Patent Publication Number: US-2019199426-A1

Title: Base station device, notification method, notification system, unmanned aircraft, and communication terminal

Description:
TECHNICAL FIELD 
     Several aspects of the present invention relate to a base station device, a notification method, a notification system, an unmanned aircraft, and a communication terminal. 
     Priority is claimed on Japanese Patent Application No. 2016-175043, filed Sep. 7, 2016, the content of which is incorporated herein by reference. 
     BACKGROUND ART 
     Currently, small unmanned aircrafts such as drones are widespread, but since cameras are generally mounted on unmanned aircrafts, from the viewpoint of privacy protection, there is a desire to know that the unmanned aircrafts has approached a house or the like in a case that the unmanned aircrafts have approached the house or the like. Patent Document 1 describes a technology in which a flying object outputs a predetermined warning in a case that the flying object approaches an obstacle or a prohibited flight area in a case that coordinates of the obstacle or the prohibited flight area have been input in advance. 
     PRIOR ART DOCUMENT 
     Patent Document 
     [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2003-127997 
     SUMMARY OF THE INVENTION 
     Problem to Be Solved by the Invention 
     However, in the technology described in Patent Document 1, there is a problem that the warning cannot be output unless coordinates of a target are set in the flying object in advance. 
     Several aspects of the present invention have been made in view of the above circumstances, and an object of the present invention is to provide a base station device, a notification method, a notification system, an unmanned aircraft, and a communication terminal capable of notifying of approach of the unmanned aircraft without information on a target being input to the unmanned aircraft in advance. 
     Means for Solving the Problems 
     Some aspects of the present invention are made to solve the above-described problem, and a first aspect of the present invention is a base station device including: a detection unit that detects approach of a mobile station device; a determination unit that determines whether or not the detected mobile station device is an unmanned aircraft; and a notification unit that notifies of the approach of the mobile station device in a case that it is determined that the mobile station device is an unmanned aircraft. 
     In addition, a second aspect of the present invention is a notification method in a base station device, the notification method including: a detection step of detecting approach of a mobile station device; a determination step of determining whether or not the detected mobile station device is an unmanned aircraft; and a notification step of notifying of the approach of the mobile station device in a case that it is determined that the mobile station device is an unmanned aircraft. 
     In addition, a third aspect of the present invention is a notification system including an unmanned aircraft, a base station device, and a communication terminal, wherein the base station device includes a wireless communication unit and a control unit, the control unit of the base station device assigns a message identifier, and transmits the assigned message identifier to the unmanned aircraft and the communication terminal via the wireless communication unit, the unmanned aircraft includes a wireless communication unit and a control unit, the control unit of the unmanned aircraft receives a message identifier transmitted by the base station device via the wireless communication unit, and informs of an approach notification including the message identifier via the wireless communication unit, the communication terminal includes an output unit, a wireless communication unit, and a control unit, and the control unit of the communication terminal causes the output unit to output information on the approach of the unmanned aircraft in a case that the approach notification of which the unmanned aircraft has informed is received via the wireless communication unit. 
     In addition, a fourth aspect of the present invention is an unmanned aircraft including a wireless communication unit and a control unit, wherein the control unit receives a message identifier transmitted by a base station device via the wireless communication unit, and informs of an approach notification including the message identifier via the wireless communication unit. 
     In addition, a fifth aspect of the present invention is a communication terminal including an output unit, a wireless communication unit, and a control unit, wherein the control unit causes the output unit to output information on approach of an unmanned aircraft in a case that approach notification of which the unmanned aircraft has informed is received via the wireless communication unit. 
     Effect of the Invention 
     According to some aspects of the present invention, it is possible to notify of approach of an unmanned aircraft without information on a target being input to the unmanned aircraft in advance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating an example of a configuration of a notification system according to a first embodiment of the present invention. 
         FIG. 2  is a schematic diagram illustrating an example of a configuration of a home base station according to the first embodiment. 
         FIG. 3  is a schematic diagram illustrating an example of a configuration of an unmanned aircraft according to the first embodiment. 
         FIG. 4  is a sequence diagram illustrating a notification process according to the first embodiment. 
         FIG. 5  is a sequence diagram illustrating a notification process according to a second embodiment of the present invention. 
         FIG. 6  is a schematic diagram illustrating an example of a configuration of a notification system according to a third embodiment of the present invention. 
         FIG. 7  is a schematic diagram illustrating an example of a configuration of a macrocell base station according to the third embodiment. 
         FIG. 8  is a sequence diagram illustrating a notification process according to the third embodiment. 
         FIG. 9  is a schematic diagram illustrating an example of a configuration of a notification system according to a fourth embodiment of the present invention. 
         FIG. 10  is a schematic diagram illustrating an example of a configuration of a communication terminal according to the fourth embodiment. 
         FIG. 11  is a sequence diagram illustrating a notification process according to the fourth embodiment. 
     
    
    
     EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that in the drawings, the same portions are denoted by the same reference numerals. 
     First Embodiment 
     First, a first embodiment of the present invention will be described. 
       FIG. 1  is a schematic diagram illustrating an example of a configuration of a notification system  1  according to the first embodiment. 
     As illustrated in  FIG. 1 , the notification system  1  includes home base stations  10 - 1  and  10 - 2  and an unmanned aircraft  20 . Hereinafter, the home base stations  10 - 1  and  10 - 2  may be collectively referred to as a home base station  10 . 
     The home base station  10  includes a small base station device (a home eNodeB [indoor base station device], a micro cell eNodeB [micro cell base station device]), a pico cell eNodeB [picocell base station device], or a femto cell eNodeB [femtocell base station device]) which wirelessly transmits and receives data to and from a mobile station device (user equipment). A radius of a cell (a range that radio waves reach) in which the home base station  10  provides a service is a relatively narrow range of, for example, several meters to tens of meters. That is, the home base station  10  is a base station device having a narrow range (typically, a radius of several meters to tens of meters) in which communication with the mobile station device is possible. The home base station  10  is installed, for example, in each residential space of an apartment. Further, the home base stations  10 - 1  and  10 - 2  are communicably connected to each other via a network. In the first embodiment, the number of the home base stations  10  is not limited to two as illustrated and may be one or may be more than two. 
     The unmanned aircraft  20  is, for example, a drone and is a small aircraft capable of performing flight in an unmanned manner through remote control or automatic control. The unmanned aircraft  20  is a mobile station device that wirelessly transmits and receives data to and from the home base station  10 . In the first embodiment, the number of unmanned aircrafts  20  is not limited to one and may be more than one. 
     Next, an overview of the notification system  1  will be described. 
     The unmanned aircraft  20  searches its surroundings, detects the home base station  10  to which the unmanned aircraft  20  can connect, and performs flight while connecting to the detected home base station  10 . The home base station  10  determines whether or not the mobile station device that has performed the connection procedure is the unmanned aircraft  20 . In the connection procedure, the mobile station device transmits a unique identifier (ID) of the mobile station device, an identifier indicating a model of the mobile station device, communication capability of the mobile station device, and a reason for a connection request to the home base station  10 . For example, in a case that information indicating the unmanned aircraft  20  is included in the unique identifier, the home base station  10  determines whether or not the mobile station device is the unmanned aircraft  20  based on the unique identifier. Alternatively, the home base station  10  may send the received unique identifier to a server device and inquire about whether or not the mobile station device is the unmanned aircraft  20 . 
     In a case that the home base station  10  determines that the connected mobile station device is the unmanned aircraft  20 , the home base station  10  notifies of the approach of the unmanned aircraft  20 . For example, the home base station  10  outputs a warning message (information on the approach) for notifying of the approach of the unmanned aircraft  20  as sound. Alternatively, the home base station  10  displays the warning message (the information on the approach) for notifying of the approach of the unmanned aircraft  20 . Accordingly, a person near the home base station  10  can know of the approach of the unmanned aircraft  20 . 
     Next, a configuration of the home base station  10  according to the first embodiment will be described. 
       FIG. 2  is a schematic diagram illustrating an example of the configuration of the home base station  10  according to the first embodiment. The home base station  10  includes a control unit  101 , a wireless communication unit  102 , a network communication unit  103 , a storage unit  104 , a sound output unit  105 , and a display unit  106 . 
     The control unit  101  includes a detection unit  1011 , a determination unit  1012 , and a notification unit  1013 , and controls the home base station  10 . The detection unit  1011  detects approach of the mobile station device. For example, the detection unit  1011  detects the approach of the mobile station device based on information that the mobile station device has transmitted based on informing information. Specifically, the detection unit  1011  determines that the mobile station device has approached in a case that a connection procedure with the mobile station device has been performed via the wireless communication unit  102 . The determination unit  1012  determines whether or not the detected mobile station device is the unmanned aircraft  20 . For example, the determination unit  1012  determines whether or not the mobile station device is the unmanned aircraft  20  based on the information received from the mobile station device in the connection procedure. In a case that it is determined that the mobile station device is the unmanned aircraft  20 , the notification unit  1013  notifies of the approach of the unmanned aircraft  20 . For example, the notification unit  1013  causes the sound output unit  105  to output a warning message for notifying of the approach of the unmanned aircraft  20  as sound. 
     Alternatively, the notification unit  1013  causes the display unit  106  to display the warning message for notifying of the approach of the unmanned aircraft  20 . 
     The wireless communication unit  102  wirelessly communicates with the mobile station device. The network communication unit  103  communicates with another communication device such as the home base station  10  via a network. The storage unit  104  stores various pieces of data (including informing information) to be used by the home base station  10 . The sound output unit  105  is a speaker that outputs sound. The display unit  106  includes a light emitting diode (LED) or a liquid crystal display and displays information. The sound output unit  105  or the display unit  106  constitutes an output unit that outputs information on the approach of the unmanned aircraft  20 . 
     Next, the configuration of the unmanned aircraft  20  according to the first embodiment will be described. 
       FIG. 3  is a schematic diagram illustrating an example of a configuration of the unmanned aircraft  20  according to this embodiment. The unmanned aircraft  20  includes a control unit  201 , a wireless communication unit  202 , a storage unit  203 , an imaging unit  204 , and a flight control unit  205 . 
     The control unit  201  controls the unmanned aircraft  20 . The wireless communication unit  202  wirelessly communicates with a base station device such as the home base station  10 . The storage unit  203  stores various types of information to be used by the unmanned aircraft  20 . The imaging unit  204  is a camera that images its surroundings. The flight control unit  205  controls a moving direction, a moving speed, and the like of the unmanned aircraft  20 . 
     Next, a notification process according to the first embodiment will be described. 
       FIG. 4  is a sequence diagram illustrating a notification process according to the first embodiment. 
     (Step S 101 ) The home base station  10  regularly transmits informing information. 
     (Step S 102 ) In a case that the unmanned aircraft  20  receives the informing information from the home base station  10 , the unmanned aircraft  20  performs a connection procedure with the home base station  10  based on the received informing information. 
     (Step S 103 ) In a case that the home base station  10  determines that a mobile station device that has performed the connection procedure is the unmanned aircraft  20 , the home base station  10  outputs a warning message for notifying of approach of the unmanned aircraft  20  as a sound or the like. Thereafter, the process ends. 
     In a case that the connection with the unmanned aircraft  20  is released, the home base station  10  may notify that the unmanned aircraft  20  has left. 
     As described above, according to the first embodiment, the notification system  1  includes the home base station  10  and the unmanned aircraft  20 . The home base station  10  includes the detection unit  1011  that detects the approach of the mobile station device, the determination unit  1012  that determines whether or not the detected mobile station device is the unmanned aircraft  20 , and the notification unit  1013  that notifies of the approach of the mobile station device in a case that it is determined that the mobile station device is the unmanned aircraft  20 . The detection unit  1011  detects the approach of the mobile station device based on the connection procedure based on the informing information. The notification unit  1013  causes the sound output unit  105  or the display unit  106  to output the warning message for notifying of the approach of the unmanned aircraft  20 . 
     Accordingly, it is possible to notify of the approach of the unmanned aircraft  20  without information on a target being input to the unmanned aircraft  20  in advance. Therefore, it is possible to output a warning about the approach of an unknown unmanned aircraft  20 . 
     Second Embodiment 
     Next, a second embodiment of the present invention will be described. Since a configuration of a notification system  1  according to the second embodiment is the same as that according to the first embodiment, description thereof will be omitted. In the second embodiment, the home base station  10  is different from that in the first embodiment in that other nearby home base stations  10  are also notified of the approach of the unmanned aircraft  20 . 
     In a case that it is determined that the mobile station device is the unmanned aircraft  20 , the notification unit  1013  of the home base station  10  in the second embodiment causes the sound output unit  105  or the display unit  106  to output a warning message for notifying of the approach of the unmanned aircraft  20  and transmits an unmanned aircraft approach notification (informing information) for notifying of the approach of the unmanned aircraft  20  to the nearby home base stations  10  via the network communication unit  103 . Information on the nearby home base stations  10  is preset and stored in the storage unit  104 . In a case that the notification unit  1013  receives the unmanned aircraft approach notification from the other home base station  10  via the network communication unit  103 , the notification unit  1013  causes the sound output unit  105  or the display unit  106  to output a warning message for notifying of the approach of the unmanned aircraft  20 . 
     Next, a notification process according to the second embodiment will be described. 
       FIG. 5  is a sequence diagram illustrating a notification process according to the second embodiment. 
       FIG. 5  illustrates a process in a case that the home base station  10 - 1  and the home base station  10 - 2  are approaching. 
     Since processes from step S 201  to step S 203  are the same as the processes from step S 101  to step S 103  described above, description thereof will be omitted. 
     (Step S 204 ) The home base station  10 - 1  transmits an unmanned aircraft approach notification to the nearby home base station  10 - 2 . 
     (Step S 205 ) In a case that the home base station  10 - 2  receives the unmanned aircraft approach notification, the home base station  10 - 2  outputs a warning message for notifying of the approach of the unmanned aircraft  20  as a sound or the like. Thereafter, the process ends. 
     As described above, according to the second embodiment, the notification system  1  includes the home base station  10  and the unmanned aircraft  20 . The home base station  10  includes the detection unit  1011  that detects the approach of the mobile station device, the determination unit  1012  that determines whether or not the detected mobile station device is the unmanned aircraft  20 , and the notification unit  1013  that notifies of the approach of the mobile station device in a case that it is determined that the mobile station device is the unmanned aircraft  20 . The detection unit  1011  detects the approach of the mobile station device based on the connection procedure based on the informing information. The notification unit  1013  causes the sound output unit  105  or the display unit  106  to output the warning message for notifying of the approach of the unmanned aircraft  20 , and notifies the other home base station  10  of the approach of the unmanned aircraft  20 . The notification unit  1013  of the home base station  10  having received the notification of the approach of the unmanned aircraft  20  causes the sound output unit  105  or the display unit  106  to output the warning message for notifying of the approach of the unmanned aircraft  20 . 
     The unmanned aircraft  20  performs the connection procedure with only one base station device and does not perform the connection procedure with a plurality of base station devices at the same time. Therefore, in the first embodiment, in a case that the unmanned aircraft  20  has approached a plurality of base station devices at the same time, only one of the plurality of base station devices can notify of the approach of the unmanned aircraft  20 . That is, in a case that the plurality of base station devices are at positions close to each other, base station devices other than the one base station that has performed the connection procedure with the unmanned aircraft  20  cannot notify of the approach of the unmanned aircraft  20 . On the other hand, in the second embodiment, since the home base station  10  connecting to the unmanned aircraft  20  notifies other nearby home base stations  10  of the approach of the unmanned aircraft  20 , the other home base stations  10  can also output a warning message for notifying of the approach of the unmanned aircraft  20 . That is, even in a case that the unmanned aircraft  20  has approached the plurality of home base stations  10  at the same time, the plurality of home base stations  10  can notify of the approach of the unmanned aircraft  20  substantially at the same time. Accordingly, it is possible to notify of the approach of the unmanned aircraft  20  without information on a target being input to the unmanned aircraft  20  in advance. Therefore, it is possible to output a warning about the approach of an unknown unmanned aircraft  20 . 
     Third Embodiment 
     Next, a third embodiment of the present invention will be described. 
       FIG. 6  is a schematic diagram illustrating an example of a configuration of the notification system  1 A according to the third embodiment. 
     The notification system  1 A according to the third embodiment includes a macrocell base station  30 , in addition to the configuration of the notification system  1  according to the first embodiment or the second embodiment. Since other configurations are the same as those of the first embodiment or the second embodiment, description thereof will be omitted. 
     The macrocell base station  30  is a macrocell base station device (macrocell eNode B) that wirelessly transmits and receives data to and from a mobile station device. A radius of a cell to be provided by the macrocell base station  30  is in a relatively wide range of, for example, hundreds of meters to tens of kilometers. That is, the macrocell base station  30  is a base station device having a wide range in which communication with the mobile station device is possible (typically, a radius of hundreds of meters to tens of kilometers). The macrocell base station  30  communicably connects to the home base station  10  via a network. 
     A cell C 0  illustrated in  FIG. 6  is a cell that is provided by the macrocell base station  30 . A cell C 1  is a cell that is provided by the home base station  10 - 1 . A cell C 2  is a cell that is provided by the home base station  10 - 2 . As illustrated in  FIG. 6 , the cell of the home base station  10  is a region of a part of the cell C 0  of the macrocell base station  30 . 
     Next, an overview of the notification system  1 A will be described. 
     The unmanned aircraft  20  searches its surroundings to detect the macrocell base station  30  or the home base station  10  to which the unmanned aircraft  20  can connect, and performs flight while connecting to the detected macrocell base station  30  or the detected home base station  10 . An operation in a case that the unmanned aircraft  20  connects to the home base station  10  is the same as that in the first embodiment or the second embodiment. 
     On the other hand, in a case that the unmanned aircraft  20  has connected to the macrocell base station  30 , the macrocell base station  30  transmits a cell search request to the connected unmanned aircraft  20  to request search for a cell to which the unmanned aircraft  20  can connect. In a case that the unmanned aircraft  20  receives the cell search request from the macrocell base station  30 , the unmanned aircraft  20  replies to the macrocell base station  30  with a cell search report for reporting the cell to which the unmanned aircraft  20  can connect, based on the informing information received from the home base station  10 . In a case that the macrocell base station  30  receives the cell search report, the macrocell base station  30  transmits an unmanned aircraft approach notification for notifying the home base station  10  of the cell included in the received cell search report of the approach of the unmanned aircraft  20 . In a case that the home base station  10  receives the unmanned aircraft approach notification from the macrocell base station  30 , the home base station  10  outputs a warning message for notifying of the approach of the unmanned aircraft  20  through sound or a display. Accordingly, a person near the home base station  10  can know of the approach of the unmanned aircraft  20 . 
     Next, a configuration of the macrocell base station  30  according to the third embodiment will be described. 
       FIG. 7  is a schematic diagram illustrating an example of the configuration of the macrocell base station  30  according to the third embodiment. The macrocell base station  30  includes a control unit  301 , a wireless communication unit  302 , a network communication unit  303 , and a storage unit  304 . 
     The control unit  301  includes a detection unit  3011 , a determination unit  3012 , and a notification unit  3013 , and controls the macrocell base station  30 . The detection unit  3011  detects the approach of the mobile station device. For example, the detection unit  3011  detects the approach of the mobile station device based on the information that the mobile station device has transmitted based on the informing information transmitted by the home base station  10 . More specifically, the detection unit  3011  detects that the mobile station device has approached the home base station  10  of the cell included in the cell search report received via the wireless communication unit  302 , based on the cell search report. The determination unit  3012  determines whether or not the detected mobile station device is the unmanned aircraft  20 . For example, the determination unit  3012  determines whether or not the mobile station device is the unmanned aircraft  20  based on the information transmitted from the mobile station device in the connection procedure or the unique identifier of the mobile station device included in the cell search report. In a case that it is determined that the mobile station device is the unmanned aircraft  20 , the notification unit  3013  notifies of the approach of the mobile station device. For example, the notification unit  3013  transmits an unmanned aircraft approach notification to the home base station  10  of the cell included in the cell search report. That is, the notification unit  3013  notifies the home base station  10  that the unmanned aircraft  20  has detected based on the informing information transmitted by the home base station  10  of the approach of the unmanned aircraft  20 . 
     The wireless communication unit  302  wirelessly communicates with the mobile station device. The network communication unit  303  communicates with a communication device such as the home base station  10  via a network. The storage unit  304  stores various types of information to be used by the macrocell base station  30 . 
     Next, a notification process according to the third embodiment will be described. 
       FIG. 8  is a sequence diagram illustrating the notification process according to the third embodiment. 
     (Step S 301 ) The home base station  10  regularly transmits informing information. The unmanned aircraft  20  receives the informing information transmitted from the home base station  10 . 
     (Step S 302 ) The unmanned aircraft  20  performs a connection procedure with the macrocell base station  30 . The macrocell base station  30  determines whether or not a mobile station device that has made the connection procedure is the unmanned aircraft  20 . 
     (Step S 303 ) The macrocell base station  30  transmits a cell search request to the unmanned aircraft  20 . 
     (Step S 304 ) In a case that the unmanned aircraft  20  receives the cell search request, the unmanned aircraft  20  generates a cell search report based on the informing information received from the home base station  10  and transmits the generated cell search report to the macrocell base station  30 . 
     (Step S 305 ) In a case that the macrocell base station  30  receives the cell search report, the macrocell base station  30  transmits an unmanned aircraft approach report to the home base station  10  of a cell included in the cell search report. 
     (Step S 306 ) In a case that the home base station  10  receives the unmanned aircraft approach report, the home base station  10  outputs a warning message for notifying of the approach of the unmanned aircraft  20  through sound or the like. Thereafter, the process ends. 
     As described above, according to the third embodiment, the notification system  1 A includes the home base station  10 , the unmanned aircraft  20 , and the macrocell base station  30 . The macrocell base station  30  includes the detection unit  3011  that detects the approach of the mobile station device, the determination unit  3012  that determines whether or not the detected mobile station device is the unmanned aircraft  20 , and the notification unit  3013  that notifies of the approach of the mobile station device in a case that it is determined that the mobile station device is the unmanned aircraft  20 . The unmanned aircraft  20  transmits a cell search report to the macrocell base station  30  based on the informing information of which the home base station  10  has informed. The notification unit  3013  of the macrocell base station  30  notifies the home base station  10  of the cell included in the cell search report received from the unmanned aircraft  20  of the approach of the unmanned aircraft  20 . The notification unit  1013  of the home base station  10  having received the notification of the approach of the unmanned aircraft  20  causes the sound output unit  105  or the display unit  106  to output the warning message for notifying of the approach of the unmanned aircraft  20 . 
     Accordingly, it is possible to output the warning message to the home base station  10  with which the unmanned aircraft  20  is in approach, by interworking the macrocell base station  30  with the home base station  10  even in a case that the unmanned aircraft  20  is present within the cell of the home base station  10 , but connects to the macrocell base station  30 , in addition to the effects of the first embodiment or the second embodiment. Accordingly, it is possible to notify of the approach of the unmanned aircraft  20  without information on a target being input to the unmanned aircraft  20  in advance. Therefore, it is possible to output a warning about the approach of an unknown unmanned aircraft  20 . 
     Fourth Embodiment 
     Next, a fourth embodiment of the present invention will be described. 
       FIG. 9  is a schematic diagram illustrating an example of a configuration of a notification system  1 B according to the fourth embodiment. 
     The notification system  1 B according to the fourth embodiment includes a communication terminal  40  in addition to the configuration of the notification system  1 A according to the third embodiment. The unmanned aircraft  20  and the communication terminal  40  are in the cell C 0  provided by the macrocell base station  30 . Here, the unmanned aircraft  20  and the communication terminal  40  perform long term evolution (LTE) device to device (D2D) communication to perform direct communication without passing through a base station device. Since other configurations are the same as those of the third embodiment, description thereof will be omitted. 
     The communication terminal  40  is a mobile station device that wirelessly transmits and receives data to and from the macrocell base station  30 . The communication terminal  40  is, for example, a mobile phone, a smart phone, a personal digital assistant (PDA). In the fourth embodiment, the number of the communication terminals  40  is not limited to one as illustrated, and may be more than one. 
     Next, an overview of the notification system  1 B will be described. 
     The unmanned aircraft  20  searches for surroundings to detect the macrocell base station  30  or the home base station  10  to which the unmanned aircraft  20  can connect, and performs flight while connecting to the detected macrocell base station  30  or the detected home base station  10 . An operation in a case that the unmanned aircraft  20  connects to the macrocell base station  30  or the home base station  10  is the same as in the first to third embodiments. 
     The communication terminal  40  transmits interest information registration for the approach of the unmanned aircraft  20  to the macrocell base station  30 . An identifier (ProSe Application ID) indicating content to be informed, a unique identifier (UE Identity) of the mobile station device, and a message type (Command) are included in the interest information registration. A value indicating the approach of the unmanned aircraft  20  is set in the identifier indicating the content to be informed. Further, the message type is “monitor”. In a case that the macrocell base station  30  receives the interest information registration from the communication terminal  40 , the macrocell base station  30  replies to the communication terminal  40  with reception filter assignment. A value (Discovery Filter) for determining whether or not a discovery message is a message for informing of the approach of the unmanned aircraft  20  is included in the reception filter assignment. A value (ProSe Application Code (message identifier)) indicating that the discovery message is a message for informing of the approach of the unmanned aircraft  20  is included in the Discovery Filter. 
     On the other hand, in a case that the unmanned aircraft  20  performs handover to the macrocell base station  30 , the unmanned aircraft  20  transmits a message registration for the approach of the unmanned aircraft  20  to the macrocell base station  30 . An identifier (ProSe Application ID) indicating content to be informed, a unique identifier (UE Identity) of the mobile station device, and a message type (Command) are included in the message registration. A value indicating the approach of the unmanned aircraft  20  is set in the identifier indicating the content to be informed. Further, the message type is “announce”. In a case that the macrocell base station  30  receives the message registration from the unmanned aircraft  20 , the macrocell base station  30  replies the unmanned aircraft  20  with transmission message assignment. A value (ProSe Application Code) to be temporarily assigned to the ProSe Application ID and used for the discovery message is included in the transmission message assignment. A value indicating that the discovery message is a message for informing of the approach of the unmanned aircraft  20  is set in the ProSe Application Code. 
     The unmanned aircraft  20  transmits the discovery message including the ProSe Application Code assigned in the transmission message assignment to the communication terminal  40 . 
     In a case that the received discovery message includes the ProSe Application Code assigned in the reception filter assignment, the communication terminal  40  determines that the unmanned aircraft  20  has approached, and transmits a warning message for notifying of the approach of the unmanned aircraft  20  through sound or a display. Accordingly, a user of the communication terminal  40  can know of the approach of the unmanned aircraft  20 . 
     That is, in a case that the detection unit  3011  of the macrocell base station  30  in the third embodiment receives the message registration via the wireless communication unit  102 , the detection unit  3011  determines that the mobile station device has approached. Further, the determination unit  3012  determines whether or not the mobile station device is the unmanned aircraft  20  based on the unique identifier of the mobile station device included in the message registration. The notification unit  3013  notifies the communication terminal  40  of the approach of the unmanned aircraft  20  by transmitting transmission message assignment for the message registration to the unmanned aircraft  20 . That is, the notification unit  3013  assigns, to the unmanned aircraft  20 , a transmission message for transmitting an indication indicating that the message for notifying of the approach of the unmanned aircraft  20  is received, to the registered communication terminal  40 . For example, the notification unit  3013  assigns a message identifier and transmits the assigned message identifier to the unmanned aircraft  20  and the communication terminal  40  via the wireless communication unit  102 . 
     The control unit  201  of the unmanned aircraft  20  in the third embodiment informs of the approach notification from the wireless communication unit  202  using the transmission message assigned from the macrocell base station  30 . 
     For example, the control unit  201  receives the message identifier transmitted by the macrocell base station  30 , via the wireless communication unit  202 . The control unit  201  informs of an approach notification including the received message identifier via the wireless communication unit  202 . 
       FIG. 10  is a schematic diagram illustrating an example of a configuration of the communication terminal  40  according to the third embodiment. The communication terminal  40  includes a control unit  401 , a wireless communication unit  402 , a storage unit  403 , a sound output unit  404 , and a display unit  405 . 
     The control unit  101  controls the communication terminal  40 . For example, in a case that the control unit  401  has received, via the wireless communication unit  402 , the approach notification of which the unmanned aircraft  20  has informed using the transmission message assigned from the macrocell base station  30 , the control unit  401  causes the sound output unit  404  to output a warning message (information on approach) for notifying of the approach of the unmanned aircraft  20  as sound. Alternatively, the control unit  401  causes the display unit  405  to display the warning message for notifying of the approach of the unmanned aircraft  20 . 
     The wireless communication unit  402  wirelessly communicates with the unmanned aircraft  20  or the base station device. The storage unit  403  stores various pieces of data to be used by the communication terminal  40 . The sound output unit  404  is a speaker that outputs sound. The display unit  405  includes an LED or a liquid crystal display and displays information. 
     The sound output unit  404  or the display unit  405  constitutes an output unit that outputs information on the approach of the unmanned aircraft  20 . 
     Next, a notification process according to the third embodiment will be described. 
       FIG. 11  is a sequence diagram illustrating the notification process according to this embodiment. 
     (Step S 401 ) The communication terminal  40  transmits the interest information registration for the approach of the unmanned aircraft  20  to the macrocell base station  30 . 
     (Step S 402 ) In a case that the macrocell base station  30  receives the interest information registration, the macrocell base station  30  transmits reception filter assignment to the received interest information registration to the communication terminal  40 . 
     (Step S 403 ) The unmanned aircraft  20  transmits message registration for the approach of the unmanned aircraft  20  to the macrocell base station  30 . 
     (Step S 404 ) In a case that the macrocell base station  30  receives the message registration, the macrocell base station  30  transmits transmission message assignment for the received message registration to the unmanned aircraft  20 . 
     (Step S 405 ) The unmanned aircraft  20  transmits a discovery message based on the received transmission message assignment. 
     (Step S 406 ) In a case that the communication terminal  40  receives the discovery message corresponding to the reception filter assigned in step S 402 , the communication terminal  40  determines that the unmanned aircraft  20  has approached, and transmits a warning message for notifying of the approach of the unmanned aircraft  20  through sound or the like. Thereafter, the process ends. 
     It should be noted that the processes of steps S 401  to S 402  described above may be performed at any time before step S 405  and, for example, may be performed between the step S 403  and the step S 404  or after the step S 404 . 
     As described above, according to the third embodiment, the notification system  1 B includes the home base station  10 , the unmanned aircraft  20 , the macrocell base station  30 , and the communication terminal  40 . The macrocell base station  30  includes the detection unit  3011  that detects the approach of the mobile station device, the determination unit  3012  that determines whether or not the detected mobile station device is the unmanned aircraft  20 , and the notification unit  3013  that notifies of the approach of the unmanned aircraft  20  in a case that it is determined that the mobile station device is the unmanned aircraft  20 . The notification unit  3013  assigns, to the unmanned aircraft  20 , a message for transmitting an indication indicating that the message for notifying of the approach of the unmanned aircraft  20  is received, to the registered communication terminal  40 . The unmanned aircraft  20  informs of an approach notification using the message assigned from the macrocell base station  30 . In a case that the communication terminal  40  receives the approach notification from the unmanned aircraft  20 , the communication terminal  40  outputs information on the approach of the unmanned aircraft  20 . 
     Accordingly, the unmanned aircraft  20  can notify only the communication terminal  40  to which the reception filter has been assigned, of the approach using the transmission message, in addition to the effects of the first to third embodiments. Therefore, it is possible to notify only a person requesting the notification of the approach of the unmanned aircraft  20 . 
     It should be noted that some of the units, such as the control unit  101 , the control unit  201 , the control unit  301 , or the control unit  401 , of the home base station  10 , the unmanned aircraft  20 , the macrocell base station  30 , and the communication terminal  40  in the above embodiments is realized by a computer. In this case, the control unit may be realized by recording a program for realizing a control function thereof on a computer-readable recording medium, loading the program recorded on the recording medium into a computer system, and executing the program. It should be noted that the “computer system” described herein is a computer system built into the home base station  10 , the unmanned aircraft  20 , the macrocell base station  30 , or the communication terminal  40  and includes an operating system (OS) or hardware such as a peripheral device. Further, the “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disc, a ROM, or a CD-ROM, or a storage device such as a hard disk built into the computer system. Further, the “computer-readable recording medium” may also include a recording medium that dynamically holds a program for a short period of time, such as a communication line in a case that the program is transmitted over a network such as the Internet or a communication line such as a telephone line or a recording medium that holds a program for a certain period of time, such as a volatile memory inside a computer system including a server and a client in such a case. Further, the program may be a program for realizing some of the above-described functions or may be a program capable of realizing the above-described functions in combination with a program previously stored in the computer system. 
     Further, some of the units, such as the control unit  101 , the control unit  201 , the control unit  301 , or the control unit  401 , of the home base station  10 , the unmanned aircraft  20 , the macrocell base station  30 , or the communication terminal  40  in the respective embodiments described above may be realized as an integrated circuit such as large scale integration (LSI). Further, for example, the control unit  101 , the control unit  201 , the control unit  301 , and the control unit  401  may be integrated and realized as a processor. Further, an integrated circuit realization scheme is not limited to the LSI and the control unit may be realized as a dedicated circuit or a general-purpose processor. Further, in a case in which an integrated circuit realization technology with which the LSI is replaced appears with the advance of a semiconductor technology, an integrated circuit according to the technology may be used. 
     Although the embodiments of the present invention have been described in detail with reference to the drawings, specific configurations are not limited to those described above, and various design modifications and the like are possible without departing from the gist of the present invention. For example, the respective configurations described in the first to fourth embodiments can be arbitrarily combined. 
     In the above-described embodiments, the home base station  10  or the macrocell base station  30  determines whether or not the mobile station device is the unmanned aircraft  20  based on the unique identifier of the mobile station device, but the present invention is not limited thereto, and the home base station  10  or the macrocell base station  3  may determine whether or not the mobile station device is the unmanned aircraft  20  based on other information. For example, the home base station  10  or the macrocell base station  30  may determine whether or not the mobile station device is the unmanned aircraft  20  based on an identifier indicating a model of the mobile station device. Alternatively, in a case that a value indicating the unmanned aircraft  20  is included in a parameter of the communication capability of the mobile station device, the home base station  10  or the macrocell base station  30  may determine whether or not the mobile station device is the unmanned aircraft  20  based on communication capability of the mobile station device. Alternatively, in a case that the value indicating the unmanned aircraft  20  is included in a parameter of the reason for a connection request, the home base station  10  or the macrocell base station  30  may determine whether or not the mobile station device is the unmanned aircraft  20  based on the reason for a connection request. 
     Further, in the above-described embodiments, the home base station  10  notifies of the approach of the unmanned aircraft  20  through sound output or a display, but a notifying method is not limited thereto. For example, the home base station  10  may display a warning message for notifying a mobile station device in the cell that is provided by the home base station  10  of the approach of the unmanned aircraft  20 . Alternatively, the home base station  10  may transmit a mail for notifying of the approach of the unmanned aircraft  20  to a specific mail address. 
     (1) A base station device including a detection unit that detects the approach of a mobile station device, a determination unit that determines whether or not the detected mobile station device is an unmanned aircraft, and a notification unit that notifies of the approach of the mobile station device in a case that it is determined that the mobile station device is an unmanned aircraft. 
     (2) The base station device according to (1), wherein the detection unit detects the approach of the mobile station device based on information which has been transmitted from the mobile station device based on informing information transmitted by the base station device. 
     (3) The base station device according to (1) or (2), including an output unit, wherein the notification unit causes the output unit to output information on the approach of the mobile station device. 
     (4) The base station device according to any one of (1) to (3), wherein the notification unit notifies other base station devices of the approach of the mobile station device. 
     (5) The base station device according to any one of (1) to (4), wherein the base station device is a macrocell base station device, and the notification unit notifies a small base station device having a cell that is a part of a cell of the macrocell base station device of the approach of the mobile station device. 
     (6) The base station device according to (5), wherein the notification unit notifies the small base station device that the mobile station device has detected based on informing information transmitted by the small base station device of the approach of the mobile station device. 
     (7) A notification method in a base station device, the notification method including a detection step of detecting approach of a mobile station device; a determination step of determining whether or not the detected mobile station device is an unmanned aircraft; and a notification step of notifying of the approach of the mobile station device in a case that it is determined that the mobile station device is an unmanned aircraft. 
     (8) A notification system including an unmanned aircraft, a base station device, and a communication terminal, wherein the base station device includes a wireless communication unit and a control unit, the control unit of the base station device assigns a message identifier, and transmits the assigned message identifier to the unmanned aircraft and the communication terminal via the wireless communication unit, the unmanned aircraft includes a wireless communication unit and a control unit, the control unit of the unmanned aircraft receives a message identifier transmitted by the base station device via the wireless communication unit, and informs of an approach notification including the message identifier via the wireless communication unit, the communication terminal includes an output unit, a wireless communication unit, and a control unit, and the control unit of the communication terminal causes the output unit to output information on the approach of the unmanned aircraft in a case that the approach notification of which the unmanned aircraft has informed is received via the wireless communication unit. 
     (9) An unmanned aircraft including a wireless communication unit and a control unit, wherein the control unit receives a message identifier transmitted by a base station device via the wireless communication unit, and informs of an approach notification including the message identifier via the wireless communication unit. 
     (10) A communication terminal including an output unit, a wireless communication unit, and a control unit, wherein the control unit causes the output unit to output information on approach of an unmanned aircraft in a case that approach notification of which the unmanned aircraft has informed is received via the wireless communication unit. 
     INDUSTRIAL APPLICABILITY 
     Some aspects of the present invention are applicable to, for example, a base station device, a notification method, a notification system, an unmanned aircraft, and a communication terminal in which it is necessary to notify of approach of the unmanned aircraft without information on a target being input to the unmanned aircraft in advance. 
     DESCRIPTION OF THE REFERENCE SYMBOLS 
       1 ,  1 A,  1 B Notification system 
       10  Home base station 
       20  Unmanned aircraft 
       30  Macrocell base station 
       40  Communication terminal 
       101  Control unit 
       102  Wireless communication unit 
       103  Network communication unit 
       104  Storage unit 
       105  Sound output unit 
       106  Display unit 
       201  Control unit 
       202  Wireless communication unit 
       203  Storage unit 
       204  Imaging unit 
       205  Flight control unit 
       301  Control unit 
       302  Wireless communication unit 
       303  Network communication unit 
       304  Storage unit 
       401  Control unit 
       402  Wireless communication unit 
       403  Storage unit 
       404  Sound output unit 
       405  Display unit 
       1011 ,  3011  Detection unit 
       1012 ,  3012  Determination unit 
       1013 ,  3013  Notification unit