Patent Publication Number: US-2013244697-A1

Title: Position management system, apparatus and method for distributing position data

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a technology for distributing predetermined position data. 
     2. Description of the Related Art 
     Conventionally, the position of a communication terminal of a user is identified by using a GPS (Global Positioning System). With the GPS, wireless signals indicating time are transmitted from approximately 30 GPS satellites orbiting the earth. Then, a communication terminal located on earth uses its receiver to receive the wireless signals and calculates the difference between the time in which the wireless signals are transmitted from the GPS satellites and the time in which the wireless signals from the GPS satellites are received by the receiver of the communication terminal. The communication terminal performs the calculation with respect to at least 4 GPS satellites and identifies its position on earth based on the result of the calculation. 
     In recent years, size and power consumption of the receiver used for GPS communication are becoming smaller. For example, a GPS receiver is installed in a small battery-powered communication terminal such as a mobile phone. 
     However, with the GPS, it is difficult for the wireless signals of the GPS to reach a communication terminal located indoors. Therefore, another system is desired for indoor positioning. One example of such system is IMES (Indoor MEssaging System). 
     A distribution apparatus, which distributes wireless signals by using IMES, can distribute the wireless signals with the same electric waveform as the electric waveform of the wireless signals transmitted by GPS satellites. Therefore, the communication terminals that receive the wireless signals can use the same reception hardware (hardware used for reception) as the reception hardware used for GPS communication. Further, reception software (software used for reception) used for GPS communication can also be used by slightly modifying the reception software. Because position data indicating the position of the IMES distribution apparatus is distributed instead of time data (data indicating time), the communication terminal that receives the wireless signals simply needs to receive the position data and does not need to calculate time difference unlike outdoor positioning. 
     For example, Japanese Laid-Open Patent Publication No. 2011-145873 discloses a position management method using IMES. With this method, in a case where a communication terminal receives position data from an IMES distribution apparatus mounted to an indoor ceiling, a management server can manage the position of the communication terminal by transmitting the position data and a terminal ID of the communication terminal from the communication terminal to an access point in a wireless LAN according to an IEEE802.11x communication standard and transferring the position data and the terminal ID from the access point to the management server. 
     However, in order to transmit the position data and the terminal ID from the communication terminal according to a wireless LAN communication standard as described in Japanese Laid-Open Patent Publication No. 2011-145873, a wireless LAN transmitter is required for the communication terminal. Further, compared to a GPS receiver (whose power consumption is reduced in recent years) or an IMES receiver, a wireless LAN transmitter consumes a significantly large amount of power. Therefore, the communication terminal as a whole (including both the receiver and the transmitter) cannot take advantage of the reduction of power consumption of the GPS receiver because power consumption of the wireless LAN transmitter is not reduced even where power consumption of the GPS receiver is reduced. 
     Therefore, it is difficult to improve power reduction performance of the communication terminal. 
     SUMMARY OF THE INVENTION 
     The present invention may provide a position management system, an apparatus and a method for distributing position data that substantially obviates one or more of the problems caused by the limitations and disadvantages of the related art. 
     Features and advantages of the present invention are set forth in the description that follows, and in part will become apparent from the description and the accompanying drawings, or may be learned by practice of the invention according to the teachings provided in the description. Objects as well as other features and advantages of the present invention will be realized and attained by a position management system, an apparatus and a method for distributing position data particularly pointed out in the specification in such full, clear, concise, and exact terms as to enable a person having ordinary skill in the art to practice the invention. 
     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, an embodiment of the present invention provides a distribution apparatus including a distribution unit configured to distribute position data indicating a position of the distribution apparatus, a reception unit configured to receive data from a communication terminal that received the position data distributed by the distribution unit, the data received from the communication terminal including terminal identification data for identifying the communication terminal and the position data, and a transmission unit configured to transmit terminal setting data of the communication terminal, wherein the reception unit is configured to receive the terminal setting data from a position data management system according to an inquiry transmitted from the communication terminal. 
     Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating an overall configuration of a position management system according to an embodiment of the present invention; 
         FIG. 2  is a schematic diagram illustrating an external configuration of an electric device in a case where the electric device is an LED type fluorescent lighting apparatus according to an embodiment of the present invention; 
         FIG. 3  is a schematic diagram illustrating a state where a communication device is placed on a management object according to an embodiment of the present invention; 
         FIG. 4  is a schematic diagram illustrating a hardware configuration of a main body of an electric device in a case where the electric device is an LED type fluorescent lighting apparatus according to an embodiment of the present invention; 
         FIG. 5  is a hardware configuration of an LED lamp in a case where an electric device is an LED type fluorescent lighting apparatus according to an embodiment of the present invention; 
         FIG. 6  is a schematic diagram illustrating position data distributed by a distribution apparatus according to an embodiment of the present invention; 
         FIG. 7  is a schematic diagram illustrating a hardware configuration of a communication terminal according to an embodiment of the present invention; 
         FIG. 8  is a schematic diagram illustrating an example of a format of position data according to an embodiment of the present invention; 
         FIG. 9  is a schematic diagram illustrating a data structure of data including position data according to an embodiment of the present invention; 
         FIG. 10  is a schematic diagram illustrating a hardware configuration of a management object in a case where the management object is a mobile phone according to an embodiment of the present invention; 
         FIG. 11  is a schematic diagram illustrating a hardware configuration of a gateway according to an embodiment of the present invention; 
         FIG. 12  is a schematic diagram illustrating a hardware configuration of a position data management system according to an embodiment of the present invention; 
         FIG. 13  is a schematic diagram illustrating an example of management data managed by a position data management system according to an embodiment of the present invention; 
         FIG. 14  is a block diagram illustrating functions (function components) of a distribution apparatus and a communication terminal according to an embodiment of the present invention; 
         FIG. 15  is a block diagram illustrating functions (function components) of a management object in a case where the management object is a personal computer or a mobile phone according to an embodiment of the present invention; 
         FIG. 16  is a block diagram illustrating functions (function components) of a gateway and a position data management system according to an embodiment of the present invention; 
         FIG. 17  is a sequence diagram illustrating an operation of establishing a communication network in a ceiling according to an embodiment of the present invention; 
         FIG. 18  is a sequence diagram illustrating an operation of distributing position data according to an embodiment of the present invention; 
         FIG. 19  is a sequence diagram illustrating an operation of determining position data to be used by a communication terminal and determining a transmission destination of the position data according to an embodiment of the present invention; 
         FIG. 20  is a flowchart illustrating an operation that begins when position data is received by a communication terminal and ends when the position data is stored by the communication terminal according to an embodiment of the present invention; 
         FIG. 21  is a schematic diagram illustrating a state of communication between a distribution apparatus and a communication terminal according to an embodiment of the present invention; 
         FIG. 22  is a flowchart illustrating an operation of determining a transmission destination according to an embodiment of the present invention; 
         FIG. 23  is a sequence diagram illustrating mainly a process of managing position data according to an embodiment of the present invention; 
         FIG. 24  is a schematic diagram illustrating an example of a screen of a position data management system according to an embodiment of the present invention; 
         FIG. 25  is a schematic diagram illustrating another example of a screen of a position data management system according to an embodiment of the present invention; 
         FIG. 26  is a schematic diagram illustrating terminal setting data stored in a communication terminal according to an embodiment of the present invention; 
         FIG. 27  is a schematic diagram illustrating a communication data format of a terminal setting data that is transmitted from a position data management system after an inquiry is transmitted from a communication terminal to a position data management system via a distribution apparatus according to an embodiment of the present invention; 
         FIG. 28  is a schematic diagram illustrating management data (including terminal setting data) stored in a storage unit of a position data management system according to an embodiment of the present invention; 
         FIG. 29  is a block diagram illustrating functions (function components) of a distribution apparatus and a communication terminal according to another embodiment of the present invention; 
         FIG. 30  is a block diagram illustrating functions (function components) of a management object in a case where the management object is a personal computer or a mobile phone according to another embodiment of the present invention; 
         FIG. 31  is a block diagram illustrating functions (function components) of a gateway and a position data management system according to another embodiment of the present invention; 
         FIG. 32  is a flowchart of an operation of receiving position data based on terminal setting data and storing the received position data according to an embodiment of the present invention; 
         FIG. 33  is a flowchart illustrating an operation of a transmitting position data from a communication terminal based on terminal setting data according to an embodiment of the present invention; 
         FIG. 34  is a sequence diagram illustrating a process of inquiring for terminal setting data according to an embodiment of the present invention; and 
         FIG. 35  is a sequence diagram illustrating another process of inquiring for terminal setting data according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Next, embodiments of the present invention are described with reference to the accompanying drawings. 
       FIG. 1  is a schematic diagram illustrating an overall configuration of a position management system  1  according to an embodiment of the present invention. 
     As illustrated in  FIG. 1 , the position management system  1  according to an embodiment of the present invention includes, for example, multiple distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) placed on a ceiling β in an indoor area α (also referred to as “indoors a”), multiple communication terminals ( 5   a ,  5   b ,  5   c ,  5   d ,  5   e ,  5   f ,  5   g ,  5   h ) placed on a floor in the indoor area α, and a position data management system  9 . 
     Each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) stores position data (Xa, Xb, Xc, Xd, Xe, Xf, Xg, Xh) indicating a position in which each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) is to be placed. After the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) are placed to corresponding positions, the position data stored in each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) indicates the position in which each of the distribution apparatuses is being placed. Each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) distributes the stored position data (Xa, Xb, Xc, Xd, Xe, Xf, Xg, Xh) in a direction toward the floor of the indoor area α. Further, each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) stores apparatus identification data (Ba, Bb, Bc, Bd, Be, Bf, Bg, Bh) that identifies (distinguishes) each of the distribution apparatuses ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ). 
     A given distribution apparatus among the multiple distribution apparatus ( 3   a ,  3   b ,  3   c ,  3   d ,  3   e ,  3   f ,  3   g ,  3   h ) may be hereinafter indicated as “distribution apparatus  3 ”. A given communication terminal among the multiple communication terminals ( 5   a ,  5   b ,  5   c ,  5   d ,  5   e ,  5   f ,  5   g ,  5   h ) may be hereinafter indicated as “communication terminal  5 ”. Further, a given position data among the multiple position data (Xa, Xb, Xc, Xd, Xe, Xf, Xg, Xh) may be hereinafter indicated as “position data X”. A given apparatus identification data among the multiple apparatus identification data (Ba, Bb, Bc, Bd, Be, Bf, Bg, Bh) may be hereinafter referred to as “apparatus identification data B”. One example of the apparatus identification data B is a MAC (Media Access Control) address. 
     On the other hand, each of the communication terminals ( 5   a ,  5   b ,  5   c ,  5   d ,  5   e ,  5   f ,  5   g ,  5   h ) stores terminal identification data (Aa, Ab, Ac, Ad, Ae, Af, Ag, Ah) that identifies (distinguishes) each of the communication terminals ( 5   a ,  5   b ,  5   c ,  5   d ,  5   e ,  5   f ,  5   g ,  5   h ). A given terminal identification data among the terminal identification data (Aa, Ab, Ac, Ad, Ae, Af, Ag, Ah) may be hereinafter referred to as “terminal identification data A”. One example of the terminal identification data A is a MAC address. In a case where the communication terminal  5  receives position data X from the distribution apparatus  3 , the communication terminal  5  transmits its own terminal identification data A (i.e. terminal identification data A of the communication terminal  5 ) and its own position data (position data X of the communication terminal  5 ) to the distribution apparatus  3 . 
     Each distribution apparatus  3  is installed inside a corresponding electric device ( 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   h ) or externally mounted to the electric device ( 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   h ). The electric devices ( 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   h ) are placed to the ceiling β in the indoor area α. A given electric device among the electric devices ( 2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f ,  2   h ) may be hereinafter referred to as “electric device  2 ”. 
     Each electric device  2  supplies electric power to each distribution apparatus  3 . Among the electric devices  2  according to the embodiment of  FIG. 1 , the electric device  2   a  is an LED (Light Emitting Diode) type fluorescent lighting apparatus; the electric device  2   b  is a ventilation fan; the electric device  2   c  is an access point of a wireless LAN (Local Area Network); the electric device  2   d  is a speaker; the electric device  2   e  is an emergency lamp; the electric device  2   f  is a fire alarm or a smoke detector; the electric device  2   g  is a security camera; and the electric device  2   h  is an air conditioner. 
     The electric devices  2  are not limited to those illustrated in  FIG. 1  as long as the electric device  2  can feed electric power to the transmitting device  3 . For example, other than the electric devices  2  illustrated in  FIG. 1 , the electric device  2  may also be a typical lighting apparatus such as a fluorescent lamp other than an LED type fluorescent lamp or an incandescent lamp, or a burglar alarm for detecting intrusion from the outside. 
     On the other hand, each communication terminal  5  is mounted to the outside of corresponding management objects ( 4   a ,  4   b ,  4   c ,  4   d ,  4   e ). The position of each of the management objects ( 4   a ,  4   b ,  4   c ,  4   d ,  4   e ) is managed by the position data management system  9 . 
     Among the management objects ( 4   a ,  4   b ,  4   c ,  4   d ,  4   e ) according to the embodiment of  FIG. 1 , the management object  4   a  is a bag; the management object  4   b  is a table; the management object  4   c  is a projector; the management object  4   d  is a television conference terminal; the management object  4   e  is a MFP (Multi-Function Product) including, for example, a copying function; and the management object  4   f  is a broom. 
     Further, the management object  4   g  is a personal computer (PC). In a case where a function (s) of the communication terminal  5  is installed in the personal computer, the management object  4   g  is also a communication terminal  5   g . The management object  4   h  is a mobile phone such as a smart phone. In a case where a function(s) of the communication terminal  5  is installed in the mobile phone, the management object  4   h  is also a communication terminal  5   h . A given management object among the management objects ( 4   a ,  4   b ,  4   c ,  4   d ,  4   e ,  4   f ,  4   g ,  4   h ) may be hereinafter referred to as “management object  4 ”. 
     The management objects  4  are not limited to those illustrated in  FIG. 1 . For example, other than the management objects  4  illustrated in  FIG. 1 , the management object  4  may also be a facsimile machine, a scanner, a printer, a copier, an electronic blackboard, an air cleaner, a shredder, a vending machine, a wristwatch, a camera, an electronic game device, a wheelchair, or a medical device such as an endoscope. 
     Next, an example of a method for managing position data by using the position management system  1  is described. 
     In this embodiment, the distribution apparatus  3   a , which is provided at the ceiling β in the indoor area α, uses wireless communication to transmit the position data Xa indicating the position at which the distribution apparatus  3   a  is placed (installed). Thereby, the communication terminal  5   a  receives the position data Xa distributed from the distribution apparatus  3   a . Then, the communication terminal  5   a , uses wireless communication to transmit terminal identification data (data for identifying (distinguishing) a terminal) Aa and position data Xa of the communication terminal  5   a  to the distribution apparatus  3   a . In this case, the communication terminal  5   a  transmits (returns) the identification data Xa received from the distribution apparatus  3   a  back to the distribution apparatus  3   a.    
     Thereby, the distribution apparatus  3   a  receives the terminal identification data Aa and the position data Xa from the communication terminal  5   a . Then, the distribution apparatus  3   a  uses wireless communication to transmit the terminal identification data Aa and the position data Xa to the gateway  7 . Then, the gateway  7  transmits the terminal identification data Aa and the position data Xa to the position data management system  9  via a LAN  8   e . An administrator of the position data management system  9  can locate the position of the communication terminal  5   a  (management object  4   a ) in the indoor area α by managing the terminal identification data Aa and the position data Xa with the position data management system  9 . 
     Further, as illustrated in  FIG. 1 , among the communication terminals, the communication terminals  5   g ,  5   h , in particular, can particularly calculate the position on earth by receiving wireless signals (including, for example, time data, orbit data) in the outdoor area γ from a GPS satellite  999 . Then, the communication terminals  5   g ,  5   h  can use a mobile communication system (e.g., 3G (3 rd  Generation) system, 4G (4 th  Generation) system) to transmit terminal identification data Ag, Ah and position data Xg, Xh to the position data management system  9  via a base station  8   a , a mobile communication network  8   b , a gateway  8   c , the Internet  8 D, and the LAN  8   e , respectively. 
     It is to be noted that the communication network  8  according to an embodiment of the present invention is constituted by the base station  8   a , the mobile communication network  8   b , the gateway  8   c , the Internet  8   d , the LAN Be, and the gateway  7 . Further, positioning (position measurement) of latitude and longitude on earth requires at least 3 GPS satellites (4 GPS satellites if altitude is also included),  FIG. 1  illustrates one GPS satellite  999  for the sake of convenience. 
     Next, an external configuration of the LED type fluorescent lighting apparatus  2   a  is described with reference to  FIG. 2 . The LED type fluorescent lighting apparatus  2   a  is one example of the electric device  2 .  FIG. 2  is a schematic diagram illustrating an external configuration of the electric device  2  in a case where the electric device  2  is an LED type fluorescent lighting apparatus  2   a.    
     As illustrated in  FIG. 2 , the LED type fluorescent lighting apparatus (electric device)  2   a  is a straight tube type lamp. The LED type fluorescent lighting apparatus  2   a  includes a main body  120  that is attached to the ceiling β of the indoor area α of  FIG. 1  and an LED lamp  130  that is attached to the main body  120 . 
     Sockets  121   a  and  121   b  are provided on each end part of the main body  120 . The socket  121   a  includes power feeding terminals  124   a   1 ,  124   a   2  for feeding power to the LED lamp  130 . Further, the socket  121   b  includes power feeding terminals  124   b   1 ,  124   b   2  also for feeding power to the LED lamp  130 . Thereby, the main body  120  can supply electric power from the below-described power source  1000  to the LED lamp  130 . 
     The LED lamp  130  includes a translucent cover  131 , caps  132   a ,  132   b  provided on each end part of the translucent cover  131 , and the distribution apparatus  3   a  inside the translucent cover  131 . The translucent cover  131  is formed of, for example, a resin material (e.g., acrylic resin). The translucent cover  131  is provided in a manner covering a light source inside the LED lamp  130 . 
     Further, the cap  132   a  includes terminal pins  152   a   1 ,  152   a   2  that are connected to corresponding power feeding terminals  124   a   1 ,  124   a   2  of the socket  121   a . The cap  132   b  includes terminal pins  152   b   1 ,  152   b   2  that are connected to corresponding power feeding terminals  124   b   1 ,  124   b   2  of the socket  121   b . By mounting the LED lamp  130  to the main body  120 , electric power can be supplied from the main body  120  to each of the terminal pins  152   a   1 ,  152   a   2 ,  152   b   1 ,  152   b   2  via corresponding power feeding terminals  124   a   1 ,  124   a   2 ,  124   b   1 ,  124   b   2 . Thereby, the LED lamp  130  can radiate light to the outside by way of the translucent cover  131 . The distribution apparatus  3   a  is operated by the electric power supplied from the main body  120 . 
     Next, a status of the communication terminal  5  being placed on an upper surface of the management object  4  is described with reference to  FIG. 3 . In this embodiment, the management object  4  is a table  4   b .  FIG. 3  is a schematic diagram illustrating a state where the communication device  5  is placed on the management object  4  according to an embodiment of the present invention. 
     As illustrated in  FIG. 3 , the communication device  5   b  is mounted to the upper surface of the management object  4   b . The communication device  5   b  may be mounted to the management object  4   b  by using, for example, a double-sided tape. Alternatively, the communication device  5   b  may simply be placed on the management object  4   c.    
     Next, with reference to  FIGS. 4 and 5 , a hardware configuration of the electric device  2  is described in a case where the electric device  2  is the LED type fluorescent lighting apparatus  2   a .  FIG. 4  is a schematic diagram illustrating a hardware configuration of a main body of the electric device  2  in a case where the electric device  2  is the LED type fluorescent lighting apparatus  2   a .  FIG. 5  is a hardware configuration of the LED lamp  130  in a case where the electric device  2  is the LED type fluorescent lighting apparatus  2   a.    
     As illustrated in  FIG. 4 , the main body  120  mainly includes a ballast  122 , lead wires  123   a ,  123   b , and power feeding terminals  124   a   1 ,  124   a   2 ,  124   b   1 ,  124   b   2 . 
     The ballast  122  controls the electric current supplied from an external power source  1000 . The ballast  122  and the power feeding terminals  124   a ,  124   a   2 ,  124   b   1 ,  124   b   2  are electrically connected by the lead wires  123   a ,  123   b . Thereby, electric power can be stably supplied from the ballast  122  to each of the power feeding terminals  124   a ,  124   a   2 ,  124   b   1 ,  124   b   2  via the lead wires  123   a ,  123   b.    
     As illustrated in  FIG. 5 , the LED lamp  130  mainly includes a power control unit  140 , lead wires  151   a ,  151   b , terminal pins  152   a   1 ,  1522 ,  152   b   1 ,  152   b   2 , lead wires  153 ,  154 ,  155 , and the distribution apparatus  3   a . The power control unit  140  controls the electric current supplied from the power source  1000 . The power control unit  140  mainly includes a current monitoring circuit  141  and a smoothing circuit  142 . The current monitoring circuit  141  rectifies the electric current input from the power source  1000 . The smoothing circuit  142  smoothens the electric current rectified by the current monitoring circuit  141  and supplies power to each of the terminal pins  152   a   1 ,  1522 ,  152   b   1 ,  152   b   2  via the lead wires  151   a ,  151   b.    
     The power control unit  140  and the terminal pins  152   a   1 ,  1522 ,  152   b   1 ,  152   b   2  are electrically connected by the lead wires  151   a ,  151   b . The power control unit  140  and the distribution apparatus  3   a  are electrically connected by the lead wire  154 . Although multiple LEDs  160  may be actually attached to the power control unit  140 ,  FIG. 5  illustrates a single LED  160  attached to the power control unit for the sake of convenience. The configuration of LED lamp  130  is substantially the same as a common LED lamp except that the LED lamp  130  includes the distribution apparatus  3   a.    
     Next, the distribution apparatus  3   a  according to an embodiment of the present invention is described. The distribution apparatus  3   a  includes a voltage transformer  100 , a lead wire  155 , a control unit  11 , a position data distribution unit  12 , and a wireless communication unit  13 . The voltage transformer  100  is electrically connected to the control unit  11 , the position data distribution unit  12 , and the wireless communication unit  13  via the lead wire  155 . 
     The voltage transformer  100  transforms the voltage supplied from the power control unit  140  to a driving voltage of the distribution apparatus  3   a  and supplies the transformed voltage to the control unit  11 , the position data distribution unit  12 , and the wireless communication unit  13 . 
     The control unit  11  includes a CPU (Central Processing Unit)  101  for controlling overall operations of the control unit  11 , a ROM (Read Only Memory)  102  for storing basic input/output programs therein, a RAM (Random Access Memory)  103  used as a work area of the CPU  101 , an interface (I/F)  108   a  for transmitting/receiving signals with respect to the position data distribution unit  12 , an interface  108   b  for transmitting/receiving signals with respect to the wireless communication unit  13 , and a bus line (e.g., address bus, data bus)  109  for electrically connecting the units and elements included in the control unit  11 . 
     The position data distribution unit  12  includes a CPU  201  for controlling overall operations of the position data distribution unit  12 , a ROM  202  for storing basic input/output programs and the position data Xa therein, a communication circuit  204  and an antenna for distributing the position data Xa, the I/F  208  for transmitting/receiving signals with respect to the control unit  11 , and a bus line (e.g., address bus, data bus)  209  for electrically connecting the units and elements included in the position data distribution unit  12 . 
     The communication circuit  204  distributes the position data Xa by way of the antenna  204   a  by using IMES technology. As described above, IMES, which is also referred to as indoor GPS, is a technology used for indoor positioning. The range in which the position data X can reach (distribution range of position data X) is virtually illustrated with broken lines in  FIG. 1 . In a case where the height of the ceiling β of the indoor area a is approximately 3 meters, a transmission output is set to the IMES in the embodiment of  FIG. 1 , so that the radius of a virtual circle (illustrated with broken lines on the floor of the indoor area α) of the distribution range of the position data X is approximately 5 meters. However, by changing the settings of the transmission output of the IMES, the radius of the distribution range of the position data X can be set to be less than or greater than 5 meters. 
     The position data Xa indicates a position in which the LED type fluorescent lighting apparatus (electric device)  2   a  is placed. As illustrated in  FIG. 6 , the position data Xa includes items such as floor number, latitude, longitude, and building number.  FIG. 6  is a schematic diagram illustrating the position data Xa distributed by the distribution apparatus  3   a.    
     The item “floor number” indicates the floor of the building in which the electric device  2   a  is placed. The item “latitude” indicates the latitude of the position in which the electric device  2   a  is placed. The item “longitude” indicates the longitude of the position in which the electric device  2   a  is placed. The item “building number” indicates the number of the building in which the electric device  2   a  is placed. In the example illustrated in  FIG. 6 , the electric device  2   a  indicates that the electric device is placed at a position having a north latitude of 35.459555 degrees and a east longitude of 139.387110 degrees on the 16 th  floor of building C. Alternatively, latitude may be indicated by south latitude and longitude may be indicated by west longitude. 
     Returning to  FIG. 5 , the wireless communication unit  13  includes a CPU  301  for controlling overall operations of the wireless communication unit  13 , a ROM  302  for storing basic input/output programs and the apparatus identification data Ba therein, a RAM  303  used as a work area of the CPU  301 , a communication circuit  304  and an antenna  304   a  for receiving the position data Xa and the terminal identification data Aa and transmitting the received data to the gateway  17 , an interface (I/F)  308  for transmitting/receiving signals with respect to the control unit  11 , and a bus line (e.g., address bus, data bus)  309  for electrically connecting the units and elements included in the wireless communication unit  13 . 
     The wireless communication unit  13  transmits/receives data by using a 920 MHz band. Because the 920 MHz band has high radio wave reachability, data can be transmitted from the distribution apparatus  3   a  to the gateway  7  even in a case where there is a column or wall of a building between the distribution apparatus  3   a  and the gateway  7 . 
     The communication circuit  304  transmits/receives data by using at least the physical layer of an architecture model described in the IEEE802.15 standard. The communication circuit  304  performs the transmission/reception of data by using the antenna  304   a . In this case where the physical layer of an architecture model described in the IEEE802.15 standard is used, a MAC address of the distribution apparatus  3  (wireless communication unit  13 ) may be used as the apparatus identification data B for identifying the distribution apparatus  3  (wireless communication unit  13 ). 
     Alternatively, the communication circuit  304  may transmit/receive data by using the physical layer of an architecture model described in the IEEE802.15 standard and a MAC layer of ZigBee (registered trademark). In this case where the physical layer the physical layer of an architecture model described in the IEEE802.15 standard and a MAC layer of ZigBee (registered trademark) are used, the distribution apparatus  3  transmits/receives data by using the 800 MHz band, the 900 MHz band, or the 2.4 GHz band in accordance to the region in which the band is used (e.g., Japan, U.S.A., Europe) with respect to the gateway  7  via another adjacent or neighboring distribution apparatus  3  (multi-hop communication). By using the multi-hop communication in which data is transmitted by way of other distribution apparatuses  3 , it may take some time for the wireless communication unit  13  of each distribution apparatus  3  to perform a routing process. However, by using the multi-hop communication, the wireless communication unit  13  of each distribution apparatus  3  can perform communication with electric power that is enough to reach the nearest distribution data. Therefore, the multi-hop communication has an advantage of operating with a small amount of power. 
     The position data Xa may be stored in the below-described storage unit  29  of the distribution apparatus  3   a  before the distribution apparatus  3   a  is shipped from a factory of the manufacturer of the distribution apparatus  3   a . Alternatively, the position data Xa may be stored in the storage unit  29  after the distribution apparatus  3   a  is shipped from the factory. For example, in a case of mounting the electric device  2   a  to the ceiling β, the position data Xa may be stored in the storage unit  29  by the person mounting the electric device  2   a  to the ceiling β. Alternatively, the position data Xa transmitted from an external device (e.g., position data management system  9 ) by wireless communication via the gateway  7  and receives by the communication circuit  304  of the wireless communication unit  13 . Thereby, the position data Xa can be stored in the ROM  202  of the position data distribution unit  12  by the control unit  11 . 
     Next, a hardware configuration of the communication terminal  5  is described with reference to  FIG. 7 .  FIG. 7  is a schematic diagram illustrating the hardware configuration of the communication terminal  5  according to an embodiment of the present invention. 
     As illustrated in  FIG. 7 , the communication terminal  5  includes a control unit  14  and a wireless communication unit  15 . 
     The control unit  14  includes a CPU  401  for controlling overall operations of the control unit  14 , a ROM  402  for storing basic input/output programs therein, a RAM  403  used as a work area of the CPU  401 , a communication circuit  404  and an antenna  404   a  for receiving the position data Xa, an acceleration sensor  405  for detecting acceleration of the communication terminal  5 , an interface (I/F)  408  for transmitting/receiving signals with respect to the wireless communication unit  15 , and a bus line (e.g., address bus, data bus)  409  for electrically connecting the units and elements included in the control unit  14 . The control unit  14  also includes a button battery  406  for driving the communication terminal  5 . Not only can the communication terminal  5  be driven by the button battery, but may be driven by a common battery (e.g., double A battery, triple A battery) or a battery dedicated to the communication terminal  5 . 
     The communication circuit  404  receives the position data X being distributed by using IMES. The communication circuit  404  receives the distributed position data X with the antenna  404   a . The control unit  14  supplies the electric power of the button battery  406  to the wireless communication unit  15  via a connector  409   a . The control unit  14  transmits/receives data (signals) with respect to the wireless communication unit  15  by way of the I/F  408  and the connector  409   b.    
     The acceleration sensor  405  detects changes of the acceleration of the communication terminal  5 . Changes of the acceleration of the communication terminal  5  may be detected, for example, when the communication terminal  5  starts moving, when the moving of the communication terminal  5  stops, or when the communication terminal  5  is tilted (inclined). In a case where change of acceleration is detected when the CPU  401  is not operating (stopped), the acceleration sensor  405  transmits a signal to the CPU  401  for causing the CPU  401  to start operation. Thereby, the CPU  401  begins to operate and also transmits a signal to the communication circuit  404  for causing the communication circuit  404  to start operation. Thereby, in a case where the position data X is being distributed by the distribution apparatus  3 , the communication circuit  404  of the communication terminal  5  can start receiving the position data X via the antenna  404   a.    
     On the other hand, the wireless communication unit  15  basically has the same configuration as the above-described configuration of the wireless communication unit  13 . Thus, the wireless communication unit  15  can transmit/receive data with respect to the wireless communication unit  13  of the distribution apparatus  3  by using the same band used by the wireless communication unit  13 . As illustrated in  FIG. 7 , the wireless communication unit  15  includes a CPU  501  for controlling overall operations of the wireless communication unit  15 , a ROM  502  for storing basic input/output programs and the terminal identification data A therein, a RAM  503  used as a work area of the CPU  501 , a communication circuit  504  and an antenna  504   a  for transmitting the position data X or the terminal identification data A, an interface (I/F)  508  for transmitting/receiving signals with respect to the control unit  14 , and a bus line (e.g., address bus, data bus)  509  for electrically connecting the units and elements included in the wireless communication unit  15 . Alternatively, the wireless communication unit  15  may also use ZigBee (registered trademark). 
     The communication circuit  504  obtains the position data X stored in the RAM  403  of the control unit  14  by way of the connector  409   b  according to an instruction(s) from the CPU  501 . Further, the communication circuit  504  reads out the terminal identification data A stored in the ROM  502  and transmits the terminal identification data A together with the obtained position data X to the distribution apparatus  3  via the antenna  504   a.    
     The configuration of the position data X transmitted by the communication circuit  504  may have a format as illustrated in  FIG. 8 .  FIG. 8  is a schematic diagram illustrating an example of a format of the position data X according to an embodiment of the present invention. In the example illustrated in  FIG. 8 , the fields “floor number”, “latitude”, “longitude”, and “building number” are represented with 9 bits, 21 bits, 21 bits, and 8 bits, respectively. The format of each of the fields complies with the IMES standard. The actual format of the position data X is also added with a header defined according to the communication system, and checksum data. As illustrated in  FIG. 9 , the data structure of the data to be transmitted by the communication circuit  504  may include “transmission destination”, “transmission source”, and “data content (e.g., position data X).  FIG. 9  is a schematic diagram illustrating a data structure of data including position data X according to an embodiment of the present invention. 
     Next, a hardware configuration of the management object  4   h  is described with reference to  FIG. 10 . In this embodiment, the management object  4   h  (communication terminal  5   h ) is a mobile phone. 
     As illustrated in  FIG. 10 , the management object  4   h  (communication terminal  5   h ) includes a CPU  601  for controlling overall operations of the communication terminal  5   h , a ROM  602  for storing basic input/output programs therein, a RAM  603  used as a work area of the CPU  601 , a EEEPROM (Electrically Erasable and Programmable ROM)  604  for reading/writing data according to the controls of the CPU  601 , a CMOS (Complementary Metal Oxide Semiconductor) sensor  605  for imaging (capturing) an object and obtaining image data of the object according to the controls of the CPU  601 , one or a variety of acceleration/bearing sensors (e.g., electromagnetic compass for detecting earth magnetism, a gyrocompass, an acceleration sensor)  606 , and a media drive  608  for controlling reading/writing (recording) of data with respect to a recording medium or media (e.g., flash memory)  607 . The recording medium  607  is configured to detach/attach with the management object  4   h  (communication terminal  5   h ) for having recorded data read therefrom or new data recorded (written) thereto in accordance with the controls of the media drive  608 . 
     An operating system (OS), various program, and various data that are executed by the CPU  601  are stored in the EEPROM  604 . The CMOS sensor  605  is a charged coupled device (CCD) that captures light of an image of an object and converts the image into electron charges. As long as an image can be captured, the CMOS sensor  605  may be a sensor other than the CCD sensor. 
     The management object  4   h  (communication terminal  5   h ) may also include an audio input unit  11  for converting audio into audio signals, an audio output unit  612  for converting audio signals into audio, an antenna  613   a , a communication unit  613  for performing communications (transmission/reception) with a nearest base station  8   a  by using wireless communication signals via the antenna  613   a , a GPS reception unit  614  for receiving GPS signals from the GPS satellite  999 , a display (e.g., liquid crystal display, organic electroluminescence (EL) display)  615  for displaying, for example, an image of an object or various icons, a touch panel  616  including a pressure-sensitive type or an electrostatic type display panel for detecting a position in the display panel touched with a finger or a stylus, and a bus line (e.g., address bus, data bus)  610  for electrically connecting the units and elements included in the management object  4   h  (communication terminal  5   h ). Further, a battery dedicated for the management object  4   h  (communication terminal  5   h ) is provided in the management object  4   h  (communication terminal  5   h ) for driving the management object  4   h  (communication terminal  5   h ). The audio input unit  611  includes a microphone for inputting audio. The audio output unit  612  includes a speaker for outputting audio. 
     The GPS reception unit  614  of the management object  4   h  (communication terminal  5   h ) has substantially the same configuration as a GPS reception unit of a typical mobile phone. However, the firmware of the program stored in the ROM  602  may be slightly adjusted (modified) for achieving seamless data reception from the distribution apparatus  3  of the indoor area α and the GPS satellite  999  of the outdoor area γ. The acceleration/bearing sensor  606  serves to provide the processes of the acceleration sensor  605  of  FIG. 7 . 
     Because the hardware configuration of the management object  4   g  (communication terminal  5   g ), which is a personal computer, has substantially the same configuration as the hardware configuration of the position data management system  9  of  FIG. 9 , further explanation of the hardware configuration of the management object  4   g  (communication terminal  5   g ) is omitted. However, in a case where the management object  4   g  (communication terminal  5   g ) is a personal computer, an external device I/F (e.g., USB (Universal Serial Bus) (similar to the external device I/F) is connected to a GPS antenna. However, in a case of a personal computer equipped with a GPS antenna, there is no need for connecting the external device I/F to the GPS antenna. 
     Next, a hardware configuration of the gateway  7  according to an embodiment of the present invention is described with reference to  FIG. 11 .  FIG. 11  is a schematic diagram illustrating the hardware configuration of the gateway  7  according to an embodiment of the present invention. 
     As illustrated in  FIG. 11 , the gateway  7  includes a wireless communication unit  17  and a wired communication unit  18 . As described below, regardless of whether position data X distributed from the same distribution apparatus  3  is received numerous times within a predetermined period, the received position data is handled as a single position data X. 
     The wireless communication unit  17  basically has the same configuration as the above-described configuration of the wireless communication unit  13 . Thus, the wireless communication unit  17  can transmit/receive data with respect to the wireless communication unit  13  of the distribution apparatus  3  by using the same band used by the wireless communication unit  13 . As illustrated in  FIG. 11 , the wireless communication unit  17  includes a CPU  701  for controlling overall operations of the wireless communication unit  17 , a ROM  702  for storing basic input/output programs and the apparatus identification data C therein, a RAM  703  used as a work area of the CPU  701 , a communication circuit  704  and an antenna  704   a  for transmitting data such as the position data X, an interface (I/F)  708  for transmitting/receiving signals with respect to the wired communication unit  18 , and a bus line (e.g., address bus, data bus)  709  for electrically connecting the units and elements included in the wireless communication unit  17 . 
     Alternatively, the wireless communication unit  17  may also use ZigBee (registered trademark). The apparatus identification data C is data that is unique to the gateway  7  (communication unit  17 ) for identifying the gateway  7  (communication unit  17 ). The apparatus identification data C may be, for example, a MAC address. 
     On the other hand, as illustrated in  FIG. 11 , the wired communication unit  18  includes a CPU  801  for controlling overall operations of the wired communication unit  18 , a ROM  802  for storing basic input/output programs and the apparatus identification data D therein, a RAM  803  used as a work area of the CPU  801 , an Ethernet controller  805 , an interface (I/F)  808   a  for transmitting/receiving signals with respect to the wireless communication unit  17 , an interface (I/F) for transmitting/receiving signals with respect to the LAN  8   e  via a cable  809 , and a bus line (e.g., address bus, data bus)  809  for electrically connecting the units and elements included in the wired communication unit  18 . 
     The CPU  801  and the Ethernet controller  805  perform controls for converting a communication method (communication protocol) conforming to IEEE802.15.4 to a communication method (communication protocol) conforming to IEEE802.3 and performing Ethernet packet communications to transmit/receive various data distributed from the distribution apparatus  3 . 
     The apparatus identification data D is data that is unique to the gateway  7  (communication unit  18 ) for identifying the gateway  7  (communication unit  18 ). The apparatus identification data D may be, for example, an IP (Internet Protocol) address. Although a MAC address is stored in the ROM  802 , description of the MAC address is omitted for simplifying the description of the communication with respect to the position data management system  9 . 
     Next, a hardware configuration of the position data management system  9  according to an embodiment of the present invention is described with reference to  FIG. 12 .  FIG. 12  is a schematic diagram illustrating the hardware configuration of the position data management system  9  according to an embodiment of the present invention. 
     The position data management system  9  is constituted by a computer. For example, the position data management system  9  includes a CPU  901  for controlling overall operations of the position data management system  9 , a ROM  902  for storing a program (e.g., IPL (Initial Program Loader)) used for driving the CPU  901  therein, a RAM  903  used as a work area of the CPU  901 , a HD (Hard Disk)  904  for storing various data such as programs for the position data management system  9  or system identification data E therein, a HDD (Hard Disk Drive) for controlling reading/writing (recording) data with respect to the HD  904  according to the controls of the CPU  901 , a media drive  907  for controlling reading/writing (recording) of data with respect to a recording medium or media (e.g., flash memory)  906 , a display  908  for displaying various data (e.g., cursors, menus, windows, characters, images), a network interface (I/F)  909  for performing data communications (transmission/reception) by way of a communication network  8 , a keyboard  911  including multiple keys for inputting various data such as characters, numerals, and instructions, a mouse  912  for performing, for example, selection and execution of various instructions, selection of a process object, and moving of a cursor, a CD-ROM (Compact Disc Read Only Memory) driver  914  for controlling reading/writing (recording) of data with respect to a detachable recording medium (e.g., CD-ROM), a communication circuit  915  and an antenna  915   a  for performing wireless communication, an external device I/F  916  for connecting to an external device, and a bus line (e.g., address bus, data bus)  910  for electrically connecting the units and elements included in the position data management system  9 . 
     The system identification data E is data that is unique to the position data management system  9  for identifying the position data management system  9 . The system identification data E may be, for example, an IP address. Although a MAC address is stored in the ROM  902 , description of the MAC address is omitted for simplifying the description of the communication with respect to the gateway  7 . 
     Management data F (see  FIG. 13 ) and layout data G are stored in the HD  904 .  FIG. 13  is a schematic diagram illustrating an example of the management data F managed by the position data management system  9  according to an embodiment of the present invention. As described below, the layout data includes data pertaining to, for example, a particular floor as illustrated in  FIG. 25 . 
     As illustrated in  FIG. 13 , the management data F has terminal identification data A, device name data, owner name data (administrator name data), position data X, and reception time/date data that are associated to each other. 
     As described above, the terminal identification data A is for identifying the communication terminal  5 . The device name data is data indicating the name of the management object  4  or the name of the communication terminal  5 . The owner name data (administrator name data) is data indicating the name of the owner or the administrator of the communication terminal  5 . The position data X is the above-described data illustrated in  FIG. 6 . The reception time/date data is data indicating the time and date in which data such as position data X from the gateway  7  is received by the position data management system  9 . 
     The terminal identification data A, the device name data, and the owner name data (administrator name data) are associated to each other beforehand and managed by the position data management system  9 . In a case where the position data management system  9  receives the position data X and the terminal identification data A from the gateway  7 , the position data management system  9  adds the received position data X and the terminal identification data A to a record portion of the management data F that includes the same terminal identification data A as the received terminal identification data A. 
     Further, in a case of newly receiving position data X and the terminal identification data A from the gateway  7  in a state where a corresponding position data X and its reception time/date data are already being managed by the position data management system  9 , the position data management system  9  overwrites the managed position data and the reception time/date data with the newly received position data and its new reception time/date data. 
     Alternatively, in a case of newly receiving position data X and the terminal identification data A from the gateway  7  in a state where a corresponding position data X and its reception time/date data are already being managed by the position data management system  9 , the position data management system  9  may generate a new record and record (write) the newly received position data and its new reception time/date data instead of overwriting the managed position data and reception time/date data. 
     Next, a function configuration of the position management system  1  according to an embodiment of the present invention is described with reference to  FIGS. 14-16 . Along with describing the functional configuration with reference to  FIGS. 14-16 , a relationship between the function configuration and the hardware configurations illustrated in  FIGS. 10-12  are described. 
       FIG. 14  is a block diagram illustrating functions (function components) of the distribution apparatus  3  and the communication terminal  5  according to an embodiment of the present invention. As illustrated in  FIG. 14 , the distribution apparatus  3  includes functions or function components such as a transformation unit  10 , a distribution control unit  20 , and a wireless communication control unit  30 . The transformation unit  10  is a function component (function) that is implemented by operating the voltage transformer  100  illustrated in  FIG. 5 . 
     The distribution control unit  20  is a function component (function) that is implemented by operating the control unit  11  and the position data distribution unit  12  illustrated in  FIG. 5 . The wireless communication control unit  30  is a function component (function) that is implemented by operating the control unit  11  and the wireless communication unit  13  illustrated in  FIG. 5 . 
     The distribution control unit  20  includes a storage unit  29  constituted by the ROM  202  illustrated in  FIG. 5 . The storage unit  29  stores the position data X therein. The distribution control unit  20  includes a distribution unit  21 , a communication unit  27 , and a storage/readout unit  28 . 
     The distribution unit  21  distributes the position data X within a distributable range. The distribution unit  21  is a function component (function) that is implemented mainly by the processes of the CPU  201  and the communication circuit  204  illustrated in  FIG. 5 . 
     The communication unit  27  performs data (signal) communication (i.e. transmits/receives data (signals)) with respect to the wireless communication control unit  30 . The communication unit  27  is a function component (function) that is implemented mainly by the processes of the CPUs  101 ,  201 , the interfaces  108   a ,  208 , and the buses  109 ,  209 . 
     The storage/readout unit  28  stores various data (e.g., position data X) and reads out the stored data. The storage/readout unit  28  is a function component (function) that is implemented mainly by the processes of the CPUs ( 101 ,  201 ). 
     The wireless communication control unit  30  includes a storage unit  39  that is constituted by the RAM  303  illustrated in  FIG. 5 . The storage unit  39  stores the apparatus identification data B therein. 
     A transmission/reception unit  31  transmits/receives various data with respect to the communication unit  5  or the gateway  7  by way of wireless communication. The transmission/reception unit  31  is a function component (function) that is implemented mainly by the processes of the CPU  301  and the communication circuit  304  illustrated in  FIG. 5 . 
     A communication unit  37  performs data (signal) communication with respect to the distribution control unit  20 . The communication unit  37  is a function component (function) that is implemented mainly by the processes of the CPUs  101 ,  301 , the interfaces  108 B,  308 , and the buses  109 ,  309 . 
     A storage/readout unit  38  stores various data in the storage unit  29  and reads out the stored data. 
     Next, a function configuration of the communication terminal  5  according to an embodiment of the present invention is described. 
     The communication terminal  5  includes functions or function components such as a reception control unit  40  and a wireless communication control unit  30 . 
     The reception control unit  40  includes a storage unit  49  which is constituted by the RAM  403  illustrated in  FIG. 7 . The storage unit  49  can store the position data X distributed from the distribution apparatus  3  therein. The reception control unit  40  includes a reception unit  41 , a detection unit  42 , a determination unit  43 , a measurement unit  44 , a communication unit  47 , and a storage/readout unit  48 . 
     The reception unit  41  receives the position data X distributed from the distribution apparatus  3 . Further, the reception unit  41  switches between a state capable of receiving the position data X and a state unable to receive the position data X. The reception unit  41  is a function component (function) that is implemented mainly by the processes of the CPU  401  and the communication circuit  404  illustrated in  FIG. 7 . 
     The detection unit  42  detects the movement (including tilt) of the communication terminal  5  and causes the reception unit  41  to start operation (e.g., data reception). The detection unit  42  is a function component (function) that is implemented mainly by the processes of the CPU  401  and the acceleration sensor  405 . Instead of the acceleration sensor  405 , the function of the detection unit  42  may be implemented with a motion sensor using, for example, inertial force or magnetic force. 
     The determination unit  43  determines whether at least a single position data X has been received by the reception unit  41 . Further, the determination unit  43  determines whether the position data X corresponding to each one of multiple distribution apparatuses  3  has been received by the reception unit  41 . The determination unit  43  is a function component (function) that is implemented mainly by the processes of the CPU  401  illustrated in  FIG. 7 . In a case where the position data X is received from the same distribution apparatus  3  for a multiple number of times within the below-described predetermined time, the multiply received distribution data X are handled as a single distribution data. 
     In a case where the determination unit  43  determines that position data X corresponding to each of the multiple distribution apparatuses  3  have been received, the measurement unit  44  measures the signal strength of each of the position data X received from the multiple distribution apparatuses  3 . The measurement unit  44  is a function component (function) that is implemented mainly by the CPU  401  illustrated in  FIG. 7 . 
     The communication unit  47  performs data (signal) communication with respect to the wireless communication unit  50 . The communication unit  47  is a function component (function) that is implemented mainly by the processes of the CPU  401 , the I/F  408 , and the bus  409  illustrated in  FIG. 7 . 
     The storage/readout unit  48  stores various data (e.g., position data X) in the storage unit  49  and reads out the stored data from the storage unit  49 . The storage/readout unit  48  is a functional component (function) that is implemented by the CPU  401 . 
     The wireless communication unit  50  includes a storage unit  59  which is constituted by the RAM  503  illustrated in  FIG. 5 . The storage unit  59  stores the position data A therein. The wireless communication unit  50  also includes a transmission/reception unit  51 , a determination unit  53 , a measurement unit  54 , a communication unit  57 , and a storage/readout unit  58 . 
     The transmission/reception unit  51  transmits/receives various data with respect to the distribution apparatus  3  by way of wireless communication. The transmission/reception unit  51  is a function component (function) implemented mainly by the CPU  501  and the communication circuit  504  illustrated in  FIG. 7 . 
     The determination unit  53  determines whether at least a single apparatus identification data B has been received by the reception unit  51 . Further, the determination unit  53  determines whether the apparatus identification data B corresponding to each one of multiple distribution apparatuses  3  has been received by the reception unit  51 . The determination unit is a function component (function) that is implemented mainly by the processes of the CPU  501  illustrated in  FIG. 7 . In a case where the apparatus identification data B is received from the same distribution apparatus  3  for a multiple number of times within the below-described predetermined time, the multiply received apparatus identification data B are handled as a single apparatus identification data. 
     In a case where the determination unit  53  determines that apparatus identification data B corresponding to each of the multiple distribution apparatuses  3  have been received, the measurement unit  54  measures the signal strength of each of the apparatus identification data B received from the multiple distribution apparatuses  3 . The measurement unit  54  is a function component (function) that is implemented mainly by the CPU  501  illustrated in  FIG. 7 . 
     The communication unit  57  performs data (signal) communication with respect to the reception control unit  40 . The communication unit  57  is a function component (function) that is implemented mainly by the processes of the CPU  501 , the I/F  508 , and the bus  509  illustrated in  FIG. 7 . 
     The storage/readout unit  58  stores various data (e.g., apparatus identification data A, B) in the storage unit  59  and reads out the stored data from the storage unit  59 . The storage/readout unit  58  is a function component (function) that is implemented by the CPU  501 . 
     Next, a function configuration of a management object ( 4   g ,  4   h ) is described with reference to  FIG. 15 .  FIG. 15  is a block diagram illustrating functions (function components) of the management object  4  in a case where the management object is a personal computer  4   g  or a mobile phone  4   h.    
     As illustrated in  FIG. 15 , the management object ( 4   g ,  4   h ) includes a storage unit  69  that is constituted by the EEEPROM  604  illustrated in  FIG. 10  or the RAM  903  and the HD  904  illustrated in  FIG. 12 . The management object ( 4   g ,  4   h ) also includes a reception unit  61 , a detection unit  62 , a determination unit  63 , a measurement unit  64 , a determination unit  66 , a measurement unit  67 , and a storage/readout unit  68 . 
     The reception unit  61  has the same function as the reception unit  41 . The reception unit  61  is a function component (function) that is implemented mainly by the processes of the CPU  601  and the GPS unit  614  illustrated in  FIG. 10  or the processes of the CPU  901  and the GPS antenna connected to the external device I/F unit  916  illustrated in  FIG. 12 . 
     The detection unit  62  has the same function as the detection unit  42 . The detection unit  62  is a function component (function) that is implemented mainly by the processes of the CPU  601  and the acceleration/bearing sensor  606  illustrated in  FIG. 10  or the processes of the CPU  901  and the acceleration sensor connected to the external device I/F  916  illustrated in  FIG. 12 . 
     The determination unit  63  has the same function as the determination unit  43 . The determination unit  63  is a function component (function) that is implemented mainly by the processes of the CPU  601  illustrated in  FIG. 10  or the processes of the CPU  901  illustrated in  FIG. 12 . 
     The measurement unit  64  has the same function as the measurement unit  44 . The measurement unit  64  is a function component (function) that is implemented mainly by the CPU  601  illustrated in  FIG. 10  or the processes of the CPU  901  illustrated in  FIG. 12 . 
     The transmission/reception unit  65  has the same function as the transmission/reception unit  51 . The transmission/reception unit  65  is a function component (function) that is implemented mainly by the processes of the CPU  601  and the communication unit  613  illustrated in  FIG. 10  or the processes of the CPU  901  and the communication unit  915  illustrated in  FIG. 12 . 
     The determination unit  66  has the same function as the determination unit  53 . The determination unit  66  is a function component (function) that is implemented mainly by the processes of the CPU  601  illustrated in  FIG. 10  or the processes of the CPU  901  illustrated in  FIG. 12 . 
     The measurement unit  67  has the same function as the measurement unit  54 . The measurement unit  67  is a function component (function) that is implemented mainly by the CPU  601  illustrated in  FIG. 10  or the processes of the CPU  901  illustrated in  FIG. 12 . 
     The storage/readout unit  68  has the same function as the storage/readout unit  48  or the storage/readout unit  58 . The storage/readout unit  68  is a function component (function) that is implemented mainly by the CPU  601  illustrated in  FIG. 10  or the processes of the CPU  901  illustrated in  FIG. 12 . 
     Next, a function configuration of the gateway  7  according to an embodiment of the present invention is described with reference to  FIG. 16 .  FIG. 16  is a block diagram illustrating functions (function components) of the gateway  7  and the position data management system  9  according to an embodiment of the present invention. 
     The gateway  7  includes functions or function components such as a wireless communication control unit  70  and a wired communication control unit  80 . 
     The wireless communication control unit  70  basically has the same function as the wireless communication control unit  30  of the distribution apparatus  3 . The wireless communication control unit  70  is a function component (function) that is implemented by the processes of the wireless communication unit  17  illustrated in  FIG. 11 . 
     The wireless communication control unit  70  includes a storage unit  79  that is constituted by the RAM  703  illustrated in  FIG. 11 . The storage unit  79  has the apparatus identification data C stored therein. The wireless communication control unit  70  also includes a transmission/reception unit  71 , a communication unit  77 , and a storage/readout unit  78 . 
     The transmission/reception unit  71  transmits/receives various data with respect to the distribution apparatus  3  by way of wireless communication. The transmission/reception unit  71  is a function component (function) that is implemented mainly by the processes of the CPU  701  and the communication circuit  704  illustrated in  FIG. 11 . 
     The communication unit  77  performs data (signal) communication with respect to the wired communication control unit  80 . The communication unit  77  is a function component (function) that is implemented mainly by the CPU  701 , the I/F  708 , and the bus  709 . 
     The storage/readout unit  78  stores various data in the storage unit  79  and reads out the stored data from the storage unit  79 . The storage/readout unit  78  is a function component (function) that is implemented mainly by the CPU  801 . 
     The wired communication control unit  80  includes a storage unit  89  constituted by the RAM  803  illustrated in  FIG. 11 . The storage unit  89  has the apparatus identification data D stored therein. The wired communication control unit  80  also includes a transmission/reception unit  81 , a conversion unit  82 , a communication unit  87 , and a storage/readout unit  88 . The wired communication control unit  80  is a function component (function) implemented by the wired communication unit  18  illustrated in  FIG. 11 . 
     The transmission/reception unit  81  transmits/receives data with respect to the position data management system  9  by way of wired communication. The transmission/reception unit  81  is a functional component (function) that is implemented mainly by the processes of the CPU  801  and the I/F  808   b  illustrated in  FIG. 11 . 
     The conversion unit  82  performs controls for converting communication methods, so that Ethernet packet communication can be performed with the various data transmitted from the distribution apparatus  3 . The conversion unit  82  is a function component (function) that is implemented mainly by the CPU  801  and the Ethernet controller  805  illustrated in  FIG. 11 . 
     The communication unit  87  performs data (signal) communication with respect to the wireless communication control unit  70 . The communication unit  87  is a function component (function) implemented mainly by the processes of the CPU  801 , the I/F  808   a , and the bus  809 . 
     The storage/readout unit  98  stores various data in the storage unit  89  and reads out the stored data from the storage unit  89 . The storage/readout unit  98  is a function component (function) that is implemented mainly by the processes of the CPU  801 . 
     Next, a function configuration of the position data management system  9  according to an embodiment of the present invention is described with reference to  FIG. 16 . 
     The position data management system  9  includes a storage unit  99  that is constituted by the RAM  903  and the HD  904  illustrated in  FIG. 12 . The storage unit  99  has the system identification data E, the management data F, and the layout data G stored therein. The position data management system  9  also includes a transmission/reception unit  91 , an operation input reception unit  92 , a search unit  93 , a display control unit  94 , and a storage/readout unit  98 . 
     The transmission/reception unit  91  transmits/receives various data with respect to the gateway  7  by way of wired communication or wireless communication. Further, the transmission/reception unit  91  transmits/receives various data with respect to the communication terminal  5   h  in the outdoor area γ via the communication network  8 . The transmission/reception unit  91  is a function component (function) that is implemented mainly by the processes of the CPU  901  and the network I/F or the communication circuit  915  illustrated in  FIG. 12 . 
     The operation input reception unit  92  receives various inputs or selections from the administrator of the position data management system  9 . The operation input reception unit  92  is a function component (function) that is implemented mainly by the processes of the CPU  901  and the keyboard  911 , and the mouse  912 . 
     The search unit  93  searches the management data F of the storage unit  99  by way of the storage/readout unit  98  based on search conditions input to the operation input reception unit  92 . The search unit  93  is a function component (function) that is implemented mainly by the processes of the CPU  901 . 
     The display control unit  94  performs controls for displaying various data (e.g., images, characters) on the display  908 . The display control unit  94  is a function component (function) that is implemented mainly by the processes of the CPU  901 . 
     The storage/readout unit  98  stores various data in the storage unit  99  and reads out stored data from the storage unit  99 . The storage/readout unit  98  is a function component (function) that is implemented mainly by the processes of the CPU  901 . 
     Next, operations according to an embodiment of the present invention are described with reference to  FIGS. 17 and 25 . 
     First, an operation of establishing (building) a communication network in the ceiling β of the indoor area α is described with reference to  FIG. 17 .  FIG. 17  is a sequence diagram illustrating an operation of establishing a communication network in a ceiling. 
     First, when a user switches on the power of each electric device  2  in the indoor area α, the storage/readout unit  38  (see  FIG. 14 ) of the wireless communication control unit  30  in each distribution apparatus  3  reads out apparatus identification data B from the storage unit  39  (Step S 1 ). Then, the transmission/reception unit  31  transmits a participation request including the apparatus identification data B of the distribution apparatus  3  itself to the gateway  7  (Step S 2 ). Thereby, the transmission/reception unit  71  of the wireless communication control unit  70  of the gateway  7  receives the participation request. 
     Then, the storage/readout unit  78  of the wireless communication control unit  70  reads out the apparatus identification data C from the storage unit (Step S 3 ). Then, the transmission/reception unit  71  transmits a participation response including the apparatus identification data B, C (Step S 4 ) to the distribution apparatus  3 . Thereby, the transmission/reception unit  31  of the wireless communication control unit  30  of the distribution apparatus  3  receives the participation response. Because the participation response includes the apparatus identification data B transmitted in Step S 2 , the wireless communication unit  30  performs the process of receiving the participation response of Step S 4  in association with the process of transmitting the participation request of Step S 2 . Then, the storage/readout unit  38  stores the apparatus identification data C in the storage unit (Step S 5 ). Accordingly, by storing the apparatus identification data C of the gateway  7  at the side of the distribution apparatus  3 , a communication network between the distribution apparatus  3  and the gateway  7  can be established. 
     Next, an operation of distributing position data X from the ceiling β in the direction of the floor of the indoor area α (as illustrated in  FIG. 1 ) is described with reference to  FIG. 18 .  FIG. 18  is a sequence diagram illustrating an operation of distributing position data X according to an embodiment of the present invention. For the sake of convenience,  FIG. 18  illustrates an example where a distribution system  6  is constituted by two distribution apparatuses  3   a ,  3   b . In the example of  FIG. 18 , the distribution apparatus  3   a  distributes position data Xa and the distribution apparatus  3   b  distributes position data Xb. In the example of  FIG. 18 , the communication terminal  5  is positioned within a range (distributable range) in which position data Xa, Xb are distributable from the distribution apparatuses  3   a ,  3   b , respectively. 
     First, the storage/readout unit  28  of the distribution control unit  20  of the distribution apparatus  3   a  reads out position data Xa of the distribution apparatus  3   a  itself from the storage unit  29  (Step S 23 - 1 ). Then, the distribution unit  21  of the distribution control unit  20  of the distribution apparatus  3   a  distributes the position data Xa within the distributable range (Step S 24 - 1 ). Likewise, the storage/readout unit  28  of the distribution control unit  20  of the distribution apparatus  3   b  reads out position data Xb of the distribution apparatus  3   b  itself from the storage unit  29  (Step S 23 - 2 ). Then, the distribution unit  21  of the distribution control unit  20  of the distribution apparatus  3   b  distributes the position data Xb within the distributable range (Step S 24 - 2 ). It is, however, to be noted that the communication terminal  5  is unable to receive the position data Xa, Xb if operation of the reception part  41  of the communication terminal  5  is not started. 
     Next, an operation of determining the position data X to be used by the communication terminal  5  and determining the transmission destination of the position data X is described with reference to  FIG. 19 .  FIG. 19  is a sequence diagram illustrating an operation of determining the position data X to be used by the communication terminal  5  and determining the transmission destination of the position data X.  FIG. 19  illustrates an example of receiving the position data X transmitted from the distribution apparatus Xa with the communication terminal but transmitting the position data Xa to the distribution apparatus Xb rather than the transmission source of the position data Xa (i.e. rather than the distribution apparatus Xa). 
     First, as illustrated in  FIG. 19 , the storage/readout unit  48  of the reception control unit  40  of the communication terminal  5  stores one of the position data Xa, Xb distributed by the distribution apparatus  3   a ,  3   b  in the storage unit  49  (Step S 41 ). Among the position data Xa, Xb distributed by the distribution apparatus  3   a ,  3   b , the position data that is to be stored in the storage unit  49  is the position data having the highest signal strength among the position data Xa, Xb when received by the communication terminal  5 . Accordingly, the position indicated by the position data X stored in the storage unit  49  (i.e. one of the position data Xa or Xa in the example of  FIG. 19 ) is to be managed as the position of the communication terminal  5  in a subsequent process by the position data management system  9 . 
     The process performed in Step S 41  is described in further detail with reference to  FIG. 20 .  FIG. 20  is a flowchart illustrating an operation that begins when position data X is received by the communication terminal  5  and ends when the position data X is stored by the communication terminal  5  according to an embodiment of the present invention. 
     First, the detection unit  42  of the reception control unit  40  of the communication terminal  5  starts and continues to detect the starting of movement of the communication terminal  5  (Step S 41 - 1 , No in Step S 41 - 2 ). Then, in a case where the detection unit  42  detects the starting of movement of the communication terminal  5  (Yes in Step S 41 - 2 ), the detection unit  42  starts and continues to detect the stopping of movement of the communication terminal  5  (Step S 41 - 3 , S 41 - 4 ). More specifically, in a case where operation (processing) of the CPU  401  of  FIG. 7  is in a stopped state, the acceleration sensor  405 , upon detecting change of acceleration, transmits a signal indicating the starting of movement of the communication terminal (i.e. signal instructing the CPU  401  to start operating) to the CPU  401 . Thereby, the CPU  401  starts to operate (processing). Then, the CPU  401  maintains a state of operating until receiving a signal from the acceleration sensor  405  indicating that the movement of the communication terminal  5  has stopped. It is to be noted that movement of the communication terminal  5  includes tilting of the communication terminal  5 . 
     Then, in a case where the detection unit  42  detects the stopping of movement of the communication terminal  5  (Yes in Step S 41 - 4 ), the reception unit  41  switches to a state capable of receiving position data distributed from the distribution apparatus  3  (Step S 41 - 5 ). More specifically, in a case where the CPU  407  of  FIG. 7  receives a signal indicating the stopping of movement of the communication terminal  5  from the acceleration sensor  505 , the CPU  407  transmits a signal to the communication circuit  404  instructing the communication circuit  404  to start operating. Thereby, the communication circuit  404  starts to operate. In a case where position data Xa, Xb are received from the distribution apparatus  3   a  and  3   b , the communication circuit  404  of the control unit  14  of the communication terminal  5  starts reception of position data Xa, Xb by way of the antenna  404   a.    
     Then, after the reception unit  41  is switched to the state capable of receiving the position data X, the determination unit  43  determines whether at least a single position data X has been received within a predetermined time (e.g., within 5 seconds) (Step S 41 - 6 ). In the description of the example of  FIG. 20 , it is assumed that position data Xa and Xb have been received within the predetermined time. 
     In a case where the determination unit  43  determines that at least a single position data X has been received within the predetermined time (Yes in Step S 41 - 6 ), the determination unit  43  determines whether multiple position data X have been received (Step S 41 - 7 ). 
     In a case where the determination unit  43  determines that multiple position data X have been received (Yes in Step S 41 - 7 ), the measurement unit  44  measures the signal strength of each of the multiple position data X upon receipt by the reception unit  41  (Step S 41 - 8 ). In the example of  FIG. 20 , it is assumed that the signal strength of the position data Xa is stronger than the signal strength of the position data Xb as a result of the measurement by the measurement unit  44 . 
     Then, the storage/readout unit  48  stores the position data X having the highest signal strength in the storage unit  49  according to the measurement of Step S 41 - 8  (Step S 41 - 9 ). In this example, the position data Xa is stored in the storage unit  49 . 
     In a case where the determination unit  43  determines that not a single position data X has been received within the predetermined time (No in Step S 41 - 6 ), the storage/readout unit  43  stores failure data indicating failure of receiving position data X in the storage unit  49  (Step S 41 - 10 ). 
     Further, in a case where the determination unit  43  determines that multiple position data have not been received within the predetermined time (No in Step S 41 - 7 ), the storage/readout unit  48  stores the single position data X in the storage unit  49  (Step S 41 - 11 ). 
     Then, after the processes in Steps S 41 - 9 , S 41 - 10 , or S 41 - 11 , the reception unit  41  switches to a state of being unable to receive the position data X (Step S 41 - 12 ). More specifically, the CPU  407  of  FIG. 7  transmits a signal to the communication circuit  404  instructing the communication circuit  404  to stop operating. Accordingly, because the reception of the position data X is performed only after the moving of the communication terminal is stopped, the frequency of performing battery change can be reduced even where a small capacity battery such as the button battery  406  is used. This contributes to power saving (energy saving). 
     As described above, the reception unit  41  is switched to a state capable of receiving the position data X after the starting of movement of the communication terminal  5  (Yes in Step S 41 - 2 ) and the stopping of movement of the communication terminal (Yes in Step S 41 - 4 ). In other words, the trigger for switching the reception unit  41  to a state capable of receiving position data is the execution (detection) of both the starting of movement of the communication terminal  5  and the stopping of movement of the communication terminal  5 . Alternatively, the reception unit  41  may be switched to a state capable of receiving the position data X after the starting of movement of the communication terminal  5  (Yes in Step S 41 - 2 ). In other words, the processes of Step S 41 - 3  and S 41 - 4  may be omitted, so that the trigger for switching the reception unit  41  to a state capable of receiving position data is the execution (detection) of the starting of movement of the communication terminal  5 . Alternatively, the processes of Step S 41 - 1  and S 41 - 2  may be omitted, so that the trigger for switching the reception unit  41  to a state capable of receiving position data is the execution (detection) of the stopping of movement of the communication terminal  5 . 
     Then, returning to  FIG. 19 , the communication unit  47  of the reception control unit  40  transmits a command (start command) to the wireless communication control unit  50  instructing to start operating (Step S 42 ). Thereby, when the communication unit  57  of the wireless communication unit  50  receives the start command, the performing of the following processes is started. 
     First, the storage/readout unit  58  of the wireless communication control unit  50  of the communication terminal  5  reads out the terminal identification data A of the communication terminal  5  itself from the storage unit  59  (Step S 43 ). Then, the transmission/reception unit  51  transmits a participation request including the terminal identification data A to the distribution apparatuses  3   a ,  3   b . Each of the distribution apparatuses  3   a ,  3   b  receives the participation request from the communication terminal  5 . 
     Then, the storage/readout unit  38  of the wireless communication unit  30  of the distribution apparatus  3   a  reads out the apparatus identification data Ba of the distribution apparatus  3   a  itself from the storage unit  39  (Step S 45 - 1 ). Then, the transmission/reception unit  31  of the distribution apparatus  3   a  transmits a participation response including the terminal identification data A and the apparatus identification data Ba to the communication terminal  5  (Step S 46 - 1 ). Thereby, the transmission/reception unit  51  of the wireless communication control unit  50  of the communication terminal  5  receives the participation response. Because the terminal identification data A transmitted in Step S 44  is included in the participation response, the communication terminal  5  performs the process of receiving the participation response of Step S 46 - 1  in association with the process of transmitting the participation request of Step S 44 . Then, the storage/readout unit  58  of the wireless communication control unit  50  of the communication terminal  5  stores the apparatus identification data Ba in the storage unit  59  (Step S 47 - 1 ). 
     Similarly, at the side of the distribution apparatus  3   b , the storage/readout unit  38  of the wireless communication control unit  30  of the distribution apparatus  3   b  reads out the apparatus identification data Bb of the distribution apparatus  3   b  itself from the storage unit  39  (Step S 45 - 2 ). Then, the transmission/reception unit  31  of the distribution apparatus  3   b  transmits a participation response including the terminal identification data A and the apparatus identification data Bb to the communication terminal  5  (Step S 46 - 2 ). Thereby, the transmission/reception unit  51  of the wireless communication control unit  50  of the communication terminal  5  receives the participation response. Then, the storage/readout unit  58  of the wireless communication control unit  50  of the communication terminal  5  stores the apparatus identification data Bb in the storage unit  59  (Step S 47 - 2 ). 
     Then, the wireless communication control unit  50  determines the position data X received from the distribution apparatus  3  and the distribution apparatus  3  (transmission destination) to which the terminal identification data A of the communication terminal  5  itself is to be transmitted (Step S 48 ). Next, the process of Step S 48  is described in detail with reference to  FIG. 22 . Before describing the process of Step S 48 , the background of the process of Step S 48  is described with reference to  FIGS. 5 ,  14 , and  21 .  FIG. 21  is a schematic diagram illustrating a state of communication between the distribution apparatus  3  and the communication terminal  5 . 
     As illustrated in  FIG. 14 , the communication between the distribution control unit  20  of the distribution apparatus  3  and the reception control unit  40  of the communication terminal  5  is separate from the communication between the wireless communication control unit  30  of the distribution apparatus  3  and the wireless communication control unit  50  of the communication terminal  5 . Further, the reception control unit  40  receives the position data X from the distribution apparatus  3  that is the distribution source whereas the wireless communication control unit  50  transmits (returns) the position data X together with the terminal identification data A of the communication terminal  5  itself to the distribution apparatus  3 . 
     However, if the distribution control unit  20  and the wireless communication control unit  30  are to be provided in all of the distribution apparatuses, the cost for installing the distribution apparatuses would be significantly high in a case where the distribution apparatuses  3  are provided in the indoor area α covering a large area (large floor space) (Pattern  1 ). 
     Further, there may be a case where the distribution apparatus  3   a  can distribute the position data Xa but cannot receive the terminal identification data A and the position data Xa from the communication terminal  5  due to, for example, malfunction of the wireless communication control unit  30  of the distribution apparatus  3  (Pattern  2 ). 
     Further, in a case where multiple distribution apparatuses  3  ( 3   a ,  3   b ) are installed to the ceiling β, there may be a case where the signal strength of the data of the participation response received from the wireless communication control unit  30  of the distribution apparatus  3   b  is higher than the signal strength of the data of the participation response received from the wireless communication control unit  30  of the distribution apparatus  3   a  (see Step S 46 - 1 ,  46 - 2 ) depending on the position of the communication terminal  5  in the indoor area α even if the signal strength of the position data X received from the distribution control unit  20  of the distribution apparatus  3   a  is higher than the signal strength of the position data X received from the distribution control unit  20  of the distribution apparatus  3   b  (see Step S 24 - 1 ,  24 - 2 ) (Pattern  3 ). 
     In the above-described Patterns  1 - 3 , although the communication terminal  5  receives position data Xa from the distribution apparatus  3   a  (distribution source), the communication terminal  5  transmits the terminal identification data A of the communication terminal  5  itself and the position data Xa to a distribution apparatus  3  other than the distribution apparatus  3   a  (in this case, distribution apparatus  3   b ) as illustrated in  FIG. 21 . In the following, the above-described case where the distribution apparatus  3  of the distribution source is different from distribution apparatus  3  of the transmission destination is described with reference to  FIGS. 14 and 20 . 
     The determination unit  53  of the wireless communication control unit  50  of the communication terminal  5  illustrated in  FIG. 14  determines whether at least a single participation response is received within a predetermined time (e.g., 5 seconds) with respect to the transmission of the participation request from the transmission/reception unit  51  to each of the distribution apparatuses  3   a ,  3   b  (Step S 48 - 1 ). That is, the determination unit  53  determines whether at least a single apparatus identification data B is received within a predetermined time with respect to the starting of the transmission of the terminal identification data A. 
     Then, in a case where the determination unit  53  determines that at least a single participation response is received (Yes in Step S 48 - 1 ), the determination unit  53  further determines whether multiple participation responses have been received (Step S 48 - 2 ). That is, the determination unit  53  determines whether multiple apparatus identification data B have been received within the predetermined time with respect to the starting of the transmission of the terminal identification data A. 
     In a case where the determination unit  53  determines that multiple participation responses have been received (Yes in Step S 48 - 2 ), the measurement unit  54  measures the signal strength of each of the participation responses upon receipt by the transmission/reception unit  51  (Step S 48 - 3 ). In this example, the process of Step S 48 - 3  is executed because the wireless communication control unit  50  of the communication terminal  5  receives participation responses from the distribution apparatus  3   a ,  3   b  in Step S 46 - 1 , S 46 - 2 . 
     Next, a case where the determination unit  53  determines that signal strength of the participation response from the distribution apparatus  3   b  is higher than the signal strength of the participation response (according to the measurement results of Step S 48 - 3 ) is described. As illustrated in  FIG. 22 , the storage/readout unit  58  stores the apparatus identification data B (in this example, apparatus identification data Bb) included in the participation response having the highest signal strength in the storage unit  59  according to the measurement of Step S 48 - 3  (Step S 48 - 4 ). 
     In a case where the determination unit  53  determines that not a single participation response has been received within the predetermined time (No in Step S 48 - 1 ), the process of determining the transmission destination is terminated. Further, in a case where the determination unit  53  determines that multiple participation responses have not been received within the predetermined time (No in Step S 48 - 2 ), the storage/readout unit  58  stores the apparatus identification data B included in the single participation response in the storage unit  59  (Step S 48 - 5 ). 
     Thereby, the distribution apparatus  3  indicated with the apparatus identification data B in the storage unit  59  (stored by the storage/readout unit  58 ) is determined as the destination (transmission destination) to which data is to be transmitted from the communication terminal  5 . 
     Then, after the processes of Step S 48 - 4  or Step S 48 - 5 , the transmission/reception unit  51  generates a data structure (as illustrated in  FIG. 9 ) of the data to be transmitted to the transmission destination determined according to Step S 48  (Step S 49 ). In this example, the data structure generated by the transmission/reception unit  51  includes the apparatus identification data Bb of the distribution apparatus  3   b  (transmission destination), the terminal identification data Ah of the communication terminal  5   h  (transmission source), and the data content (e.g., position data Xa of the distribution apparatus  3   a  (distribution source)) that are sequentially arranged. 
     Then, in the communication terminal  5   h , the operation of the transmission/reception unit  51 , the determination unit  53 , the measurement unit  54 , the communication unit  57 , and the storage/readout unit  58  of the wireless communication control unit  50  stop operating (Step S 51 ). Accordingly, by stopping operation (processing) of the function components (functions) constituting the communication control unit  50  after the transmission/reception unit  51  completes transmitting the data including the position data X to the distribution apparatus  3 , power can be saved. The function components (functions) constituting the communication control unit  50  can restart operation (processing) when a new start command is received from the reception control unit  40  in Step S 42 . 
     Next, an operation which starts by the distribution apparatus  3  receiving the data including the position data X and ends by the position data management system  9  managing the management data F is described with reference to  FIG. 23 .  FIG. 23  is a sequence diagram illustrating mainly a process of managing position data X. 
     As illustrated in  FIG. 23 , first, the wireless communication control unit  30  of the distribution apparatus  3  generates data to be transmitted to the gateway  7 . The wireless communication control unit  30  generates a data structure in a similar manner as the Step S 49  (Step S 61 ). In this example, the data structure generated by the wireless communication control unit  30  includes the apparatus identification data C of the gateway  7  (transmission destination), the apparatus identification data Bb of the distribution apparatus  3   b  (transmission source), and the data content (e.g., position data Xa of the distribution apparatus  3   a  (distribution source), terminal identification data A of the communication terminal (transmission source of the position data Xa)) that are sequentially arranged. 
     Then, the transmission/reception unit  31  of the wireless communication unit  30  of the distribution apparatus  3   b  transmits data having a data structure generated in Step S 61  to the gateway  7  (Step S 62 ). Thereby, the transmission/reception unit  71  of the wireless communication control unit  70  of the gateway  7  receives the data transmitted from the distribution apparatus  3   b.    
     Then, the communication unit  77  of the wireless communication control unit  70  transfers the data received in Step S 62  to the communication unit  87  of the gateway  7  (Step S 63 ). Thereby, the wired communication control unit  80  receives the data transferred from the wired communication control unit  70 . 
     Then, the conversion unit  82  of the wired communication control unit  80  performs controls for converting a communication method complying with the IEEE802.15.4 standard to a communication method complying with the IEEE802.3 standard, so that Ethernet packet communication can be performed with the data transmitted from the distribution apparatus  3   b . Then, the transmission/reception unit  81  of the wired communication control unit  80  generates data to be transmitted to the position data management system  9  (Step S 65 ). The transmission/reception unit  81  generates a data structure in a similar manner as the Step S 61 . In this example, the data structure of the data generated by the transmission/reception unit  81  includes the system identification data E of the position data management system  9  (transmission destination), the apparatus identification data D of the gateway  7  (transmission source), and the data content (e.g., position data Xa of the distribution apparatus  3   a  (distribution source), terminal identification data A of the communication terminal  5  (transmission source of the position data Xa)) that are sequentially arranged. 
     Then, the transmission/reception unit  81  of the wired communication control unit  80  of the gateway  7  transmits the data generated in Step S 65  to the position data management system  9  (Step S 66 ). Thereby, the transmission/reception unit  91  of the position data management system  9  receives the data transmitted from the gateway  7 . 
     Then, the storage/readout unit  98  of the position data management system  9  performs a process of managing position data by associating data indicating the time/date of receiving data (e.g., time/date of receiving position data X) and the position data X with respect to the terminal identification data A already stored in the storage unit  99  and storing the associated data as the management data F (see  FIG. 13 ) in the HD  904  (Step S 67 ). 
     By managing the management data F with the position data management system  9 , the administrator of the position data management system  9  can perform a search as illustrated in  FIGS. 24 and 25 .  FIGS. 24 and 25  are schematic diagrams illustrating examples of the screens displayed with the position data management system  9  according to an embodiment of the present invention. 
     For example, by having the administrator operate, for example, the keyboard  911  or the mouse  912  illustrated in  FIG. 12 , the operation input reception unit  92  receives an operation input, and the display control unit  94  reads out the management data F by way of the storage/readout unit  98  and displays a search screen (as illustrated in  FIG. 24 ) on the display  908 . For example, the search screen displays a search list indicating device names corresponding to each owner name (or administrator name). Further, a checkbox is displayed on the right side of the device name. Further, a button “execute search” is displayed on the lower right side of the search list for executing a search. The example of  FIG. 24  illustrates a case of searching the position of the device “UCS P3000” owned by the owner belonging to “sales department 1”. 
     In a case where the administrator operates, for example, the keyboard  911  or the mouse  912  and checks (marks) the checkbox corresponding to the device name of the device (management object  4 ) whose position is desired to be searched, the operation input reception unit  92  receives the input of checking the checkbox. Then, after the administrator checks all of the checkbox(es) corresponding to the devices whose positions are desired to be searched, the operation input reception unit  92  receives input of search execution when the administrator presses the button “execute search”. Then, the search unit  93  searches the management data F stored in the storage unit  99  based on the device name corresponding to the checked check box. Thereby, the search unit  93  extracts a part of the management data F including a corresponding position data X and layout data G indicating, for example, the floor of the position indicated by the position data X. 
     Then, as illustrated in  FIG. 25 , the display control unit  94  displays a search result screen on the display  908  based on the management data F and the layout data G. For example, a layout diagram indicating the floor “Building A, 4 th  floor” of the device “ICS P3000” and data items of the management data F (e.g., position data X, reception date/time) are displayed in the search result screen of  FIG. 25 . Thereby, the administrator of the position data management system  9  can visually recognize the position of the management object  4  (communication terminal  5 ). 
     In the above-described embodiment of the present invention, the distribution apparatus  3  not only includes the distribution unit  21  but also the transmission/reception unit  31 . Thus, as long as the communication terminal  5  is positioned within a range in which position data X can be distributed from the distribution apparatus  3  (distributable range of the distribution apparatus  3 ), the communication terminal  5  need only to transmit the position data X and the terminal identification data A within the distributable range of the distribution apparatus  3 . Therefore, the communication terminal  5  can transmit data with a minimal amount of power (minimal power consumption). Accordingly, the distribution apparatus  3  contributes to power saving of the communication terminal  5 . 
     Further, because the process of receiving position data is started only in a case where movement of the communication terminal  5  is stopped (after the movement of the communication terminal  5 ), the power consumption of the battery can be reduced to a small capacity. Thereby, power can be saved. Further, because operations of the components constituting the wireless communication control unit  50  is stopped once the transmission/reception unit  51  completes transmitting data such as the position data X to the distribution apparatus  3 , power can be saved. Accordingly, owing to the saving of power, the frequency of performing battery change can be reduced even where a small capacity battery such as the button battery  406  is used, to thereby facilitate the workload of the user. 
     Further, as illustrated in  FIG. 21 , installation cost of the distribution apparatus  3  can be reduced because the distribution apparatus  3   b  can be used to receive the position data Xa and the terminal identification data A from the communication terminal  5  instead of the distribution apparatus  3   a  (corresponding to the above-described Pattern  1 ). Further, even in a case where the wireless communication control unit  30  malfunctions, position data Xa and the terminal identification data A can be obtained from the communication terminal  5  in the distribution system  6  (corresponding to the above-described Pattern  2 ). Further, because position data X and terminal identification data A can be transmitted to the distribution apparatus  3  capable of communicating with highest signal strength, the position data X and the terminal identification data A can be more reliably obtained from the communication terminal  5  in the distribution system  6  (corresponding to the above-described Pattern  3 ). 
     The position data management system  9  can be configured by a single computer. Alternatively, position data management system  9  may be configured by dividing the position data management system  9  into multiple elements (functions, function components or storage units) and assign one or more computers to the elements. 
     Further, a recording medium (e.g., CD-ROM) on which programs of the above-described embodiment are recorded or a hard disk in which the programs are stored may be domestically or internationally provided as a program product. 
     The determination unit  63  serving as a first determination unit may include the determination unit  53  serving as a second determination unit. That is, the first and second determination units are not only provided separately but also may constitute a single unit. Likewise, the measurement unit  64  serving as a first measurement unit may include the measurement unit  67  serving as a second measurement unit. That is, the first and second measurement units are not only provided separately but also may constitute a single unit. 
     (Example of Using Terminal Setting Data) 
     Next, an example where each of the communication terminals performs an inquiry of terminal setting data (data pertaining to settings of a communication terminal) H with respect to the position data management system  9  is described. As illustrated in  FIG. 26 , the terminal setting data H includes items such as “operation mode 1”, “operation mode 2”, “operation mode 3”, and “transmission output”.  FIG. 26  is a schematic diagram illustrating the terminal setting data H stored in the communication terminal  5  according to an embodiment of the present invention. The terminal setting data H may be stored in at least one of the storage unit  49 ,  59  of the communication terminal  5 , and the storage unit  69  of the management object  5   g.    
     The operation mode 1 indicates the timing in which the communication device  5  receives the position data X transmitted from the distribution apparatus  3  (i.e. timing in which the reception unit  41  starts operating). An item “PE” (indicating a predetermined period of operation”) or an item “RT” (indicating a predetermined time of operation) may be set to the item “operation mode 1”. For example, in a case where “PE” is set, a predetermined period (e.g., seconds) in which the reception unit  41  starts operation may also be set to the item “PE”. The item “PE30” indicated in the “operation mode 1” in  FIG. 26  indicates that the reception unit  41  periodically starts operation at intervals of 30 seconds. Although not illustrated in  FIG. 26 , in a case where “RT” is set to the “operation mode 1”, a predetermined time (e.g., hour/minutes) in which the reception unit  41  starts operation may also be set to the item “RT”. For example, an item “RT1230” may be set to “operation mode 1” for indicating that the reception unit  41  starts operation at the time of 12:30. The method for designating the period or time of item “PE” or “RT” is arbitrary. Further, the name of the items “PE” and “RT” (and also the below-described “SE”) may be defined depending on, for example, the purpose of use and an arbitrary name may be assigned to the items of “operation mode 1”. 
     The operation mode 2 indicates the timing in which the communication device  5  transmits the terminal identification data A and the position data X to the distribution apparatus  3  (i.e. timing in which the start command is transmitted in Step S 42  of  FIG. 34 ). Similar to “operation mode 1”, items “PE” or “RT” may be set to the item “operation mode 2”. In addition, an item “SE” (indicating that the communication device  5  is to transmit the terminal identification data A and the position data X immediately after the reception unit  41  receives the position data X from the distribution apparatus  3 ). In other words, in a case where “SE” is set to the item “operation mode 2”, the process of Step S 42  is executed immediately after the process of Step S 41  as illustrated in the sequence diagram of  FIG. 19 . 
     The operation mode 3 indicates the timing in which the communication device  5  transmits an inquiry of terminal setting data H bound for the position data management system  9  to the distribution apparatus  3 . Items “PE”, “RT”, or “SE” may be set to the item “operation mode 3”. Upon receiving a response to the inquiry from the position data management system  9 , the communication terminal  5  updates the terminal setting data H by using the terminal setting data H received from the position data management system  9 . 
     The item “transmission output” indicates the strength of the electric wave (radio wave) output in the wireless communication by the communication circuit  504  of the communication terminal  5 . In  FIG. 26 , the item “transmission output” is indicated with in units of “dBm”. However, other units that can be applied to the communication circuit  504  of the communication terminal  5  may also be used. The wireless communication unit  15  of the communication terminal  5  controls the strength of electric waves, so that the communication circuit  504  transmits wireless signals based on the settings of the item “transmission output” by way of the antenna  504   a . Similarly, in a case where the communication terminal  5  is the management object  6 , the strength of electric waves is controlled, so that the communication unit  613  transmits wireless signals based on the settings of the item “transmission output” by way of the antenna  613   a.    
     The items “operation mode 1” to “operation mode 3” may be set separately. 
       FIG. 27  is a schematic diagram illustrating a communication data format of the terminal setting data H that is transmitted from the position data management system  9  after an inquiry is transmitted from the communication terminal  5  to the position data management system  9  via the distribution apparatus  3  according to an embodiment of the present invention. Given bits strings indicating “PE”, “RT” or “SE” (only “PE” or “RT” for item “operation mode” are stored in the items “operation mode 1” to “operation mode 3”. Further, in a case where “PE” or “RT” is set to the operation modes, setting values indicating a predetermined period or a predetermined time may also be stored. Further, a setting value indicated in a predetermined unit may be stored in the item “transmission output”. The number of bits of the stored data may be arbitrarily set. 
       FIG. 28  is a schematic diagram illustrating management data F (including terminal setting data H) stored in the storage unit  99  of the position data management system  9  according to an embodiment of the present invention. The management data F of  FIG. 28  is configured having the terminal setting data H of each communication terminal  5  added to the management data illustrated in  FIG. 13 . Accordingly, the position data management system  9  manages the terminal setting data H of each communication terminal  5  by using the terminal identification data A as a key. The management data F of  FIG. 28  may also include “transmission date/time” indicating the date and time of transmitting the terminal setting data H to the communication terminal  5 . Accordingly, when the position data management system  9  receives an inquiry of terminal setting data H from the communication terminal  5 , the position data management system  9  transmits the terminal setting data H of the communication terminal  5  including the management data F to the communication terminal  5 . 
       FIGS. 29 and 30  are block diagrams corresponding to the block diagrams of  FIGS. 14 and 15  illustrating the distribution apparatus  3  and the communication terminal  5  according to an embodiment of the present invention. In the embodiments illustrated in  FIGS. 29 and 30 , the terminal setting data H is stored in the storage unit  49  and the storage unit  59  of the communication terminal  5  (or the storage unit  69  of the management object  5   g ). The same terminal setting data is stored in the storage unit  49  and the storage unit  59 . The determination unit  43  and the determination unit  53  (or the determination unit  63  and  66 ) determines the operation modes and setting values of the terminal setting data H read out by the storage/readout unit  48 ,  58 , or (storage/readout unit  68 ). 
       FIG. 31  is a block diagram corresponding to  FIG. 15  illustrating the gateway  7  and the position data management system  9  according to an embodiment of the present invention. In the embodiment illustrated in  FIG. 31 , the terminal setting data H is stored in the management data F stored in the storage unit  99  of the position data management system  9 . 
     Next, further details of the processes using the terminal setting data H (illustrated in  FIGS. 26-31 ) are described with reference to  FIG. 19  and  FIGS. 32-35 . 
     In Step S 41  of  FIG. 19 , the below-described operation illustrated in the flowchart of  FIG. 32  may be performed instead of the operation illustrated in the flowchart of  FIG. 20 .  FIG. 32  is a flowchart of an operation of receiving position data based on the settings of operation mode 1 of the terminal setting data H and storing the received position data according to an embodiment of the present invention. 
     First, the storage/readout unit  48  of the communication terminal  5  reads out the operation mode 1 and its setting values from the terminal setting data H stored in the storage unit  49  (Step S 410 - 1 , No in Step S 410 - 2 ). Then, the determination unit  43  determines whether the timing for receiving position data X is appropriate based on the operation mode 1 and/or its setting values (Step S 410 - 2 ). The determination unit  43  may refer to the time in which the position data X was received the previous time (previous reception time of position data X). The storage/readout unit  48  may read out the previous reception time of position data X stored in the storage unit  49 . In a case where the determination unit  43  determines that the current time is the appropriate timing for receiving the position data X (Yes in Step S 410 - 2 ), the reception unit  41  switches to a state capable of receiving the position data distributed by the distribution apparatus  3  (Step S 410 - 3 ). More specifically, in a case where the CPU  401  illustrated in  FIG. 7  determines that the current time is the time for receiving the position data X, the CPU  401  transmits a signal to the communication circuit  404  instructing the communication circuit  404  to start operating. Thereby, the communication circuit  404  starts to operate. In a case where the position data Xa, Xb are distributed from the distribution apparatuses  3   a ,  3   b , respectively, the communication circuit  404  of the control unit  14  of the communication terminal  5  can start receiving the position data Xa and Xb by way of the antennal  404   a . The subsequent processes performed in Steps S 410 - 4  to S 410 - 10  correspond to the processes performed in Steps S 41 - 6  to S 41 - 12  of  FIG. 20 . 
     The process performed in Step S 42  of  FIG. 19  is described in further detail with reference to  FIG. 33 .  FIG. 33  is a flowchart illustrating an operation of the communication unit  47  of the communication terminal  5  instructing the wireless communication control unit  50  to start operating based on the settings of the operation mode 2 of the terminal setting data H according to an embodiment of the present invention. 
     First, the storage/readout unit  48  of the communication terminal  5  reads out the operation mode 2 and its setting values from the terminal setting data H stored in the storage unit  49  (Step S 420 - 1 , No in Step S 420 - 2 ). Then, the determination unit  43  determines whether the timing for transmitting position data X is appropriate based on the operation mode 2 and/or its setting values (Step S 420 - 2 ). The determination unit  43  may refer to the time in which the position data X was received the previous time (previous reception time of position data X). The storage/readout unit  48  may read out the previous reception time of position data X stored in the storage unit  49 . In a case where the determination unit  43  determines that the current time is the appropriate timing for transmitting the position data X (Yes in Step S 420 - 2 ), the communication unit  47  transmits a command to the wireless communication control unit  50  instructing the wireless communication unit  50  to start operating (Step S 420 - 3 ). 
     Then, returning to  FIG. 19 , the processes of Step S 43  to S 50  can be performed. In a case where “SE” is set to “operation mode 2” of the terminal setting data H, the process of Step S 42  is performed immediately after process of Step S 41 . 
     Next, an operation for inquiring a terminal setting data H from the communication terminal  5  to the position data management system  9  and an operation for receiving the terminal setting data H from the position data management system  9  are described with reference to  FIGS. 34 and 35 .  FIG. 34  is a sequence diagram illustrating a process of transmitting an inquiry from the communication terminal  5  to the distribution apparatus  3  and a process of receiving the terminal setting data H from the distribution apparatus  3  according to an embodiment of the present invention.  FIG. 35  is a sequence diagram illustrating a process of the distribution apparatus  3  relaying the inquiry from the communication terminal  5  and the terminal setting data H from the position data management system  9  according to an embodiment of the present invention. 
     First, the flow of the processes illustrated in  FIG. 34  is described. The storage/readout unit  58  of the communication terminal  5  reads out the terminal setting data H from the storage unit  59  (Step S 71 ). Then, the determination unit  53  of the communication terminal  5  determines whether inquiry of the terminal setting data H is possible based on the operation mode 3 and/or its setting values (Step S 72 ). The determination unit  53  may refer to the time in which an inquiry of terminal setting data H was transmitted the previous time (previous inquiry time of terminal setting data H). The storage/readout unit  58  may read out the previous inquiry time of terminal setting data H stored in the storage unit  59 . In a case where the determination unit  43  determines that the inquiry of the terminal setting data H is possible, the transmission/reception unit  51  generates a data structure (illustrated in  FIG. 9 ) of data to be transmitted to the distribution apparatus  3  (transmission destination) (Step S 73 ). In this example, the data structure generated in Step S 73  includes the apparatus identification data B of the distribution apparatus  3   b  (transmission destination), the terminal identification data A of the communication terminal  5  (transmission source), and the data content (e.g., terminal identification data A of the communication terminal  5 , data of a predetermined bit string for indicating that the data is an inquiry of the terminal setting data H from the communication terminal  5  and is shared beforehand between the communication terminal  5  and the position data management system  9 ) that are sequentially arranged. Then, the transmission/reception unit  51  transmits the data having the data structure generated in Step S 73  (e.g., terminal setting data A of the communication terminal  5 , and data of a predetermined bit string for indicating that the data is an inquiry of the terminal setting data H from the communication terminal  5 ) to the distribution apparatus  3  (Step S 74 ). Thereby, the wireless communication control unit  30  of the distribution apparatus  3  receives the inquiry transmitted from the communication terminal  5 . Then, after the processes of  FIG. 35 , the wireless communication control unit  30  of the distribution apparatus  3  receives data including the terminal setting data H from the position data management system  9  and transmits the received terminal setting data H to the communication terminal  5  (Step S 75 ). The storage/readout unit  58  of the communication terminal  5  stores the received data including the terminal setting data H in the storage unit  59  (Step S 76 ). In a case where the terminal setting data H is already stored in the storage unit  59 , the terminal setting data H already stored in the storage unit  59  may be updated with the newly received terminal setting data H. Then, the communication unit  57  of the communication terminal  5  transmits the received terminal setting data H to the communication unit  47  of the reception control unit  40  (Step S 77 ). Then, the storage/readout unit  48  stores the received terminal setting data H in the storage unit  49  (Step S 78 ). In a case where the terminal setting data H is already stored in the storage unit  49 , the terminal setting data H already stored in the storage unit  49  may be updated with the newly received terminal setting data H. 
     In a case where the data received by the wireless communication control unit  50  of the communication terminal  5  indicates that there is no corresponding terminal setting data H in the position data management system  9  (described in detail below), the performing of the processes in Step S 76  to Step S 78  may be omitted. 
     Next, the flow of the processes illustrated in  FIG. 35  is described. First, as illustrated in the process of Step S 73  of  FIG. 34 , the wireless communication control unit  30  of the distribution apparatus  3  generates a data structure of the data to be transmitted to the gateway  7  (Step S 81 ). In this example, the data structure of the data generated in Step S 81  includes the apparatus identification data C of the gateway  7  (transmission destination), the apparatus identification data B of the distribution apparatus  3  (transmission source), and the data content (e.g., terminal identification data A of the communication terminal  5 , data of a predetermined bit string for indicating that the data is an inquiry of the terminal setting data H from the communication terminal  5 ) that are sequentially arranged. 
     Then, the transmission/reception unit  31  of the wireless communication control unit  30  of the distribution apparatus  3  transmit the data having the data structure generated in Step S 81  to the gateway  7  (Step S 82 ). Thereby, the transmission/reception unit  71  of the wireless communication control unit  70  of the gateway  7  receives data transmitted from the distribution apparatus  3 . 
     Then, the communication unit  77  of the wireless communication control unit  70  transfers the data received in Step S 82  to the communication unit  87  of the gateway  7  (Step S 83 ). Thereby, the wired communication control unit  80  receives the data transferred from the wireless communication control unit  70 . 
     Then, the conversion unit  82  of the wired communication control unit  80  performs controls for converting a communication method complying with the IEEE802.15.4 standard to a communication method complying with the IEEE802.3 standard, so that Ethernet packet communication can be performed with the data transmitted from the distribution apparatus  3   b . Then, the transmission/reception unit  81  of the wired communication control unit  80  generates data to be transmitted to the position data management system  9  (Step S 85 ). The transmission/reception unit  81  generates the data in a similar manner as the Step S 81 . In this example, the data structure of the data generated by the transmission/reception unit  81  includes the system identification data E of the position data management system  9  (transmission destination), the apparatus identification data D of the gateway  7  (transmission source), and the data content (e.g., terminal identification data A of the communication terminal  5 , data of a predetermined bit string for indicating that the data is an inquiry of the terminal setting data H from the communication terminal  5 ) that are sequentially arranged. 
     Then, the transmission/reception unit  81  of the wired communication control unit  80  of the gateway  7  transmits the data generated in Step S 85  to the position data management system  9  (Step S 86 ). Thereby, the transmission/reception unit  91  of the position data management system  9  receives the data transmitted from the gateway  7 . 
     Then, when the position data management system  9  receives the data including the inquiry of the terminal setting data H from the gateway  7 , the storage/readout unit  98  reads out the terminal setting data H corresponding to the terminal setting data H included in the received data, from the storage unit  99  (Step S 87 ). Then, the transmission/reception unit  91  of the position data management system  9  generates a data structure of the data to be transmitted to the communication terminal  5  in a manner illustrated in Step S 73  of  FIG. 34  (Step S 88 ). In this example, the data structure of the data generated by the transmission/reception unit  91  includes the apparatus identification data C of the gateway  7  (transmission destination), the system identification data E of the position data management system  9  (transmission source), and the data content (e.g., terminal identification data A of the communication terminal  5 , terminal setting data H of the communication terminal  5  having the data configuration illustrated in  FIG. 27 ) that are sequentially arranged. Then, the transmission/reception unit  91  of the position data management system  9  transmits the data having the data structure generated in Step S 88  to the gateway  7  (Step S 89 ). Thereby, the transmission/reception unit  81  of the gateway  7  receives the data transmitted from the position data management system  9 . The time in which the data is transmitted to the gateway  7  is stored in the management data F of  FIG. 28 . In a case where no terminal setting data H corresponding to the terminal identification data A cannot be read out in Step S 87  (i.e. no terminal setting data H corresponding to the terminal identification data A stored in the storage unit  99 ), the transmission/reception unit  91  of the position data management system  9  may include data indicating no corresponding setting data in the data content of the data structure generated in Step S 87 . For example, the data may have a bit string entirely constituted by 0 in the data structure illustrated in  FIG. 27 . 
     Then, the conversion unit  82  of the wired communication control unit  80  of the gateway  7  converts the communication method complying with the IEEE802.3 standard to the communication method complying with the IEEE802.15.4 standard. The data of the converted communication method is transferred to the wireless communication control unit  77  (Step S 91 ). Then, the transmission/reception unit  71  of the wireless communication control unit  70  generates a data structure of the data to be transmitted to the distribution apparatus  3  in a manner illustrated in Step S 88  (Step S 92 ). In this case, the data structure includes the apparatus identification data B of the distribution apparatus  3  (transmission destination), the apparatus identification data D (transmission source), and the data content (e.g., terminal identification data A of the communication terminal  5 , terminal setting data H of the communication terminal having the data structure illustrated in  FIG. 27 ). The apparatus identification data set as the transmission destination is not limited to the distribution apparatus  3 . The data having the data structure generated in Step S 92  need only be transmitted to the communication terminal  5  via a communication network formed by the wireless communication control unit  70 . Accordingly, the apparatus identification data B of an arbitrary distribution apparatus  3  or the terminal identification data A of the communication terminal  5  may be selected as the transmission destination according to route data of the communication network at the time of executing the process in Step S 92 . 
     Then, the transmission/reception unit  71  of the wireless communication control unit  70  of the gateway  7  transmits the data having the data structure generated in Step S 92  to the distribution apparatus  3  or another distribution apparatus located on an optimum route to the communication terminal  5  (Step S 93 ). Thereby, the transmission/reception unit  31  of the distribution apparatus  3  can receive the data transmitted from the gateway  7 . 
     With the above-described embodiment, the position data management system  9  can unify (consolidate) the management of the terminal setting data H of each of the communication terminals  5 . Further, each communication terminal  5  can periodically transmit an inquiry of the terminal setting data H to the position data management system  9  at a predetermined period, a predetermined time, or at a timing for transmitting position data. For example, the communication terminal  5  can control the communication amount for transmitting an inquiry to a minimal amount by transmitting an inquiry of the terminal setting data of the communication terminal itself at a timing of receiving the position data X. This contributes to power saving of the communication terminal  5 . 
     The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention. 
     The present application is based on Japanese Priority Application Nos. 2012-056958 and 2012-226948 filed on Mar. 14, 2012 and Oct. 12, 2012, respectively, the entire contents of which are hereby incorporated by reference.