 of an HTTP status code) via the mobile phone line  102 . In S 1004 , the control unit  200  of the mobile terminal  104  determines whether or not the response to the access is the given error response (for example, 204 of an HTTP status code) set in the first server  112  of the coupling destination. If the response is not the given error response (NO in S 1004 ), the flow proceeds to S 1005 . In S 1005 , the control unit  200  determines that the mobile terminal  104  is subjected to access limitation and redirection is carried out. 
         [0063]    In S 1006 , the control unit  200  changes the determination criterion of the communication quality used to determine whether or not to select the wireless LAN line  103  by the simultaneous communication function to the second quality higher than the first quality for the normal state. In S 1007 , the control unit  200  determines whether or not the communication quality of the wireless LAN line  103  is higher than the second quality. If the communication quality of the wireless LAN line  103  is equal to or lower than the second quality (NO in S 1007 ), the flow proceeds to S 1008  and the control unit  200  carries out communications via the mobile phone line  102 . Then, the flow returns to S 1007 . On the other hand, if the communication quality of the wireless LAN line  103  is higher than the second quality (YES in S 1007 ), the flow proceeds to S 1009 . In S 1009 , the control unit  200  fixes the distribution destination of data to be communicated to the first radio interface  221  and carries out communications by the wireless LAN line  103 . Subsequently, in S 1010 , the control unit  200  determines whether or not communications of a given number of times of communication coupling have been carried out. If communications of the given number of times of communication coupling have not been carried out (NO in S 1010 ) the control unit  200  continues communications by the wireless LAN line  103  while fixing the distribution destination of data to be communicated to the first radio interface  221 , and the flow repeats the processing of S 1010 . On the other hand, if communications of the given number of times of communication coupling have been carried out (YES in S 1010 ), the flow proceeds to S 1011 . In S 1011 , the control unit  200  releases the fixing of the distribution destination of data to be communicated to the first radio interface  221  and carries out simultaneous communications. Furthermore, the control unit  200  changes the determination criterion of the communication quality from the second quality to the first quality and the flow returns to S 1001 . 
         [0064]    Furthermore, if the access point  131  is not an access point used in the wireless LAN line  103  in which access limitation can be set in S 1002  (NO in S 1002 ), the flow proceeds to S 1013 . If the response is the given error response in S 1004  (YES in S 1004 ), the flow proceeds to S 1012  and the control unit  200  determines that the mobile terminal  104  is not subjected to access limitation. Also in this case, the flow proceeds to S 1013 . 
         [0065]    In S 1013 , the control unit  200  attempts to access the first server  112  set to return the given error (for example, 204 of an HTTP status code) via the wireless LAN line  103 . In S 1014 , the control unit  200  determines whether or not the response to the access is the given error response (for example, 204 of an HTTP status code) set in the first server  112  of the coupling destination. If the response is the given error response (YES in S 1014 ), the mobile terminal  104  is not subjected to redirection to the authentication server  111  and therefore the control unit  200  determines that the mobile terminal  104  has been authenticated in S 1015 , followed by the return of the flow to S 1001 . 
         [0066]    On the other hand, if the response is not the given error response in S 1014  (NO in S 1014 ), the mobile terminal  104  is subjected to redirection to the authentication server  111  and the flow proceeds to S 1016 . In S 1016 , the control unit  200  fixes the distribution destination of data to be communicated to the first radio interface  221  and attempts to access the first server  112  set to return the given error via the wireless LAN line  103 . In S 1017 , the contra unit  200  determines whether or not the response is the given error response set in, the first server  112  of the coupling destination. The given error response may be 204 of an HTTP status code for example. If the response is not the given error response (NO in S 1017 ), the flow returns to S 1016  and repeats the processing. The user may carry out web authentication in the period of the repetitive processing of S 1016  and S 1017 . 
         [0067]    If the response is the given error response in S 1017  (YES in S 1017 ), the web authentication has been completed and thus the flow proceeds to S 1018 . The control unit  200  releases the fixing of the distribution destination of data to be communicated to the first radio interface  221  and carries out simultaneous communications, followed by the return of the flow to S 1001 . 
         [0068]    In the above operation flow of  FIG. 10 , in the processing from S 1001  to S 1006 , the control unit  200  of the mobile terminal  104  functions as the changing unit  201  for example. In the processing from S 1007  to S 1010 , the control unit  200  of the mobile terminal  104  functions as the fixing unit  202  for example. In the processing of S 1011 , the control unit  200  of the mobile terminal  104  functions as the changing unit  201  and the fixing unit  202  for example. 
         [0069]      FIGS. 11A and 113  are diagrams exemplifying a flow of communications in the web authentication processing according to the embodiment.  FIG. 11A  exemplifies the web authentication processing in the case in which the mobile terminal  104  is not subjected to access limitation. In  FIG. 11A , communications may be carried out similarly to  FIG. 6A  for example until the mobile terminal  104  carries out communications via the mobile phone line  102  after train departure. Subsequently, suppose that the user arrives at a different station and couples to the access point  131  of the wireless LAN line  103  belonging to a different subnet. In this case, first the mobile terminal  104  attempts to access the first server  112  set to return the given error by the mobile phone line  102 . If the mobile terminal  104  is not subjected to access limitation, the response is the given error (for example, 204 of an HTTP status code) from the first server  112 . In this case, the mobile terminal  104  attempts to access the first server  112  by the wireless LAN line  103 . If the mobile terminal  104  has not been authenticated, the access to the first server  112  is redirected to the authentication server  111  and the mobile terminal  104  receives success in the access (for example, 200 OK of an HTTP status code) from the authentication server  111 . In this case, the mobile terminal  104  fixes communications to the wireless LAN line  103  so as not to cause communications for the authentication to flow to the mobile phone line  102 . Furthermore, the mobile terminal  104  attempts to access the first server  112  and carries out polling until the response to the access becomes the given error (for example, 204 of an HTTP status code). If the response becomes the given error, the mobile terminal  104  determines that the authentication has been completed, and starts simultaneous communications. 
         [0070]    Furthermore,  FIG. 11B  is a diagram exemplifying the web authentication processing in the case in which the mobile terminal  104  is subjected to access limitation. In  FIG. 11B , communications may be carried out similarly to  FIG. 6A  for example until the mobile terminal  104  carries out communications via the mobile phone line  102  after train departure. Subsequently, suppose that the user arrives at a different station and couples to the access point  131  of the wireless LAN line  103  belonging to a different subnet. In this case, first the mobile terminal  104  attempts to access the first server  112  by the mobile phone line  102 . If access limitation is imposed on the mobile terminal  104 , the access to the first server  112  is redirected to the second server  113 , which notifies the access limitation, and the response is success (for example, 200 OK of an HTTP status code). In this case, the mobile terminal  104  sets the determination criterion of the communication quality for determining whether or not to distribute data to the wireless LAN line  103  in simultaneous communications to the second quality higher than the first quality for the normal state. Due to this, communications are carried out by the mobile phone line  102  until favorable communication quality is obtained. Then, if the communication quality becomes higher and more favorable than the second quality, the mobile terminal  104  fixes communications to the wireless LAN line  103  and carries out web authentication until communications of a given number of times of communication coupling are carried out, and completes the authentication. Thereafter, the mobile terminal  104  starts simultaneous communications. 
         [0071]    As described above, according to the embodiment, the control unit  200  of the mobile terminal  104  can determine whether or not access limitation is imposed on the self-device. Furthermore, if access limitation is imposed on the self-device, the control unit  200  changes the determination criterion of the communication quality used for determining whether or not to distribute data to the wireless LAN line  103  in simultaneous communications from the first quality to the second quality higher than the first quality. Then, when the communication quality becomes the state of being more favorable than the second quality, the control unit  200  fixes communications to the wireless LAN line  103  and carries out web authentication until communications of a given number of times of communication coupling are carried out, and completes the authentication in the interim. For this reason, the control unit  200  can suppress the flowing of packets to the mobile phone line  102  in the authentication also when access limitation is imposed on the self-device. Therefore, according to the embodiment, failure in the authentication processing can be suppressed. 
         [0072]    Furthermore, after communications of the given number of times of communication coupling are carried out, it is estimated that the authentication has been completed. Thus, the fixing of communications to the wireless LAN line  103  is released and the determination criterion is returned from the second quality to the first quality. For this reason, simultaneous communications using the mobile phone line  102  and the wireless LAN line  103  can be carried out after the completion of the authentication. 
         [0073]    The communication quality may include the received radio wave intensity and the link speed between the access point  131  of the wireless LAN line  103  and the first radio interface  221  for example. For example, also when the received radio wave intensity between the access point  131  of the wireless LAN line  103  and the first radio interface  221  is high, a low link speed causes, communication failure in some cases. Furthermore, for example, also when the link speed between the access point  131  of the wireless LAN line  103  and the first radio interface  221  is high, low received radio wave intensity causes communication failure in some cases. For this reason, by carrying out determination of e.g. S 1007  by using both the received radio wave intensity and the link speed as the communication quality, initiation of processing of web authentication in a situation in which the authentication fails attributed to the communication quality can be avoided more accurately. 
         [0074]    Although the embodiment is exemplified in the above, the embodiment is not limited thereto. For example, the above-described operation flow is exemplification and the embodiment is not limited thereto. If possible, the operation flow may be carried out with change in the order of the processing and may include further processing additionally or part of processing may be omitted. For example, the processing of S 1005 , S 1012 , and S 1015  in  FIG. 10  does not have to be executed. Furthermore, in another embodiment, the operation flow of  FIG. 10  may be changed to proceed to the processing of S 1006  when YES is obtained as the determination result in S 1001 . That is, the processing from S 1002  to S 1005  and from S 1012  to S 1018  may be omitted. In this case, for example, also when the mobile terminal  104  is not subjected to access limitation, web authentication is carried out by the processing from S 1006  to S 1011  and thereby failure in the processing of the web authentication can be suppressed. 
         [0075]    Furthermore, in the above-described example, the case in which communications are fixed to the wireless LAN line  103  until communications of a given number of times of communication coupling are carried out in S 1010  is exemplified. However, the embodiment is not limited thereto. For example, on the basis of the data communication amount of communications carried out through a browser instead of the number of times of communication coupling, the determination of S 1010  may be carried out so that communications may be fixed to the wireless LAN line  103  in the period until the completion of the authentication. Alternatively, the determination of S 1010  may be carried out on the basis of another value such as the time so that communications may be fixed to the wireless LAN line  103  in the period until the completion of the authentication. The given number of times of communication coupling used for the determination in S 1010  can be set by acquiring the trend in the number of times of communication coupling of communications carried out through an application such as a browser in the period from S 1016  to the timing when YES is obtained as the determination result in S 1017  for example. 
         [0076]      FIG. 12  is a diagram exemplifying a hardware configuration of a computer  1200  for implementing the mobile terminal  104  according to an embodiment. The hardware configuration of the computer  1200  for implementing the mobile terminal  104  of  FIG. 12  includes a processor  1201 , a memory  1202 , a reading device  1204 , a communication interface  1206 , an input/output interface  1207 , and a display device  1210  for example. The processor  1201 , the memory  1202 , the reading device  1204 , the communication interface  1206 , and the input/output interface  1207  are coupled to each other via a bus  1208  for example. 
         [0077]    The processor  1201  provides functions of part or all of the above-described respective functional units by executing a radio communication program in which the procedure of the above-described operation flow is described for example by use of the memory  1202 . For example, the processor  1201  functions as the changing unit  201  and the fixing unit  202  by executing the radio communication program stored in the memory  1202 . Furthermore, the storing unit  210  includes the memory  1202  and an attachable/detachable storage medium  1205  for example. In the memory  1202  of the mobile terminal  104 , information on the first quality and the second quality, which are the determination criteria of the communication quality, and so forth are stored for example. 
         [0078]    The memory  1202  is a semiconductor memory for example and may include a RAM area and a ROM area. The RAM is an abbreviation for Random Access Memory. Furthermore, the ROM is an abbreviation for Read Only Memory. 
         [0079]    The reading device  1204  accesses the attachable/detachable storage medium  1205  in accordance with an instruction by the processor  1201 . The attachable/detachable storage medium  1205  is implemented by a semiconductor device (USB memory, etc.), a medium to and from which information is input and output by magnetic action (magnetic disc, etc.), a medium to and from which information is input and output by optical action (CD-ROM, DVD, etc.), and so forth for example. The USB is an abbreviation for Universal Serial Bus. The CD is an abbreviation for Compact Disc. The DVD is an abbreviation for Digital Versatile Disk. 
         [0080]    The communication interface  1206  couples to a network  1220  in accordance with an instruction by the processor  1201  and transmits and receives data. The above-described communication unit  220  is the communication interface  1206  for example. The communication interface  1206  may include radio communication equipment that operates as the first radio interface  221 , which couples to the access point  131 , and radio communication equipment that operates as the second radio interface  222 , which couples to the base station  121 , for example. The input/output interface  1207  may be an interface between an input device and an output device for example. The input device is a device, such as a keyboard and a mouse, that accepts instructions from a user for example. The output device is a sound device such as a speaker and a printing device such as a printer for example. Furthermore, the input/output interface  1207  is coupled to the display device  1210 . The display device  1210  may be a display for example. Moreover, the above-described display screens of  FIG. 4  and  FIG. 8  may be displayed on the display device  1210  for example. 
         [0081]    The respective programs according to the embodiment are provided to the mobile terminal  104  in the following forms for example. 
         [0082]    (1) the programs are installed on the memory  1202  in advance. 
         [0083]    (2) the programs are provided by the attachable/detachable storage medium  1205 . 
         [0084]    (3) the programs are provided from a server  1230  such as a program server. 
         [0085]    The hardware configuration of the computer  1200  described with reference to  FIG. 12  is exemplification and the embodiment is not limited thereto. For example, functions of part or all of the above-described functional units may be implemented as hardware based on FPGA, SoC, etc. The FPGA is an abbreviation for Field Programmable Gate Array. The SoC is an abbreviation for System-on-a-chip. 
         [0086]    In the above, several embodiments are described. However, embodiments are not limited to the above-described embodiments and may be understood as what includes various kinds of modified forms and alternative forms of the above-described embodiments. For example, it will be understood that various kinds of embodiments can be embodied by modifying a constituent element within such a range as not to depart from the gist and range thereof. Furthermore, it will be understood that various embodiments can be carried out by combining, as appropriate, plural constituent elements disclosed in the above-described embodiments. Moreover, it will be understood by those skilled in the art that various embodiments can be carried out by deleting or replacing several constituent elements from all constituent elements represented in the embodiments or adding several constituent elements to the constituent elements represented in the embodiments. 
         [0087]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited, examples and, conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.