JP2018191089A - Wireless communication device, communication control method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve communication stability of a wireless communication device existing in the skies.SOLUTION: A wireless communication device mounted on a flying body comprises: a wireless unit that receives a wireless signal transmitted from a wireless base station; a cell counting unit that counts the number of cells of the wireless base station identified by the wireless signal received by the wireless unit; and a communication controller that, in a case where the increase number or the decrease number in a predetermined time period, of the number of cells per unit time as the counting result of the cell counting unit is equal to or more than a predetermined threshold, changes a communication partner selection method for selecting the wireless base station as a communication partner among a plurality of wireless base stations as communication partner candidates.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless communication apparatus, a communication control method, and a computer program.

  Conventionally, a handover technique for switching a radio base station to which a mobile terminal is connected by radio is known (see, for example, Patent Document 1).

JP 2014-192738 A

In this conventional technique, information on a radio base station to be handed over by the mobile terminal is acquired based on the position information of the mobile terminal and the information on the reception quality at the mobile terminal.
However, in the above-described conventional technology, information regarding an appropriate radio base station to be handed over by a mobile terminal existing in the sky cannot be acquired, and communication of the mobile terminal existing in the sky becomes unstable. There was a possibility. This is due to the fact that the sky is more visible than the ground. Since the sky is more visible than the ground, radio signals arrive from more wireless base stations in the sky than on the ground even at the same horizontal position (latitude and longitude). For this reason, when a situation occurs in which the radio base station having the same level of reception quality as the handover destination candidate increases from the ground, the appropriate radio base to which the mobile terminal existing in the sky is to be handed over Information about the station could not be acquired, and there was a possibility that the communication of the mobile terminal existing in the sky would become unstable.

  The present invention has been made in consideration of such circumstances, and an object thereof is to improve the stability of communication of a wireless communication device existing in the sky.

(1) According to one aspect of the present invention, a wireless communication device mounted on a flying object is identified by a wireless unit that receives a wireless signal transmitted from a wireless base station and the wireless signal received by the wireless unit A cell counting unit that counts the number of cells of the radio base station, and a plurality of cell counts per unit time of the counting result of the cell counting unit when a predetermined number of increase or decrease is equal to or greater than a predetermined threshold, And a communication control unit that changes a communication partner selection method for selecting the wireless base station as a communication partner from the wireless base stations as communication partner candidates.
(2) One aspect of the present invention is the wireless communication device according to (1), wherein the communication control unit is configured to select the communication partner selection method when the increase in the number of cells per unit time is equal to or greater than a predetermined threshold. Is a wireless communication device that changes to a predetermined communication partner selection method for the sky.
(3) One aspect of the present invention further includes a flying object moving direction determination unit that determines whether the moving direction of the flying object is a vertical direction or a horizontal direction in the wireless communication device according to (1), The communication control unit uses the communication partner selection method when the moving direction of the flying object is a horizontal direction according to a determination result of the flying object moving direction determination unit when the communication partner selection method for the sky is used. Is changed from the above-mentioned communication partner selection method for sky to a predetermined communication partner selection method for sky horizontal movement.
(4) One aspect of the present invention is the wireless communication apparatus according to any one of (1) to (3), wherein the communication control unit is configured such that a decrease number of the number of cells per unit time is greater than or equal to a predetermined threshold value. In the case of the wireless communication device, the communication partner selection method is changed to a predetermined ground communication partner selection method.
(5) According to one aspect of the present invention, in the wireless communication device according to any one of (1) to (4), a horizontal position information acquisition unit that acquires horizontal position information indicating a horizontal position of the flying object The communication control unit increases the measurement interval of the number of cells per unit time by a predetermined time when it is determined that the moving range of the flying object is a fixed range based on the horizontal position information. , A wireless communication device.
(6) One aspect of the present invention is the wireless communication apparatus according to any one of (1) to (5), wherein the communication partner selection method controls handover between the wireless base stations of a plurality of communication partner candidates. It is a radio communication apparatus that is to change a handover parameter for
(7) One aspect of the present invention is the wireless communication apparatus according to (6), wherein the communication control unit acquires the handover parameter candidate from the wireless base station that is accessed from a flight location of the flying object. It is a communication device.
(8) One aspect of the present invention is the wireless communication apparatus according to any one of (1) to (5), wherein the communication partner selection method prohibits handover for a certain period of time.
(9) According to one aspect of the present invention, in the wireless communication apparatus according to (8), the communication control unit receives information indicating the handover prohibition time from the wireless base station that is accessed from a flight location of the flying object. A wireless communication device to be acquired.
(10) One aspect of the present invention is the wireless communication device according to any one of (1) to (5), wherein the communication partner selection method performs simultaneous communication from among the wireless base stations of a plurality of communication partner candidates. A radio communication apparatus is to change the number of radio base stations to be performed.
(11) According to one aspect of the present invention, in the wireless communication device according to any one of (1) to (10), the authentication information of the flying object is acquired from an authentication information storage unit provided in the flying object, and the authentication information Is transmitted to an authentication server that performs authentication of the flying object to request authentication of the flying object, and the communication control unit authenticates the request result of the authentication of the flying object of the authentication requesting unit. The wireless communication apparatus changes the communication partner selection method when the request is passed, and does not change the communication partner selection method when the request result is authentication failure.

(12) One aspect of the present invention is a communication control method for a radio communication device mounted on a flying body, wherein the radio communication device receives a radio signal transmitted from a radio base station; A cell counting step in which the radio communication device counts the number of cells of the radio base station identified by the radio signal received in the radio reception step; and Communication partner selection for selecting the radio base station of the communication partner from the radio base stations of a plurality of communication partner candidates when the number of increase or decrease of the number of cells per unit time is equal to or greater than a predetermined threshold And a communication control step for changing the method.

(13) One aspect of the present invention is a wireless communication device mounted on a flying object, the wireless communication device including a wireless unit that receives a wireless signal transmitted from a wireless base station. A cell counting function for counting the number of cells of the radio base station identified by the received radio signal, and an increase or decrease in the number of cells per unit time of the counting result of the cell counting function is a predetermined number. A computer program for realizing a communication control function for changing a communication partner selection method for selecting the wireless base station of a communication partner from among the wireless base stations of a plurality of communication partner candidates when the threshold is equal to or greater than a threshold is there.

  According to the present invention, it is possible to improve the stability of communication of a wireless communication device existing in the sky.

It is a block diagram which shows an example of a function structure of the aircraft 1 which concerns on one Embodiment. It is an external view which shows an example of the external appearance structure of the flying body 1 which concerns on one Embodiment. It is a block diagram which shows an example of the hardware constitutions of the radio | wireless communication apparatus 100 which concerns on one Embodiment. It is a block diagram which shows an example of a function structure of the radio | wireless communication apparatus 100 which concerns on one Embodiment. It is a figure which shows the structural example of the handover parameter candidate data 141 which concerns on one Embodiment. It is a figure which shows the structural example of the parameter change area information 142 which concerns on one Embodiment. It is a figure which shows the structural example of the adjacent cell list 143 which concerns on one Embodiment. It is a flowchart of Example 1 of the communication control method which concerns on one Embodiment. It is a flowchart of Example 2 of the communication control method which concerns on one Embodiment. It is a flowchart of Example 3 of the communication control method according to an embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating an example of a functional configuration of the flying object 1 according to the present embodiment. FIG. 2 is an external view showing an example of an external configuration of the flying object 1 according to the present embodiment. First, the mechanical configuration of the flying object 1 will be described with reference to FIG. In FIG. 2, the flying object 1 includes a motor 60 and a rotor RT. The motor 60 gives lift and propulsion to the flying object 1 by rotating the rotor RT. In this example, the flying object 1 includes motors 61 to 64. The motors 61 to 64 rotate the corresponding rotors RT1 to RT4. By controlling the drive current supplied to each motor 60, the flight altitude, direction, and traveling direction of the aircraft 1 can be controlled.

  The flying object 1 includes a camera 40. The imaging unit, that is, the camera 40 images a landscape around the flying object 1. In this example, the imaging direction of the camera 40 matches the nose direction HDG of the flying object 1. In this case, the camera 40 images a landscape in front of the flying object 1. The camera 40 outputs a captured landscape image.

  Next, the functional configuration of the aircraft 1 will be described with reference to FIG. In FIG. 1, the flying object 1 includes a flight control unit 10, a flight positioning unit 30, a camera 40, a motor 60, a power supply unit 80, and a wireless communication device 100. The flight control unit 10 includes an authentication information storage unit 12.

  The flight positioning unit 30 measures the position of the flying object 1 and outputs a positioning value as a measurement result. The positioning value indicates a horizontal position (latitude and longitude) and a vertical position (altitude). The flight positioning unit 30 includes an altimeter as a means for measuring the position in the vertical direction. As a means for measuring the position of the flight positioning unit 30 in the horizontal direction, for example, GPS (Global Positioning System) may be used.

  The wireless communication device 100 communicates with a wireless base station that exists outside the aircraft 1. The wireless communication device 100 communicates with a device outside the flying object 1 (for example, a remote control device of the flying object 1) via the wireless base station. The radio base station with which the radio communication apparatus 100 communicates may be, for example, a radio base station of a mobile phone network of a communication method such as LTE (Long Term Evolution), or a radio of a communication method such as IEEE 802.11. It may be a wireless base station (access point (AP)) of a LAN (Local Area Network).

  The flight control unit 10 controls the flight of the flying object 1 by controlling the drive current supplied to the motor 60. The flight route of the flying object 1 may be set in the flight control unit 10 before the flight, or may be set or changed in the flight control unit 10 by communication of the wireless communication device 100 during the flight. The flight control unit 10 controls the motor 60 so that the flying object 1 flies along the flight route while comparing the flight route and the positioning value output from the flight positioning unit 30.

  The flight control unit 10 receives flight control from a device external to the aircraft 1 by the wireless communication device 100 or transmits flight monitoring data indicating a flight state to a device external to the aircraft 1. . Examples of the flight monitoring data include an image captured by the camera 40.

  The flight control unit 10 includes an authentication information storage unit 12. The authentication information storage unit 12 stores authentication information of the flying object 1. The authentication information of the flying object 1 is information unique to the flying object 1. When the authentication information of the flying object 1 is provided to an authentication server (not shown) that authenticates the flying object 1, the authentication object is authenticated by the authentication server.

  The function of the flight control unit 10 may be realized by dedicated hardware, or is configured by a CPU (Central Processing Unit) and a memory to realize the function of the flight control unit 10 The function may be realized by the CPU executing a computer program for doing so.

  The power supply unit 80 includes a battery that is a power supply of the flying object 1 and a power supply monitoring unit that monitors the remaining charge of the battery. The power supply unit 80 notifies the flight control unit 10 of the remaining charge of the battery. The flight control unit 10 executes a predetermined flight control process based on the remaining battery charge notified from the power supply unit 80. For example, the flight control unit 10 controls the flight of the flying object 1 so as to return to the original location where the flight started when the remaining charge of the battery becomes a predetermined threshold value or less.

  FIG. 3 is a block diagram illustrating an example of a hardware configuration of the wireless communication device 100 according to the present embodiment. In FIG. 3, the wireless communication device 100 includes a CPU 101, a storage unit 102, a wireless unit 103, and a positioning unit 104. These units are configured to exchange data.

  The CPU 101 controls the wireless communication device 100. This control function is realized by the CPU 101 executing a computer program. The storage unit 102 stores a computer program executed by the CPU 101 and various data.

  The radio unit 103 receives a radio signal transmitted from the radio base station. The radio unit 103 transmits a radio signal received by the radio base station. The radio unit 103 connects to a radio base station by radio. The wireless communication apparatus 100 performs communication with a wireless base station to which the wireless unit 103 is connected wirelessly.

  The positioning unit 104 measures the position of the wireless communication device 100 and outputs a positioning value as a measurement result. The positioning value indicates a horizontal position (latitude and longitude). As the positioning unit 104, for example, GPS may be used.

  The function of the wireless communication device 100 is realized by the CPU 101 executing a computer program. The wireless communication device 100 may be configured using a general-purpose computer device, or may be configured as a dedicated hardware device. The wireless communication device 100 may be a mobile communication terminal device such as a smartphone, for example.

  FIG. 4 is a block diagram illustrating an example of a functional configuration of the wireless communication device 100 according to the present embodiment. In FIG. 4, the wireless communication device 100 includes a wireless measurement unit 121, a cell counting unit 122, a communication control unit 123, a horizontal position information acquisition unit 124, an aircraft moving direction determination unit 125, and an authentication request unit 126. And a data storage unit 140. The data storage unit 140 stores handover parameter candidate data 141, parameter change area information 142, and a neighboring cell list 143. The data storage unit 140 is provided in the storage unit 102 of the wireless communication apparatus 100.

  The wireless measurement unit 121 measures the wireless quality index value based on the wireless signal received by the wireless unit 103. The wireless quality index value is an index value of the quality of wireless communication of the wireless communication apparatus 100. Radio quality index values include, for example, RSSI (Received Signal Strength Indicator), SINR (Signal to Interference Noise power Ratio), RSRP (Reference Signal Received Power), and the like. It is.

  The cell counting unit 122 counts the number of cells of the radio base station identified by the radio signal received by the radio unit 103. Hereinafter, an example of a cell identification method in which the cell counting unit 122 identifies the cell of the radio base station will be shown.

(Example 1 of cell identification method)
In Example 1 of the cell identification method, the cell of the radio base station is identified by the frequency of the radio signal received by the radio unit 103. When the frequency of the first radio signal received by the radio unit 103 is different from the frequency of the second radio signal, the cell counting unit 122 determines whether the first cell of the first radio signal and the second cell of the second radio signal are Two cells are detected.

(Example 2 of cell identification method)
In Example 2 of the cell identification method, the cell of the radio base station is identified by the cell identification information (cell ID) indicated by the radio signal received by the radio section 103. When the first cell ID of the first radio signal received by the radio unit 103 is different from the second cell ID of the second radio signal, the cell counting unit 122 receives the first cell ID and the second cell ID of the first cell ID. Two cells with the second cell are detected.

(Example 3 of cell identification method)
In Example 3 of the cell identification method, the cell of the radio base station is identified by the frequency of the radio signal received by the radio unit 103 and the cell ID indicated by the radio signal. The cell counting unit 122 sets the first cell ID of the first cell ID when the first cell ID of the first radio signal and the second cell ID of the second radio signal are different for each frequency of the radio signal received by the radio unit 103. Two cells, one cell and the second cell with the second cell ID, are detected.

  Note that the cells to be counted by the cell counting unit 122 may be limited by the reception strength of the radio signal. For example, among the radio signals received by the radio unit 103, only the cells identified by the radio signal whose radio signal reception intensity is within a predetermined range (cell count target condition range) are set as the count targets of the cell count unit 122. May be. The reception strength of the radio signal is, for example, RSSI, RSRP, or the like. The cell count target condition range is, for example, a range of candidate destination condition.

  The communication control unit 123 controls communication performed using the wireless unit 103. The communication control unit 123 changes a communication partner selection method for selecting a communication partner radio base station from a plurality of communication partner candidate radio base stations as one control of communication performed using the radio unit 103. An example of the communication partner selection method of the present embodiment is to change a handover parameter for controlling handover between a plurality of communication partner candidate radio base stations. Another example of the communication partner selection method of the present embodiment is to change the number of radio base stations that perform communication at the same time from among a plurality of communication partner candidate radio base stations.

  The communication control unit 123 changes the communication partner selection method to a predetermined flying communication partner selection method when the ascent determination condition for determining that the flying object 1 has risen from the ground to the sky is satisfied. The communication partner selection method for the sky is a communication partner selection method suitable for the case where the flying object 1 (wireless communication device 100) exists in the sky. The communication control unit 123 changes the communication partner selection method to a predetermined ground communication partner selection method when the descent determination condition for determining that the flying object 1 has descended from the sky to the ground is satisfied. The ground communication partner selection method is a communication partner selection method suitable for the case where the flying object 1 (wireless communication device 100) exists on the ground. Details of the communication control method in which the communication control unit 123 changes the communication partner selection method will be described later.

  The horizontal position information acquisition unit 124 acquires horizontal position information indicating the position of the flying object 1 in the horizontal direction. As an example of this embodiment, the horizontal position information acquisition unit 124 acquires the positioning value of the positioning unit 104 of the wireless communication device 100 mounted on the flying object 1. The positioning value of the positioning unit 104 of the wireless communication device 100 mounted on the flying object 1 is horizontal position information indicating the horizontal position of the flying object 1.

  Note that the horizontal position information acquisition unit 124 may use the flight positioning unit 30 of the aircraft 1. In this case, the wireless communication device 100 acquires the horizontal position (latitude and longitude) of the positioning value of the flight positioning unit 30 via the flight control unit 10. When the horizontal position information acquisition unit 124 uses the flight positioning unit 30 of the flying object 1, the wireless communication device 100 may include the positioning unit 104 or may not include the positioning unit 104.

  The flying object moving direction determination unit 125 determines whether the moving direction of the flying object 1 is the vertical direction or the horizontal direction. For example, the flying object moving direction determination unit 125 determines the positioning values (“horizontal position (latitude and longitude)” and “vertical position (altitude)) of the flight positioning unit 30 of the flying object 1 via the flight control unit 10. )) Is acquired, and it is determined whether the moving direction of the flying object 1 is the vertical direction or the horizontal direction based on the positioning value. Note that the wireless communication device 100 includes an acceleration sensor and a gyro sensor, and the flying object moving direction determination unit 125 determines whether the moving direction of the flying object 1 is the vertical direction or the horizontal direction based on the detection results of these sensors. May be judged.

  The authentication request unit 126 acquires the authentication information of the flying object 1 from the authentication information storage unit 12 of the flight control unit 10 provided in the flying object 1 and transmits the authentication information to an authentication server that authenticates the flying object 1. To request authentication of the aircraft 1. The authentication request unit 126 receives a response (pass or fail of authentication) to the request for authentication of the aircraft 1 from the authentication server.

The data storage unit 140 stores handover parameter candidate data 141, parameter change area information 142, and a neighboring cell list 143.
The handover parameter candidate data 141 will be described with reference to FIG. FIG. 5 is a diagram illustrating a configuration example of the handover parameter candidate data 141 according to the present embodiment. In FIG. 5, the handover parameter candidate data 141 has a plurality (three in the example of FIG. 5) of handover (HO) parameter sets. The HO parameter set is a set of handover parameters for controlling handover between a plurality of communication partner candidate radio base stations. Note that the combination of handover parameters included in the HO parameter set in FIG. 5 is an example, and the combination of handover parameters included in the HO parameter set is arbitrarily set according to the applied radio communication system.

  The HO parameter set has HO parameter set application conditions. The HO parameter set application condition for a certain HO parameter set is a condition for applying the HO parameter set. For example, the HO parameter set application condition “HO candidate cell number <5” of the HO parameter set 1 indicates that the HO parameter set 1 is applied when the number of HO candidate cells is less than five.

  The parameter change area information 142 will be described with reference to FIG. FIG. 6 is a diagram illustrating a configuration example of the parameter change area information 142 according to the present embodiment. In FIG. 6, the parameter change area information 142 includes a cell ID (parameter change area cell ID) of a cell in an area for which a handover parameter is to be changed.

The neighbor cell list 143 will be described with reference to FIG. FIG. 7 is a diagram illustrating a configuration example of the neighboring cell list 143 according to the present embodiment. The neighboring cell list 143 is provided to the wireless communication apparatus 100 from the wireless base station to which the wireless unit 103 connects wirelessly. The wireless communication apparatus 100 receives the neighbor cell list 143 from the wireless base station to which the wireless unit 103 connects wirelessly and stores it in the data storage unit 140. In FIG. 7, the neighbor cell list 143 describes the cell ID (connection cell ID) of the wireless base station that provides the neighbor cell list 143. The adjacent cell list 143 includes a cell ID (adjacent cell ID) of a cell adjacent to the cell of the connected cell ID, and usage frequency information indicating a radio frequency used by the cell of the adjacent cell ID in association with the adjacent cell ID. be written.
Note that the radio base station may provide the radio communication apparatus 100 with a plurality of adjacent cell lists 143 according to altitude. For example, the radio base station may provide the radio communication apparatus 100 with the terrestrial neighbor cell list 143 and the sky neighbor cell list 143. This is because a cell adjacent to the cell of the same radio base station may change between the ground and the sky. In the terrestrial adjacent cell list 143 provided by the radio base station, when the radio communication apparatus 100 exists on the ground, a connection cell ID of a cell adjacent to the cell of the radio base station is described. In the adjacent cell list 143 for the sky provided by the radio base station, when the radio communication apparatus 100 exists in the sky, the connection cell ID of the cell adjacent to the cell of the radio base station is described. The wireless communication apparatus 100 uses the terrestrial adjacent cell list 143 when it is determined that it exists on the ground, and uses the adjacent cell list 143 for the sky when it determines that it exists in the sky. Thereby, the precision of selection of the communication partner of the radio | wireless communication apparatus 100 can be improved.

  Next, Example 1, Example 2, and Example 3 of the communication control method according to the present embodiment will be sequentially described with reference to FIG. 8, FIG. 9, and FIG.

[Example 1 of communication control method]
Example 1 of the communication control method according to the present embodiment will be described with reference to FIG. FIG. 8 is a flowchart of Example 1 of the communication control method according to the present embodiment. In Example 1 of the communication control method, the communication control unit 123 includes a plurality of communication partners when the number of increase or decrease in the number of cells per unit time of the counting result of the cell counting unit 122 is equal to or greater than a predetermined threshold. A communication partner selection method for selecting a communication partner radio base station from candidate radio base stations is changed.

  The communication control process of FIG. 8 is started in accordance with the start of the flight of the aircraft 1. For example, in the flying object 1, when the flight start signal indicating the start of the flight of the flying object 1 is input from the flight control unit 10 to the wireless communication device 100, the wireless communication device 100 starts the process of FIG. Alternatively, the wireless communication device 100 may start the processing of FIG. 8 by instructing the wireless communication device 100 to start the communication control process of FIG.

(Step S11) The communication control unit 123 starts the measurement period timer T1. The measurement period timer T1 is a timer that measures a predetermined period (measurement period) for measuring the number of increase or decrease in the number of cells per unit time of the counting result of the cell counting unit 122. The timer period of the measurement period timer T1 is set in advance. The timer period of the measurement period timer T1 can be arbitrarily set by the operator. For example, the operator may determine the timer period of the measurement period timer T1 according to the planned ascending speed and descending speed of the flying object 1. As an example of a method for determining the timer period of the measurement period timer T1, the timer period of the measurement period timer T1 is shortened as the planned ascent and descent speed of the flying object 1 increases.

(Step S12) The communication control unit 123 resets the cell counting unit 122 and starts the unit time timer T2. When the cell counter 122 is reset, the cell count value SUM of the cell counter 122 is reset to zero. The unit time timer T2 is a timer that measures the unit time for measuring the number of cells per unit time of the counting result of the cell counting unit 122. The timer period of the unit time timer T2 is set in advance. The timer period of the unit time timer T2 can be arbitrarily set by the operator. However, the timer period of the unit time timer T2 is shorter than the timer period of the measurement period timer T1.

(Step S13) The radio unit 103 receives a radio signal transmitted from the radio base station.

(Step S14) The cell counting unit 122 determines whether there is an additional cell (additional cell) of the radio base station identified by the radio signal received by the radio unit 103. This cell identification method is preset. For example, the operator can use any one of the above-described cell identification method example 1, example 2 or example 3 according to the communication method of the radio base station existing around the flight location of the aircraft 1. Set to 100. If there is an additional cell, the process proceeds to step S15, and if there is no additional cell, the process proceeds to step S16.

(Step S15) The cell counting unit 122 adds the number of additional cells (number of additional cells) to the cell count value SUM.

(Step S16) The communication control unit 123 determines that the unit time timer T2 has expired. If the unit time timer T2 has expired, the process proceeds to step S17. If not, the process proceeds to step S18.

(Step S17) The communication control unit 123 records the cell count value SUM as the number of cells per unit time at the measurement time in association with the current time (measurement time).

(Step S18) The communication control unit 123 determines the expiration of the measurement period timer T1. If the measurement period timer T1 has expired, the process proceeds to step S19. If the measurement period timer T1 has not expired, the process returns to step S12 to measure the number of cells per unit time.

(Step S19) The communication control unit 123 calculates the increase or decrease in the number of cells per unit time in the current measurement period (the timer period of the measurement period timer T1) based on the record of the number of cells per unit time. As a result, if the number of cells per unit time increases during this measurement period, the increase in the number of cells per unit time is calculated, while if the number of cells per unit time decreases, the number of cells per unit time is calculated. The reduction number of is calculated.

(Step S20) The communication control unit 123 determines whether the increase or decrease in the number of cells per unit time of the calculation result is equal to or greater than a predetermined threshold value. The threshold is preset. The threshold can be arbitrarily set by the operator. For example, the operator may determine the threshold according to the planned ascending speed and descending speed of the aircraft 1. As an example of the method for determining the threshold value, the threshold value is reduced as the scheduled ascent and descent speed of the flying object 1 increases. If the result of determination in step S20 is greater than or equal to the threshold value, the process proceeds to step S21, and if not, the process proceeds to step S22.

(Step S21) The communication control unit 123 changes the communication partner selection method. An example of a method for changing the communication partner selection method is shown below.

(Example 1 of changing communication partner selection method)
The communication control unit 123 changes the communication partner selection method to a predetermined aerial communication partner selection method when the increase in the number of cells per unit time is equal to or greater than a predetermined increase determination threshold (when the increase determination condition is satisfied). . As an example of a method for determining the ascent judgment threshold value, the value is determined to be larger than the increase in the number of cells per unit time on the ground at the flight location of the aircraft 1. When the ascent determination condition is satisfied, it can be determined that the flying object 1 has risen from the ground to the sky. Thereby, the communication control unit 123 changes the communication partner selection method to an aerial communication partner selection method suitable for the case where the flying object 1 (wireless communication device 100) is present in the sky.
In addition, the other example of a raise judgment condition is shown below.
(Another example of rising judgment conditions 1)
The same number of cells per unit time continues for a predetermined period.
(Other example 2 of rising judgment conditions)
Although the radio field intensity of a cell (adjacent cell) adjacent to the cell of the radio base station (connection base station) to which the radio communication apparatus 100 is connected has increased, the radio field intensity of the cell of the connection base station has decreased. It was detected that
(Other example 3 of rising judgment conditions)
The increase number or absolute number of the number of cells per unit time of cells other than the adjacent cells is not less than a predetermined threshold.
(Other example 4 of rising judgment conditions)
The threshold value used for the rising determination condition is set according to the flight region of the aircraft 1. The threshold value used for the rising determination condition may be different depending on the flight region of the aircraft 1.

(Example 2 of changing communication partner selection method)
The communication control unit 123 changes the communication partner selection method to a predetermined ground communication partner selection method when the decrease number of cells per unit time is equal to or greater than a predetermined decrease determination threshold (when the decrease determination condition is satisfied). . As an example of a method for determining the descent determination threshold value, the value is determined to be a larger value than the number of decrease in the number of cells per unit time on the ground at the flight location of the flying object 1. When the descent determination condition is satisfied, it can be determined that the flying object 1 has descended from the sky to the ground. Thereby, the communication control unit 123 changes the communication partner selection method to the ground communication partner selection method suitable for the case where the flying object 1 (the wireless communication device 100) exists on the ground.
Other examples of the descent determination condition are shown below.
(Another example of the descent judgment condition 1)
The same number of cells per unit time continues for a predetermined period.
(Another example 2 of the descent judgment condition)
It has been detected that the radio field strength of the cell of the connected base station has increased even though the radio field strength of the adjacent cell has decreased.
(Another example 3 of descent judgment conditions)
The decrease or absolute number of the number of cells per unit time of cells other than the adjacent cells is greater than or equal to a predetermined threshold.
(Other example 4 of the descent judgment condition)
The threshold value used for the descent determination condition is set according to the flight region of the aircraft 1. The threshold value used for the descent determination condition may vary depending on the flight region of the aircraft 1.

(Step S22) The wireless communication apparatus 100 determines the end of the process. For example, in the air vehicle 1, when the flight end signal indicating the end of the flight of the air vehicle 1 is input from the flight control unit 10 to the wireless communication device 100, the wireless communication device 100 ends the processing of FIG. Alternatively, the wireless communication device 100 may end the processing of FIG. 8 by instructing the wireless communication device 100 from the communication device 100 to end the communication control processing of FIG. If it is determined that the process is terminated, the process of FIG. 8 is terminated. If it is not the end of the process, the process returns to step S11 to start the next measurement period.

[Example 2 of communication control method]
Example 2 of the communication control method according to the present embodiment will be described with reference to FIG. FIG. 9 is a flowchart of Example 2 of the communication control method according to the present embodiment. In Example 2 of the communication control method, the communication control unit 123 includes a plurality of cells in the cell of the radio base station identified by the radio signal received by the radio unit 103 that do not exist in the neighboring cell list 143. A communication partner selection method for selecting a communication partner radio base station from among communication partner candidate radio base stations is changed.

  The communication control process of FIG. 9 is started in accordance with the start of the flight of the aircraft 1. For example, in the flying object 1, when the flight start signal indicating the start of the flight of the flying object 1 is input from the flight control unit 10 to the wireless communication device 100, the wireless communication device 100 starts the process of FIG. Alternatively, the wireless communication device 100 may start the processing of FIG. 9 by instructing the wireless communication device 100 to start the communication control processing of FIG. 9 from a device outside the flying object 1 by communication.

(Step S31) The radio unit 103 receives a radio signal transmitted from the radio base station.

(Step S32) The communication control unit 123 refers to the neighboring cell list 143. This adjacent cell list 143 to be referred to (reference target adjacent cell list 143) is an adjacent cell list 143 in which the same connection cell ID as the cell ID of the radio base station to which the radio unit 103 is connected by radio is described.

(Step S <b> 33) The communication control unit 123 determines whether a cell (non-adjacent cell) that does not exist in the reference target neighboring cell list 143 exists among the cells of the wireless base station identified by the wireless signal received by the wireless unit 103. Determine whether. As a result of this determination, if there is a non-adjacent cell, the process proceeds to step S34, and if not, the process proceeds to step S35.
Note that, as a cell to be determined whether or not a non-adjacent cell exists, a non-adjacent cell having a radio field intensity lower than a predetermined radio field intensity among non-adjacent cells may be a target.
In addition, as a condition for determining that a non-adjacent cell exists (non-adjacent cell determination condition), an example of the following non-adjacent cell determination condition may be applied.
(Example 1 of non-adjacent cell determination condition)
Non-adjacent cells exist continuously for a predetermined period.
(Example 2 of non-adjacent cell determination conditions)
The number of non-adjacent cells is greater than or equal to a predetermined threshold.

  Examples 1 and 2 of the non-adjacent cell determination conditions described above may be applied singly or in combination. Further, information on what non-adjacent cell determination conditions the radio communication apparatus 100 applies may be provided to the radio communication apparatus 100 from a radio base station to which the radio communication apparatus 100 is connected.

(Step S34) The communication control unit 123 changes the communication partner selection method to a predetermined communication partner selection method for the sky. This is because the sky is more visible than the ground, so it is considered that the possibility that a radio signal of a non-adjacent cell that does not exist in the reference target neighboring cell list 143 will be received from a distance is higher than the ground. It is.

(Step S35) The wireless communication apparatus 100 determines the end of the process. For example, in the flying object 1, when the flight end signal indicating the end of the flight of the flying object 1 is input from the flight control unit 10 to the wireless communication device 100, the wireless communication device 100 ends the process of FIG. Alternatively, the wireless communication device 100 may end the processing of FIG. 9 by instructing the wireless communication device 100 from the communication device 100 to end the communication control processing of FIG. If it is determined that the process is terminated, the process of FIG. 9 is terminated. If it is not the end of the process, the process returns to step S31 to continue the process of FIG.

The wireless communication apparatus according to Example 2 of the communication control method described above is
In a wireless communication device mounted on a flying object,
A radio unit for receiving a radio signal transmitted from the radio base station;
A neighbor cell list storage unit that stores a neighbor cell list received from the radio base station to which the radio unit is wirelessly connected;
When there is a cell that does not exist in the neighboring cell list among the cells of the radio base station identified by the radio signal received by the radio unit, communication is performed from among the radio base stations of a plurality of communication partner candidates. A communication control unit that changes a communication partner selection method for selecting the wireless base station of the partner;
A wireless communication device may be provided.

The communication control method according to the above-described communication control method example 2 is:
A communication control method for a wireless communication device mounted on a flying object,
A wireless reception step in which the wireless communication device receives a wireless signal transmitted from a wireless base station;
A neighboring cell list storage step of storing the neighboring cell list received from the wireless base station to which the wireless communication device is wirelessly connected in a neighboring cell list storage unit;
When there is a cell that does not exist in the neighboring cell list among the cells of the radio base station identified by the radio signal received by the radio signal received by the radio reception step, the plurality of communication partner candidates A communication control step of changing a communication partner selection method for selecting the wireless base station of the communication partner from among the wireless base stations;
A communication control method including

The computer program according to Example 2 of the communication control method described above is
A computer of the wireless communication device equipped with a wireless unit that receives a wireless signal transmitted from a wireless base station, which is a wireless communication device mounted on a flying body,
A neighboring cell list storage function for storing a neighboring cell list received from the wireless base station to which the wireless unit is wirelessly connected;
When there is a cell that does not exist in the neighboring cell list among the cells of the radio base station identified by the radio signal received by the radio unit, communication is performed from among the radio base stations of a plurality of communication partner candidates. A communication control function for changing a communication partner selection method for selecting the wireless base station of the partner;
It may be a computer program for realizing.

[Example 3 of communication control method]
An example 3 of the communication control method according to the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart of Example 3 of the communication control method according to the present embodiment. In Example 3 of the communication control method, the communication control unit 123 performs communication from a plurality of communication partner candidate radio base stations when the radio quality index value of the measurement result of the radio measurement unit 121 satisfies a predetermined sky index condition. The communication partner selection method for selecting the partner radio base station is changed.

  The communication control process of FIG. 10 is started when the flight of the flying object 1 starts. For example, in the flying object 1, when the flight start signal indicating the start of the flight of the flying object 1 is input from the flight control unit 10 to the wireless communication device 100, the wireless communication device 100 starts the process of FIG. Alternatively, the wireless communication device 100 may start the processing of FIG. 10 by instructing the wireless communication device 100 to start the communication control process of FIG.

(Step S41) The radio unit 103 receives a radio signal transmitted from the radio base station.

(Step S42) Based on the radio signal received by the radio unit 103, the radio measurement unit 121 measures the radio quality index value of the cell of the radio base station (connected base station) to which the radio communication apparatus 100 is connected. . The measured radio quality index value may be, for example, any one of RSSI, RSRP, and SINR, or may be plural.
(Step S43) The communication control unit 123 determines whether or not the wireless quality index value of the measurement result of the wireless measurement unit 121 satisfies a predetermined sky index condition. The sky index condition is a condition for determining that the flying object 1 (wireless communication apparatus 100) exists in the sky. An example of the sky index condition is shown below.

(Example 1 of sky index conditions)
When the wireless quality index value is RSSI, the sky index condition is that the measured value of RSSI is equal to or higher than the sky RSSI determination threshold. As an example of a method for determining the above-mentioned RSSI determination threshold value, the value is determined to be larger than the measured value of RSSI on the ground at the flight location of the flying object 1. This is because it is considered that RSSI increases from the ground because the sky is more visible than the ground.

(Example 2 of the sky index condition)
When the wireless quality index value is RSRP, the sky index condition is that the measured value of RSRP is equal to or higher than the sky RSRP determination threshold. As an example of a method for determining the above-mentioned RSRP determination threshold value, the RSRP determination threshold value is determined to be larger than the RSRP measurement value on the ground at the flight location of the flying object 1. This is because the RSRP is considered to increase more than the ground because the sky is more visible than the ground.

(Example 3 of the sky index condition)
When the radio quality index value is SINR, the sky index condition is that the measured value of SINR is less than the sky SINR determination threshold. As an example of the determination method of the sky SINR determination threshold, the value is determined to be smaller than the measured value of SINR on the ground of the flight location of the flying object 1. This is because there is a possibility that the reception power of both the desired wave and the interference wave is increased because the line of sight is clearer than the ground, but the interference wave is further increased than the ground wave than the desired wave. This is because the SINR is considered to deteriorate more than the ground.

  In addition, when using two or more among RSSI, RSRP, and SINR as a radio | wireless quality parameter | index value, it uses combining the example of said applicable sky parameter | index conditions. In this case, satisfying the sky index condition of all the radio quality index values may be a condition that the determination “whether the sky index condition is satisfied” in step S43 is “YES” or any one of a plurality of radio quality indices. Satisfying the sky index condition of the value may be a condition in which the determination “whether the sky index condition is satisfied?” In step S43 is “YES”, or satisfying the sky index condition of at least one radio quality index value. The determination “whether the sky index condition is satisfied” in step S43 may be “YES”. The condition under which the determination “whether the sky index condition is satisfied?” In step S43 is “YES” may be determined according to, for example, the wireless environment of the flight location of the aircraft 1.

  As a result of the determination in step S43, if the sky index condition is satisfied, the process proceeds to step S44, and if not, the process proceeds to step S45.

(Step S44) The communication control unit 123 changes the communication partner selection method to a predetermined communication partner selection method for the sky.

(Step S45) The wireless communication apparatus 100 determines the end of the process. For example, in the flying object 1, when the flight end signal indicating the end of the flight of the flying object 1 is input from the flight control unit 10 to the wireless communication apparatus 100, the wireless communication apparatus 100 ends the process of FIG. Alternatively, the wireless communication device 100 may end the processing of FIG. 10 by instructing the wireless communication device 100 to end the communication control processing of FIG. When it is determined that the process is finished, the process of FIG. 10 is finished. If it is not the end of the process, the process returns to step S41 to continue the process of FIG.

The wireless communication apparatus according to Example 3 of the communication control method described above is
In a wireless communication device mounted on a flying object,
A radio unit for receiving a radio signal transmitted from the radio base station;
A radio measurement unit that measures a radio quality index value based on the radio signal received by the radio unit;
Communication partner selection method for selecting the wireless base station of the communication partner from among the wireless base stations of a plurality of communication partner candidates when the wireless quality index value of the measurement result of the wireless measurement unit satisfies a predetermined sky index condition A communication control unit for changing
A wireless communication device may be provided.

The communication control method according to the above-described communication control method example 3 is:
A communication control method for a wireless communication device mounted on a flying object,
A wireless reception step in which the wireless communication device receives a wireless signal transmitted from a wireless base station;
A wireless measurement step in which the wireless communication device measures a wireless quality index value based on the wireless signal received in the wireless reception step;
When the wireless quality index value of the measurement result of the wireless measurement step satisfies a predetermined sky index condition, the wireless communication device selects the wireless base station of the communication partner from among the wireless base stations of a plurality of communication partner candidates. A communication control step for changing a communication partner selection method to be selected;
A communication control method including

The computer program according to Example 3 of the communication control method described above is
A computer of the wireless communication device equipped with a wireless unit that receives a wireless signal transmitted from a wireless base station, which is a wireless communication device mounted on a flying body,
A wireless measurement function for measuring a wireless quality index value based on the wireless signal received by the wireless unit;
Communication partner selection method for selecting the wireless base station of the communication partner from among the wireless base stations of a plurality of communication partner candidates when the wireless quality index value of the measurement result of the wireless measurement function satisfies a predetermined sky index condition A communication control function to change
It may be a computer program for realizing.

  Next, an example of the communication partner selection method according to this embodiment will be described.

[Example 1 of communication partner selection method]
Example 1 of the communication partner selection method is to change a handover parameter for controlling handover between a plurality of communication partner candidate radio base stations. In the sky, a situation occurs in which the number of radio base stations having the same level of reception quality that are candidates for the handover destination increases compared to the ground. As a result, there is a possibility that the communication of the wireless communication device 100 existing in the sky may become unstable due to occurrence of a handover failure such as a handover failure or frequent handovers. Therefore, in the communication partner selection method example 1, the handover parameter is changed to suppress the occurrence of a handover failure, thereby preventing the communication of the wireless communication device 100 existing in the sky from becoming unstable. The following is an example of a method for changing handover parameters.

(Example 1 of changing handover parameter)
The trigger time (Time To Trigger: TTT) in the sky (the communication partner selection method for the sky) is set longer than the value on the ground (the communication partner selection method for the ground). The TTT is a protection time from when a measurement report transmission condition that triggers a handover is established in the wireless communication apparatus 100 until the wireless communication apparatus 100 transmits the measurement report. As the TTT becomes longer, an effect of suppressing frequent handovers can be obtained. As an example of a method for determining the TTT value in the sky, the value is determined to be larger than the TTT value on the ground of the flight location of the flying object 1.

(Example 2 of changing handover parameter)
Handover is prohibited in the sky (the communication partner selection method for the sky). For example, TTT is set to infinity. As a result, handover does not occur. Note that the time during which handover is prohibited (handover prohibited time) may be limited to a certain time. The handover prohibition time is set in advance.

  The communication control unit 123 may acquire handover parameter candidates from a radio base station that is accessed from the flight location of the aircraft 1. The radio base station at each flight location holds a handover parameter candidate suitable for the ground and a handover parameter candidate suitable for the sky at the flight location. For example, the handover parameter candidate data 141 illustrated in FIG. 5 is retained. The communication control unit 123 suppresses occurrence of a handover failure by acquiring and using a handover parameter candidate (for example, the handover parameter candidate data 141) from a radio base station that is accessed from the flight location of the aircraft 1. it can. Similarly to the handover parameter candidate, the communication control unit 123 may acquire information indicating the handover prohibition time from the radio base station that is accessed from the flight location of the aircraft 1.

[Example 2 of communication partner selection method]
Example 2 of the communication partner selection method is to change the number of radio base stations (the number of simultaneous communication base stations) that simultaneously perform communication from among a plurality of candidate radio base stations. In the sky, a situation occurs in which the number of radio base stations having the same level of reception quality increases as compared to the ground. From this, by increasing the communication partner radio base station with which the radio communication device 100 existing in the sky communicates at the same time from the ground and performing the multi-base station cooperative communication, the communication speed of the radio communication device 100 can be improved. Communication reliability can be improved. As an example of a method for determining the number of simultaneous communication base stations (the communication partner selection method for the sky) of the wireless communication device 100 existing in the sky, the actual value of the number of simultaneous communication base stations on the ground at the flight location of the flying object 1 (terrestrial communication) The value is determined to be larger than the partner selection method.

  Next, a modification according to this embodiment will be described.

[Variation 1 according to this embodiment]
The authentication request unit 126 acquires the authentication information of the flying object 1 from the authentication information storage unit 12 of the flight control unit 10 provided in the flying object 1 and transmits the authentication information to an authentication server that authenticates the flying object 1. To request authentication of the aircraft 1. The authentication request timing of the flying object 1 is, for example, a timing that matches the start of the flying of the flying object 1. For example, in the flying object 1, when a flight start signal indicating the start of flight of the flying object 1 is input from the flight control unit 10 to the wireless communication device 100, the authentication requesting unit 126 of the wireless communication device 100 authenticates the flying object 1. Make a request. Alternatively, the authentication request unit 126 of the wireless communication device 100 requests the authentication of the flying object 1 by instructing the wireless communication device 100 from the device outside the flying object 1 by communication to the wireless communication device 100. You may go. The authentication request unit 126 receives a response (pass or fail of authentication) to the request for authentication of the aircraft 1 from the authentication server. The communication control unit 123 changes the communication partner selection method when the authentication request result of the flying object 1 of the authentication request unit 126 is authentication successful, and performs communication when the request result is authentication failure. Do not change partner selection method. According to the first modification according to the present embodiment, only the wireless communication device 100 mounted on the flying object 1 can surely change the communication partner selection method.

  Note that the aircraft 1 authenticates the wireless communication device 100 using unique information of a SIM (Subscriber Identity Module) card included in the wireless communication device 100, and only the wireless communication device 100 that has passed the authentication selects the communication partner. A method change may be implemented. Alternatively, the wireless base station to which the wireless communication device 100 is connected may authenticate the wireless communication device 100, and only the wireless communication device 100 that has passed the authentication may change the communication partner selection method. For example, it is possible to encrypt information necessary for changing the communication partner selection method (for example, handover parameter candidates) and provide the decryption key only to the wireless communication apparatus 100 that has passed authentication to decrypt the encrypted information. It may be.

[Variation 2 according to this embodiment]
The horizontal position information acquisition unit 124 acquires horizontal position information indicating the position of the flying object 1 in the horizontal direction. The communication control unit 123 determines whether the moving range of the flying object 1 is a fixed range based on the horizontal position information acquired by the horizontal position information acquisition unit 124. As an example of this determination method, if the size of the range of the position indicated by the horizontal position information (latitude, longitude) falls within a predetermined size, the moving range of the flying object 1 is determined to be a certain range, If not, it is determined that the moving range of the flying object 1 is not a certain range. When the communication control unit 123 determines that the moving range of the flying object 1 is a certain range, the communication control unit 123 increases the measurement interval of the number of cells per unit time by a predetermined time (measurement standby time). As an example of a method for extending the measurement interval of the number of cells per unit time by a predetermined time, the cell counter 122 is reset in step S12 of the flowchart of Example 1 of the communication control method in FIG. After that, the unit time timer T2 is started, and the process proceeds to step S13. According to the second modification according to the present embodiment, when the flying object 1 moves within a certain range and the wireless environment does not change, the frequency of measuring the number of cells per unit time is reduced, and the wireless communication device 100 The load can be reduced and the power consumption can be reduced.

[Modification 3 according to this embodiment]
The flying object moving direction determination unit 125 determines whether the moving direction of the flying object 1 is the vertical direction or the horizontal direction. As an example of this determination method, the aircraft movement direction determination unit 125 uses the flight positioning unit 30 of the aircraft 1. The wireless communication device 100 acquires the positioning values (“horizontal position (latitude and longitude)” and “vertical position (altitude)”) of the flight positioning unit 30 via the flight control unit 10. The flying object movement direction determination unit 125 calculates a horizontal movement amount and a vertical movement amount within a predetermined time based on the positioning value of the flight positioning unit 30. The flying object moving direction determination unit 125 determines that the moving direction of the flying object 1 is the vertical direction when the moving amount in the vertical direction is larger than the moving amount in the horizontal direction in the calculation result. On the other hand, the flying object moving direction determination unit 125 determines that the moving direction of the flying object 1 is the horizontal direction when the moving amount in the horizontal direction is larger than the moving amount in the vertical direction in the calculation result.
Note that the flight control unit 10 outputs a movement direction signal indicating the moving direction (vertical direction or horizontal direction) of the flying object 1, and the flying object moving direction determination unit 125 determines the moving direction (vertical direction or horizontal direction) indicated by the movement direction signal. It may be determined that (horizontal direction) is the moving direction of the flying object 1.

  The communication control unit 123 sets the communication partner selection method in the sky when the moving direction of the flying object 1 is horizontal according to the determination result of the flying object moving direction determination unit 125 in the case of using the air communication partner selection method. The communication partner selection method is changed to a predetermined sky horizontal movement communication partner selection method. The communication partner selection method for sky horizontal movement is a communication partner selection method suitable when the flying object 1 (wireless communication device 100) is moving in the horizontal direction in the sky. This is because even if the flying object 1 (wireless communication device 100) is moving in the horizontal direction, the wireless base stations that transmit wireless signals reaching the wireless communication device 100 are different one after another. This is because it is preferable to use a communication partner selection method (a communication partner selection method for sky horizontal movement) that is suitable for the situation because it changes to a radio base station. Below, an example of the communication partner selection method for sky horizontal movement is shown.

(Example 1 of communication partner selection method for sky horizontal movement)
In Example 1 of the communication partner selection method for sky horizontal movement, the communication partner selection method for sky horizontal movement is the same as the ground communication partner selection method. As described above, when the flying object 1 (wireless communication apparatus 100) is moving in the horizontal direction even when it is in the sky, the wireless base stations that are the transmission sources of the wireless signals that reach the wireless communication apparatus 100 are one after another. Change to a different radio base station. Since this is considered to be similar to the situation of moving on the ground, the ground communication partner selection method is used as the communication partner selection method for horizontal flight.

(Example 2 of communication partner selection method for sky horizontal movement)
In Example 2 of the communication partner selection method for sky horizontal movement, the communication partner selection method for sky horizontal movement is an intermediate method between the ground communication partner selection method and the sky communication partner selection method. For example, an intermediate value between the ground TTT and the sky TTT is set to the sky horizontal movement TTT. Alternatively, an intermediate value between the number of ground simultaneous communication base stations and the number of sky simultaneous communication base stations is set to the number of sky horizontal movement simultaneous communication base stations.

[Modification 4 according to this embodiment]
The communication control unit 123 refers to the parameter change area information 142, and in the cell of the radio base station identified by the radio signal received by the radio unit 103, the parameter change area cell ID included in the parameter change area information 142 and It is determined whether there is a cell (parameter change area cell) having the same cell ID. As a result of this determination, the communication control unit 123 changes the communication partner selection method when there is a parameter change region cell, and does not change the communication partner selection method when there is no parameter change region cell. According to the fourth modification according to the present embodiment, it is possible to specify a region where the communication partner selection method is changed.

[Variation 5 according to this embodiment]
The communication control unit 123 acquires, from the flight control unit 10, remaining charge information indicating the remaining charge amount of the battery that is the power source of the flying object 1. The flight control unit 10 is notified of remaining charge information from the power supply unit 80. When the remaining charge amount indicated by the remaining charge information is less than a predetermined remaining charge threshold value, the communication control unit 123 relaxes the condition for changing the communication partner selection method to the air communication partner selection method. As a result, the flying communication partner selection method is used quickly while the flying object 1 (wireless communication apparatus 100) is rising. For example, when the flying TTT is used, handover failures or frequent handovers occur. The battery can be prevented from being wasted.

[Modification 6 according to this embodiment]
When the cell count per unit time of the counting result of the cell counting unit 122 is either continuously increasing or decreasing for a predetermined period, the communication control unit 123 selects a communication partner from a plurality of candidate wireless base stations for communication. The communication partner selection method for selecting the wireless base station is changed. A situation in which the number of cells per unit time in the counting result of the cell counting unit 122 continuously increases for a predetermined period is considered to be a situation in which the aircraft 1 (wireless communication device 100) is rising. This is because, when the flying object 1 (wireless communication apparatus 100) is rising, the line of sight becomes better, so that up to a certain altitude, the wireless base station that is the transmission source of the wireless signal reaching the wireless communication apparatus 100 is This is because it continues to increase. From this, the communication control unit 123 changes the communication partner selection method to the airborne communication partner selection method when the number of cells per unit time of the counting result of the cell counting unit 122 continues to increase for a predetermined period. When the flying object 1 (wireless communication device 100) rises above a certain altitude, the distance between the wireless communication device 100 and each wireless base station becomes too long, and this time the wireless communication device turns around. The number of radio base stations that have transmitted radio signals reaching 100 continues to decrease.

  On the other hand, the situation in which the number of cells per unit time in the counting result of the cell counting unit 122 continuously decreases for a predetermined period is considered to be a situation where the aircraft 1 (wireless communication device 100) is descending. This is because, when the flying object 1 (wireless communication apparatus 100) is descending, the line of sight gradually deteriorates, so that the number of wireless base stations that transmit wireless signals reaching the wireless communication apparatus 100 continues to decrease. Because. Therefore, the communication control unit 123 changes the communication partner selection method to the ground communication partner selection method when the number of cells per unit time of the counting result of the cell counting unit 122 continues to decrease for a predetermined period.

  The above is description of the modification which concerns on this embodiment.

  According to the above-described embodiment, when the wireless communication device 100 exists in the sky, the communication stability of the wireless communication device 100 existing in the sky can be improved by using the communication partner selection method for the sky. it can. Further, when the wireless communication device 100 exists on the ground, it is possible to return to the ground communication partner selection method. For this reason, when the cellular network system constructed to provide the mobile communication service for the ground is applied to the wireless communication device 100 mounted on the flying object 1, the wireless communication device 100 is also in the sky. This can contribute to providing stable communication. Thereby, since the said communication is stabilized when controlling the flying body 1 by communication by the radio | wireless communication apparatus 100, the effect which the reliability of the remote control of the flying body 1 improves is acquired.

  Further, according to the above-described embodiment, it is possible to determine whether the flying object 1 is raised or lowered without using the measurement value of the altimeter. Thereby, it is not necessary to convert, for example, handover parameter candidates according to the measured value of the altimeter.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  For example, the flying object on which the wireless communication device 100 according to the above-described embodiment is mounted may be an automatically-controlled flying object, a remotely-controlled flying object, or a human being. It may be a manned flying object that a certain pilot rides on the flying object.

In addition, a computer program for realizing the functions of each device described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disc), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Flying object, 10 ... Flight control part, 12 ... Authentication information storage part, 30 ... Flight positioning part, 40 ... Camera, 60 ... Motor, 80 ... Power supply part, 100 ... Wireless communication apparatus, 101 ... CPU, 102 ... Memory , 103 ... Wireless unit, 104 ... Positioning unit, 121 ... Wireless measuring unit, 122 ... Cell counting unit, 123 ... Communication control unit, 124 ... Horizontal position information acquisition unit, 125 ... Aircraft movement direction determination unit, 126 ... Authentication request unit, 140... Data storage unit

Claims (13)

In a wireless communication device mounted on a flying object,
A radio unit for receiving a radio signal transmitted from the radio base station;
A cell counting unit for counting the number of cells of the radio base station identified by the radio signal received by the radio unit;
When the increase or decrease in the number of cells per unit time of the counting result of the cell counting unit is equal to or greater than a predetermined threshold, the radio of the communication partner from among the radio base stations of a plurality of communication partner candidates A communication control unit for changing a communication partner selection method for selecting a base station;
A wireless communication device comprising: The communication control unit, when the increase in the number of cells per unit time is equal to or greater than a predetermined threshold, changes the communication partner selection method to a predetermined over-the-air communication partner selection method,
The wireless communication apparatus according to claim 1. A flying object moving direction determination unit for determining whether the moving direction of the flying object is a vertical direction or a horizontal direction;
The communication control unit uses the communication partner selection method when the moving direction of the flying object is a horizontal direction according to a determination result of the flying object moving direction determination unit when the communication partner selection method for the sky is used. Is changed from the above communication partner selection method for the sky to a predetermined communication partner selection method for the sky horizontal movement,
The wireless communication apparatus according to claim 2. The communication control unit changes the communication partner selection method to a predetermined ground communication partner selection method when the decrease in the predetermined number of cells per unit time is equal to or greater than a predetermined threshold.
The radio | wireless communication apparatus of any one of Claim 1 to 3. A horizontal position information acquisition unit for acquiring horizontal position information indicating a horizontal position of the flying object;
When the communication control unit determines that the moving range of the flying object is a fixed range based on the horizontal position information, the measurement interval of the number of cells per unit time is increased by a predetermined time.
The radio | wireless communication apparatus of any one of Claim 1 to 4. The communication partner selection method is to change a handover parameter for controlling handover between the radio base stations of a plurality of communication partner candidates.
The radio | wireless communication apparatus of any one of Claim 1 to 5. The communication control unit acquires the handover parameter candidate from the radio base station that is accessed from the flight location of the aircraft.
The wireless communication apparatus according to claim 6. The communication partner selection method is to prohibit handover for a certain period of time.
The radio | wireless communication apparatus of any one of Claim 1 to 5. The communication control unit acquires information indicating the handover prohibition time from the radio base station that is accessed from the flight location of the aircraft.
The wireless communication apparatus according to claim 8. The communication partner selection method is to change the number of the radio base stations that perform simultaneous communication from among the radio base stations of a plurality of communication partner candidates.
The radio | wireless communication apparatus of any one of Claim 1 to 5. An authentication request unit that acquires authentication information of the flying object from an authentication information storage unit included in the flying object, transmits the authentication information to an authentication server that authenticates the flying object, and requests authentication of the flying object; Prepared,
The communication control unit changes the communication partner selection method when the request result of the authentication of the flying object of the authentication request unit is authentication success, and when the request result is authentication failure Do not change the communication partner selection method,
The radio | wireless communication apparatus of any one of Claim 1 to 10. A communication control method for a wireless communication device mounted on a flying object,
A wireless reception step in which the wireless communication device receives a wireless signal transmitted from a wireless base station;
A cell counting step in which the radio communication device counts the number of cells of the radio base station identified by the radio signal received in the radio reception step;
When the wireless communication device has a predetermined number of increase or decrease of the number of cells per unit time of the counting result of the cell counting step being equal to or greater than a predetermined threshold value, A communication control step of changing a communication partner selection method for selecting the wireless base station of the communication partner from,
Including a communication control method. A computer of the wireless communication device equipped with a wireless unit that receives a wireless signal transmitted from a wireless base station, which is a wireless communication device mounted on a flying body,
A cell counting function for counting the number of cells of the radio base station identified by the radio signal received by the radio unit;
When the number of increase or decrease of the number of cells per unit time of the counting result of the cell counting function is equal to or greater than a predetermined threshold, the radio of the communication partner is selected from among the radio base stations of a plurality of communication partner candidates A communication control function for changing a communication partner selection method for selecting a base station;
Computer program for realizing.

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