Patent Description:
Patent literature <NUM> (<CIT>) discloses a wireless communication device to perform long-range communication and short-range communication with a target device. The wireless communication device assesses whether or not short-range wireless communication with the target device is possible, and reduces radio field intensity of long-range communication upon assessing that short-range communication is possible.

Patent literature <NUM> (US Patent Application Publication <CIT>) discloses a Bluetooth control system including a head unit for acquiring a door open or closed signal from doors of a vehicle when the doors are opened or closed. The head unit selectively turns on or off Bluetooth connection of a mobile device using a set application based on the door open or closed signal.

Wireless communication in an aircraft or another moving body is restricted by various factors. When a remote controller for a passenger to operate a display device is made wireless in an aircraft or another moving body, a radio field outputted by the remote controller is similarly restricted. Therefore, it has been substantially difficult to make the remote controller wireless.

The present disclosure provides a display device, a radio field control system, and a radio field control method that are effective in controlling the setting of a radio field outputted by a remote controller or another wireless terminal to an appropriate state in a moving body.

A display device according to the present disclosure is defined in claim <NUM>.

A radio field control system according to the present disclosure comprises the above display device and the wireless terminal. The wireless terminal is capable of wirelessly connecting to the display device, and the wireless terminal is configured to change the output of the first radio field in accordance with the establishment of the setting of the first radio field made by the controller.

A radio field intensity control method according to the present disclosure is defined in claim <NUM>.

Embodiments are described in detail below with reference to the drawings as appropriate. However, unnecessarily detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions for substantially the same configuration may be omitted.

It should be noted that the accompanying drawings and the descriptions below are provided for those skilled in the art to sufficiently understand the present disclosure, and are not intended to limit the subject matter set forth in the claims.

Conventionally, passengers in aircraft have wanted to use wireless remote controllers to operate display devices each placed in a seat. However, wireless communication used in aircraft moving across national borders is restricted to the laws and jurisdiction of each country. For example, depending on the laws and jurisdiction of each country and rules of airline companies, it may be necessary to refrain from using wireless signals at times such as takeoff and landing. Furthermore, it is necessary to suppress the burden of maintaining the remote controller including, inter alia, replacing and charging a battery.

The present embodiment describes a display device, a radio field intensity control system, and a radio field intensity control method in which a passenger can use a remote controller wirelessly in a restricted wireless communication environment, and the burden of maintaining the remote controller can be suppressed by suppressing battery consumption.

A radio field intensity control system <NUM> according to Embodiment <NUM> is disposed in an aircraft, which is one example of a moving body, as shown in <FIG>.

The radio field intensity control system <NUM> comprises display devices <NUM> each disposed in a seat, remote controllers <NUM> (one example of wireless terminals) of the display devices <NUM>, and a management device <NUM> to provide videos, music, and other content to the display devices <NUM>, as shown in <FIG> and <FIG>. The management device <NUM> is connected to an aircraft management system <NUM>. The aircraft management system <NUM> is also connected to wireless access points (APs) <NUM> disposed in the aircraft. The management device <NUM> can acquire information pertaining to the usage status of the wireless access points <NUM> from the aircraft management system <NUM>. The wireless access points <NUM> are access points for WiFi® or another type of wireless communication. The wireless access points <NUM> connect smartphones, tablets, or other wireless terminals (not shown) used by the passengers to the Internet. A plurality of wireless access points <NUM> are placed according to the size of the aircraft cabin and the number of seats.

The radio field intensity control system <NUM> can connect to the aircraft management system <NUM>, and acquires flight information (one example of operation information) of the aircraft as shall be described hereinafter. The aircraft management system <NUM> acquires, updates, and stores the flight information of the aircraft. The flight information includes, inter alia, position information (latitude, longitude, etc.), altitude information, seat information (seat numbers, etc.), airframe information (model, etc.), and schedule information (flight schedule including scheduled arrival time, departure time, etc., and speed, direction of travelling, etc.) of the aircraft.

The radio field intensity control system <NUM> may function as part of an in-flight entertainment (IFE) system.

The configuration of the devices of the radio field intensity control system <NUM> shall be described below with reference to <FIG>.

A display device <NUM> is installed in each seat, and each display device displays content such as videos and music and other information distributed from the management device <NUM>. The display device <NUM> performs actions such as displaying information and adjusting volume in accordance with operation of the remote controller <NUM> by the passenger. The display device <NUM> also adjusts a radio field intensity of the remote controller <NUM> as shall be described hereinafter.

The display device <NUM> is provided with a CPU <NUM> for performing functions of the display device <NUM>, a storage unit <NUM>, a wired communication unit <NUM>, a wireless communication unit <NUM>, a monitor <NUM>, and a camera <NUM>, as shown in <FIG>.

The CPU <NUM> (one example of a controller) includes circuitry to execute the functions of the display device <NUM>. By executing predetermined programs, the CPU <NUM> executes functions of a data acquisition unit <NUM>, a radio field intensity establishment unit <NUM>, and a radio field intensity information generation unit <NUM>.

The data acquisition unit <NUM> acquires data for establishing the radio field intensity of the remote controller <NUM>. The data pertains to flight information transmitted from the management device <NUM>.

The radio field intensity establishment unit <NUM> establishes, on the basis of the acquired flight information data, a radio field intensity for the remote controller <NUM> to connect to the display device <NUM>. Establishing the radio field intensity includes, for example, increasing the intensity of the radio field, reducing the intensity of the radio field, setting radio output to OFF, or changing a radio frequency band.

The radio field intensity information generation unit <NUM> generates radio field intensity information including a value of the established radio field intensity or a command to set the radio output to OFF, and transmits the radio field intensity information to the remote controller <NUM> via the wireless communication unit <NUM>. The radio field intensity information includes the established radio field intensity value, the frequency band, etc..

The storage unit <NUM> is, for example, a semiconductor memory. The storage unit <NUM> stores data transmitted from the management device <NUM> and a program for controlling the display device <NUM>.

The wired communication unit <NUM> (one example of a first receiver) includes, for example, a connection terminal, and is connected to the management device <NUM> via a cable, relay equipment, etc. The wired communication unit <NUM> receives flight information from the management device <NUM>.

The wireless communication unit <NUM> (one example of a transmitter) has an antenna for conducting wireless communication, a wireless circuit, etc., and communicates data to the wireless terminal by wireless communication. The wireless communication unit <NUM> includes a Bluetooth® communication unit <NUM>. The Bluetooth® communication unit <NUM> communicates with the remote controller <NUM>, which is paired according to the Bluetooth® standard. Communication with the remote controller <NUM> may be performed using another wireless communication standard as long as the standard is suitable for short-range wireless communication.

The monitor <NUM> has an LCD, an organic EL display, or another display screen. The monitor <NUM> is attached in a back portion of a front seat, or another position that is easily visible when the passenger is seated. The monitor <NUM> may be provided with a touch panel.

The camera <NUM> (one example of an imaging unit) is disposed so as to have the area forward of the monitor <NUM> as an imaging range. The camera <NUM> images the passenger sitting in front of the monitor <NUM>, and acquires an image of the passenger.

The remote controller <NUM> transmits a signal to the display device <NUM> and actuates the display device <NUM> in accordance with operation by the passenger.

The remote controller <NUM> is equipped with a battery <NUM> as a power source, as shown in <FIG>. The battery may be a primary battery or a secondary battery, but when the battery is used in an aircraft, a manganese dry battery may be used in consideration of safety (to avoid the risk of liquid leakage, ignition, etc.) and the burden of maintenance.

The remote controller <NUM> is further provided with a CPU <NUM>, a storage unit <NUM> a Bluetooth® communication unit <NUM>, an operation unit <NUM>, and a power source unit <NUM>.

The CPU <NUM> includes circuitry to execute functions of the remote controller <NUM>. By executing a predetermined program, the CPU <NUM> executes a function of a radio field intensity setting unit <NUM>, a wireless ON/OFF switching unit <NUM>, or a display device operation command unit <NUM>.

The radio field intensity setting unit <NUM> sets/changes a radio field intensity of the Bluetooth® communication unit <NUM> in accordance with radio field intensity information received from the display device <NUM>.

The wireless ON/OFF switching unit <NUM> sets the output of the radio field of the Bluetooth® communication unit <NUM> to OFF in accordance with the radio field intensity information received from the display device <NUM>. Setting the output of the radio field to OFF is, for example, setting the output of the radio field outputted by the remote controller <NUM> to <NUM>. Alternatively, the output of the radio field may be set to OFF by setting the power source of the remote controller <NUM> to OFF.

The display device operation command unit <NUM> generates a command signal to actuate the display device <NUM> in accordance with operation of the operation unit <NUM> by the passenger, and transmits the command signal via the Bluetooth® communication unit <NUM>. The command signal is, for example, a command signal for changing a channel, adjusting volume, switching screens, selecting a menu, etc..

The storage unit <NUM> is, for example, a semiconductor memory. The storage unit <NUM> stores data and a program for controlling the remote controller <NUM>.

The Bluetooth® communication unit <NUM> communicates with the display device <NUM>, which is paired according to the Bluetooth® standard. Communication with the remote controller <NUM> may be performed using another wireless communication standard as long as the standard is suitable for short-range wireless communication.

The operation unit <NUM> is, for example, a plurality of buttons arranged on the outer surface of the remote controller <NUM>. The buttons include a power button, a channel button, a volume button, a menu selection button, etc. Alternatively, the remote controller <NUM> may be provided with a liquid crystal, organic EL, or other type of display screen and a touch panel, and a plurality of buttons for operation may be displayed on the display screen.

The power source unit <NUM> controls the supply of power from the battery <NUM> to the individual parts of the remote controller <NUM>. The power source unit <NUM> sets the power source of the remote controller <NUM> to ON or OFF.

The remote controller <NUM> may be in a configuration enabled for wired use in addition to wireless use. For example, a cradle (not shown) of the remote controller <NUM> may be attached to a predetermined position on the seat. The cradle is connected to the corresponding display device <NUM> and the management device <NUM> by wire. The power source may be set to OFF while the remote controller <NUM> is set in the cradle.

The management device <NUM> is connected to a plurality of display devices <NUM> via a wired cable or relay equipment. The management device <NUM> is, for example, a computer device functioning as a server. The management device <NUM> can connect to one or more display devices <NUM>, and delivers content to the display devices <NUM> for the users sitting in front of the display devices <NUM>.

The management device <NUM> is provided with a CPU <NUM>, a storage unit <NUM>, and a communication unit <NUM>, as shown in <FIG>.

The CPU <NUM> executes the functions of the management device <NUM> by executing predetermined programs. The management device <NUM> executes a function of a data information transmission unit <NUM>. The data information transmission unit <NUM> transmits the aforementioned flight information data to the display device <NUM> via the communication unit <NUM>.

The storage unit <NUM> is, for example, a semiconductor memory or a magnetic memory. The storage unit <NUM> stores software and various pieces of data used in the management device <NUM>. The storage unit <NUM> includes a flight information storage unit <NUM> to receive flight information from the aircraft management system <NUM>. The flight information is, for example, received and updated at predetermined time intervals.

The communication unit <NUM> includes circuitry for communicating with other computer equipment, such as a network card or a network adapter. The communication unit <NUM> is connected to the display devices <NUM> and the aircraft management system <NUM> via cables, etc..

The following is a description, made with reference to <FIG>, mainly of the actions in radio field intensity control performed by the display device <NUM>.

As shown in <FIG>, when the display device <NUM> is connected to the paired remote controller <NUM> (Yes in S1), the display device <NUM> executes a process of establishing the radio field intensity of the remote controller <NUM> (described hereinafter) (S2). Step S2 is repeated as long as the connection of the remote controller <NUM> is not terminated (S3).

The remote controller <NUM> outputs a radio field having a predetermined intensity (e.g., a radio field having a default intensity) in an initial state after the power source is set to ON.

<FIG> shows one example of the process of establishing the radio field intensity of the remote controller <NUM>. First, the data acquisition unit <NUM> of <FIG> acquires flight information data from the management device <NUM> via the Bluetooth® communication unit <NUM> (S201). The example described here is a case in which the flight information includes flying states (landing state, takeoff state, stable flying, etc.) and the aircraft is in a state of taking off. The radio field intensity establishment unit <NUM> determines the current radio field intensity (S202). When the aircraft is in a state of taking off, the radio field intensity establishment unit <NUM> establishes that the radio field intensity will be changed by setting the radio field output to OFF (Yes in S203). The radio field intensity information generation unit <NUM> generates radio field intensity information (sets the radio field output to OFF) and transmits this information to the remote controller <NUM> via the Bluetooth® communication unit <NUM> (S204).

In the remote controller <NUM>, the wireless ON/OFF switching unit <NUM> sets the radio field output of the Bluetooth® communication unit <NUM> to OFF in accordance with the radio field intensity information received from the display device <NUM>. Therefore, the remote controller <NUM> can automatically set the radio field output to OFF in accordance with a situation in which the aircraft is taking off and the use of the radio field is restricted.

After the radio field output has been set to OFF, the remote controller <NUM> may be reset and returned to an initial state (in which a radio field of a predetermined intensity is outputted) in accordance with a predetermined condition. For example, the remote controller <NUM> may be returned to the initial state after a predetermined time has elapsed or the remote controller <NUM> has been set in the cradle. After the radio field output of the remote controller <NUM> has been set to OFF, and the display device <NUM> has assessed that the current state allows for radio field output, the display device <NUM> may pair with the remote controller <NUM> and may once again execute the radio field intensity establishment process of step S2 via the connection of step S1 in <FIG>.

<FIG> shows the details of controlling the radio field intensity of the remote controller <NUM> corresponding to the details of the flight information. As shown in <FIG>, when the flight information indicates a taking off state or a landing state, the radio field output is set to OFF. When the aircraft is taking off or landing, there are cases in which the passenger is unable to use the display device <NUM> as well as cases in which wireless communication is restricted on safety or jurisdictional grounds; therefore, the radio field output of the remote controller <NUM> is set to OFF.

Furthermore, the radio field output is set to OFF when the position of the aircraft is under the jurisdiction of a specified country from the flight information and the use of a radio field is prohibited (position information A). Alternatively, when the position of the aircraft is under the jurisdiction of a predetermined country from the flight information and the use of a radio field is restricted (position information B), the radio field output is lowered. Alternatively, when the position of the aircraft is under the jurisdiction of a predetermined country from the flight information and the frequency band used by the remote controller <NUM> is not permitted (position information C), the frequency band is changed.

In addition, depending on the type of the aircraft, a predetermined wireless technology (e.g., Bluetooth®) may not be useable. In this case (e.g., airframe information A), the radio field output is set to OFF.

In addition, the radio field output may be increased or decreased in accordance with the seat information. For example, if the seat is first class, the distance between the display device <NUM> and the passenger is greater, and the radio field output is therefore increased. If the seat is economy class, the distance between the display device <NUM> and the passenger is smaller, and the radio field output is therefore reduced.

"Increasing the radio field output" includes outputting a radio field having a higher radio field intensity than the current radio field determined in step S202 of <FIG>, or increasing the output to a predetermined radio field intensity included in the radio field intensity information. When the current radio field intensity is sufficiently strong, it is determined in step S203 of <FIG> that the radio field intensity does not need to be changed, and it is acceptable to not change the radio field intensity. Similarly, "reducing the radio field output" includes outputting a radio field having a lower radio field intensity than the current radio field determined in step S202 of <FIG>, or reducing the output to a predetermined radio field intensity included in the radio field intensity information. When the current radio field intensity is sufficiently weak, it is determined in step S203 of <FIG> that the radio field intensity does not need to be changed, and it is acceptable to not change the radio field intensity.

Furthermore, when the altitude at which the aircraft flies falls below a predetermined value, the radio field output may be increased. For example, if there is an aircraft at an altitude close to the ground, there could be interference with a radio field from the ground. Therefore, the output of the radio field of the remote controller <NUM> may be increased.

In the display device <NUM>, the radio field intensity control system <NUM>, or the radio field intensity control method according to the Embodiment <NUM>, the display device <NUM> receives the flight information of the aircraft, establishes the intensity of the radio field to be outputted by the remote controller <NUM> in order to connect with the display device <NUM> on the basis of the flight information, and transmits radio field intensity information indicating the intensity of the radio field to the remote controller <NUM>. In the remote controller <NUM>, the output of the radio field is changed in accordance with the received radio field intensity information.

Therefore, the display device <NUM> can perceive the state of the aircraft and the wireless communication environment in real time, and establish and control the optimal radio field intensity of the remote controller <NUM> in accordance with this perceived information. Consequently, the passenger can use the remote controller wirelessly even in a restricted wireless communication environment. In addition, by not increasing the radio field intensity of the remote controller <NUM> more than necessary, the consumption of the battery of the remote controller <NUM> can be suppressed, and the burden of maintaining the remote controller <NUM> can therefore be suppressed.

As above, the above embodiment has been described as an example of the technology disclosed in the present application. However, this example is not provided by way of limitation as to the technology in the present disclosure; the technology can be applied to embodiments in which changes, replacements, additions, omissions, etc., are made as appropriate. It is also possible to combine the constituent elements described in the above embodiment to form a new embodiment.

The management device <NUM> acquires information indicating the presence or absence of connections made by display devices <NUM> to the remote controller <NUM>. The management device <NUM> calculates the number of display devices <NUM> connected to remote controllers <NUM> (hereinafter referred to as the number of connections) and transmits this number as data to the relevant display devices <NUM>.

The data acquisition unit <NUM> of <FIG> acquires data on the number of connections from the management device <NUM> (S211). The radio field intensity establishment unit <NUM> determines the current radio field intensity (S212). The radio field intensity establishment unit <NUM> determines whether or not to change the radio field intensity on the basis of the current radio field intensity (S213). In other words, the radio field intensity establishment unit <NUM> establishes whether or not to change (increase or reduce) the radio field output by referring to information indicating a radio field intensity corresponding to the number of connections, which has been determined and stored in advance. The radio field intensity information generation unit <NUM> generates radio field intensity information as in Embodiment <NUM>, and transmits this information to the remote controller <NUM> via the Bluetooth® communication unit <NUM> (S214).

A greater number of connections between display devices <NUM> and the remote controllers <NUM> correlates with a commensurately higher likelihood that there will be radio field interference with other display devices <NUM>. Accordingly, in the present embodiment, when there are a large number of connections with the remote controllers <NUM>, radio field interference can be avoided by increasing the radio field output. When there are a small number of connections with the remote controllers <NUM>, the battery consumption of the remote controller <NUM> can be suppressed by reducing the radio field output.

The radio field intensity may be established or changed in accordance with the number of wireless terminals connected to wireless access points <NUM> (e.g., a wireless LAN) that use the same frequency band used for the communication of the remote controller <NUM> (e.g., Bluetooth®), either instead of or in addition to the number of display devices <NUM> connected to remote controllers <NUM> described above.

(<NUM>) <FIG> shows an example of the process of establishing the radio field intensity of a remote controller <NUM> according to another embodiment. The radio field intensity establishment process shown in <FIG> is similar to that of <FIG> and is equivalent to the process of step S2 in <FIG>. The radio field intensity establishment process shown in <FIG> differs from that of Embodiment <NUM> in that the radio field intensity is established in accordance not with the flight information but with intensity of a radio field (e.g., of WiFi) other than the radio field used by the remote controller <NUM>.

The display device <NUM> shown in <FIG> detects the intensity of the radio field (referred to below as a peripheral radio field) received by the antenna of the wireless communication unit <NUM> (one example of a second receiver) (S221). The radio field intensity establishment unit <NUM> determines the current radio field intensity from the remote controller <NUM> (S222). The radio field intensity establishment unit <NUM> determines whether or not the radio field intensity needs to be changed on the basis of the current radio field intensity (S223). In other words, the radio field intensity establishment unit <NUM> establishes whether to increase or reduce the radio field intensity of the remote controller <NUM> in accordance with the intensity of the peripheral radio field. The radio field intensity information generation unit <NUM> generates radio field intensity information as in Embodiment <NUM>, and transmits this information to the remote controller <NUM> via the Bluetooth® communication unit <NUM> (S224).

A stronger peripheral radio field of the display device <NUM> correlates with a commensurately higher possibility of interference with the radio field of the remote controller <NUM>. Accordingly, in the present embodiment, when the peripheral radio field of the display device <NUM> is strong (e.g., when the intensity of the peripheral radio field exceeds a predetermined value), radio field interference can be avoided by increasing the radio field output of the remote controller <NUM>. When the peripheral radio field of the display device <NUM> is weak (e.g., when the intensity of the peripheral radio field falls below another predetermined value), the battery consumption of the remote controller <NUM> can be suppressed by reducing the radio field output of the remote controller <NUM>.

(<NUM>) <FIG> shows an example of the process of establishing the radio field intensity of a remote controller <NUM> according to another embodiment. The radio field intensity establishment process shown in <FIG> is similar to that of <FIG> and is equivalent to the process of step S2 in <FIG>. The radio field intensity establishment process shown in <FIG> differs from that of Embodiment <NUM> in that the radio field intensity is established in accordance not with the flight information but with the distance between the display device <NUM> and the passenger.

The display device <NUM> shown in <FIG> uses the camera <NUM> to capture an image of the passenger in front of the monitor <NUM>, and acquires an image of the passenger (S231). The data acquisition unit <NUM> determines the distance between the monitor <NUM> and the passenger from this image (S232). The radio field intensity establishment unit <NUM> determines the current radio field intensity from the remote controller <NUM> (S233). The radio field intensity establishment unit <NUM> determines whether or not the radio field intensity needs to be changed on the basis of the current radio field intensity (S234). In other words, the radio field intensity establishment unit <NUM> establishes whether to increase or reduce the radio field intensity in accordance with the distance between the monitor <NUM> and the passenger. The radio field intensity information generation unit <NUM> generates radio field intensity information as in Embodiment <NUM>, and transmits this information to the remote controller <NUM> via the Bluetooth® communication unit <NUM> (S235).

When the distance between the passenger and the monitor <NUM> is great (e.g., when the distance between the passenger and the monitor <NUM> exceeds a predetermined value), the radio field output of the remote controller <NUM> is increased. It is thereby possible to execute stable wireless communication between the display device <NUM> and the remote controller <NUM>. When the distance between the passenger and the monitor <NUM> is small (e.g., when the distance between the monitor <NUM> and the passenger falls below another predetermined value), the radio field output of the remote controller <NUM> is reduced. The battery consumption of the remote controller <NUM> can thereby be suppressed.

The image for determining the distance between the monitor <NUM> and the passenger may be an image captured by another camera installed in the aircraft. In this case, the display device <NUM> may acquire the image from the management device <NUM>.

(<NUM>) The embodiments of (<NUM>)-(<NUM>) above be carried out individually or in plurality, or any one or all may be carried out in combination with Embodiment <NUM>.

(<NUM>) In the above embodiments, the management device <NUM> and the display devices <NUM> are connected by wires, but may be connected wirelessly.

(<NUM>) In the above embodiments, the radio field intensity control system <NUM> is provided with a management device <NUM>, display devices <NUM>, and remote controllers <NUM>, but may be provided with the display devices <NUM> and remote controllers <NUM> alone.

(<NUM>) WiFi and Bluetooth® described above are not provided by way of limitation as to the wireless communication protocol. Other wireless communication protocols may be used.

(<NUM>) In the above embodiments, a part or all of the processing of each functional block may be performed by a program. A part or all of the processing of each functional block may be executed by a processor in a computer. In addition, the program for performing each process may be stored in a hard disk, or ROM, or another storage device, and read out and executed in ROM or RAM.

(<NUM>) In the above embodiments, instead of a CPU or another processor, the system may include a processor configured from a dedicated electronic circuit designed to perform a predetermined function. In addition, the processor may be configured from one or a plurality of processors. In addition, use of the term "device" in the present specification may include cases of a plurality of constituent elements (devices, modules (components), etc.), and it does not matter whether or not all the constituent elements are in the same casing. There are also cases in which a plurality of devices stored in separate casings and connected via a network and one device in which a plurality of modules are stored in one casing may be referred to as a system.

(<NUM>) The above-described processes are not provided by way of limitation as to the flowcharts shown in <FIG> and <FIG>. The order of each process may be partially interchanged or the steps may be executed in parallel.

(<NUM>) In the above embodiments, an example in which the radio field intensity control system <NUM> of the present disclosure is installed in an aircraft was described. However, this example is not provided by way of limitation as to the present disclosure. The location where the radio field intensity control system <NUM> is installed may be a train, a bus, a ship, or another moving object or vehicle. In this case, radio field intensity control is executed in accordance with the operation information of individual vehicles.

Claim 1:
A display device (<NUM>) that is disposed in a moving body and is capable of wirelessly connecting to a wireless terminal, the display device (<NUM>) configured to display information in accordance with an operation of the wireless terminal by a passenger of the moving body,
the display device (<NUM>) comprising:
a first receiver configured to receive operation information, which is information pertaining to operation of the moving body;
a controller (<NUM>) configured to, on a basis of the operation information, establish an intensity of a first radio field to be outputted by the wireless terminal in order to connect to the display device (<NUM>); and
a transmitter configured to transmit radio field intensity information indicating the intensity of the first radio field to the wireless terminal characterized in that
the moving body is an aircraft, the operation information indicates at least one of a flying state, position, altitude, and seat information of the aircraft, and
establishing the intensity of the first radio field includes establishing to increase the output of the first radio field, reduce the output of the first radio field, set the output of the first radio field to OFF, or change the frequency band of the first radio field.