Patent Publication Number: US-2022224402-A1

Title: System, communication apparatus, computer-readable storage medium and control method

Description:
The contents of the following Japanese patent application(s) are incorporated herein by reference:
     NO. 2019-183223 filed in JP on Oct. 3, 2019   NO. PCT/JP2020/031039 filed in WO on Aug. 17, 2020   

    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a system, a communication apparatus, a computer-readable storage medium and a control method. 
     2. Related Art 
     A flight vehicle configured to establish a service link with a communication terminal on the ground, establish a feeder link using a directional antenna with a gateway on the ground, and provide a wireless communication service to a communication terminal is known (for example, refer to Patent Document 1). 
     PRIOR ART DOCUMENT 
     Patent Document 
     
         
         [Patent Document 1] Japanese Patent Application Publication No. 2019-135823 
       
    
     3. Technical Problem 
     When two communication apparatuses communicate with each other using a directional antenna, at least one of which is loaded on a mobile object, it is desirable that a technology can be provided to be able to support to realize a high communication quality as unaffected as possible by the movement of the mobile object. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates one example of a system  10 . 
         FIG. 2  schematically illustrates one example of a flow of a process of the system  10 . 
         FIG. 3  schematically illustrates one example of a calibration orbit  300 . 
         FIG. 4  schematically illustrates one example of a radio wave strength graph  312 . 
         FIG. 5  schematically illustrates one example of a radio wave strength graph  314 . 
         FIG. 6  schematically illustrates one example of the calibration orbit  300 . 
         FIG. 7  schematically illustrates one example of a radio wave strength graph  316 . 
         FIG. 8  schematically illustrates one example of a functional configuration of a communication apparatus  100 . 
         FIG. 9  schematically illustrates one example of a functional configuration of a communication apparatus  200 . 
         FIG. 10  schematically illustrates a HAPS  400  that is one example of the mobile object  20 . 
         FIG. 11  schematically illustrates one example of a functional configuration of a communication apparatus  500 . 
         FIG. 12  schematically illustrates one example of a hardware configuration of a computer  1200  that functions as the communication apparatus  100 , the communication apparatus  200  or the communication apparatus  500 . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, (some) embodiment(s) of the present invention will be described. The embodiment(s) do(es) not limit the invention according to the claims. And all the combinations of the features described in the embodiment(s) are not necessarily essential to means provided by aspects of the invention. 
       FIG. 1  schematically illustrates one example of a system  10 . The system  10  includes a communication apparatus  100  and a communication apparatus  200 , at least one of which is loaded on a mobile object. In the example shown in  FIG. 1 , the communication apparatus  100  is installed fixedly, and the communication apparatus  200  is loaded on the mobile object  20 . 
     The mobile object  20  may be any object as long as it is autonomously moveable. Examples of the mobile object  20  include an automobile, a ship, a drone, and a flight vehicle such as HAPS (High Altitude Platform Station) and so on. 
     The communication apparatus  100  includes a control antenna  102  and a directional antenna  104 . The control antenna  102  may be an antenna with the directionality lower than that of the directional antenna  104 . The control antenna  102  is, for example, an omni-antenna. 
     The communication apparatus  200  includes a control antenna  202  and a directional antenna  204 . The control antenna  202  may be an antenna with a lower directionality than that of the directional antenna  204 . The control antenna  202  is, for example, an omni-antenna. 
     The communication apparatus  100  and the communication apparatus  200  perform a wireless communication by the directional antenna  104  and the directional antenna  204 . Since the location and posture of the communication apparatus  200  change due to the movement of the mobile object  20 , the communication apparatus  100  is required to perform a calibration so that the directional antenna  104  directs correctly to the direction of the communication apparatus  200 . On the other hand, the communication apparatus  200  is also required to perform a calibration so that the directional antenna  204  directs correctly to the direction of the communication apparatus  100 . However, if the calibrations of both devices are performed, the receipt levels of the both devices change, and calibration failure happens, for example, the time required for the calibration becomes longer, the calibration is no longer possible or the like. 
     In contrast, the communication apparatus  100  and the communication apparatus  200  of the present embodiment take turns performing the calibration by having the other perform the calibration in response to the other receiving notification information indicating that the calibration of one has been completed. 
     For example, firstly, the communication apparatus  200  transmits, to the communication apparatus  100 , the mobile object information including the location information of the mobile object  20  by the wireless communication between the control antenna  202  and the control antenna  102 . The location information of the mobile object  20  may include latitude, longitude, and altitude of the mobile object  20 . The mobile object information may further include the moving direction of the mobile object  20 . The mobile object information may further include the movement velocity of the mobile object  20 . 
     The mobile object information of the mobile object  20  may be provided to the communication apparatus  200  by the mobile object control apparatus  22  that controls the movement of the mobile object  20 . The communication apparatus  200  may transmit the mobile object information acquired from the mobile object control apparatus  22  to the communication apparatus  100 . The mobile object control apparatus  22  may include various types of sensors such as a location measuring sensor like a GPS sensor, a gyro sensor and an acceleration sensor, and may manage the location, moving direction and movement velocity of the mobile object  20 . 
     The communication apparatus  200  may prestore the location information of the communication apparatus  100 , and controls the direction of the directional antenna  204  to direct to the communication apparatus  100  based on the location and posture of the mobile object  20 . The communication apparatus  100  estimates, with the mobile object information received from the communication apparatus  200 , the direction, with reference to the location of the communication apparatus  100 , in which the communication apparatus  200  is located, and controls the direction of the directional antenna  104  to direct to the communication apparatus  200 . 
     Then, for example, the communication apparatus  100  performs the calibration of the directional antenna  104 , by measuring the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  while continuously changing the direction of the directional antenna  104 . The communication apparatus  100  may specify the direction of the directional antenna  104  to which the radio wave receipt intensity from the directional antenna  204  is the strongest, and complete the calibration by making the direction direct to the directional antenna  104 . The communication apparatus  100  transmits the notification information to the communication apparatus  200  in response to the completion of the calibration of the directional antenna  104 . The notification information may indicate the completion of the calibration. 
     The communication apparatus  200  performs the calibration of the directional antenna  204 , by measuring the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  while continuously changing the direction of the directional antenna  204  in response to the receipt of the notification information. The communication apparatus  200  may specify the direction of the directional antenna  204  to which the radio wave receipt intensity from the directional antenna  104  is the strongest, and complete the calibration by making the direction direct to the directional antenna  204 . The communication apparatus  100  transmits the notification information to the communication apparatus  200  in response to the completion of the calibration of the directional antenna  204 . The notification information may indicate the completion of the calibration. 
     In this way, the calibration can be performed alternately by notifying to each other that the calibration has been completed and controlling not to perform the calibration until calibration of the other device is completed. In this way, resonance caused by starting the calibration simultaneously can be prevented. 
     In  FIG. 1 , the example of the case where the communication apparatus  100  is fixedly installed is described, but the communication apparatus  100  may also be loaded on the mobile object. In this case, the communication apparatus  100  may transmit the mobile object information including the location information of the mobile object to the communication apparatus  200  by the wireless communication between the control antenna  102  and the control antenna  202 . 
       FIG. 2  schematically illustrates one example of a flow of a process of the system  10 . Herein, the flow of the process where the communication apparatus  100  and the communication apparatus  200  alternately perform the calibration is shown. 
     In step (which may be abbreviated to S)  102 , the communication apparatus  200  transmits the mobile object information of the mobile object  20  to the communication apparatus  100  by the wireless communication between the control antenna  202  and the control antenna  102 . In S 104 , the communication apparatus  200  transmits the beacon signal by the directional antenna  204 . 
     In S 106 , the communication apparatus  100  starts the calibration of the directional antenna  104 . The communication apparatus  100  searches for a direction in which the radio wave receipt intensity is the strongest, by measuring the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  while continuously changing the direction of the directional antenna  104 . The communication apparatus  100  specifies the direction of the directional antenna  104  in which the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  is the strongest, and completes the calibration by making the direction to direct to the directional antenna  104  (S 108 ). 
     In S 110 , the communication apparatus  100  transmits the beacon signal by the directional antenna  104 . In S 112 , the communication apparatus  200  starts the calibration of the directional antenna  204 . The communication apparatus  200  searches for a direction in which the radio wave receipt intensity is the strongest, by measuring the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  while continuously changing the direction of the directional antenna  204 . The communication apparatus  200  specifies the direction of the directional antenna  204  in which the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  is the strongest, and completes the calibration by making the direction to direct to the directional antenna  204  (S 114 ). With these steps, the first calibration is completed. 
     In S 116 , the communication apparatus  100  starts the calibration of the directional antenna  104 . The communication apparatus  100  may perform the calibration of the directional antenna  104  by measuring the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  when the data communication between the communication apparatus  100  and the communication apparatus  200  using the directional antenna  104  and the directional antenna  204  is performed. It should be noted that the communication apparatus  200  may transmit the beacon signal as appropriate by the directional antenna  204 , and the communication apparatus  100  may perform the calibration of the directional antenna  104  by measuring the radio wave receipt intensity of the beacon signal by the directional antenna  104 . The communication apparatus  100  transmits, according to the completion of the calibration (S 118 ), the notification information to the communication apparatus  200  by the wireless communication between the control antenna  102  and the control antenna  202  (S 120 ). 
     The communication apparatus  200  starts the calibration of the directional antenna  204  according to the receipt of the notification information (S 122 ). The communication apparatus  200  may perform the calibration of the directional antenna  204  by measuring the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  when the data communication between the communication apparatus  200  and the communication apparatus  100  using the directional antenna  204  and the directional antenna  104  is performed. It should be noted that the communication apparatus  100  may transmit the beacon signal as appropriate by the directional antenna  104 , and the communication apparatus  200  may perform the calibration of the directional antenna  204  by measuring the radio wave receipt intensity of the beacon signal by the directional antenna  204 . 
     The communication apparatus  200  transmits, according to the completion of the calibration (S 124 ), the notification information to the communication apparatus  100  by the wireless communication between the control antenna  202  and the control antenna  102  (S 126 ). By repeating the processes from S 116  to S 126 , the calibration may be performed continuously between the communication apparatus  100  and the communication apparatus  200  alternately. 
       FIG. 3  schematically illustrates one example of the calibration orbit  300 .  FIG. 4  schematically illustrates one example of the radio wave strength graph  312 .  FIG. 5  schematically illustrates one example of the radio wave strength graph  314 . 
     The calibration orbit  300  shown in  FIG. 3  includes a lateral orbit  302  and a longitudinal orbit  304 . The communication apparatus  100 , for example, changes the direction of the directional antenna  104  along the lateral orbit  302  firstly, and next, changes the direction of the directional antenna  104  along the longitudinal orbit  304 . 
     The radio wave strength graph  312  indicates the change of the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  when the direction of the directional antenna  104  is changed along the lateral orbit  302  by the communication apparatus  100 . The radio wave strength graph  314  indicates the change of the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  when the direction of the directional antenna  104  is changed along the longitudinal orbit  304  by the communication apparatus  100 . 
       FIG. 6  schematically illustrates another example of the calibration orbit  300 .  FIG. 7  schematically illustrates one example of the radio wave strength graph  316 . 
     The calibration orbit  300  shown in  FIG. 6  includes a gyratory orbit  306 . The communication apparatus  100  changes the direction of the directional antenna  104  along the gyratory orbit  306 . The radio wave strength graph  316  indicates the change of the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  when the direction of the directional antenna  104  is changed along the gyratory orbit  306  by the communication apparatus  100 . 
       FIG. 8  schematically illustrates one example of a functional configuration of the communication apparatus  100 . The communication apparatus  100  includes a mobile object information storage unit  112 , a mobile object information receiving unit  114 , an antenna control unit  120 , a notification information transmitting unit  132 , a notification information receiving unit  134 , a history storage unit  142 , an estimation model generation unit  144  and an estimation model storage unit  146 . 
     The mobile object information storage unit  112  stores mobile object-related information that relates to the mobile object  20  of the communication object. For example, when the mobile object  20  moves along a predetermined movement path or travels in circles in a predetermined movement path, the mobile object information storage unit  112  stores the information indicating the movement path of the mobile object  20 . 
     The mobile object information receiving unit  114  receives the mobile object information including the location information of the mobile object  20 . The mobile object information receiving unit  114  may receive the mobile object information by the wireless communication between the control antenna  102  and the control antenna  202  from the communication apparatus  200  of the mobile object  20 . The mobile object information may include a moving direction of the mobile object  20 . The mobile object information may also include a movement velocity of the mobile object  20 . The mobile object information receiving unit  114  stores the received mobile object information in the mobile object information storage unit  112 . 
     The antenna control unit  120  controls the directional antenna  104 . The antenna control unit  120  includes a tracking control unit  122  and an adjustment performing unit  124 . 
     The tracking control unit  122  predicts the location of the mobile object  20  based on the mobile object information stored in the mobile object information storage unit  112  received by the mobile object information receiving unit  114 , and adjusts the direction of the directional antenna  104  to track the mobile object  20  based on the predicted location. The tracking control unit  122  may adjust the physical pointing direction of the directional antenna  104 . The tracking control unit  122  predicts, for example, the location of the destination of the mobile object  20  based on the location information, moving direction and movement velocity included in the mobile object information, and adjusts the direction of the directional antenna  104  to make the directional antenna  104  direct to the direction of the predicted location. 
     The adjustment performing unit  124  performs the calibration of the directional antenna  104 . The adjustment performing unit  124  performs the calibration of the directional antenna  104  by measuring the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  while changing the direction of the directional antenna  104  continuously. The adjustment performing unit  124  may change the physical pointing direction of the directional antenna  104  continuously. 
     The adjustment performing unit  124 , for example, searches for the direction in which the radio wave receipt intensity is the strongest, by measuring the radio wave receipt intensity from the directional antenna  204  by the directional antenna  104  while changing the direction of the directional antenna  104  continuously. The adjustment performing unit  124  may specify the direction of the directional antenna  104  in which the radio wave receipt intensity of the directional antenna  204  by the directional antenna  104  is the strongest, and complete the calibration by making the directional antenna  104  direct to the direction. 
     The notification information transmitting unit  132  transmits the notification information to the communication apparatus  200  according to the completion of the calibration of the directional antenna  104  by the adjustment performing unit  124 . The notification information transmitting unit  132  may transmit the notification information to the communication apparatus  200  via the control antenna  102 . The notification information transmitting unit  132  may transmit the notification information to the communication apparatus  200  by the wireless communication between the control antenna  102  and the control antenna  202 . 
     The notification information receiving unit  134  receives the notification information transmitted according to the completion of the calibration of the directional antenna  204  by the communication apparatus  200 . The notification information receiving unit  134  may receive the notification information via the control antenna  102 . The notification information receiving unit  134  may receive the notification information transmitted by the wireless communication between the control antenna  202  and the control antenna  102  by the communication apparatus  200 . 
     The adjustment performing unit  124  may perform the calibration of the directional antenna  104  according to the receipt of the notification information from the communication apparatus  200  by the notification information receiving unit  134 , without performing the calibration of the directional antenna  104  during performing the calibration of the directional antenna  204  by the communication apparatus  200 . 
     The history storage unit  142  stores the history of the mobile object information stored in the mobile object information storage unit  112  and the direction of the directional antenna  104  after adjustment by the adjustment performing unit  124  in a location indicated by the location information included in the mobile object information. 
     The estimation model generation unit  144  generates an estimation model that estimates the direction of the directional antenna  104  after adjustment from the mobile object information, by using, as teacher data, the mobile object information and the direction of the directional antenna  104  after adjustment included in a plurality of pieces of history stored in the history storage unit  142 . 
     The estimation model storage unit  146  stores the estimation model generated by the estimation model generation unit  144 . When the plurality of pieces of history stored in the history storage unit  142  are provided to other apparatuses and estimation models are generated by the other apparatuses, the estimation model storage unit  146  may acquire and store the estimation models generated by the other apparatuses from the other apparatuses. 
     The adjustment performing unit  124  may use the estimation model stored in the estimation model storage unit  146  to adjust the direction of the directional antenna  104 . For example, the adjustment performing unit  124  adjusts the direction of the directional antenna  104  based on the direction of the directional antenna  104  after adjustment that is estimated by using the estimation model from the received mobile object information by the mobile object information receiving unit  114 . The adjustment performing unit  124  adjusts, for example, the estimated direction of the directional antenna  104  to match the direction of the directional antenna  104  after adjustment. 
     Particularly, when the mobile object  20  travels in circles, in the location through which the mobile object  20  is to pass, the direction of the directional antenna  104  and the directional antenna  204  are likely to be compatible by adjusting the direction of the directional antenna  104  to be the same as the direction in which the mobile object  20  used to pass through the location. The adjustment performing unit  124  can save the time for searching for the direction in which the radio wave receipt intensity is the strongest with the calibration by performing the adjustment of the directional antenna  104  using the estimation model. 
       FIG. 9  schematically illustrates one example of the functional configuration of the communication apparatus  200 . The communication apparatus  200  includes a target information storage unit  212 , a mobile object information acquisition unit  214 , a mobile object information transmitting unit  216 , an antenna control unit  220 , a notification information transmitting unit  232 , a notification information receiving unit  234 , a history storage unit  242 , an estimation model generation unit  244  and an estimation model storage unit  246 . 
     The target information storage unit  212  stores the target information related to the communication object. The target information storage unit  212  stores, for example, the location information of the communication apparatus  100 , which is the communication object. 
     The mobile object information acquisition unit  214  acquires the mobile object information of the mobile object  20  loaded with the communication apparatus  200 . The mobile object information acquisition unit  214  may acquire the mobile object information from the mobile object control apparatus  22  of the mobile object  20 . 
     The mobile object information transmitting unit  216  transmits the mobile object information acquired by the mobile object information acquisition unit  214  to the communication apparatus  100 . The mobile object information transmitting unit  216  may transmit the mobile object information to the communication apparatus  100  by the wireless communication between the control antenna  202  and the control antenna  102 . 
     The antenna control unit  220  controls the directional antenna  204 . The antenna control unit  220  includes a tracking control unit  222  and an adjustment performing unit  224 . 
     The tracking control unit  222  adjusts the direction of the directional antenna  204  to track the communication apparatus  100  based on the target object information stored in the target information storage unit  212  and the mobile object information acquired by the mobile object information acquisition unit  214 . The tracking control unit  222  may specify the relative locational relationship with the communication apparatus  100  based on the target object information and the mobile object information, and the directional antenna  204  may adjust the direction of the directional antenna  204  to direct to the direction of the communication apparatus  100 . The tracking control unit  222 , for example, specifies the relative locational relationship between the directional antenna  204  and the communication apparatus  100  by predicting the posture and location of the mobile object  20  based on the location information, the moving direction and the movement velocity included in the mobile object information, and the directional antenna  204  adjusts the direction of the directional antenna  204  to direct to the direction of the communication apparatus  100 . 
     The adjustment performing unit  224  performs the calibration of the directional antenna  204 . The adjustment performing unit  224  performs the calibration of the directional antenna  204  by measuring the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  while changing continuously the direction of the directional antenna  204 . The adjustment performing unit  224  may change continuously the physical pointing direction of the directional antenna  204 . 
     The adjustment performing unit  224 , for example, searches for the direction in which the radio wave receipt intensity is the strongest by measuring the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  while changing continuously the direction of the directional antenna  204 . The adjustment performing unit  224  may specify the direction of the directional antenna  204  in which the radio wave receipt intensity from the directional antenna  104  by the directional antenna  204  is the strongest, and complete the calibration by making the directional antenna  204  direct to the direction. 
     The notification information transmitting unit  232  transmits the notification information to the communication apparatus  100  according to the completion of the calibration of the directional antenna  204  by the adjustment performing unit  224 . The notification information transmitting unit  232  may transmit the notification information to the communication apparatus  100  via the control antenna  202 . The notification information transmitting unit  232  may transmit the notification information to the communication apparatus  100  by the wireless communication between the control antenna  202  and the control antenna  102 . 
     The notification information receiving unit  234  receives the notification information transmitted according to the completion of the calibration of the directional antenna  104  by the communication apparatus  100 . The notification information receiving unit  234  may receive the notification information via the control antenna  202 . The notification information receiving unit  234  may receive the notification information transmitted by the wireless communication between the control antenna  102  and the control antenna  202  by the communication apparatus  100 . 
     The adjustment performing unit  224  may perform the calibration of the directional antenna  204  according to the receipt of the notification information from the communication apparatus  100  by the notification information receiving unit  234  without performing the calibration of the directional antenna  204  while performing the calibration of the directional antenna  104  by the communication apparatus  100 . 
     The history storage unit  242  stores the history of the mobile object information acquired by the mobile object information acquisition unit  214  and the direction of the directional antenna  204  after adjustment that is adjusted by the calibration of the directional antenna  204  by the adjustment performing unit  224  in the location shown by the location information included in the mobile object information. 
     The estimation model generation unit  244  generates the estimation model that estimates the direction of the directional antenna  204  after adjustment from the mobile object information, using, as the teacher data, the mobile object information and the direction of the directional antenna  204  after adjustment included in the plurality of pieces of history stored in the history storage unit  242 . 
     The estimation model storage unit  246  stores the estimation model generated by the estimation model generation unit  244 . When the plurality of pieces of history stored in the history storage unit  242  are provided by the other apparatuses, and the estimation models are generated by the other apparatuses, the estimation model storage unit  246  may acquire the estimation models generated by the other apparatuses from the other apparatuses and store them. 
     The adjustment performing unit  224  may adjust the direction of the directional antenna  204  using the estimation model stored in the estimation model storage unit  246 . For example, the adjustment performing unit  224  adjusts the direction of the directional antenna  204  based on the direction of the directional antenna  204  after adjustment, which is estimated using the estimation model, from the mobile object information acquired by the mobile object information acquisition unit  214 . The adjustment performing unit  224  adjusts the direction of the directional antenna  204  to match the estimated direction of the directional antenna  204  after adjustment, for example. 
       FIG. 10  schematically illustrates a HAPS  400  as one example of the mobile object  20 . The HAPS  400  may be one example of a flight vehicle. The HAPS  400  includes a vehicle  402 , a central unit  404 , a propeller  406 , a pod  408  and a solar panel  410 . The central unit  404  includes a control apparatus  420  and a communication apparatus  500  that are not illustrated. 
     The electrical power generated by the solar panel  410  is stored in one or more batteries arranged in at least any of the vehicle  402 , the central unit  404  and the pod  408 . The electrical power stored in the battery is utilized by each component included in the HAPS  400 . 
     The control apparatus  420  may control the flight of the HAPS  400 . The control apparatus  420  controls the flight of the HAPS  400  by controlling the rotation of the propeller  406 , for example. Also, the control apparatus  420  may control the flight of the HAPS  400  by changing the angle of a flap or an elevator that is not illustrated. The control apparatus  420  includes various types of sensors such as a location measuring sensor such as a GPS sensor, a gyro sensor and an acceleration sensor, and may manage the location, the moving direction and the movement velocity of the HAPS  400 . 
     The communication apparatus  500  includes an control antenna  502 , a FL (Feeder Link) antenna  504  and a SL (Service Link) antenna  506 . The FL antenna  504  is an antenna for the feeder link. The FL antenna  504  may be one example of the directional antenna. The communication apparatus  500  forms the feeder link with the communication apparatus  100  on the ground by the FL antenna  504 . The communication apparatus  500  and the communication apparatus  100  form the feeder link using the FL antenna  504  and the directional antenna  104 . 
     The control antenna  502  is an antenna with a lower directionality than the FL antenna  504 . The control antenna  502  may be an omni-antenna, for example. The control antenna  502  may be one example of the control antenna  202 . The communication apparatus  500  and the communication apparatus  100  may form the C2 (Command Control) link by the control antenna  502  and the control antenna  102 , and communicate by the C2 link. 
     The SL antenna  506  is an antenna for the service link. The SL antenna  506  may be an antenna with a lower directionality than the FL antenna  504 , and a higher directionality than the control antenna  502 . The communication apparatus  500  forms the cell  508  on the ground by the SL antenna  506 . The communication apparatus  500  forms the service link with the user terminal  30  inside the cell  508  by the SL antenna  506 . 
     The user terminal  30  may be any terminal as long as it is a communication terminal that can be communicate with the communication apparatus  500 . For example, the user terminal  30  is a mobile phone such as a smartphone. The user terminal  30  may also be a tablet terminal, a PC (Personal Computer) and the like. The user terminal  30  may also be a so-called IoT (Internet of Thing) device. The user terminal  30  may include all things corresponding to so-called IoE (Internet of Everything). 
     The communication apparatus  500  may provide a wireless communication service to the user terminal  30  by relaying the communication between the user terminal  30  and the network  40  on the ground together with the communication apparatus  100 . The network  40  may include a core network that is provided by a telecommunication carrier. The core network may comply with any mobile communication system, for example, it complies with the 3G (3rd Generation) communication system, the LTE (Long Term Evolution) communication system, the 4G (4th Generation) communication system, and the 5G (5th Generation) or later communication system, and the like. The network  40  may include the Internet. 
     The HAPS  400 , for example, establishes the service link with each communication apparatus  100  arranged in each location on the ground and communicates with the network  40  on the ground via the communication apparatus  100 . The HAPS  400  covers the ground area with the cell  508  while flying in circles along the circular flight path in the sky of the ground area of the targeted for coverage, for example. The flight path may be a regular circle, an ellipse and so on, or even a figure eight. The circling flight of the HAPS  400  in the sky of the ground area may be described as a fixed-point flight. Also, the HAPS  400 , for example, covers the entire of the ground area by moving in the sky of the ground area while covering a part of the ground area of the targeted for coverage by the cell  508 . 
       FIG. 11  schematically illustrates one example of the functional configuration of the communication apparatus  500 . The communication apparatus  500  includes a target information storage unit  512 , a mobile object information acquisition unit  514 , a mobile object information transmitting unit  516 , an antenna control unit  520 , a notification information transmitting unit  532 , a notification information receiving unit  534 , a communication relay unit  540 , a history storage unit  542 , an estimation model generation unit  544  and an estimation model storage unit  546 . 
     The target information storage unit  512  stores target information related to the communication object. The target information storage unit  512  stores the location information of the communication apparatus  100  that is the communication object, for example 
     The mobile object information acquisition unit  514  acquires the mobile object information of the HAPS  400  loaded with the communication apparatus  200 . The mobile object information acquisition unit  514  may receive the mobile object information from the control apparatus  420  of the HAPS  400 . 
     The mobile object information transmitting unit  516  transmits the mobile object information acquired by the mobile object information acquisition unit  514  to the communication apparatus  100 . The mobile object information transmitting unit  516  may transmit the mobile object information to the communication apparatus  100  by the wireless communication between the control antenna  502  and the control antenna  102 . 
     The antenna control unit  520  controls the FL antenna  504 . The antenna control unit  520  includes a tracking control unit  522  and an adjustment performing unit  524 . 
     The tracking control unit  522  adjusts the direction of the FL antenna  504  to track the communication apparatus  100  based on the target object information stored in the target information storage unit  512  and the mobile object information acquired by the mobile object information acquisition unit  514 . The tracking control unit  522  may specify the relative locational relationship with the communication apparatus  100  based on the target object information and the mobile object information, and the FL antenna  504  may adjust the direction of the FL antenna  504  to direct to the direction of the communication apparatus  100 . The tracking control unit  522 , for example, specifies the relative locational relationship between the FL antenna  504  and the communication apparatus  100  by predicting the posture and the location of the HAPS  400  based on the location information, the moving direction and the movement velocity included in the mobile object information, and the FL antenna  504  adjusts the direction of the FL antenna  504  to direct to the direction of the communication apparatus  100 . 
     The adjustment performing unit  524  performs the calibration of the FL antenna  504 . The adjustment performing unit  524  performs the calibration of the FL antenna  504  by measuring the radio wave receipt intensity from the directional antenna  104  by the FL antenna  504  while changing continuously the direction of the FL antenna  504 . The adjustment performing unit  524  may change continuously the physical pointing direction of the FL antenna  504 . 
     The adjustment performing unit  524 , for example, searches for the direction in which the radio wave receipt intensity is the strongest, by measuring the radio wave receipt intensity from the directional antenna  104  by the FL antenna  504  while changing continuously the direction of the FL antenna  504 . The adjustment performing unit  524  may specify the direction of the FL antenna  504  in which the radio wave receipt intensity from the directional antenna  104  by the FL antenna  504  is the strongest and complete the calibration by making the FL antenna  504  to direct to the direction. 
     The notification information transmitting unit  532  transmits the notification information to the communication apparatus  100  according to the completion of the calibration of the FL antenna  504  by the adjustment performing unit  524 . The notification information transmitting unit  532  may transmit the notification information to the communication apparatus  100  via the control antenna  502 . The notification information transmitting unit  532  may transmit the notification information to the communication apparatus  100  by the wireless communication between the control antenna  502  and the control antenna  102 . 
     The notification information receiving unit  534  receives the notification information transmitted according to the completion of the calibration of the directional antenna  104  by the communication apparatus  100 . The notification information receiving unit  534  may receive the notification information via the control antenna  502 . The notification information receiving unit  534  may receive the notification information transmitted by the wireless communication between the control antenna  102  and the control antenna  502  by the communication apparatus  100 . 
     The adjustment performing unit  524  may perform the calibration of the FL antenna  504  according to the receipt of the notification information from the communication apparatus  100  by the notification information receiving unit  534 , without performing the calibration of the FL antenna  504  during performing the calibration of the directional antenna  104  by the communication apparatus  100 . 
     The communication relay unit  540  relays the communication between the user terminal  30  and the communication apparatus  100 . The communication relay unit  540  may relay the communication between the user terminal  30  and the communication apparatus  100  by transmitting the data received from the user terminal  30  via the service link to the communication apparatus  100  via the feeder link. Herein, the adjustment performing unit  124  of the communication apparatus  100  may perform the calibration of the directional antenna  104  by measuring the radio wave receipt intensity by the directional antenna  104  of the wave modulation including the data transmitted by the communication apparatus  500 . In this way, by making it possible to perform the calibration utilizing the wave modulation when relaying the data communication between the user terminal  30  and the communication apparatus  100 , the need to interrupt data communication to transmit a beacon signal for calibration can be eliminated, and the calibration can be performed efficiently. 
     The history storage unit  542  stores the history of the mobile object information acquired by the mobile object information acquisition unit  514  and the direction of the FL antenna  504  after adjustment that is adjusted by the calibration of the FL antenna  504  by the adjustment performing unit  524  in the location shown by the location information included in the mobile object information. 
     The estimation model generation unit  544  generates an estimation model that estimates the direction of the FL antenna  504  after adjustment from the mobile object information, by using, as teacher data, the mobile object information and the direction of the FL antenna  504  after adjustment included in a plurality of pieces of history stored in the history storage unit  542 . 
     The estimation model storage unit  546  stores the estimation model generated by the estimation model generation unit  544 . When the plurality of pieces of history stored in the history storage unit  542  are provided by other apparatuses and estimation models are generated by the other apparatuses, the estimation model storage unit  546  may acquire and store the estimation models generated by the other apparatuses from the other apparatuses. 
     The adjustment performing unit  524  may use the estimation model stored in the estimation model storage unit  546  to adjust the direction of the FL antenna  504 . For example, the adjustment performing unit  524  adjusts the direction of the FL antenna  504  based on the direction of the FL antenna  504  after adjustment, which is estimated using the estimation model, from the mobile object information acquired by the mobile object information acquisition unit  514 . The adjustment performing unit  524 , for example, adjusts the estimated direction of the FL antenna  504  to match the direction of the FL antenna  504  after adjustment. 
       FIG. 12  schematically illustrates one example of a hardware configuration of a computer  1200  that functions as a communication apparatus  100 , a communication apparatus  200  or a communication apparatus  500 . A program that is installed in the computer  1200  can cause the computer  1200  to function as one or more sections of the apparatus of the present embodiment or cause the computer  1200  to execute operations associated with the apparatus of the present embodiment or the one or more sections, and/or cause the computer  1200  to execute the process of the present embodiment or steps thereof. Such programs may be executed by a central processing unit (CPU)  1212  in order to cause the computer  1200  to execute a specific operation associated with some or all of the flowchart and the blocks in the block diagrams described in the present specification. 
     The computer  1200  according to the present embodiment includes the CPU  1212 , a RAM  1214 , and a graphics controller  1216  which are mutually connected by a host controller  1210 . The computer  1200  also includes a communication interface  1222 , a storage device  1224 , and an input and output unit such as an IC card drive which are connected to the host controller  1210  via an input and output controller  1220 . The storage device  1224  may be a hard disk drive, a solid state drive, or the like. The computer  1200  also includes legacy input/output units such as a ROM  1230  and a keyboard, which are connected to the input/output controller  1220  via an input/output chip  1240 . 
     The CPU  1212  operates according to the programs stored in the ROM  1230  and the RAM  1214 , thereby controlling each unit. The graphics controller  1216  is configured to acquire image data generated by the CPU  1212  in a frame buffer or the like provided in the RAM  1214  or in itself, and cause the image data to be displayed on a display device  1218 . 
     The communication interface  1222  communicates with other electronic devices via a network. The storage device  1224  stores programs and data used by the CPU  1212  in the computer  1200 . The IC card drive reads programs and data from an IC card, and/or writes programs and data into the IC card. 
     The ROM  1230  stores therein boot programs or the like executed by the computer  1200  at the time of activation, and/or stores programs depending on hardware of the computer  1200 . The input/output chip  1240  may also be configured to connect various input/output units to the input/output controller  1220  via a USB port, a parallel port, a serial port, a keyboard port, a mouse port or the like. 
     The programs are provided via a computer readable storage medium such as an IC card. The programs are read from a computer readable storage medium, installed in the storage device  1224 , the RAM  1214 , or the ROM  1230  which is also an example of the computer readable storage medium, and executed by the CPU  1212 . Information processing written in these programs is read by the computer  1200 , and provides cooperation between the programs and the various types of hardware resources described above. An apparatus or a method may be configured by realizing an operation or processing of information according to a use of the computer  1200 . 
     For example, when communication is performed between the computer  1200  and an external device, the CPU  1212  may execute a communication program loaded in the RAM  1214 , and instruct the communication interface  1222  to execute communication processing based on processing written in the communication program. The communication interface  1222 , under the control of the CPU  1212 , reads transmission data stored in a transmission buffer processing region provided in a recording medium such as the RAM  1214 , the storage device  1224 , or the IC card, transmits the read transmission data to the network, or writes receipt data received from the network into a receipt buffer processing region or the like provided on the recording medium. 
     In addition, the CPU  1212  may cause all or necessary portion of a file or a database stored in the external recording medium such as the storage device  1224  or the IC card, to be read by the RAM  1214 , and execute various types of processing on the data on the RAM  1214 . Next, the CPU  1212  may write back the processed data to the external recording medium. 
     Various types of programs and various types of information such as data, a table, and a database may be stored in the recording medium, and subjected to information processing. The CPU  1212  may execute, on the data read from the RAM  1214 , various types of processing including various types of operations, information processing, conditional judgement, conditional branching, unconditional branching, information retrieval/replacement, or the like described in any part in the present disclosure and specified by instruction sequences of the programs, and writes back the results to the RAM  1214 . In addition, the CPU  1212  may retrieve information in a file, a database, or the like in the recording medium. For example, when a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU  1212  may retrieve, out of the plurality of entries, an entry with the attribute value of the first attribute specified that meets a condition, read the attribute value of the second attribute stored in the entry, and thereby acquire the attribute value of the second attribute associated with the first attribute meeting a predetermined condition. 
     The above-described program or software modules may be stored in the computer-readable storage medium on or near the computer  1200 . In addition, a recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer readable storage medium, so that the programs are provided to the computer  1200  via the network. 
     In the present embodiment, blocks of the flowcharts and the block diagrams may represent steps of processes in which operations are executed or sections of apparatuses responsible for performing operations. A specific step and “unit” may be implemented by a dedicated circuit, a programmable circuit supplied along with a computer readable instruction stored on a computer readable storage medium, and/or a processor supplied along with the computer readable instruction stored on the computer readable storage medium. A dedicated circuit may include digital and/or analog hardware circuits and may include integrated circuits (IC) and/or discrete circuits. The programmable circuit may include, for example, a reconfigurable hardware circuit including logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logical operations, and a flip-flop, a register, and a memory element, such as a field programmable gate array (FPGA) and a programmable logic array (PLA). 
     The computer readable storage medium may include any tangible device capable of storing an instruction executed by an appropriate device, so that the computer readable storage medium having the instruction stored thereon constitutes a product including an instruction that may be executed in order to provide means to execute an operation specified by a flowchart or a block diagram. Examples of the computer-readable storage medium may include an electronic storage medium, a magnetic storage medium, an optical storage medium, a magneto-electric storage medium, a semiconductor storage medium, and the like. More specific examples of the computer readable storage medium may include a floppy (registered trademark) disk, a diskette, a hard disk, a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM or flash memory), an electrically erasable programmable read only memory (EEPROM), a static random access memory (SRAM), a compact disk read only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray (registered trademark) disk, a memory stick, an integrated circuit card, or the like. 
     The computer-readable instructions may include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcodes, firmware instructions, state setting data, or any of source codes or object codes described in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk (registered trademark), JAVA (registered trademark), or C++, and conventional procedural programming languages, such as “C” programming languages or similar programming languages. 
     The computer readable instruction may be provided to a general purpose computer, a special purpose computer, or a processor or a programmable circuit of another programmable data processing apparatus locally or via a local area network (LAN), a wide area network (WAN) such as the Internet or the like in order that the general purpose computer, the special purpose computer, or the processor or the programmable circuit of another programmable data processing apparatus is to execute the computer readable instruction to provide means to execute operations specified by the flowchart or the block diagram. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. 
     While the embodiments of the present invention have been described, the technical scope of the invention is not limited to the above described embodiments. It is apparent to persons skilled in the art that various alterations and improvements can be added to the above-described embodiments. It is also apparent from the scope of the claims that the embodiments added with such alterations or improvements can be included in the technical scope of the invention. 
     The operations, procedures, steps, and stages of each process performed by an apparatus, system, program, and method shown in the claims, embodiments, or diagrams can be performed in any order as long as the order is not indicated by “prior to,” “before,” or the like and as long as the output from a previous process is not used in a later process. Even if the process flow is described using phrases such as “first” or “next” in the claims, embodiments, or diagrams, it does not necessarily mean that the process must be performed in this order. 
     EXPLANATION OF REFERENCES 
     
         
         
           
               10 : system;  20 : mobile object;  22 : mobile object control apparatus;  30 : user terminal;  40 : network;  100 : communication apparatus;  102 : control antenna;  104 : directional antenna;  112 : mobile object information storage unit;  114 : mobile object information receiving unit;  120 : antenna control unit;  122 : tracking control unit;  124 : adjustment performing unit;  132 : notification information transmitting unit;  134 : notification information receiving unit;  142 : history storage unit;  144 : estimation model generation unit;  146 : estimation model storage unit;  200 : communication apparatus;  202 : control antenna;  204 : directional antenna;  212 : target information storage unit;  214 : mobile object information acquisition unit;  216 : mobile object information transmitting unit;  220 : antenna control unit;  222 : tracking control unit;  224 : adjustment performing unit;  232 : notification information transmitting unit;  234 : notification information receiving unit;  242 : history storage unit;  244 : estimation model generation unit;  246 : estimation model storage unit;  302 : lateral orbit;  304 : longitudinal orbit;  312 : radio wave strength graph;  314 : radio wave strength graph;  306 : gyratory orbit;  316 : radio wave strength graph;  400 : HAPS;  402 : vehicle;  404 : central unit;  406 : propeller;  408 : pod;  410 : solar panel;  420 : control apparatus;  500 : communication apparatus;  502 : control antenna;  504 : FL antenna;  506 : SL antenna;  508 : cell;  512 : target information storage unit;  514 : mobile object information acquisition unit;  516 : mobile object information transmitting unit;  520 : antenna control unit;  522 : tracking control unit;  524 : adjustment performing unit;  532 : notification information transmitting unit;  534 : notification information receiving unit;  540 : communication relay unit;  542 : history storage unit;  544 : estimation model generation unit;  546 : estimation model storage unit;  1200 : computer;  1210 : host controller;  1212 : CPU;  1214 : RAM;  1216 : graphics controller;  1218 : display device;  1220 : input/output controller;  1222 : communication interface;  1224 : storage device;  1230 : ROM;  1240 : input/output chip