Patent Publication Number: US-2021181295-A1

Title: Positioning system, positioning method, and recording medium

Description:
TECHNICAL FIELD 
     The present invention relates to a method of deriving a position of a communication device. 
     BACKGROUND ART 
     A wireless communication terminal (hereinafter, referred to as a “terminal”) such as a smartphone generally specifies a position of the terminal by using a GPS. Herein, the GPS is an abbreviation of Global Positioning System. 
     However, there is a case that a position of a terminal is desired to be acquired in a situation that the terminal cannot use the GPS, or in an environment that use of the GPS is difficult even when the GPS is usable. For example, the terminal may be within a tunnel or in a shadow of a building, and a GPS radio wave may not reach the terminal. 
     As a method in which the terminal can acquire a position thereof without using the GPS, a method employing a three-point positioning method by radio quality information relating to a radio wave to be received from three or more base stations relating to wireless communication to be performed by the terminal is known (see PTL 1). Herein, the radio quality information is, for example, at least either one of a received electric field strength and a propagation time relating to the radio wave to be received. 
     PTL 2 discloses a radio terminal in which detection of a radio link disconnection is performed, information relating to the radio link disconnection is stored, and information indicating storing the information relating to the radio link disconnection and information relating to a moving speed are notified to a radio network. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Japanese Unexamined Patent Application Publication No. H10-239416 
     [PTL 2] Japanese Unexamined Patent Application Publication No. 2017-127015 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, when a three-point positioning method is employed by using a radio wave in a frequency band in which a terminal performs wireless communication, there is a case that it is difficult to derive a position. Such a case is, for example, a case in which the radio wave in the frequency band from three or more base stations does not reach the terminal with a sufficient strength. 
     An object of the present invention is to provide a positioning system and the like capable of deriving a position of a communication device, even when it is difficult to use a GPS, and derive the position of the communication device by a radio wave in an allocated frequency band. 
     Solution to Problem 
     A positioning system according to the present invention includes: a reception processing unit that derives second frequency band quality information being information representing quality of a second frequency band radio wave that is a radio wave in a second frequency band being a frequency band that does not overlap a first frequency band allocated to wireless communication to be performed by a communication device, and is received from a second frequency band communicator for transmitting the second frequency band radio wave; and a deriving unit that derives and outputs second frequency band position information being information representing a position of the communication device being derived from the second frequency band quality information relating to each of three or more of the second frequency band communicators. At least a position of the reception processing unit out of the reception processing unit and the deriving unit lies within the communication device. 
     Advantageous Effects of Invention 
     A positioning system and the like according to the present invention are able to derive a position of a communication device, even when it is difficult to use a GPS, and derive the position of the communication device by a radio wave in an allocated frequency band. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  a conceptual diagram illustrating a configuration example of a positioning system according to a first example embodiment. 
         FIG. 2  is an image diagram illustrating an example of a positional relation among a communication device, the first frequency band base station, and the second frequency band base station. 
         FIG. 3  is a conceptual diagram illustrating a first processing flow example of processing to be performed by a processing unit of a positioning device according to the first example embodiment. 
         FIG. 4  is a conceptual diagram illustrating a first processing flow example of processing to be performed by a processing unit of a communication device according to the first example embodiment. 
         FIG. 5  is a conceptual diagram illustrating processing of replacing processing of S 104  to S 109  illustrated in  FIG. 3 . 
         FIG. 6  is a conceptual diagram illustrating a second processing flow example of processing to be performed by the processing unit of the communication device according to the first example embodiment. 
         FIG. 7  is a conceptual diagram illustrating a configuration example of a positioning system according to a second example embodiment. 
         FIG. 8  is a conceptual diagram illustrating a processing flow example of processing to be performed by a processing unit of a communication device according to the second example embodiment. 
         FIG. 9  is a conceptual diagram illustrating a processing flow example of processing to be performed by a processing unit of a positioning device according to a third example embodiment. 
         FIG. 10  is a conceptual diagram illustrating a processing flow example of processing to be performed by a processing unit of a communication device according to the third example embodiment. 
         FIG. 11  is a conceptual diagram illustrating a hardware configuration example of an information processing device capable of achieving a positioning device and a communication device according to each of the example embodiments. 
         FIG. 12  is a block diagram illustrating a minimum configuration of a positioning system according to an example embodiment. 
     
    
    
     EXAMPLE EMBODIMENT 
     A positioning system according to any of example embodiments performs derivation of a position of a communication device by a second frequency band radio wave being a radio wave other than a first frequency band radio wave being a radio wave in a frequency band for use in wireless communication by the communication device. Therefore, the positioning system is able to derive a position of the communication device, even when it is difficult to derive the position of the communication device by the first frequency band radio wave. 
     First Example Embodiment 
     A first example embodiment is an example embodiment relating to a positioning system for deriving a position of a communication device by an external positioning device. 
     [Configuration and Operation] 
       FIG. 1  is a conceptual diagram illustrating a configuration of a positioning system  501 , which is an example of the positioning system according to the first example embodiment. 
     The positioning system  501  includes a positioning device  301  and a communication device  401 . 
     The positioning device  301  is a device for deriving a position of the communication device  401 . The positioning device  301  is connected to a network  801 . A connection method thereof is optional. 
     The positioning device  301  includes a communication unit  306 , a processing unit  316 , and a storage unit  326 . 
     The processing unit  316  causes the communication unit  306  to transmit setting information to the communication device  401  at the time of deriving a position of the communication device  401 . The setting information is information for causing the communication device  401  to receive a second frequency radio wave being a radio wave in a second frequency band. Herein, the second frequency band is a frequency band other than a first frequency band, and which does not overlap the first frequency band to be described next. The first frequency band is a frequency band allocated to the communication device  401  for wireless communication (transmission and reception) to be performed by the communication device  401 . The communication device  401  performs communication with equipment and the like connected to the network  801  via a first frequency band base station being a base station to which the first frequency band is allocated for wireless communication by a first frequency band radio wave being a radio wave in the first frequency band. 
     The setting information includes, for example, information representing the second frequency band. 
     The second frequency band is a frequency band in which a second frequency band communication device being a communication device to which the second frequency band is allocated for wireless communication performs communication with equipment and the like connected to the network  801  via a second frequency band base station. The second base station is a base station to which the second frequency band is allocated for wireless communication. The communication device  401  is not the second frequency band communication device. 
     The setting information is stored in advance in the storage unit  326 . 
     The processing unit  316  waits, from the communication device  401 , transmission of second frequency band radio quality information being radio quality information in the second frequency band, regarding three or more different second frequency band base stations. The second frequency band radio quality information is radio quality information regarding the second frequency band radio wave from the second frequency band base station from which the communication device  401  can receive the second frequency band radio wave. The radio quality information is information representing quality of a radio wave that reaches the communication device  401 . The radio quality information includes, for example, at least either one of a received electric field strength and a propagation time regarding a radio wave that reaches the communication device  401  from a certain base station. The propagation time is a propagation time of the second frequency radio wave between the communication device  401  and a certain second frequency band base station. The propagation time is, for example, a difference between a transmission time of the second frequency band radio wave in the base station that transmits the second frequency band radio wave, and a reception time of the second frequency band radio wave in the communication device  401 . 
     The radio quality information further includes an identifier (ID) representing a base station that transmits the radio wave. The ID is, for example, a cell ID relating to the base station. 
     When receiving, from the communication device  401 , transmission of the second frequency band radio quality information regarding three or more second frequency band base stations, the processing unit  316  derives, from pieces of the second frequency band radio quality, position information representing a position of the communication device  401 . The processing unit  316  performs the derivation by the three-point positioning method described in the section of the Background Art. 
     In the following description, a position derived from the second frequency band radio quality information is referred to as a “second frequency band position”. 
     In the foregoing description, a case is described in which the processing unit  316  derives a position of the communication device  401  only from second frequency band radio quality information relating a second frequency band base station. Alternatively, the processing unit  316  may derive a position of the communication device  401  by using in combination first frequency band radio quality information being the radio quality information of the first frequency band radio wave, which is transmitted by the communication device  401  and received from the first frequency band base station. 
     In this case, the processing unit  316  causes the communication device  401  to transmit, to the positioning device  301  via the communication unit  306 , the first frequency band radio quality information regarding the three or more first frequency band base stations. Then, the processing unit  316  derives, from the pieces of the first frequency band radio quality information, a position of the communication device  401  by the above-described three-point positioning method. In the following description, a position derived from the first frequency band radio quality information is referred to as a “first frequency band position”. 
     Then, the processing unit  316  derives a third position from the first frequency band position and the second frequency band position. The third position is, for example, an intermediate position between the first frequency band position and the second frequency band position. Then, the processing unit  316  sets the third position as a position of the communication device  401 . 
     The communication unit  306  performs communication with predetermined equipment connected to the network  801  in response to an instruction from the processing unit  316 . The equipment includes the communication device  401 . 
     The storage unit  326  stores in advance a program and information necessary for the operation to be performed by the processing unit  316  and the communication unit  306 . The information includes the setting information. 
     The storage unit  326  further stores information instructed by the communication unit  306  or the processing unit  316 . 
     The storage unit  326  further reads information instructed by the communication unit  306  or the processing unit  316 , and transmits the information to a designated one out of the communication unit  306  and the processing unit  316 . 
     The communication device  401  is, for example, a communication terminal. The communication terminal is, for example, a mobile terminal such as a smartphone. 
     The communication device  401  includes a main communication unit  406 , a sub reception unit  411 , a processing unit  416 , a sub processing unit  421 , and a storage unit  426 . The main communication unit  406 , the sub reception unit  411 , the processing unit  416 , the sub processing unit  421 , and the storage unit  426  are, for example, installed in one housing. 
     The processing unit  416  causes the main communication unit  406  to perform communication by the above-described first frequency band radio wave with predetermined equipment connected to the network  801  via the above-described first frequency band base station. The equipment includes the positioning device  301 . 
     When the setting information is transmitted from the positioning device  301 , the processing unit  416  causes the storage unit  426  to store the setting information. Then, the processing unit  416  causes the sub processing unit  421  to acquire the second frequency band radio quality information based on the setting information. 
     The sub processing unit  421  may have a hardware configuration common to the processing unit  416 . 
     When the second frequency band radio quality information is stored in the storage unit  426  by the sub processing unit  421 , the processing unit  416  causes the main communication unit  406  to transmit the second frequency band radio quality information to the positioning device  301 . 
     When being instructed to transmit the first frequency band radio quality information from the positioning device  301 , the processing unit  416  tries to acquire the first frequency band radio quality information regarding a first frequency band radio wave received by the main communication unit  406 . At this occasion, when a received electric field strength is included in the radio quality information, the processing unit  416  derives the received electric field strength, for example, by a signal level of an electric signal detected by the main communication unit  406  after reception. When the propagation time is included in the radio quality information, the processing unit  416  derives the propagation time, for example, by subtracting the transmission time from a reception time of the first frequency band radio wave in the communication device  401 . Herein, the transmission time is a transmission time of the first frequency band radio wave in the frequency band base station, which is included in the first frequency band radio wave. Alternatively, the processing unit  416  may derive the propagation time by a well-known round trip method. 
     The processing unit  416  causes the storage unit  426  to store the derived first frequency band radio quality information. Then, the processing unit  416  causes the main communication unit  406  to transmit the first frequency band radio quality information to the positioning device  301 . 
     The main communication unit  406  performs communication with predetermined equipment connected to the network  801  via the first frequency band base station by the first frequency band radio wave in response to an instruction from the processing unit  416 . The equipment includes the positioning device  301 . 
     The sub reception unit  411  receives the second frequency band radio wave that reaches from the second frequency band base station in response to an instruction from the sub processing unit  421 . Then, the sub reception unit  411  transmits the received information to the sub processing unit  421 . The sub reception unit  411  does not transmit the second frequency band radio wave. 
     When the above-described setting information is stored in the storage unit  426  by the processing unit  416 , the sub processing unit  421  causes the sub reception unit  411  to receive the second frequency band radio wave, based on the setting information. Then, the sub processing unit  421  tries to acquire the second frequency band radio quality information by the second frequency band radio wave received by the sub reception unit  411 . 
     When the second frequency band radio quality information is acquired, the sub processing unit  421  causes the storage unit  426  to store the acquired second frequency band radio quality information. 
     At this occasion, when the received electric field strength is included in the radio quality information, the sub processing unit  421  derives a received electric field strength of the received second frequency band radio wave, for example, by a signal level of an electric signal by the sub reception unit  411  after reception. When the propagation time is included in the radio quality information, the sub processing unit  421  derives a propagation time of the second frequency band radio wave, for example, by subtracting a transmission time of the second frequency band radio wave, which is included in the second frequency band radio wave, from a reception time of the second frequency band radio wave. Alternatively, the sub processing unit  421  may derive the propagation time by a well-known round trip method. 
     Then, the sub processing unit  421  causes the processing unit  416  and the main communication unit  406  to transmit the derived second frequency band radio quality information to the positioning device  301 . 
     The storage unit  426  stores in advance a program and information for causing each of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421  to perform the above-described operation. The storage unit  426  further stores information instructed from each of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 . The storage unit  426  further reads information instructed from each of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 , and transmits the information to a designated one out of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 . 
       FIG. 2  is an image diagram illustrating a layout example of a communication device, the first frequency band base station, and the second frequency band base station. 
     White dots illustrated in  FIG. 2  indicate first frequency band base stations. Black dots indicate second frequency band base stations. 
     In  FIG. 2 , the first frequency band base stations located near the communication device  401  are three base stations, namely, first frequency band base stations A 1  to A 3 . Each of the first frequency band base stations A 1  to A 3  is connected to the network  801  illustrated in  FIG. 1 . 
     It is assumed that the communication device  401  is able to receive the first frequency band radio wave emitted from at least one of the first frequency band base stations A 1  to A 3 . Further, it is assumed that the first frequency band radio wave emitted from the communication device  401  is receivable by the associated first frequency band base station. In this case, the communication device  401  is able to perform communication with equipment connected to the network illustrated in  FIG. 1  via the first frequency band base station. The equipment includes the positioning device  301 . 
     Then, it is assumed that the communication device  401  is also able to receive the first frequency band radio wave emitted from any of the first frequency band base stations A 1  to A 3 . In this case, the communication device  401  is able to acquire the first frequency band radio quality information regarding the first frequency band radio wave emitted from the first frequency band base station. 
     It is assumed that eleven second frequency band base stations, namely, second frequency band base stations B 1  to B 11 , are present around the communication device  401 . It is assumed that the communication device  401  is able to receive the second frequency band radio wave emitted from each of the second frequency band base stations B 2 , B 4 , B 8 , and B 9  nearby. In this case, the communication device  401  is able to acquire the second frequency band radio quality information regarding the second frequency band radio wave emitted from each of the second frequency band base stations B 2 , B 4 , B 8 , and B 9 . 
     Herein, it is assumed that the communication device  401  cannot receive a first frequency band radio wave from any of the first frequency band base stations A 1  to A 3 , regardless of the above. In this case, the positioning device  301  illustrated in  FIG. 1  cannot derive a position of the communication device  401  by the three-point positioning method from the first frequency band radio wave emitted from the first frequency band base stations A 1  to A 3 . Even in this case, the positioning device  301  can derive a position of the communication device  401  by the three-point positioning method, as far as the communication device  401  is able to receive a second frequency band radio wave emitted from three or more second frequency band base stations out of the second frequency band base stations B 2 , B 4 , B 8 , and B 9 . 
     [Processing Flow Example] 
       FIG. 3  is a conceptual diagram illustrating a processing flow example of processing to be performed by the processing unit  316  of the positioning device  301  illustrated in  FIG. 1 . 
     The processing unit  316  starts the processing illustrated in  FIG. 3  by an external input of starting information, for example. 
     Then, as processing of S 101 , the processing unit  316  determines whether positioning of the communication device  401  is performed. The processing unit  316  performs the determination, for example, by determining whether a timing that is set in advance for performing positioning has reached. Herein, it is assumed that the processing unit  316  is in an environment in which a clock is usable. 
     The processing unit  316  performs processing of S 102 , when a determination result by the processing of S 101  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 101  again, when the determination result by the processing of S 101  is no. 
     When processing of S 102  is performed, as the same processing, the processing unit  316  causes the communication unit  306  to transmit notification information to the communication device  401 . The notification information is information of notifying the communication device  401  of starting positioning the communication device  401 . 
     Then, as processing of S 103 , the processing unit  316  causes the communication unit  306  to transmit the above-described setting information to the communication device  401 . The setting information is information for causing the communication device  401  to receive the second frequency band radio wave, as described above. 
     Then, as processing of S 104 , the processing unit  316  determines whether the above-described second frequency band radio quality information is newly received. The second frequency band radio quality information being a determination target is limited to the one which has not yet undergone processing of S 105 . 
     The processing unit  316  performs the processing of S 105 , when a determination result by the processing of S 104  is yes. 
     On the other hand, the processing unit  316  performs processing of S 106 , when the determination result by the processing of S 104  is no. 
     When the processing of S 105  is performed, as the same processing, the processing unit  316  causes the storage unit  326  illustrated in  FIG. 1  to store second frequency band radio quality information, which is determined to be received by processing of S 104 . Then, the processing unit  316  performs the processing of S 104  again. 
     When the processing of S 106  is performed, as the same processing, the processing unit  316  determines whether a time T has elapsed from a time when the processing of S 103  finished. Herein, it is assumed that the processing unit  316  is in an environment in which a timer is usable. Further, the time T is a time that is determined in advance for the processing of S 106 . The processing of S 106  is performed for the purpose of waiting reception of second frequency band radio quality information from the communication device  401  by the time T. 
     The processing unit  316  performs processing of S 107 , when a determination result by the processing of S 106  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 104  again, when the determination result by the processing of S 106  is no. 
     When processing of S 107  is performed, as the same processing, the processing unit  316  determines whether the number of the second frequency band base stations relating to the second frequency band radio quality information stored in the storage unit  326  is three or more. Herein, it is assumed that the number of the second frequency band base stations coincides with the number of pieces of the second frequency band radio quality information. 
     The processing unit  316  performs processing of S 108 , when a determination result by the processing of S 107  is yes. 
     On the other hand, the processing unit  316  performs processing of S 110 , when the determination result by the processing of S 107  is no. 
     When processing of S 108  is performed, as the same processing, the processing unit  316  derives, from the second frequency band radio quality information relating to the three or more second frequency band base stations stored in the storage unit  326 , the second frequency band position of the communication device  401  by the three-point positioning method. 
     Then, the processing unit  316  causes the storage unit  326  to store position information representing the second frequency band position derived by the processing of S 108 . The second frequency band position stored in the storage unit  326  is output to external equipment, for example, in response to a request to the positioning device  301  by the external equipment via the network  801 . 
     When processing of S 110  is performed, as the same processing, the processing unit  316  causes the storage unit  326  to store information indicating that it is not possible to derive a second frequency band position. 
     Then, as processing of S 111 , the processing unit  316  determines whether the processing illustrated in  FIG. 3  is finished. The processing unit  316  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  316  finishes the processing illustrated in  FIG. 3 , when a determination result by the processing of S 111  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 101  again, when the determination result by the processing of S 111  is no. 
       FIG. 4  is a conceptual diagram illustrating a processing flow example of processing to be performed by the processing unit  416  of the communication device  401  illustrated in  FIG. 1 . 
     The processing unit  416  starts the processing illustrated in  FIG. 4  by an external input of starting information, for example. 
     Then, as processing of S 151 , the processing unit  416  performs initialization of making storage contents of first to third storage units in the storage unit  426  illustrated in  FIG. 1  empty. The first to third storage units are each a storage unit represented by an address, for example, and provided for storing specific information in the storage unit  426 . 
     The first storage unit is a storage unit for storing the above-described notification information (see the processing of S 102  in  FIG. 3 ), which is transmitted to the communication device  401  by the positioning device  301 . The second storage unit is a storage unit for storing the above-described setting information (see the processing of S 103  in  FIG. 3 ), which is transmitted to the communication device  401  by the positioning device  301 . The third storage unit is a storage unit for storing second frequency band radio quality information acquired by the sub processing unit  421 . 
     Next, as processing of S 152 , the processing unit  416  determines whether the notification information, of which transmission is received from the positioning device  301  by the main communication unit  406  illustrated in  FIG. 1 , is stored in the first storage unit. Herein, when the main communication unit  406  receives the notification information, it is assumed that storing the notification information in the first storage unit is determined in advance. Further, it is assumed that the processing unit  416  sequentially monitors whether the notification information is stored in the first storage unit. 
     The processing unit  416  performs processing of S 153 , when a determination result by the processing of S 152  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 152  again, when the determination result by the processing of S 152  is no. 
     When processing of S 153  is performed, as the same processing, the processing unit  416  determines whether the setting information is stored in the second storage unit. Herein, when the main communication unit  406  receives the setting information, it is assumed that storing the setting information in the second storage unit is determined in advance. Further, it is assumed that the processing unit  416  sequentially monitors whether the setting information is stored in the second storage unit. 
     The processing unit  416  performs processing of S 154 , when a determination result by the processing of S 153  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 153  again, when the determination result by the processing of S 153  is no. 
     When processing of S 154  is performed, as the same processing, the processing unit  416  instructs the sub processing unit  421  illustrated in  FIG. 1  to receive a second frequency band radio wave, based on the setting information stored in the second storage unit. 
     The sub processing unit  421  that has received the instruction causes the sub reception unit  411  to start receiving a second frequency band radio wave. 
     Then, as processing of S 155 , the processing unit  416  instructs the sub processing unit  421  to try to acquire, from the received second frequency band radio wave, the second frequency band radio quality information, and store the acquired second frequency band radio quality information into the third storage unit. 
     The sub processing unit  421  that has received the instruction tries to acquire, from the second frequency band radio wave received by the sub reception unit  411 , the second frequency band radio quality information. When the second frequency band radio quality information is acquired, the sub processing unit  421  causes the storage unit  426  to store the second frequency band radio quality information into the third storage unit. The sub processing unit  421  performs the acquisition and the storing by the number of times equal to the number of the second frequency band base stations that have transmitted the received second frequency band radio wave. 
     Next, as processing of S 156 , the processing unit  416  determines whether a time T 1  has elapsed since the processing of S 155  finished. Herein, it is assumed that the processing unit  416  is in an environment in which a timer is usable. Further, the time T 1  is a time that is determined in advance for the processing of S 156 . The processing of S 156  is performed for the purpose of waiting derivation of the second frequency band radio quality information and storing into the third storage unit by the sub processing unit  421  by the time T 1 . 
     The processing unit  416  performs processing of S 157 , when a determination result by the processing of S 156  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 156  again, when the determination result by the processing of S 156  is no. 
     When the processing of S 157  is performed, as the same processing, the processing unit  416  determines whether the second frequency band radio quality information is stored in the third storage unit. Herein, it is assumed that the processing unit  416  sequentially monitors whether the second frequency band radio quality information is stored in the third storage unit. 
     The processing unit  416  performs processing of S 158 , when a determination result by the processing of S 157  is yes. 
     On the other hand, the processing unit  416  performs processing of S 159 , when the determination result by the processing of S 157  is no. 
     When the processing of S 158  is performed, as the same processing, the processing unit  416  causes the main communication unit  406  to transmit, to the positioning unit  301 , the second frequency band radio quality information stored in the third storage unit. 
     Then, as the processing of S 159 , the processing unit  416  determines whether the processing illustrated in  FIG. 4  is finished. The processing unit  416  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  416  finishes the processing illustrated in  FIG. 4 , when a determination result by the processing of S 159  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 151  again, when the determination result by the processing of S 159  is no. 
     As described above, the positioning system  501  may derive a position of the communication device  401  by using first frequency band radio quality information in addition to second frequency band radio quality information. In the following, a processing flow example is described in a case where a position of the communication device  401  is derived by using first frequency band radio quality information in addition to second frequency band radio quality information. 
     A second processing flow example of processing to be performed by the processing unit  316  of the positioning device  301  is an example in which processing of S 104  to S 109  is replaced by processing illustrated in  FIG. 5  in the processing flow example illustrated in  FIG. 3 . 
       FIG. 5  is a conceptual diagram illustrating processing of replacing the processing of S 104  to S 109  illustrated in  FIG. 3 . 
     Succeeding to the processing of S 103  illustrated in  FIG. 3 , as processing of S 201 , the processing unit  316  determines whether a time T has elapsed from a time when the processing of S 103  finished. Herein, it is assumed that the processing unit  316  is in an environment in which a timer is usable. Further, the time T is a time that is determined in advance for the processing of S 201 . The processing of S 106  is performed for the purpose of waiting reception of first frequency band radio quality information or second frequency band radio quality information from the communication device  401  by the time T. 
     The processing unit  316  performs processing of S 206 , when a determination result by the processing of S 201  is yes. 
     On the other hand, the processing unit  316  performs processing of S 202 , when the determination result by the processing of S 201  is no. 
     When the processing of S 202  is performed, as the same processing, the processing unit  316  determines whether the above-described first frequency band radio quality information is received from the communication device  401 . 
     The processing unit  316  performs processing of S 203 , when a determination result by the processing of S 202  is yes. 
     On the other hand, the processing unit  316  performs processing of S 204 , when the determination result by the processing of S 202  is no. 
     When the processing of S 203  is performed, as the same processing, the processing unit  316  causes the storage unit  326  illustrated in  FIG. 1  to store first frequency band radio quality information, which is determined to be received by the processing of S 202 . Then, the processing unit  316  performs processing of S 204 . 
     When the processing of S 204  is performed, as the same processing, the processing unit  316  determines whether the above-described second frequency band radio quality information is received from the communication device  401 . 
     The processing unit  316  performs processing of S 205 , when a determination result by the processing of S 204  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 201  again, when the determination result by the processing of S 204  is no. 
     When the processing of S 205  is performed, as the same processing, the processing unit  316  causes the storage unit  326  illustrated in  FIG. 1  to store second frequency band radio quality information, which is determined to be received by the processing of S 204 . Then, the processing unit  316  performs the processing of S 204  again. 
     When the processing of S 206  is performed, as the same processing, the processing unit  316  determines whether the number of first radio quality base stations relating to the first frequency band radio quality information stored in the storage unit  326  is three or more. Herein, it is assumed that the number of the first frequency band base stations coincides with the number of pieces of the first frequency band radio quality information. 
     The processing unit  316  performs processing of S 207 , when a determination result by the processing of S 206  is yes. 
     On the other hand, the processing unit  316  performs processing of S 208 , when the determination result by the processing of S 206  is no. 
     When the processing of S 207  is performed, as the same processing, the processing unit  316  derives, from the first frequency band radio quality information relating to the three or more first frequency band base stations stored in the storage unit  326 , the first frequency band position of the communication device  401  by the three-point positioning method. Then, the processing unit  316  causes the storage unit  326  to store position information representing the derived first frequency band position. 
     When the processing of S 208  is performed, as the same processing, the processing unit  316  determines whether the number of second radio quality base stations relating to the second frequency band radio quality information stored in the storage unit  326  is three or more. Herein, it is assumed that the number of the second frequency band base stations coincides with the number of pieces of the second frequency band radio quality information. 
     The processing unit  316  performs processing of S 209 , when a determination result by the processing of S 208  is yes. 
     On the other hand, the processing unit  316  performs processing of S 210 , when the determination result by the processing of S 208  is no. 
     When processing of S 209  is performed, as the same processing, the processing unit  316  derives, from the second frequency band radio quality information relating to the three or more second frequency band base stations stored in the storage unit  326 , the second frequency band position of the communication device  401  by the three-point positioning method. Then, the processing unit  316  causes the storage unit  326  to store position information representing the derived second frequency band position. 
     When the processing of S 210  is performed, as the same processing, the processing unit  316  derives the third position from the first frequency band position and the second frequency band position stored in the storage unit  326 , and causes the storage unit  326  to store position information representing the third position. The processing unit  316  performs the derivation, for example, by setting the third position as an intermediate position between the first frequency position and the second frequency position. 
     At the time of the processing of S 210 , when either one of the first frequency band position and the second frequency band position is not stored in the storage unit  326 , the processing unit  316  sets the other of these positions as the third position. 
     When neither the first frequency band position nor the second frequency band position is stored in the storage unit  326 , the processing unit  316  does not derive the third position. Then, the processing unit  316  causes the storage unit  326  to store information indicating that the third position is not derived, for example. 
     Then, the processing unit  316  performs the processing of S 111  illustrated in  FIG. 3 . 
       FIG. 6  is a conceptual diagram illustrating a second processing flow example of processing to be performed by the processing unit  416  of the communication device  401  illustrated in  FIG. 1 . 
     The processing unit  416  starts the processing illustrated in  FIG. 6  by an external input of starting information, for example. 
     As processing of S 251 , the processing unit  416  performs initialization of making storage contents of first to fourth storage units in the storage unit  426  illustrated in  FIG. 1  empty. The first to fourth storage units are each a storage unit represented by an address, for example, and provided for storing specific information in the storage unit  426 . 
     The first storage unit is a storage unit for storing the above-described notification information (see the processing of S 102  in  FIG. 3 ), which is transmitted to the communication device  401  by the positioning device  301 . The second storage unit is a storage unit for storing the above-described setting information (see the processing of S 103  in FIG.  3 ), which is transmitted to the communication device  401  by the positioning device  301 . The third storage unit is a storage unit for storing second frequency band radio quality information acquired by the sub processing unit  421 . The fourth storage unit is a storage unit for storing the first frequency band radio quality information acquired by the processing unit  416 . 
     Next, as processing of S 252 , the processing unit  416  determines whether the notification information received from the positioning device  301  by the main communication unit  406  illustrated in  FIG. 1  is stored in the first storage unit. Herein, when the main communication unit  406  receives the notification information, it is assumed that storing the notification information in the first storage unit is determined in advance. Further, it is assumed that the processing unit  416  sequentially monitors whether the notification information is stored in the first storage unit. 
     The processing unit  416  performs processing of S 253 , when a determination result by the processing of S 252  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 252  again, when the determination result by the processing of S 252  is no. 
     When processing of S 253  is performed, as the same processing, the processing unit  416  determines whether the setting information is stored in the second storage unit. Herein, when the main communication unit  406  receives the setting information, it is assumed that storing the setting information in the second storage unit is determined in advance. Further, it is assumed that the processing unit  416  sequentially monitors whether the setting information is stored in the second storage unit. 
     The processing unit  416  performs processing of S 254 , when a determination result by the processing of S 253  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 253  again, when the determination result by the processing of S 253  is no. 
     When processing of S 254  is performed, as the same processing, the processing unit  416  instructs the sub processing unit  421  illustrated in  FIG. 1  to receive a second frequency band radio wave by the sub reception unit  411 , based on the setting information stored in the second storage unit. 
     The sub processing unit  421  that has received the instruction causes the sub reception unit  411  to receive a second frequency band radio wave. 
     Then, as processing of S 255 , the processing unit  416  instructs the sub processing unit  421  to try to acquire, from the second frequency band radio wave received by the sub reception unit  411 , the second frequency band radio quality information, and store the acquired second frequency band radio quality information into the third storage unit. 
     The sub processing unit  421  that has received the instruction tries to acquire, from the received second frequency band radio wave, the second frequency band radio quality information. When the second frequency band radio quality information is acquired, the sub processing unit  421  stores the second frequency band radio quality information into the third storage unit. The sub processing unit  421  performs the acquisition and the storing by the number of times equal to the number of the second frequency band base stations that have transmitted the received second frequency band radio wave. 
     Then, as processing of S 256 , the processing unit  416  tries to acquire, from the first frequency band radio wave received by the main communication unit  406 , the first frequency band radio quality information. When the first frequency band radio quality information is acquired, the processing unit  416  stores the first frequency band radio quality information into the fourth storage unit. The processing unit  416  performs the acquisition and the storing by the number of times equal to the number of the first frequency band base stations that have transmitted the received first frequency band radio wave. 
     Next, as processing of S 257 , the processing unit  416  determines whether a time T 1  has elapsed since the processing of S 255  finished. Herein, it is assumed that the processing unit  416  is in an environment in which a timer is usable. Further, the time T 1  is a time that is determined in advance for the processing of S 257 . The processing of S 257  is performed for the purpose of waiting storing of the second frequency band radio quality information into the third storage unit by the sub processing unit  421  by the time T 1 . The processing of S 257  is also performed for the purpose of acquisition of the first frequency band radio quality information and storing into the fourth storage unit by the processing unit  416  by the time T 1 . 
     The processing unit  416  performs processing of S 258 , when a determination result by the processing of S 257  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 256  again, when the determination result by the processing of S 257  is no. 
     When processing of S 258  is performed, as the same processing, the processing unit  416  at least determines whether the second frequency band radio quality information is stored in the third storage unit, or the first frequency band radio quality information is stored in the fourth storage unit. Herein, it is assumed that the processing unit  416  sequentially monitors whether the second frequency band radio quality information is stored in the third storage unit, and whether the first frequency band radio quality information is stored in the fourth storage unit. 
     The processing unit  416  performs processing of S 259 , when a determination result by the processing of S 258  is yes. 
     On the other hand, the processing unit  416  performs processing of S 260 , when the determination result by the processing of S 258  is no. 
     When the processing of S 259  is performed, as the same processing, the processing unit  416  causes the main communication unit  406  to transmit, to the positioning unit  301 , the second frequency band radio quality information stored in the third storage unit, and the first frequency band radio quality information stored in the fourth storage unit. 
     Then, as the processing of S 260 , the processing unit  416  determines whether the processing illustrated in  FIG. 6  is finished. The processing unit  416  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  416  finishes the processing illustrated in  FIG. 6 , when a determination result by the processing of S 260  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 251  again, when the determination result by the processing of S 260  is no. 
     Advantageous Effect 
     A positioning system according to the first example embodiment performs derivation of a position of a communication device by a second frequency band radio wave being a radio wave other than a first frequency band radio wave being a radio wave in a frequency band for use in wireless communication by the communication device. Therefore, the positioning system is able to derive a position of the communication device, even when it is difficult to derive the position of the communication device by the first frequency band radio wave. 
     There is a case that the positioning system derives a position (third position) of the communication device from a position (second frequency band position) derived by the second frequency band radio wave, and a position (first frequency band position) derived by the first frequency band radio wave. In this case, an error included in the second frequency band position and an error included in the first frequency band position can be absorbed at the third position. Therefore, the positioning system is able to improve derivation precision on a position of the communication device. 
     Second Example Embodiment 
     A second example embodiment is an example embodiment relating to a communication system for deriving a position of a communication device by the communication device itself. It is assumed that description on each term that starts with a first frequency band or a second frequency band in description of the second example embodiment is the same as in the first example embodiment. However, when description on these terms is inconsistent between the first example embodiment and the second example embodiment, description in the second example embodiment is preferentially used. 
     [Configuration and Operation] 
       FIG. 7  is a conceptual diagram illustrating a configuration of a positioning system  501 , which is an example of a positioning system according to the second example embodiment. 
     The positioning system  501  includes a communication device  401 . 
     The communication device  401  is, for example, a communication terminal. The communication terminal is, for example, a mobile terminal such as a smartphone. 
     The communication device  401  includes a main communication unit  406 , a sub reception unit  411 , a processing unit  416 , a sub processing unit  421 , and a storage unit  426 . 
     The processing unit  416  causes the main communication unit  406  to perform wireless communication using a first frequency band with predetermined equipment connected to a network  801  via a first frequency band base station. The first frequency band is a frequency band in which the communication device  401  to which the first frequency band is allocated as a frequency for use in wireless communication performs communication with equipment and the like connected to the network  801  via the first frequency band base station. The first frequency band base station is a base station in which the first frequency band is allocated as a frequency for use in wireless communication. 
     When positioning of the communication device  401  is performed, the processing unit  416  causes the sub processing unit  421  to acquire the second frequency band radio quality information based on setting information stored in advance in the storage unit  426 . Description on the second frequency band radio quality information is as described in the first example embodiment. 
     The sub processing unit  421  may have a same hardware configuration as the processing unit  416 . 
     When the second frequency band radio quality information regarding the three or more second frequency band base stations is stored in the storage unit  426  by the sub processing unit  421 , the processing unit  416  derives a position of the communication device  401  from these pieces of the information. The processing unit  416  performs the derivation by the three-point positioning method described in the section of the Background Art. 
     The processing unit  416  causes the storage unit  426  to store position information representing the derived second frequency band position. 
     The processing unit  416  may derive a position of the communication device  401  by using the first frequency band radio quality information in combination. 
     At this occasion, the processing unit  416  tries to acquire, by the first frequency band radio wave received by the main communication unit, the first frequency band radio quality information regarding the three or more first frequency band base stations with respect to the first frequency band radio wave received by the main communication unit  406 . At this occasion, when the received electric field strength is included in the radio quality information, the processing unit  416  derives the received electric field strength of the first frequency band radio wave, for example, by a signal level of an electric signal by the main communication unit  406  after reception. When the propagation time is included in the radio quality information, the processing unit  416  derives the propagation time of the first frequency band radio wave by subtracting, from a reception time of the first frequency band radio wave, a transmission time of the first frequency band radio wave. 
     Then, the processing unit  416  derives the first frequency band position of the communication device  401  by the above-described three-point positioning method from these pieces of the first frequency band radio quality information. 
     The processing unit  416  causes the storage unit  426  to store position information representing the derived first frequency band position. 
     Then, the processing unit  416  derives the third position from the first frequency band position and the second frequency band position. The third position is, for example, an intermediate position between the first frequency band position and the second frequency band position. Then, the processing unit  416  sets the third position as a position of the communication device  401 . 
     The processing unit  416  causes the storage unit  426  to store position information representing the derived third position. 
     The main communication unit  406  performs communication with predetermined equipment connected to the network  801  via the first frequency band base station by the first frequency band radio wave in response to an instruction from the processing unit  416 . The equipment includes a positioning device  301 . 
     The sub reception unit  411  receives the second frequency band radio wave from the second frequency band base station. Then, the sub reception unit  411  transmits the reception information to the sub processing unit  421 . 
     The sub processing unit  421  causes the sub reception unit  411  to receive the second frequency band radio wave based on the setting information stored in advance in the storage unit  426 , in response to an instruction from the processing unit  416 . Then, the sub processing unit  421  tries to acquire the second frequency band radio quality information by the second frequency band radio wave received by the sub reception unit  411 . The sub processing unit  421  performs the trial by the reception information received by the sub reception unit  411 . 
     When the second frequency band radio quality information is acquired, the sub processing unit  421  causes the storage unit  426  to store the acquired second frequency band radio quality information. 
     At this occasion, when the received electric field strength is included in the radio quality information, the sub processing unit  421  derives a received electric field strength of the second frequency band radio wave by a signal level of an electric signal by the sub reception unit  411  after reception. When the propagation time is included in the radio quality information, the sub processing unit  421  derives a propagation time of the second frequency band radio wave by subtracting, from a reception time of the radio wave, a transmission time of the radio wave, which is included in the radio wave. 
     The storage unit  426  stores in advance a program and information for causing the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421  to perform the above-described operation. The information includes the setting information. The storage unit  426  further stores information instructed from each of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 . The storage unit  426  further reads information instructed from each of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 , and transmits the information to a designated one out of the main communication unit  406 , the processing unit  416 , the sub reception unit  411 , and the sub processing unit  421 . 
     [Processing Flow Example] 
       FIG. 8  is a conceptual diagram illustrating a processing flow example of processing to be performed by the processing unit  416  of the communication device  401  illustrated in  FIG. 7 . 
     The processing unit  416  performs the processing illustrated in  FIG. 8  by an external input of starting information, for example. 
     Then, as processing of S 301 , the processing unit  416  determines whether a position of the communication device  401  is derived. The processing unit  416  performs the determination, for example, by determining whether an external input of instruction information is present. 
     The processing unit  416  performs processing of S 302 , when a determination result by the processing of S 301  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 301  again, when the determination result by the processing of S 301  is no. 
     Then, as the processing of S 302 , the processing unit  416  performs initialization of making storage contents of third and fifth storage units in the storage unit  426  illustrated in  FIG. 7  empty. The third and fifth storage units are each a storage unit represented by an address, for example, and for storing specific information in the storage unit  426 . 
     The third storage unit is a storage unit for storing second frequency band radio quality information acquired by the sub processing unit  421 . 
     On the other hand, the fifth storage unit is a storage unit in which the setting information for causing the sub processing unit  421  to receive the second frequency band radio wave is stored. The sub processing unit  421  receives the second frequency band radio wave by the setting information stored in the fifth storage unit. Therefore, for example, in the following case, the sub processing unit  421  receives the second frequency band radio wave by the setting information stored in the fifth storage unit. The case is a case that the storage unit  426  stores a plurality of types of the setting information, and the processing unit  416  causes the fifth storage unit to store one of the setting information by external input information. A case that the storage unit  426  stores a plurality of types of the setting information is, for example, a case that the storage unit  426  stores the setting information relating to a plurality of frequency bands. 
     As processing of S 303 , the processing unit  416  causes the storage unit  426  to store the setting information into the fifth storage unit. 
     Then, as processing of S 304 , the processing unit  416  instructs the sub processing unit  421  to acquire the second frequency band radio quality information, and store the acquired second frequency band radio quality information into the third storage unit. 
     The sub processing unit  421  that has received the instruction causes the sub reception unit  411  to receive the second frequency band radio wave, based on the setting information stored in the fifth storage unit. Then, the sub processing unit  421  tries to acquire the second frequency band radio quality information from the second frequency band radio wave received by the sub reception unit  411 . When the second frequency band radio quality information is acquired, the sub processing unit  421  stores the second frequency band radio quality information into the third storage unit. The sub processing unit  421  performs the acquisition and the storing by the number of times equal to the number of the second frequency band base stations that have transmitted the received second frequency band radio wave. 
     Next, as processing of S 305 , the processing unit  416  determines whether a time T 1  has elapsed since the processing of S 304  finished. Herein, it is assumed that the processing unit  416  is in an environment in which a timer is usable. Further, the time T 1  is a time that is determined in advance for the processing of S 305 . The processing of S 305  is performed for the purpose of waiting storing of the second frequency band radio quality information into the third storage unit by the sub processing unit  421  by the time T 1 . 
     The processing unit  416  performs processing of S 306 , when a determination result by the processing of S 305  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 305  again, when the determination result by the processing of S 305  is no. 
     When the processing of S 306  is performed, as the same processing, the processing unit  416  determines whether the second frequency band radio quality information relating to the three or more second frequency band base stations is stored in the third storage unit. Herein, it is assumed that the number of the second frequency band base stations coincides with the number of pieces of the second frequency band radio quality information. Further, it is assumed that the processing unit  416  sequentially monitors the number of pieces of the second frequency band radio quality information stored in the third storage unit. 
     The processing unit  416  performs processing of S 307 , when a determination result by the processing of S 306  is yes. 
     On the other hand, the processing unit  416  performs processing of S 309 , when the determination result by the processing of S 306  is no. 
     When the processing of S 307  is performed, as the same processing, the processing unit  416  derives the second frequency band position of the communication device  401  by the second frequency band radio quality information relating to the three or more second frequency band base stations stored in the third storage unit. The processing unit  416  performs the derivation by the three-point positioning method described in the first example embodiment. 
     Then, as processing of S 308 , the processing unit  416  causes the storage unit  426  to store position information representing the second frequency band position derived by the processing of S 307 . 
     Then, as the processing of S 309 , the processing unit  416  determines whether the processing illustrated in  FIG. 8  is finished. The processing unit  416  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  416  finishes the processing illustrated in  FIG. 8 , when a determination result by the processing of S 309  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 301  again, when the determination result by the processing of S 309  is no. 
     Advantageous Effect 
     Similarly to the positioning system according to a first system, the positioning system according to the second example embodiment performs derivation of a position of a communication device by a second frequency band radio wave being a radio wave other than a first frequency band radio wave being a radio wave in a frequency band for use in wireless communication by the communication device. Therefore, similarly to the positioning system according to the first example embodiment, the positioning system according to the second example embodiment is able to derive a position of the communication device, even when it is difficult to derive the position of the communication device by the first frequency band radio wave. 
     In addition to the above, the positioning system according to the second example embodiment performs derivation of the position by the communication device itself being a positioning target. Therefore, the positioning system according to the second example embodiment is able to omit communication to be performed between the communication device and a positioning device. Thus, the positioning system according to the second example embodiment is able to reduce communication load in communication to be performed between the communication device and a positioning device. 
     Third Example Embodiment 
     A third example embodiment is an example embodiment relating to a positioning system achievable in terms of long term evolution (LTE) specification. It is assumed that description on each term that starts with a first frequency band or a second frequency band in the description of the third example embodiment, regarding the description described in the first example embodiment, is the same as the description in the first example embodiment. However, when description on these terms is inconsistent between the first example embodiment and the second example embodiment, description in the second example embodiment is preferentially used. 
     [Configuration and Operation] 
     A configuration example of a positioning system according to the third example embodiment is a configuration of the positioning system  501  illustrated in  FIG. 1 . However, a positioning device illustrated in  FIG. 1  is included in a base station being the LTE compliant. A communication device  401  is an LTE terminal or the like. 
     Description on an operation of the positioning system  501  according to the third example embodiment is made by description on the following processing flow example. 
     [Processing Flow Example] 
       FIG. 9  is a conceptual diagram illustrating a processing flow example of processing to be performed by a processing unit  316  of a positioning device  301  according to the third example embodiment, which is illustrated in  FIG. 1 . 
     The processing unit  316  starts the processing illustrated in  FIG. 9  by an external input of starting information, for example. 
     Then, as processing of S 401 , the processing unit  316  determines whether a first frequency band measurement report (MR) being a MR relating to a first frequency band radio wave is transmitted from the communication device  401 . The MR is defined in accordance with the LTE standards, and is well-known. 
     The processing unit  316  performs processing of S 402 , when a determination result by the processing of S 401  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 401  again, when the determination result by the processing of S 401  is no. 
     When the processing of S 402  is performed, as the same processing, the processing unit  316  causes a storage unit  326  to store the first frequency band MR, which is determined, by the processing of S 401 , to be transmitted. 
     Then, as processing of S 403 , the processing unit  316  causes a communication unit  306  to transmit a periodical measurement setting to the communication device  401 . The periodical measurement setting is defined in accordance with the LTE standards, and is well-known. 
     Then, as processing of S 404 , the processing unit  316  causes the communication unit  306  to transmit, to the communication device  401 , setting information on a measurement configuration for measuring second frequency band radio quality. The measurement configuration and the setting information thereof are defined in accordance the LTE standards, and are well-known. 
     Then, as processing of S 405 , the processing unit  316  derives the first frequency band position by the first frequency band radio quality information included in the first frequency band MR stored in the storage unit  326  by the processing of S 402 . Herein, inclusion of the first frequency band radio quality information in the first frequency band MR is well-known. 
     However, it is not always a case that the first frequency band radio quality information relating to the first frequency band radio wave emitted from the three or more first frequency band base stations is included in the first frequency band MR. When the first frequency band radio quality information relating to the three or more first frequency band base stations is not included in the first frequency band MR, the processing unit  316  does not derive the first frequency band position. 
     When the first frequency band position is derived, the processing unit  316  causes the storage unit  326  to store position information representing the derived first frequency band position. 
     Then, as processing of S 406 , the processing unit  316  determines whether a second frequency band MR is received from the communication device  401 . 
     The processing unit  316  performs processing of S 407 , when a determination result by the processing of S 406  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 407  again, when the determination result by the processing of S 406  is no. 
     When the processing of S 407  is performed, as the same processing, the processing unit  316  causes the storage unit  326  to store a second frequency band MR, which is determined, by processing of S 406 , to be received. 
     Then, as processing of S 408 , the processing unit  316  derives the second frequency band position by the second frequency band radio quality information included in the second frequency band MR stored in the storage unit  326  by the processing of S 407 . 
     Inclusion of the second frequency band radio quality information in the second frequency band MR is well-known. 
     However, it is not always the case that the second frequency band radio quality information relating to the second frequency band radio wave emitted from the three or more second frequency band base stations is included in the second frequency band MR. When the second frequency band radio quality information relating to the three or more second frequency band base stations is not included in the second frequency band MR, the processing unit  316  does not derive the second frequency band position. 
     When the second frequency band position is derived, the processing unit  316  causes the storage unit  326  to store position information representing the derived second frequency band position. 
     Then, as processing of S 409 , the processing unit  316  derives the third position by the first frequency band position stored in the storage unit  326  by the processing of S 405 , and the second frequency band position stored in the storage unit  326  by the processing of S 408 . Description on the third position is as described in the description on the first example embodiment. 
     However, when neither the first frequency band position nor the second frequency band position is stored in the storage unit  326 , the processing unit  316  does not derive the third position. 
     When the third position is derived by processing of S 410 , the processing unit  316  causes the storage unit  326  to store position information representing the derived third position. 
     Then, as processing of S 411 , the processing unit  316  determines whether the processing illustrated in  FIG. 9  is finished. The processing unit  316  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  316  finishes the processing illustrated in  FIG. 9 , when a determination result by the processing of S 411  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 401  again, when the determination result by the processing of S 411  is no. 
       FIG. 10  is a conceptual diagram illustrating a processing flow example of processing to be performed by a processing unit  416  of the communication device  401  according to the third example embodiment, which is illustrated in  FIG. 1 . 
     The processing unit  416  starts the processing illustrated in  FIG. 10  by an external input of starting information, for example. 
     Then, as processing of S 451 , the processing unit  416  performs initialization of making storage contents of first to third storage units in the storage unit  426  illustrated in  FIG. 1  empty. Each of the first to third storage units is a storage unit represented by an address, for example, and provided for storing specific information in the storage unit  426 . 
     The first storage unit is a storage unit for storing the above-described periodical measurement setting (see the processing of S 403  in  FIG. 9 ), which is transmitted to the communication device  401  by the positioning device  301 . The second storage unit is a storage unit for storing information (see the processing of S 404  in  FIG. 9 ) for use in setting a measurement configuration for measuring second frequency band radio quality. The third storage unit is a storage unit for storing a second frequency band measurement report generated by a sub processing unit  421 . 
     Next, as processing of S 452 , the processing unit  416  determines whether a first frequency band measurement report is transmitted to the positioning device  301 . The processing unit  416  performs the determination, for example, by determining whether a predetermined timing at which a first frequency band measurement report is transmitted to the positioning device  301  has reached. Herein, it is assumed that the communication device  401  is determined to transmit, to the positioning device  301 , a first frequency band measurement report at the above-described timing. Further, it is assumed that the processing unit  416  can use a clock for determining that the above-described timing has reached. 
     The processing unit  416  performs processing of S 453 , when a determination result by the processing of S 452  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 452  again, when the determination result by the processing of S 452  is no. 
     When processing of S 453  is performed, as the same processing, the processing unit  416  generates the first frequency band MR by the first frequency band radio wave received by the communication unit  306 . Then, the processing unit  416  causes the storage unit  426  to store the generated first frequency band MR into the fourth storage unit. 
     Then, as processing of S 454 , the processing unit  416  determines whether the periodical measurement setting is stored in the first storage unit. 
     The processing unit  416  performs processing of S 455 , when a determination result by the processing of S 454  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 454  again, when the determination result by the processing of S 454  is no. 
     When the processing of S 455  is performed, as the same processing, the processing unit  416  determines whether the first frequency band measurement configuration setting information is stored in the second storage unit. 
     The processing unit  416  performs processing of S 456 , when a determination result by the processing of S 455  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 455  again, when the determination result by the processing of S 455  is no. 
     When the processing of S 456  is performed, as the same processing, the processing unit  416  instructs the sub processing unit  421  illustrated in  FIG. 1  to start receiving a second frequency band radio wave, based on the measurement configuration setting information stored in the second storage unit. 
     The sub processing unit  421  that has received the instruction causes the sub reception unit  411  to start receiving the second frequency band radio wave. 
     Then, as processing of S 457 , the processing unit  416  instructs the sub processing unit  421  to generate the above-described second frequency band MR from the received second frequency band radio wave, and store the second frequency band MR into the third storage unit. 
     The sub processing unit  421  that has received the instruction tries to acquire, from the received second frequency band radio wave, the second frequency band radio quality information. When the second frequency band radio quality information is acquired, the sub processing unit  421  stores the second frequency band radio quality information into the third storage unit. The sub processing unit  421  performs the acquisition and the storing by the number of times equal to the number of the second frequency band base stations that have transmitted the received second frequency band radio wave. Then, the sub processing unit  421  generates the second frequency band MR including the acquired second frequency band radio quality information, and causes the storage unit  426  to store the second frequency band MR into the third storage unit. 
     Next, as processing of S 458 , the processing unit  416  determines whether the second frequency band MR is stored in the third storage unit. The processing unit  416  sequentially monitors whether the second frequency band MR is stored in the third storage unit. 
     The processing unit  316  performs processing of S 459 , when a determination result by the processing of S 458  is yes. 
     On the other hand, the processing unit  316  performs the processing of S 458  again, when the determination result by the processing of S 458  is no. 
     When the processing of S 459  is performed, as the same processing, the processing unit  316  causes a main communication unit  406  to transmit, to the positioning device  301 , the second frequency band MR stored in the third storage unit. 
     Then, as processing of S 460 , the processing unit  416  determines whether the processing illustrated in  FIG. 10  is finished. The processing unit  416  performs the determination, for example, by determining whether an external input of finishing information is present. 
     The processing unit  416  finishes the processing illustrated in  FIG. 10 , when a determination result by the processing of S 460  is yes. 
     On the other hand, the processing unit  416  performs the processing of S 451  again, when the determination result by the processing of S 460  is no. 
     Advantageous Effect 
     The positioning system according to the third example embodiment provides an advantageous effect similar to the advantageous effect provided by the positioning system according to the first example embodiment, while following a processing operation between a terminal and a base station, which is defined in the LTE. 
     In the foregoing description, a case is described in which a deriving unit being a portion for deriving and outputting second frequency band position information is included in either of a communication device and a positioning device. The second frequency band position information is information representing a position of the communication device derived from the second frequency band quality information relating to each of the three or more second frequency band communicators. However, an installation position of the deriving unit is optional. For example, a part of the deriving unit may be included in the communication device, and the other part thereof may be located outside the communication device. 
       FIG. 11  is a conceptual diagram illustrating a hardware configuration example of an information processing device capable of achieving a positioning device and a communication device according to each of the example embodiments. 
     An information processing device  90  includes a communication interface  91 , an input/output interface  92 , an arithmetic device  93 , a storage device  94 , a non-volatile storage device  95 , and a drive device  96 . 
     The communication interface  91  is a communication means with which a communication device according to each of the example embodiments communicates by wired or/and wireless with an external device. When the communication device is achieved by using at least two information processing devices, these devices may be connected to be mutually communicable to each other via the communication interface  91 . 
     The input/output interface  92  is a man-machine interface such as a keyboard being one example of an input device, and a display as an output device. 
     The arithmetic device  93  is an arithmetic processing device such as a general-purpose central processing unit (CPU) and a microprocessor. The arithmetic device  93  is, for example, able to read various programs stored in the non-volatile storage device  95  to the storage device  94 , and execute processing in response to the read program. 
     The storage device  94  is a memory device being referrable from the arithmetic device  93 , such as a random access memory (RAM), and stores a program, various pieces of data, and the like. The storage device  94  may be a volatile memory device. 
     The non-volatile storage device  95  is, for example, a non-volatile storage device such as a read only memory (ROM) and a flash memory, and is able to store various programs, data, and the like. 
     The drive device  96  is, for example, a device in which data reading and writing with respect to a recording medium  97  to be described later is processed. 
     The recording medium  97  is, for example, any recording medium capable of recording data, such as an optical disk, a magneto-optical disk, and a semiconductor flash memory. 
     Each of the example embodiments according to the present invention may be achieved, for example, by configuring a communication device by the information processing device  90  exemplified in  FIG. 11 , and supplying, to the communication device, a program capable of achieving functions described in each of the example embodiments. 
     In this case, it is possible to achieve an example embodiment by causing the arithmetic device  93  to execute a program supplied to the communication device. Further, it is also possible to configure not all the functions of the communication device but a part of the functions thereof by the information processing device  90 . 
     Further, it may be configured in such a way that the program is recorded in the recording medium  97 , and the program is stored in the non-volatile storage device  95  as necessary at shipment of the communication device, at an operation stage, or the like. In this case, a method of supplying the program may employ a method for installing the program in the communication device by using an appropriate jig at a production stage before shipment, an operation stage, or the like. A method of supplying the program may employ a general procedure such as a method of downloading the program from outside via a communication line such as the Internet. 
     Note that each of the above-described example embodiments is a preferred example embodiment according to the present invention, and various modifications are available as far as the modifications do not depart from the gist of the present invention. 
       FIG. 12  is a block diagram illustrating a configuration of a positioning system  501   x  being a minimum configuration of a positioning system according to an example embodiment. 
     The positioning system  501   x  includes a reception processing unit  421   x  and a deriving unit  316   x.    
     The reception processing unit  421   x  derives second frequency band quality information being information representing quality of a second frequency band radio wave received from a second frequency band communicator for emitting the second frequency band radio wave. The second frequency band radio wave is a radio wave in a second frequency band being a frequency band that does not overlap a first frequency band allocated to an unillustrated communication device for wireless communication. 
     The deriving unit  316   x  derives and outputs second frequency band position information being information representing a position of the communication device derived from the second frequency band quality information relating to each of the three or more second frequency band communicators. 
     The reception processing unit  421   x  is located inside the communication device, and a position of the deriving unit  316   x  is optional. 
     The positioning system  501   x  derives the position by the second frequency band radio wave, which is not the first frequency band radio wave for use in wireless communication by the communication device. 
     Therefore, even when it is difficult to derive the position by the first frequency band radio wave, the positioning system  501   x  is able to derive the position by the second frequency band radio wave. 
     Specifically, the positioning system  501   x  is able to derive a position of a communication device, even when it is difficult to use a GPS, and derive the position of the communication device by a radio wave in an allocated frequency band. 
     Therefore, the positioning system  501   x  provides an advantageous effect described in the section of [Advantageous Effects of Invention] by the above-described configuration. 
     Note that the positioning system  501   x  illustrated in  FIG. 12  is, for example, the positioning system  501  illustrated in  FIG. 1  or  FIG. 7 . The communication device is, for example, the communication device  401  illustrated in  FIG. 1  or  FIG. 7 . The reception processing unit  421   x  is, for example, combination of the sub reception unit  411  and the sub processing unit  421  illustrated in  FIG. 1  or  FIG. 7 . The deriving unit  316   x  is a portion for performing the derivation out of the processing unit  316  illustrated in  FIG. 1  or the processing unit  416  illustrated in  FIG. 7 . The second frequency band communicator is, for example, the above-described second frequency band base station. The second frequency band quality information is, for example, the above-described second frequency band radio quality information. 
     In the foregoing, each of the example embodiments according to the present invention has been described. However, the present invention is not limited to the above-described example embodiments, and it is possible to add further modifications, replacements, and adjustments within the basic technical scope of the present invention. For example, a configuration of an element illustrated in each drawing is one example for aiding comprehension of the present invention, and the present invention is not limited to the configurations illustrated in these drawings. 
     The whole or part of the example embodiments disclosed above can be described as, but not limited to, the following supplementary notes. 
     (Supplementary Note 1) 
     A positioning system including: 
     a reception processing unit that derives second frequency band quality information being information representing quality of a second frequency band radio wave that is a radio wave in a second frequency band being a frequency band that does not overlap a first frequency band allocated to wireless communication to be performed by a communication device, and is received from a second frequency band communicator for transmitting the second frequency band radio wave; and 
     a deriving unit that derives and outputs second frequency band position information being information representing a position of the communication device being derived from the second frequency band quality information relating to each of three or more of the second frequency band communicators, wherein 
     at least a position of the reception processing unit out of the reception processing unit and the deriving unit lies within the communication device. 
     (Supplementary Note 2) 
     The positioning system according to supplementary note 1, wherein 
     the second frequency band quality information is information, in the communication device, representing at least either one of a received electric field strength of the second frequency band radio wave and a propagation time of the second frequency band radio wave between the second frequency band communicator and the communication device. 
     (Supplementary Note 3) 
     The positioning system according to supplementary note 1 or 2, wherein 
     the second frequency band position information is derived by a three-point positioning method. 
     (Supplementary Note 4) 
     The positioning system according to any one of supplementary notes 1 to 3, wherein 
     transmission by the second frequency band radio wave is not performed. 
     (Supplementary Note 5) 
     The positioning system according to any one of supplementary notes 1 to 4, wherein 
     the communication device includes a communication processing unit that performs communication with predetermined equipment communicably connected via a first frequency band communicator that transmits a first frequency band radio wave being a radio wave in the first frequency band. 
     (Supplementary Note 6) 
     The positioning system according to supplementary note 5, wherein 
     the communication processing unit derives first frequency band quality information being information representing quality of the first frequency band radio wave received from the first frequency band communicator, and derives and outputs first frequency band position information being information representing a position of the reception processing unit being derived from the first frequency band quality information relating to each of the three or more first frequency band communicators. 
     (Supplementary Note 7) 
     The positioning system according to supplementary note 6, wherein 
     the first frequency band position information is derived by a three-point positioning method. 
     (Supplementary Note 8) 
     The positioning system according to supplementary note 6 or 7, wherein 
     third position information being information representing a position of the reception processing unit derived from the first frequency band position information and the second frequency band position information is derived and output. 
     (Supplementary Note 9) 
     The positioning system according to any one of supplementary notes 1 to 8, wherein 
     the communication device includes the reception processing unit, and the deriving unit is outside of the communication device. 
     (Supplementary Note 10) 
     The positioning system according to any one of supplementary notes 1 to 9, wherein 
     the reception processing unit is installed inside one housing, and the deriving unit is installed outside the housing. 
     (Supplementary Note 11) 
     The positioning system according to any one of supplementary notes 1 to 8, wherein 
     the communication device includes the reception processing unit and the deriving unit. 
     (Supplementary Note 12) 
     The positioning system according to any one of supplementary notes 1 to 8, and 11, wherein 
     both of the reception processing unit and the deriving unit are installed in one housing. 
     (Supplementary Note 13) 
     The positioning system according to any one of supplementary notes 1 to 8, 11, and 12, wherein the communication device is a communication terminal. 
     (Supplementary Note 14) 
     The positioning system according to supplementary note 13, wherein 
     the communication terminal is a mobile terminal. 
     (Supplementary Note 15) 
     A positioning method including: 
     deriving second frequency band quality information being information representing quality of a second frequency band radio wave that is a radio wave in a second frequency band being a frequency band that does not overlap a first frequency band allocated to a communication device for wireless communication, and is received from a second frequency band communicator for transmitting the second frequency band radio wave; and 
     deriving and outputting second frequency band position information being information representing a position of the communication device being derived from the second frequency band quality information relating to each of three or more of the second frequency band communicators. 
     (Supplementary Note 16) 
     A positioning program causing a computer to execute: 
     processing of deriving second frequency band quality information being information representing quality of a second frequency band radio wave that is a radio wave in a second frequency band being a frequency band that does not overlap a first frequency band allocated to a communication device for wireless communication, and is received from a second frequency band communicator for transmitting the second frequency band radio wave; and 
     processing of deriving and outputting second frequency band position information being information representing a position of the communication device being derived from the second frequency band quality information relating to each of three or more of the second frequency band communicators. 
     While the invention has been particularly shown and described with reference to example embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims. 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2018-160680, filed on Aug. 29, 2018, the disclosure of which is incorporated herein in its entirety by reference. 
     REFERENCE SIGNS LIST 
     
         
           90  Information processing device 
           91  Communication interface 
           92  Input/output interface 
           93  Arithmetic device 
           94  Storage device 
           95  Non-volatile storage device 
           96  Drive device 
           97  Recording medium 
           301  Positioning device 
           306  Communication unit 
           316 ,  416  Processing unit 
           316   x  Deriving unit 
           326 ,  426  Storage unit 
           401  Communication device 
           406  Main communication unit 
           411  Sub reception unit 
           421  Sub processing unit 
           421   x  Reception processing unit 
           501 ,  501   x  Positioning system 
           801  Network 
         A 1 , A 2 , A 3  First frequency band base station 
         B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7 , B 8 , B 9 , B 10 , B 11  Second frequency band base station