Patent Publication Number: US-2016227595-A1

Title: Wireless communication control method and wireless communication control system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a wireless communication control method and a wireless communication control system that is able to be used in an airplane, a train, and the like. 
     2. Description of the Related Art 
     PTL 1 discloses a communication system in which a communication unit provided to each seat of the airplane connects with a terminal owned by a passenger and communicates with the terminal. The communication unit is able to communicate with the terminal owned by the passenger via Bluetooth (registered trademark) which is one of short range wireless communication standards. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Unexamined Japanese Patent Publication No. JP2002-359710 
     SUMMARY OF THE INVENTION 
     The present disclosure provides a wireless communication control method that improves communication quality by reducing interference between wireless communication apparatuses in a situation in which there is a plurality of wireless communication apparatuses. 
     The wireless communication control method of the present disclosure is a wireless communication control method controlling communication between a first wireless communication apparatus and a first external device, and controlling communication between a second wireless communication apparatus and a second external device, by a server apparatus, the method including receiving a connection request to the first external device from the first wireless communication apparatus, and causing the first external device to connect with the second wireless communication apparatus if the second wireless communication apparatus has been connected with the second external device upon receiving the connection request. 
     The wireless communication control method of the present disclosure is able to improve the communication quality by reducing the interference between the wireless communication apparatuses in the situation in which there is the plurality of wireless communication apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram describing an arrangement of on-board monitors in an airplane in a first exemplary embodiment; 
         FIG. 2  is a diagram describing a grouping of the on-board monitors in the airplane in the first exemplary embodiment; 
         FIG. 3  is a block diagram of a wireless communication system in the first exemplary embodiment; 
         FIG. 4  is a block diagram of a server apparatus in the first exemplary embodiment; 
         FIG. 5  is a diagram illustrating grouping information in the first exemplary embodiment; 
         FIG. 6  is a diagram illustrating connection information in the first exemplary embodiment; 
         FIG. 7  is a block diagram of an on-board monitor in the first exemplary embodiment; 
         FIG. 8  is a diagram describing connection of a smartphone with an on-board monitor in the first exemplary embodiment; 
         FIG. 9  is a diagram illustrating the connection information after the first time update in the first exemplary embodiment; 
         FIG. 10  is another diagram describing connection of the smartphone with the on-board monitor in the first exemplary embodiment; 
         FIG. 11  is a diagram illustrating the connection information after the second time update in the first exemplary embodiment; 
         FIG. 12  is a flowchart describing the connection of the smartphone with the on-board monitor in the first exemplary embodiment; and 
         FIG. 13  is a block diagram of a wireless communication system in a second exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary embodiments are described in detail below with appropriate reference to drawings. However, an unnecessarily detailed description may be omitted. For example, a detailed description of an already well known matter and a duplicate description for substantially the same configuration may be omitted. This is to avoid the unnecessarily redundant description below, and to facilitate understanding of those skilled in the art. 
     Incidentally, accompanying drawings and the description below are provided so that those skilled in the art sufficiently understand the present disclosure, and are not intended to limit the claimed subject matter. 
     First Exemplary Embodiment 
     A first exemplary embodiment is described below with reference to  FIG. 1  to  FIG. 12 . 
     [1-1. Arrangement of on-Board Monitor in Airplane] 
       FIG. 1  is a diagram describing an arrangement of on-board monitors in an airplane in a first exemplary embodiment. In  FIG. 1 , on-board monitor  200  is located for each seat  20  of a passenger inside airplane  10 . On-board monitor  200  is located on a backrest of seat  20  or a cabin wall of airplane  10 . In addition, aisle  30  is provided inside airplane  10 . 
       FIG. 2  is a diagram describing a grouping of on-board monitor  200  in airplane  10  in the first exemplary embodiment. Adjacent six on-board monitors  200  are grouped. In  FIG. 2 , six on-board monitors  200  located at the seats of seat numbers “2A,” “2B,” “2C,” “3A,” “3B,” “3C” are grouped as “group I,” and six on-board monitors  200  located at the seats of seat numbers “2D,” “2E,” “2F,” “3D,” “3E,” “3F” are grouped as “group II,” and six on-board monitors  200  located at the seats of seat numbers “2G,” “2H,” “2I,” “3G,” “3H,” “3I” are grouped as “group III.” 
     It is desirable that on-board monitors  200  are grouped so that a distance between all on-board monitors  200  is up to about 10 m that is connectable, which is defined by Bluetooth Class2 used in smartphone  300 . In addition, inside airplane  10 , it is desirable that on-board monitors  200  are grouped not to sandwich aisle  30 , to reduce obstacles as much as possible. Specifically, it is desirable that any two on-board monitors  200  in a same group are located without separating by aisle  30  or that multiple on-board monitors  200  in the same group are located without separating by aisle  30 . 
     [1-2. Configuration of Wireless Communication System] 
     Next, as an example, a wireless communication system is described including on-board monitor  200  grouped in “group I.”  FIG. 3  is a block diagram of a wireless communication system in the first exemplary embodiment. Wireless communication system  1  in  FIG. 3  includes server apparatus  100 , and on-board monitors  200 A,  200 B,  200 C,  200 D,  200 E,  200 F. On-board monitor  200 A is located at the seat number “2A;” on-board monitor  200 B is located at the seat number “2B;” on-board monitor  200 C is located at the seat number “2C;” on-board monitor  200 D is located at the seat number “3A;” on-board monitor  200 E is located at the seat number “3B;” on-board monitor  200 F is located at the seat number “3C.” 
     In addition, a passenger of the seat number “2B” owns smartphone  300 A, and a passenger of the seat number “3A” owns smartphone  300 B. 
     Server apparatus  100  is connected with each of on-board monitors  200 A- 200 E via a network cable, and establishes bidirectional communication such as distribution of contents and acquisition of sensor information from each of onboard monitors  200 A- 200 E, with each of on-board monitors  200 A- 200 E. Information such as communication connection situation of each of on-board monitors  200 A- 200 E is collectively managed by server apparatus  100 . 
     Each of on-board monitors  200 A- 200 E is able to reproduce the contents distributed from server apparatus  100  and to communicate with external devices such as smartphone  300 A,  300 B owned by the passengers, and the like. 
     On-board monitor  200 A includes touch panel  204 A and Bluetooth module  205 A. On-board monitor  200 B includes touch panel  204 B and Bluetooth module  205 B. On-board monitor  200 C includes touch panel  204 C and Bluetooth module  205 C. On-board monitor  200 D includes touch panel  204 D and Bluetooth module  205 D. On-board monitor  200 E includes touch panel  204 E and Bluetooth module  205 E. On-board monitor  200 F includes touch panel  204 F and Bluetooth module  205 F. 
     Hereinafter, on-board monitors  200 A- 200 F are collectively referred to as on-board monitor  200 . Elements included in on-board monitor  200  such as touch panels  204 A- 204 F and Bluetooth modules  205 A- 205 F are in the same manner. Touch panels  204 A- 204 F are collectively referred to as touch panel  204 , and Bluetooth modules  205 A- 205 F, are collectively referred to Bluetooth module  205 . In addition, smartphones  300 A,  300 B are collectively referred to as smartphone  300 . 
     Incidentally, in the present exemplary embodiment, six on-board monitors  200  connected with server apparatus  100  are described as one group; however, a number of on-board monitors  200  of one group is not limited to this and may be any number. In addition, a case is described when a number of smartphones owned by the passengers is two; however, the number of smartphones is not limited to this and may be any number. On-board monitor  200  is an example of wireless communication apparatuses. 
     Each of smartphones  300 A,  300 B owned by the passengers includes a wireless communication module, and is able to establish bidirectional communication with on-board monitor  200  wirelessly. Smartphone  300  is an example of the external devices. 
     [1-3. Configuration of Server Apparatus] 
     Next, a configuration of server apparatus  100  is described.  FIG. 4  is a block diagram of server apparatus  100  in the present exemplary embodiment. Server apparatus  100  includes network interface  101 , Central Processing Unit (CPU)  102 , memory  103 , and data storage  104 . 
     Network interface  101  is an interface by which CPU  102  communicates with on-board monitor  200  via the network cable. 
     CPU  102  executes programs stored in memory  103  to be described later to perform various operations and information processing. CPU  102  is able to read from memory  103  or data storage  104  and write to memory  103  or data storage  104 . In addition, CPU  102  communicates with on-board monitor  200  via network interface  101 . CPU  102  detects a connection request via Bluetooth to connect with on-board monitor  200  by smartphone  300 , and issues a search command to on-board monitor  200  according to operation to be described later. 
     Memory  103  stores the programs executed by CPU  102  and operation results of CPU  102 . Memory  103  is composed of a flash memory or a Random 
     Access Memory (RAM). 
     Data storage  104  stores the contents to be distributed to on-board monitor  200 , and grouping information and connection information of on-board monitor  200  to be described later. Data storage  104  is composed of a hard disk and the like. 
     Next, the grouping information is described.  FIG. 5  is a diagram illustrating the grouping information in the present exemplary embodiment. The grouping information illustrated in  FIG. 5  illustrates a grouping of on-board monitor  200  in airplane  10  described in  FIG. 2 . In  FIG. 5 , for “group I,” an ID “0001” of on-board monitor  200 A is associated with the seat number “2A,” an ID “0002” of on-board monitor  200 B is associated with the seat number “2B,” an ID “0003” of on-board monitor  200 C is associated with the seat number “2C,” an ID “0004” of on-board monitor  200 D is associated with the seat number “3A,” an ID “0005” of on-board monitor  200 E is associated with the seat number “3B,” and an ID “0006” of on-board monitor  200 F is associated with the seat number “3C.” 
     For “group II,” an ID “0007” of on-board monitor  200  is associated with the seat number “2D,” an ID “0008” of on-board monitor  200  is associated with the seat number “2E,” an ID “0009” of on-board monitor  200  is associated with the seat number “2F,” an ID “0010” of on-board monitor  200  is associated with the seat number “3D,” an ID “0011” of on-board monitor  200  is associated with the seat number “3E,” and an ID “0012” of on-board monitor  200  is associated with the seat number “3F.” 
     For “group III,” an ID “00013” of on-board monitor  200  is associated with the seat number “2G,” an ID “0014” of on-board monitor  200  is associated with the seat number “2H,” an ID “0015” of on-board monitor  200  is associated with the seat number “2I,” an ID “0016” of on-board monitor  200  is associated with the seat number “3G,” an ID “0017” of on-board monitor  200  is associated with the seat number “3H,” and an ID “0018” of on-board monitor  200  is associated with the seat number “3I.” 
     Next, the connection information is described.  FIG. 6  is a diagram illustrating the connection information in the present exemplary embodiment. The connection information is information indicating a number of external devices such as smartphone  300  connected with on-board monitor  200  via Bluetooth. The grouping illustrated in  FIG. 6  is the grouping of on-board monitor  200  in airplane  10  described in  FIG. 2 . In  FIG. 6 , for “group I,” to each of the IDs “0001,” “0002,” “0003,” “0004,” “0005,” “0006” of on-board monitor  200 , a number of connected devices is “0.” For “group II,” to the ID “0007” of on-board monitor  200 , the number of connected devices is “3.” To each of the IDs “0008,” “0009,” “0010,” “0011,” “0012” of on-board monitor  200 , the number of connected devices is “0.” For “group III,” to the ID “0016” of on-board monitor  200 , the number of connected devices is “4.” To each of the IDs “0013,” “0014,” “0015,” “0017,” “0018” of on-board monitor  200 , the number of connected devices is “0.” 
     [1-4. Configuration of on-Board Monitor] 
     Next, a configuration of on-board monitor  200  is described.  FIG. 7  is a block diagram of on-board monitor  200  in the present exemplary embodiment. On-board monitor  200  includes network interface  201 , CPU  202 , memory  203 , touch panel  204 , Bluetooth module  205 , and display  206 . 
     Network interface  201  is an interface by which CPU  202  communicate with server apparatus  100  via the network cable. 
     CPU  202  executes programs stored in memory  203  to perform various operations and information processing. CPU  202  is able to read from memory  103  or write to memory  103 . In addition, CPU  202  communicates with server apparatus  100  via network interface  201 . 
     Memory  203  stores programs to be executed by CPU  202  and operation results of CPU  202 . Memory  203  is composed of a flash memory or a RAM. 
     Touch panel  204  is located on a surface of display  206 . When the passenger touches a display output on display  206 , touch panel  204  transmits information indicating a position touched on touch panel  204  to CPU  202 . CPU  202  performs control in accordance with the transmitted information, and the passenger is able to operate intuitively. 
     Bluetooth module  205  includes a controller and an antenna for Bluetooth communication. Bluetooth module  205  receives a command from CPU  202  and executes a start operation of communication or a stop operation of communication, and transmits a communication state with smartphone  300  to CPU  202 . 
     Display  206  displays various contents according to a command from CPU  202 . 
     [1-5. Connection of Smartphone with on-Board Monitor] 
     It is described for connection of smartphone  300  owned by the passenger with on-board monitor  200  in wireless communication system  1  configured as described above.  FIG. 8  is a diagram describing connection of a smartphone with an on-board monitor in the first exemplary embodiment. As illustrated in  FIG. 8 , at the beginning, the passenger of the seat number “2B”, who owns smartphone  300 A, requests to connect with on-board monitor  200 B of the seat number “2B” via Bluetooth and smartphone  300 A is connected to a network inside the airplane. Since then, the passenger of the seat number “3A”, who owns smartphone  300 B, requests to connect with on-board monitor  200 D of the seat number “3A” via Bluetooth and smartphone  300 B is connected to the network inside the airplane. Operation of the above case is described. 
     The passenger who owns smartphone  300 A requests to cause on-board monitor  200 B to connect with smartphone  300 A via Bluetooth. On-board monitor  200 B notifies server apparatus  100  that a request to connect with smartphone  300 A via Bluetooth has been received. Server apparatus  100  determines on-board monitor  200  to be connected based on the connection information in  FIG. 6  stored in data storage  104 . In the connection information in  FIG. 6 , for “group I,” to each of all on-board monitors  200 , the number of connected devices is “0.” Therefore, in “group I,” this is the first time that on-board monitor  200  connects with smartphone  300  via Bluetooth. When a connection via Bluetooth is the first time, server apparatus  100  causes on-board monitor  200 B, which notified server apparatus  100  of the request, to connect with smartphone  300 A, and updates the connection information.  FIG. 9  is a diagram illustrating the connection information after the first time update. In  FIG. 9 , the number of connected devices of the ID “0002” of on-board monitor  200 B in “group I” is updated from “0” to “1.” 
     Next, the passenger who owns smartphone  300 B requests to cause on-board monitor  200 D to connect with smartphone  300 B via Bluetooth. On-board monitor  200 D notifies server apparatus  100  that a request to connect with smartphone  300 B via Bluetooth has been received. Server apparatus  100  determines on-board monitor  200  to be connected based on the connection information in  FIG. 9  stored in data storage  104 . In the connection information in  FIG. 9 , for “group I,” to the ID “0002” of on-board monitor  200 B, the number of connected devices is “1.” Server apparatus  100  causes on-board monitor  200 B, which has already established the connection, to connect with smartphone  300 B, and updates the connection information. 
       FIG. 10  is another diagram describing connection of the smartphone with the on-board monitor in the first exemplary embodiment. In  FIG. 10 , on-board monitor  200 B connects with smartphones  300 A and  300 B via Bluetooth. 
       FIG. 11  is a diagram illustrating the connection information after the second time update. In  FIG. 11 , the number of connected devices of the ID “0002” of on-board monitor  200 B in “group I” is updated from “1” to “2.” 
     Next, connection of smartphone  300  with on-board monitor  200  is described using a flowchart.  FIG. 12  is a flowchart describing the connection of the smartphone with the on-board monitor. 
     [1-5-1. Acquisition of Connection Request] 
     (S 801 ) CPU  102  in server apparatus  100  monitors a connection request from touch panel  204  on on-board monitor  200 . 
     (S 802 ) The passenger operates touch panel  204  on on-board monitor  200  located at the passenger&#39;s seat and the like to input a request to connect with smartphone  300  via Bluetooth, when considering to connect one&#39;s own smartphone  300  to the network inside the airplane. 
     When receiving the request by the passenger, CPU  202  in on-board monitor  200  transmits a request signal to server apparatus  100  via network interface  201 . On-board monitor  200  stores an ID for identifying on-board monitor  200  in memory  203 . CPU  202  transmits the ID of on-board monitor  200  with the request signal to server apparatus  100  at the same time. In the example of  FIG. 8 , the ID of on-board monitor  200 B is “0002,” and the ID of on-board monitor  200 D is “0004.” CPU  102  in server apparatus  100  detects the request signal from on-board monitor  200 . 
     [1-5-2. Identification of Group of on-Board Monitor] 
     (S 803 ) CPU  102  in server apparatus  100 , when receiving the request signal from on-board monitor  200 , identifies a group of on-board monitor  200  transmitted the request signal. CPU  102  in server apparatus  100  identifies the group of on-board monitor  200  inputted the request based on the grouping information in data storage  104  and received the ID of on-board monitor  200 . Here, in the example of  FIG. 8 , the group of on-board monitors  200 B,  200 D is “group I,” so that CPU  102  identifies that the group of on-board monitor  200  transmitted the request signal is “group I.” 
     The group of on-board monitor  200  transmitted the request signal is identified for performing subsequent processing to the other on-board monitor in the same group. 
     [1-5-3. Determination of Connection Destination] 
     (S 804 ) Server apparatus  100  determines whether or not there is on-board monitor  200  connected with smartphone  300  in the group including on-board monitor  200  transmitted the request signal, based on the connection information and the grouping information stored in data storage  104  in server apparatus  100 . CPU  102  in server apparatus  100  checks the connection information of on-board monitor  200  of the corresponding group, and determines whether or not there is on-board monitor  200  which connected with smartphone  300 . In the example of  FIG. 8 , if on-board monitor  200  that transmitted the request is on-board monitor  200 B, there is no on-board monitor  200  which connected with smartphone  300 . And if on-board monitor  200  that transmitted the request is on-board monitor  200 D, there is on-board monitor  200  which connected with smartphone  300 . 
     Here, Bluetooth communication is performed in a unit called Piconet. The Piconet is configured in one on-board monitor  200  which is a master and up to seven smartphones  300  which are slaves. Therefore, even if there is on-board monitor  200  which connected with seven smartphones  300 , it is not determined that on-board monitor  200  connected with smartphone  300 . This is because it is not possible that this on-board monitor  200  connects with any more smartphones  300 . 
     CPU  102  in server apparatus  100 , when determining that there is on-board monitor  200  that connected with smartphone  300  in the group including on-board monitor  200  transmitted the request signal (S 804 : Yes), advances processing to step S 805 , and CPU  102  in server apparatus  100 , when determining that there is no on-board monitor  200  that connected with smartphone  300  in the group including on-board monitor  200  transmitted the request signal (S 804 : No), advances the processing to step S 806 . 
     (S 805 ) CPU  102  issues a search command for surrounding smartphone  300  to on-board monitor  200  connected to the network. As the example of  FIG. 8 , when on-board monitor  200  connected to the network is on-board monitor  200 B, CPU  102  issues the search command to on-board monitor  200 B. 
     Incidentally, considering a possibility of connection failure due to low communication quality between on-board monitor  200 B and smartphone  300 B, CPU  102  may issue the search command to on-board monitor  200 D transmitted the request signal with the search command to on-board monitor  200 B at the same time. 
     (S 806 ) CPU  102  issues a search command for surrounding smartphone  300  to on-board monitor  200  transmitted the request signal. As the example of  FIG. 8 , when on-board monitor  200  transmitted the request signal is on-board monitor  200 B, CPU  102  issues the search command to on-board monitor  200 B. 
     Incidentally, in step S 806 , CPU  102  may issue the search command to another on-board monitor  200  instead of to on-board monitor  200  transmitted the request signal. For example, in the same group, CPU  102  may issue the search command to on-board monitor  200  that is a center position in the group. For determination of on-board monitor  200  that is the center position in the group, the position is identified from the seat number of on-board monitor  200  included in the same group, and a centroid position of on-board monitor  200  included in the same group is calculated, and on-board monitor  200  closest to the centroid position may be selected. In addition, determination of on-board monitor  200  that is the center position of the group is not limited to this. 
     [1-5-4. Storage of Search Result] 
     (S 807 ) CPU  202  searches for surrounding smartphone  300 , and transmits information indicating smartphone  300  detected as a search result to server apparatus  100 . When CPU  202  detects a plurality of smartphones  300 , CPU  202  transmits the information of all smartphones  300  detected to server apparatus  100 . CPU  102  in server apparatus  100  stores the search result received in data storage  104 . As the example of  FIG. 8 , when CPU  202  in on-board monitor  200 B detects smartphone  300 A, CPU  202  transmits the information indicating smartphone  300 A to server apparatus  100 , and when CPU  202  in on-board monitor  200 A detects smartphone  300 B, CPU  202  transmits the information indicating smartphone  300 B to server apparatus  100 . 
     [1-5-5. Display Command of Search Result] 
     (S 808 ) CPU  102  in server apparatus  100  commands on-board monitor  200  transmitted the request signal to display the search result stored in data storage  104  in step S 807 . As the example of  FIG. 8 , if on-board monitor  200  transmitted the request signal is on-board monitor  200 B, on-board monitor  200 B detects smartphone  300 A, so that CPU  102  commands on-board monitor  200 B to display “smartphone  300 A” as the search result. When on-board monitor  200  transmitted the request signal is on-board monitor  200 D, on-board monitor  200 D detects smartphone  300 B, so that CPU  102  commands on-board monitor  200 D to display “smartphone  300 B” as the search result. 
     Incidentally, a display method may be displaying on display  206  on on-board monitor  200 , however, it is not limited to this. 
     (S 809 ) When the passenger operates touch panel  204  to select the corresponding smartphone  300  from the search result displayed, on-board monitor  200  connects with smartphone  300  selected by the passenger, via Bluetooth. After the connection is established via Bluetooth, CPU  102  updates the connection information. In the example of  FIG. 8 , the passenger of the seat number “2A” operates touch panel  204  to select smartphone  300 A. The passenger of the seat number “3A” operates touch panel  204  to select smartphone  300 B. 
     When on-board monitor  200  connects with smartphone  300  that is able to communicate via Bluetooth, if on-board monitor  200  connects one-to-one with smartphone  300  at each seat, for example, adjacent two one-to-one connections between smartphone  300  and on-board monitor  200  via Bluetooth interfere with each other. Therefore, as described above, when on-board monitor  200  connects with smartphone  300  that is able to communicate via Bluetooth, server apparatus  100  manages a connection destination. And server apparatus  100  cause on-board monitor  200  connected with smartphone  300  in the same group to newly connect with smartphone  300 , so that the Piconet can be efficiently configured. A communication channel between on-board monitor  200  and each smartphone  300  in the same Piconet is shared by time division multiplex. Accordingly, interference can be avoided. Since each of communication channels tends to interfere with each other when there are many one-to-one connections via Bluetooth, throughput is generally increased by selecting a “short packet” mode that retransmission cost is small. However, transmission efficiency is not necessarily high because a ratio of an information byte in a packet is low. On the other hand, in the Piconet that is one-to-many connections via Bluetooth, since each of the communication channels shares by multiplexing time division slots, packet loss by the interference is small even when using a “long packet” mode. 
     With the wireless communication system of the present exemplary embodiment, by controlling the wireless communication apparatus connected in a Bluetooth communication area, the wireless communication control method and the wireless communication control system can be provided which provide a low interference, highly efficient wireless quality. 
     [1-6. Effects] 
     As described above, the wireless communication control method of the present exemplary embodiment is a wireless communication control method controlling communication between a first wireless communication apparatus and a first external device, and controlling communication between a second wireless communication apparatus and a second external device, by a server apparatus, the method including receiving a connection request to the first external device from the first wireless communication apparatus, and causing the first external device to connect with the second wireless communication apparatus if the second wireless communication apparatus has been connected with the second external device upon receiving the connection request. 
     With this configuration, if a plurality of smartphones  300  is connected with the wireless communication system, the same on-board monitor connects with a plurality of smartphones  300  and the same Piconet is preferentially configured. Therefore, even when each of the plurality of on-board monitors  200  that is a master in Bluetooth is located overlapping each communication area, by utilizing a function of master-slave operation in Bluetooth, interference can be reduced of wireless communication between smartphones  300  connected with the wireless communication system. That is, in a situation in which there is a plurality of wireless communication apparatuses, the interference is reduced between the wireless communication apparatuses, and communication quality can be improved. 
     Second Exemplary Embodiment 
     A second exemplary embodiment is described below with reference to  FIG. 13 . A point in which the present exemplary embodiment is different from the first exemplary embodiment is that server apparatus  100  and on-board monitor  200  configuring wireless communication system  2  are connected via repeaters  400 A,  400 B, and that a grouping of on-board monitor  200  is different that of from the first exemplary embodiment. The configurations of server apparatus  100 , on-board monitor  200  are the same as those of the first exemplary embodiment, so that the description of them is omitted. 
     [2-1. Configuration] 
       FIG. 13  is a block diagram of a wireless communication system in a second exemplary embodiment. Wireless communication system  2  includes server apparatus  100 , on-board monitors  200 A,  200 B,  200 C,  200 D,  200 E,  200 F, and repeaters  400 A,  400 B. Repeater  400 A is disposed between server apparatus  100  and on-board monitors  200 A- 200 C, and repeater  400 B is disposed between server apparatus  100  and on-board monitors  200 D- 200 F, and repeaters  400 A,  400 B are rooters that assign IP address for on-board monitor  200 , perform shaping signals from server apparatus  100 , and the like. On-board monitors  200  are divided into partial networks by repeaters  400 A,  400 B. In the present exemplary embodiment, the grouping of on-board monitors  200  is performed for each of the partial networks divided by repeaters  400 A,  400 B. In the network configuration of  FIG. 13 , on-board monitors  200 A- 200 C configure one group, and on-board monitors  200 D- 200 F configure another one group. Grouping information in the present exemplary embodiment is such a group configuration. The grouping information is stored in data storage  104 . 
     [2-2. Connection of Smartphone with on-Board Monitor] 
     For wireless communication system  2  configured as described above, connection of the smartphone with the on-board monitor is described below. Operation of wireless communication system  2  of the present exemplary embodiment is the same as the operation of  FIG. 12  described in the first exemplary embodiment. 
     In  FIG. 13 , on-board monitor  200 C has already connected with smartphone  300 C and on-board monitor  200 D has already connected with smartphone  300 D. In this state, a passenger requests to cause on-board monitor  200 A to connect with smartphone  300 A. Then, a request signal is transmitted to server apparatus  100 . Here, server apparatus  100  identifies a group including on-board monitor  200 A transmitted the request signal, based on the grouping information. Then, server apparatus  100  determines that on-board monitor  200  which connected with the smartphone is on-board monitor  200 C in the group identified. Incidentally, on-board monitor  200 D is not detected here since it belongs to a different group from on-board monitor  200 A. Server apparatus  100  issues a search command to on-board monitor  200 C. Subsequent operations are the same as those described in the first exemplary embodiment. 
     Other Exemplary Embodiment 
     The exemplary embodiments have been described above as examples of technique of the present disclosure. However, the technique in the present disclosure is not limited thereto, and it is also possible to apply to an exemplary embodiment in which modification, replacement, addition, omission are appropriately performed. In addition, it is possible to make a new exemplary embodiment by combining elements described in the above exemplary embodiments. 
     Therefore, the other exemplary embodiment is exemplified below. 
     In the configuration of the above exemplary embodiments, it has been described that the connection between server apparatus  100  and on-board monitor  200  is a wired network cable. By using the network cable, an effect is expected that the connection between server apparatus  100  and each on-board monitor  200  is stabilized. However, the connection is not limited to the network cable. For example, wireless connection may be used. By wireless connection, the degree of freedom in arrangement of on-board monitors  200  is increased. 
     In the above exemplary embodiment, as the grouping information, the seat number has been used for the position of on-board monitor  200 . When on-board monitors  200  are located corresponding to the seats, an amount of information can be reduced by using the seat number. However, the position of on-board monitor  200  is not limited to the seat number. For example, by using coordinates of a coordinate system to be set in an airplane for the position, identification of the position is possible even when on-board monitor  200  is not located regularly. 
     In the above exemplary embodiments, it has been described that the passenger inputs the wireless communication request from the touch panel. For input of the wireless communication request, anything may be used as far as the passenger is able to input the connection request between smartphone  300  and on-board monitor  200 , and it is not limited to the touch panel. For example, NFC (Near Field Communication) may be used that is one of short range wireless communication systems. By using the NFC, it is also possible to transmit a Bluetooth MAC address of smartphone  300  to on-board monitor  200 , so that the passenger may not select smartphone  300 . 
     In the above exemplary embodiments, it has been described that a number of on-board monitors  200  to connect with smartphone  300  in one group is one; however, the number is not limited to one. For example, when there are on-board monitors  200 B,  200 C that connected with smartphone  300  in one group and the request signal is transmitted from on-board monitor  200 A, the search command for smartphone  300  may be issued to on-board monitor  200 B that is positioned at a place closest from on-board monitor  200 A. 
     In the above exemplary embodiments, the search result of smartphone  300  by on-board monitor  200  has been stored in server apparatus  100 . However, the search result does not necessarily need to be stored in server apparatus  100 . The search result may be displayed by directly transmitting the search result from on-board monitor  200  that has searched for smartphone  300  to on-board monitor  200  on which the search result should be displayed. 
     In the above exemplary embodiments, it has been described that the passenger owns smartphone  300 . However, not limited to smartphone  300 , it may be an external device such as a personal computer, and a tablet terminal. 
     As described above, the exemplary embodiments have been described as examples of the technique of the present disclosure. For this purpose, the accompanying drawings and the detailed description have been provided. 
     Accordingly, in the elements described in the accompanying drawings and the detailed description, there may be included not only essential elements for solving the problem but also non-essential elements for solving the problem, to illustrate the above technique. Therefore, it should not be certified that those non-essential elements are essential immediately, with the fact that those non-essential elements are described in the accompanying drawings and the detailed description. 
     Further, since the above described exemplary embodiments are intended to illustrate the technique of the present disclosure, various modifications, substitutions, additions, omissions and the like can be performed within the scope of the claims or the scope of the equivalents of the claims.