JP2008061199A - Positioning server, positioning system, positioning method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a positioning system which specifies a position of a radio terminal based on the installation location of a radio base station under connection determines that a radio terminal has moved because of load distribution processing despite that the radio terminal stands still, as the connected radio base station is changed by the load distribution processing. <P>SOLUTION: The positioning system which finds location information on a radio terminal based on information on the installation location of a radio base station under connection has a means of detecting a movement for determining whether a radio terminal has moved and a means of detecting a position for specifying a position of a radio terminal based on the information on a base station to which the radio terminal is connected. When the positioning system detects a change of a radio base station to which a radio terminal is connected by the means of detecting a movement, it confirms if the change has been made following the movement of the radio terminal or load distribution control. When the change has been made by the movement of the radio terminal, the system determines that the radio terminal has moved and obtains new location information of the radio terminal by the means of detecting a position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a positioning server, a positioning system, a positioning method, and a program, and more particularly to a wireless terminal even in a wireless network in which a connection base station of a wireless terminal is automatically switched by load distribution control regardless of movement of the wireless terminal. The present invention relates to a positioning server, a positioning system, a positioning method, and a program that can detect the presence or absence of movement.

  2. Description of the Related Art Conventionally, a positioning system that identifies the position of a wireless terminal based on the installation position information of a wireless base station to which the wireless terminal is connected is a low-cost and easily realizable positioning system from a mobile phone network to a wireless LAN, Bluetooth. It is widely used to short-range wireless networks.

  However, in recent years, in order to ensure the stability of communication under a wireless network, when the load is biased to a specific wireless base station, the connection base station of the wireless terminal is forcibly switched from the wireless network side. A wireless network system having a load distribution function as described in Patent Document 1 is used.

JP 2004-320274 A

However, in a wireless network having such a load distribution function, when a positioning system that specifies the position of the wireless terminal is applied based on the wireless base station to which the wireless terminal is connected, the wireless terminal When the connected base station is forcibly switched, it is determined that the wireless terminal has moved in the positioning system because the connected base station of the wireless terminal has been changed even though the wireless terminal has not moved. Will be.
Therefore, when an external application that functions using the location information of the wireless terminal is applied to such a wireless network, there arises a problem that the accurate location of the wireless terminal cannot be provided. This is because control is performed to change the radio base station mainly for load distribution processing regardless of the presence of the positioning system.

  Therefore, the present invention determines whether the connection base station of the wireless terminal has been switched by the control on the wireless network side such as a load balancing function or whether the connection base station has been switched due to the movement of the wireless terminal, An object of the present invention is to realize a positioning system capable of detecting the presence or absence of movement of a wireless terminal.

  The first positioning server of the present invention detects a change of a base station to which a terminal is connected by the connection base station change detection means for detecting presence or absence of a change of a base station to which the terminal is connected, and the connection base station change detection means. Determining whether or not the change is caused by the load distribution process, and determining that the terminal has moved when it is determined that the change is not caused by the load distribution process, and the terminal movement determination unit When the mobile terminal determines that the terminal has moved, it has a position information update processing means for obtaining the terminal position information based on the position of the base station connected after the movement.

  In the second positioning server of the present invention, in the first positioning server, whether or not the determination as to whether or not the terminal movement determination means is caused by load distribution is based on information from a terminal or a base station. When the load balancing process is not performed, it is determined that the change is not caused by the load balancing process.

  Further, the third positioning server of the present invention is the first positioning server, wherein the connected base station change detecting means detects the presence or absence of a change in the base station to which the terminal is connected, and the peripheral base that the terminal can sense The presence / absence of a change in the station is detected, and whether or not the determination of whether or not it is caused by the load distribution in the terminal movement determination unit is a change in the connected base station or a sensing of a neighboring base station that can be sensed by the connected base station change detection unit. When the change is detected, if the base station connected to the terminal before the movement is not included in the changed base station, it is determined that the change is not caused by the load distribution process.

  In the fourth positioning server of the present invention, in the first positioning server, whether or not the base station connected to the terminal after the change is determined whether or not it is caused by load distribution in the terminal movement determining means If the terminal is not included in the base station that can be handed over, it is determined that this change is not caused by the load distribution process.

  In the fifth positioning server of the present invention, in the first positioning server, the determination as to whether or not the terminal movement determination means is caused by load distribution is a radio wave from a base station connected to the terminal before the change. When the intensity is lower than the radio wave intensity from the base station after the change, it is determined that the change is not caused by the load distribution process.

  As described above, according to the present invention, in the wireless network in which the connection base station is switched by the control of the wireless network such as the load distribution function while the wireless terminal is stationary, the connection base accompanying the movement of the wireless terminal It is possible to detect the presence or absence of a change in the position of the wireless terminal by confirming whether the station is changed or the base station is changed due to control on the wireless network side.

  Next, a first embodiment for carrying out the invention will be described in detail with reference to the drawings.

  FIG. 1 is an overall configuration diagram in the first embodiment.

  As shown in FIG. 1, the wireless network system includes a plurality of wireless terminals 500-1, 500-2, 500-3, a plurality of wireless base stations 400-1, 400-2, and one or more positioning servers 100. And a system composed of one or a plurality of application servers 200. Note that the positioning server and the application server may be the same device.

  In the example of FIG. 1, the radio base stations 400-1 and 400-2 are assumed to have the cover areas 401-1 and 401-2, respectively, and the positioning server 100, the application server 200, and the radio base station 400. -1 and 400-2 are connected to the network 300. Although not shown in FIG. 1, the system is configured using other network devices or server devices as necessary.

  First, the configuration of each part will be described.

  FIG. 2 is a configuration example of the wireless terminals 500-1, 500-2, and 500-3. The host communication interface unit 510 is connected to the radio base stations 400-1 and 400-2 and has a network interface function for communicating with other radio terminals, the positioning server 100, and the application server 200.

  The connection base station management unit 520 has a function for acquiring information for identifying a wireless base station being connected, such as the MAC address of the wireless base station to which the wireless terminal is connected, and notifying the positioning server 100 of the information.

  The load distribution control unit 530 grasps the load status of the radio base station to which the radio terminal is connected and the load status of other radio base stations, and when the load distribution processing is necessary, the radio base station and other radio terminals And a function of switching a wireless base station to be connected based on a request from the user or on own judgment.

  FIG. 3 shows a configuration example of the radio base stations 400-1 and 400-2. The network communication interface unit 410 has a network interface function for performing communication with the network 300 side serving as a backbone.

  On the other hand, the host communication interface unit 430 has a network interface function for performing communication with a wireless terminal.

  In addition, the load distribution control unit 420 grasps the load status of its own radio base station and the load status of other radio base stations, and when load distribution processing is necessary, the load distribution control unit 420 is connected to its radio base station. It has a function of switching a radio base station to be connected to a terminal or a radio terminal connected to another radio base station in some cases.

  As for load distribution control, a dedicated management device may be installed in the network 300 to centrally control the grasping of the load status and switching of base stations connected to the wireless terminals.

  Note that the load distribution control (processing) described above increases the number of radio terminals under one radio base station compared to the number of radio terminals under another base station, and the load on one radio base station is excessive. It is implemented when it becomes. For example, by reducing the radio field intensity transmitted from an overloaded radio base station and narrowing the coverage area, the number of subordinate radio terminals is reduced, and radio terminals outside the area are accommodated in other radio base stations. By doing so, the load of one radio base station can be reduced, and load distribution can be achieved as a whole network.

  In addition, information such as whether or not such load distribution processing has been performed, and when it is performed, is stored in a storage area or the like in the radio base station. This information can also be shared by a plurality of radio base stations or radio terminals existing on the network. Then, an inquiry about whether or not load distribution processing is performed from the positioning server 100 described later can be answered.

  FIG. 4 is a configuration example of the positioning server 100. The application interface unit 110 has a function for providing the location information of the wireless terminal acquired by the positioning server 100 to an external application that uses location information in the application server 200 or the like.

  The radio base station installation location database unit 120 is a database that manages installation location information of radio base stations, and is used when calculating location information of radio base stations and radio terminals connected to the base stations.

  The position detection processing unit 130 obtains a wireless base station to which a wireless terminal is connected from the terminal information storage unit 150 and refers to the wireless base station installation position database unit 120 to calculate the position information of the wireless terminal. Have. The position accuracy at this time is about the size of the cell of the radio base station.

FIG. 5 shows a configuration example of the radio base station installation position database unit 120. In the example of FIG. 5, the MAC address of the radio base station is used as the unique information 120-1 for identifying the radio base station.
Further, the logical information 120-2, the coordinate information 120-3, and the area information 120-4 are information on the position of each radio base station stored in several notation formats (formats).

  As described above, the purpose of preparing a plurality of storage formats (formats) of the location information of the radio base station is as follows.

  As described above, the positioning method of this embodiment is to perform positioning using the position information of the wireless base station to which the wireless terminal is connected. In FIG. 5, position information relating to one radio base station is prepared in advance in a plurality of notation formats (formats). Thus, when the external application needs the position information of the wireless terminal connected to the wireless base station, the position information of the wireless terminal corresponding to the required notation format of the position information can be responded.

  For example, when requesting location information of a wireless terminal having an external application in a logical information format, in this embodiment, a logical information format such as “first conference room” registered in the wireless base station installation location database unit in FIG. Then, the position information of the wireless base station to which the requesting wireless terminal is connected is returned. Also, when requested in the coordinate information format, it responds in a positional information notation format that each application can handle, such as responding in the coordinate information format of “X = 10, Y = 0, Z = 20” of the same entry. It becomes possible.

  The terminal movement detection unit 140 in FIG. 4 is a function for determining whether or not a wireless terminal has moved by identifying whether or not it is associated with the load balancing function when the wireless terminal switches the connection base station. Have That is, when the switching of the radio base station is performed with load distribution, it is determined that the radio terminal has not moved.

  The terminal information storage unit 150 in FIG. 4 has a function of managing information on a wireless base station to which a wireless terminal is connected, such as which wireless terminal is connected to which wireless base station. FIG. 6 shows a configuration example of the terminal information storage unit 150. In the example of FIG. 6, using the MAC address of the wireless terminal as the terminal ID 150-1 and the MAC address of the wireless base station to which the wireless terminal is connected as the connected base station information 150-2, Is managed together with the connection time 150-3 when the connection of the wireless terminal is confirmed.

  Also, the terminal information acquisition unit 160 of FIG. 4 acquires the base station information being connected from the wireless terminal, searches the terminal information storage unit 150, and detects the terminal movement when the connection base station of the wireless terminal is changed. Unit 140 has a function of notifying that the connected base station has been changed.

  Next, the operation flow of the entire system will be described in detail with reference to FIG. In the following description, a plurality of wireless base stations and wireless terminals configured in the example of FIG. 1 will be described using the wireless base station 400-1 and the wireless terminal 500-1.

  First, in step A0, a state in which the wireless terminal 500-1 and the wireless base station 400-1 are connected as a result of the change processing of the connected wireless base station accompanying the handover process or the load distribution process due to the movement of the wireless terminal is performed. Is shown. When the load distribution process is performed, the radio base station 400-1 obtains information on whether or not the load distribution process has been performed from the radio base station connected before the load distribution process is performed. Assume that this information is retained. Although not shown, the connection base station changing process for the load distribution process is performed by the wireless base station 400-1 to which the wireless terminal 500-1 is newly connected or other wireless terminals 500-2 existing on the same network. Etc. and the case where it is performed in cooperation with the radio base station 400-2 or the like.

  Next, the wireless terminal 500-1 acquires the connected base station information in the connected base station management unit 520, and notifies the positioning server 100 together with the terminal identification information (step A1). The process of step A1 may be performed periodically regardless of the process of step A0, or may be performed when connection to a radio base station is started or when the connected base station changes. It may be called.

  On the positioning server 100 side, when receiving the connection base station information from the wireless terminal 500-1, the terminal information acquisition unit 160 searches the terminal information storage unit 150 according to the procedure shown in the operation flow of FIG. The connected base station information 150-2 is acquired and updated to the newly received connected base station information (steps A2 and A3).

  When the already registered connection base station information 150-2 and the connection base station information newly received in step A1 are different, it is determined that the connection base station has changed, and the newly received connection base station information is added to the terminal identification information. The terminal movement detection unit 140 is notified (step A4). However, if the connection base station information newly received in step A1 and the already registered connection base station information 150-2 are the same, the process ends in step A3 and the process in step A4 is performed. Absent.

  If the connection radio base station has changed, the terminal movement detection unit 140 has performed the load distribution process to determine whether the change of the connection base station notified from the terminal information acquisition unit 160 is associated with the load distribution process. An inquiry is made to the load distribution control unit 420 of the radio base station 400-1 holding the information on whether or not (step A5). Then, in step A6, the presence / absence of load distribution processing is confirmed.

  In the example of FIG. 7, an example is shown in which the load distribution control unit 420 of the radio base station 400-1 is inquired about information regarding whether or not the load distribution processing is involved. However, when the wireless terminal 500-1 holds information indicating whether or not the load distribution processing has been performed, that is, when the wireless terminal 500-1 has led the load distribution processing, the wireless terminal 500-1 The load distribution control unit 530 on the side may be inquired. In addition, when information on whether or not load balancing has been performed is shared with other wireless terminals and wireless base stations on the same network, inquiries to other wireless terminals and wireless base stations existing on the same network May be.

  Next, the terminal movement detection unit 140 confirms whether or not the load distribution process is performed in step A6 according to the procedure shown in the operation flow of FIG. 9 to be described later. And the position detection processing unit 130 is notified together with the terminal identification information that the wireless terminal 500-1 has moved (steps A7 and A8).

  On the other hand, if it is confirmed that the load distribution process is being performed, the process ends here without determining that the terminal is moving.

  The position detection processing unit 130 that has received the notification of terminal movement searches the radio base station installation position database unit 120 using the information of the radio base station connected after movement, and from the position of the radio base station connected after movement, The position information after the movement of the wireless terminal 500-1 is acquired. Then, position information update processing, that is, processing for notifying the external application that the wireless terminal 500-1 has moved and the position information of the new wireless terminal 500-1 is performed (steps A9, A10, A11). .

  Next, the processing of the terminal information acquisition unit 160 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  The terminal information acquisition unit 160 starts processing by acquiring connection base station information from the wireless terminal 500-1 and notification of identification information of the wireless terminal 500-1 (step A1601).

  When the notification from the wireless terminal 500-1 is acquired in step A1601, the terminal information acquisition unit 160 next searches the terminal information storage unit 150, acquires the already registered connection base station information 150-2, The entry of the wireless terminal 500-1 in the terminal information storage unit 150 is updated to the connection base station information newly received in Step A1601 (Step A1602).

  Then, the connection base station information acquired in step A1601 and step A1602 is compared (step A1603). Here, when it can be determined that the respective connecting base station information is the same, it is determined that the connecting base station has not been changed, and the process ends.

  On the other hand, if the terminal connection base station information is different, it is determined that the connection base station has been changed, and the process proceeds to step A1604. In step A1604, the connection base station information and the terminal identification information newly acquired in step A1601 are notified to the terminal movement detection unit 140 as a connection base station change notification.

  Next, processing of the terminal movement detection unit 140 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  The terminal movement detection unit 140 starts the processing by acquiring the notification of the change of the connected base station from the terminal information acquisition unit 160 (step A1401).

  After acquiring the change notification of the connected base station from the terminal information acquisition unit 160, next in step A1402, whether or not the change of the connected base station is associated with the load distribution process is determined by the radio base station 400-1, The wireless terminal 500-1 or another wireless base station or wireless terminal existing on the same network is inquired (step A1402).

  If it is confirmed in step A1403 that the load distribution process is being performed for the wireless terminal 500-1, it is determined that the wireless terminal 500-1 has not moved, and the process ends here. On the other hand, if it is confirmed that the load distribution process has not been performed, it is determined that the wireless terminal 500-1 has moved, and the process of step A1404 is executed.

  In Step A1404, the position detection processing unit 130 is notified of the movement of the wireless terminal 500-1 together with the terminal identification information.

  As described above, in the first embodiment, when the radio base station to which the radio terminal is connected changes, whether the change is caused by handover processing due to movement of the radio terminal or load distribution processing Confirm. If this change is not caused by the load distribution process, it is determined that the wireless terminal has moved.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. The configuration example of the wireless network system in this embodiment is the same as that in FIG.

  In the second embodiment of the present invention, when the wireless terminal 500-1 changes the connection base station, can the wireless terminal 500-1 acquire the signal from the originally connected wireless base station after the connection change? It is characterized by determining whether or not the wireless terminal 500-1 has moved by confirming whether or not.

  First, FIG. 10 shows a configuration example of the terminal information storage unit 150 in the positioning server 100 in the present embodiment. In addition to the configuration of the terminal information storage unit 150 in the first embodiment (FIG. 6), in this embodiment, when the wireless terminal moves, it is connected before being connected to the currently connected wireless base station. It stores location acquisition base station information 151-4, which is information on the radio base station, that is, the radio base station used by the radio terminal for the previous location information acquisition.

  Further, in the present embodiment, not only the base station information to which the wireless terminal is connected but also the information about the surrounding wireless base stations in the range where the wireless terminal can communicate (sense), the peripheral base station information 151-5. The number of radio base stations is recorded as 151-6 and 151-7.

  Next, the entire operation flow in the present embodiment will be described in detail with reference to FIG. First, in step B0, as in step A0 of the first embodiment, a connection base station change process associated with a load distribution process or a handover process accompanying the movement of a terminal is performed, so that the radio terminal 500-1 and the radio base station 400-1 is connected. Next, in the connected base station management unit 520, the wireless terminal 500-1 is connected base station information and everything other than the connected base station that the wireless terminal 500-1 can communicate (sense) from the current position. Base station information (peripheral base station information) is acquired and notified to the positioning server 100 together with the terminal identification information (step B1). Note that the process of step B1 may be performed periodically regardless of the process of step B0, the connection to the radio base station is started, the connected base station changes, or the neighboring base station This may be done when station information changes.

  On the positioning server 100 side, when terminal information acquisition section 160 receives wireless terminal identification information, connection base station information, and neighboring base station information from wireless terminal 500-1 in the procedure shown in the operation flow of FIG. The terminal information storage unit 150 is searched, and the entry of the wireless terminal 500-1 is updated to the newly received connection base station information and neighboring base station information (steps B2 and B3).

  Here, when either the connected base station information or the neighboring base station information has changed, the newly connected base station information notified from the wireless terminal 500-1 is displayed together with the terminal identification information of the wireless terminal 500-1. It transmits to the terminal movement detection part 140 (step B4).

  However, if neither the connected base station information nor the neighboring base station information has changed, the process ends at step B3 and the process at step B4 is not performed.

  Next, the terminal movement detection unit 140 searches the terminal information storage unit 150 based on the terminal identification information notified from the terminal information acquisition unit 160 in the procedure shown in the operation flow of FIG. The acquired base station information and the neighboring base station information newly updated in step B2 are acquired (steps B5 and B6).

  Then, the terminal movement detection unit 140 compares the position acquisition base station information acquired in step B6 with the neighboring base station information, and if any of the neighboring base station information does not include the position acquisition base station information, to decide. The reason is as follows. The fact that the location acquisition base station (the base station to which the wireless terminal was connected before moving) is different from any of the current surrounding base stations means that the current wireless terminal cannot communicate with the location acquisition base station. . That is, the wireless terminal cannot obtain (cannot communicate with) the signal from the wireless base station that was originally connected (before movement). Therefore, this case matches the definition that the wireless terminal has moved in the present embodiment. That is, since the wireless terminal cannot obtain the signal from the base station to which it originally connected, it is determined that the wireless terminal has moved.

  On the other hand, if there is the same information as the position acquisition base station information in the neighboring base station information, the process is terminated without determining that the terminal is moving (step B7). In other words, even if either the connected base station information or the neighboring base station information changes, if the signal from the base station to which the wireless terminal after the change was originally connected can be acquired, it is determined that the terminal is moving. First, it is determined that either the connected base station information or the neighboring base station information has changed as a result of the load distribution processing or the like.

  If it is determined in step B7 that the terminal has moved, the position detection processing unit 130 is notified, and the location acquisition base station information 151-4 of the corresponding entry in the terminal information storage unit 150 is acquired in step B4. Information is updated (steps B8 and B9). This is because the next time the wireless terminal moves. In addition, the process which the position detection process part 130 performs after receiving a terminal movement notification in step B8 is the same as the process of step A9, A10, A11 in 1st Embodiment. That is, the position detection processing unit 130 obtains the position of the wireless terminal after the movement using the information of the wireless base station connected after the movement, and provides the position information and the like to the external application. Detailed description is omitted.

  Next, processing of the terminal information acquisition unit 160 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  Terminal information acquisition section 160 in this embodiment starts processing by acquiring notification of connection base station information, neighboring base station information and identification information of wireless terminal 500-1 from wireless terminal 500-1. (Step B1601).

  When the notification from the wireless terminal 500-1 is acquired in step B1601, the terminal information acquisition unit 160 next searches the terminal information storage unit 150, and the connection base station information 151- of the already registered wireless terminal 500-1. 2 and neighboring base station information 151-5, etc., and the information of the corresponding entry is updated to the connected base station information and neighboring base station information received in step B1601 (step B1602).

  Then, the connection base station information acquired in step B1601 and step B1602 is compared. In addition, the neighboring base station information acquired in step B1601 and step B1602 is also compared (step B1603). Here, when it can be determined that the connected base station information and the neighboring base station information are the same, it is determined that the connected base station has not been changed, and the processing is terminated. On the other hand, if the connected base station information or the neighboring base station information has changed, the process proceeds to step B1604.

  In Step B1604, the connection base station information newly notified from the wireless terminal 500-1 in Step B1601 is transmitted to the terminal movement detection unit 140 together with the terminal identification information of the wireless terminal 500-1.

  Next, processing of the terminal movement detection unit 140 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  The terminal movement detection unit 140 in the present embodiment starts the process by acquiring the notification from the terminal information acquisition unit 160 (step B1401).

  When the notification from the terminal information acquisition unit 160 is acquired in step B140, the terminal information storage unit 150 is searched next, and the position acquisition base station information 151- registered in the entry of the wireless terminal 500-1 acquired in step B1401. 4 and the updated neighboring base station information 151-5 and the like are acquired.

  Next, in step B1403, it is confirmed whether the acquired base station information after the update includes the same base station information as the position acquisition base station information (step B1403). Here, if the updated neighboring base station information acquired from the terminal information storage unit 150 includes the same location acquisition base station information notified, the terminal movement is not determined. The process ends.

  On the other hand, if it is not included, it is determined that the terminal has moved, and the process proceeds to step B1404 to notify the position detection processing unit 130 together with the terminal identification information that the wireless terminal 500-1 has moved. Also, the position acquisition base station information 151-4 of the wireless terminal 500-1 in the terminal information storage unit 150 is updated to the changed connection base station information acquired in step B4.

  In the above description, when the wireless terminal 500-1 changes the connection base station, has the communication (sensing) been disabled with the wireless base station to which the wireless terminal after the change (change) was originally connected? Although an example in which all determinations are made on the positioning server 100 side has been shown, in the present embodiment, a method of making this determination on the wireless terminal 500-1 side may be used. Specifically, the wireless terminal 500-1 determines whether or not communication (sensing) is impossible after the connection change with the wireless base station to which the wireless terminal was originally connected. When it is determined that the terminal has moved without being able to communicate with the base station, the positioning server 100 is notified of the movement of the wireless terminal 500-1 together with the new connection base station information to the positioning server 100, and the positioning server 100 that has received the notification It is also possible to apply a method in which it is determined that the terminal has moved and a position information update process is performed.

  As described above, in the second embodiment, when the wireless terminal changes the connection base station, it is confirmed whether the signal from the originally connected wireless base station can be acquired by this wireless terminal after the connection change. Thus, the presence / absence of movement of the wireless terminal is determined. If the signal from the wireless base station to which the wireless terminal was originally connected cannot be acquired after the connection change, it is determined that the wireless terminal has moved.

  In addition, when the above processing is performed on the positioning server side, processing related to terminal movement is concentrated on the positioning server side, so the effect of simplifying the processing on the terminal side and the amount of information held on the terminal side can be reduced. There is an effect that it can be reduced. Conversely, when the above processing is performed on the terminal side, the processing load can be distributed, so that the processing on the positioning server side can be simplified and the amount of information held in the information storage unit of the terminal can be reduced. There is an effect.

  In addition, the present embodiment can be applied even in the case of a wireless system in which the load distribution control unit of the wireless base station or the wireless terminal does not have an interface for providing information on the presence / absence of load distribution to the outside. .

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

  In the third embodiment of the present invention, for each radio base station, other radio base stations with overlapping cover areas are registered in advance as adjacent base stations, and in addition to this adjacent base station, a connection base station of a radio terminal is registered. When it changes, it is judged that the terminal moves.

  First, FIG. 14 shows a configuration example of the terminal information storage unit 150 in the present embodiment. In addition to the configuration example of the terminal information storage unit 150 in FIG. 6 shown in the first embodiment, in the configuration example of the terminal information storage unit 150 in FIG. 14, when the radio terminal moves, the currently connected radio base station Location acquisition base station information 152-4, which is information of a radio base station that was connected before connection, that is, a radio base station that the radio terminal used for previous location information acquisition, is added.

  FIG. 15 shows a configuration example of the radio base station installation position database unit 120 in the present embodiment. In addition to the configuration example of the radio base station installation location database unit 120 of FIG. 5 shown in the first embodiment of the present invention, the configuration example of the radio base station installation location database unit 120 of FIG. , 122-5B, 122-5C are added. With this adjacent base station information, when a wireless terminal exists within the coverage area of a specific wireless base station, another wireless base station that can be handed over from that is used as the adjacent base station information of this wireless base station. Register in advance. Referring to the entry 122-B in the example of FIG. 15, the radio base station information that can be handed over from the coverage area of the radio base station “AABCCDDEE11” by the radio terminal connected to the radio base station “AABCCDDEE11” From the base station information 1 and 2, it can be seen that the wireless base stations are indicated by “AABCCDDEE03” and “AABCCDDEEFF”.

  Next, the entire operation flow in the present embodiment will be described in detail with reference to FIG. In the overall operation flow shown in FIG. 16, the process from step C0 to C2 is the same as the process from step A0 to A2 in the first embodiment.

  The terminal information acquisition unit 160 of the positioning server 100 searches / updates the terminal information storage unit 150 in step C2, and connects base station information and position acquisition base station information of the wireless terminal 500-1 registered in the terminal information storage unit 150. Is acquired (step C3). That is, when the connection base station information is notified together with the terminal identification information from the wireless terminal to the terminal information acquisition unit 160 of the positioning server in step C1, the terminal information acquisition unit 160 in step C2 based on the terminal identification information 150 is searched, and “connected base station information” and “location acquisition base station information” of this wireless terminal are acquired. Thereafter, the “connected base station information” registered in the terminal information storage unit 150 is updated to the connected base station information acquired in step C1.

  Next, the terminal information acquisition unit 160 compares the newly acquired connection base station information of the wireless terminal 500-1 with the connection base station information already registered in the terminal information storage unit 150. End the process. If they are different, it is determined that the connection base station is changed, and the new connection base station information acquired in step C1 and the position acquisition base station information originally registered in the terminal information storage unit 150 acquired in step C3 are The terminal movement detection unit 140 is notified together with the identification information of the terminal 500-1 (step C4).

  Receiving the notification of these base station information in step C4, the terminal movement detection unit 140 next searches the base station installation position database unit 120 for adjacent base station information of the position acquisition base station information acquired in step C4. (Steps C5 and C6). Specifically, when there is a matching MAC address or the like in the “unique information” 122-1 of the radio base station installation location database 120 using the location acquisition base station information (MAC address or the like) as a key, the entry The “adjacent base station information” is extracted.

  If the adjacent base station information acquired in step C6 does not include the connected base station information acquired in step C4, it is determined that the terminal has moved. The reason is as follows. The fact that the currently connected base station is different from any of the neighboring base stations of the location acquisition base station (the base station that was connected before the movement) means that the wireless terminal exceeds the neighboring base station of the location acquisition base station. It is connected to the base station. Therefore, in this case, it is consistent with the definition that the wireless terminal has moved in this embodiment. That is, it is determined that the wireless terminal has moved because the wireless terminal is connected to a base station other than the adjacent base station of the wireless base station that was originally connected.

  On the other hand, if the adjacent base station information acquired in step C6 includes the new connected base station information acquired in step C4, the process ends without determining that the terminal has moved (step C7). ). In other words, even if the connected base station is changed, if the wireless terminal after the change is connected to an adjacent base station of the base station to which the original connection was originally made, it is not determined that the terminal is moved, and load distribution processing is performed. As a result, it is determined that the wireless base station to be connected has been changed.

  When it is determined in step C7 that the terminal has moved, the terminal movement detection unit 140 notifies the position detection processing unit 130 together with the terminal identification information that the wireless terminal 500-1 has moved in step C8 (step C8). Also, the terminal movement detection unit 140 updates the position acquisition base station information 152-4 of the wireless terminal 500-1 in the terminal information storage unit 150 with the newly connected base station information acquired in Step C4 (Step C9). ).

  Note that the processing performed by the position detection processing unit 130 after receiving the terminal movement notification in step C8 is the same as the processing in steps A9, A10, and A11 in the first embodiment, and thus the description thereof is omitted.

  Next, the process of the terminal information acquisition unit 160 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  Terminal information acquisition section 160 in the present embodiment starts processing by acquiring new connection base station information and notification of terminal identification information from wireless terminal 500-1 in step C1 of FIG. (Step C1601).

  When the notification from the wireless terminal 500-1 is acquired in step C1601, the terminal information acquisition unit 160 next searches / updates the terminal information storage unit 150, and the wireless terminal 500-1 registered in the terminal information storage unit 150 is registered. Connected base station information and position acquisition base station information are acquired (step C1602).

  Next, in step C1603, the terminal information acquisition unit 160 compares the newly acquired connection base station information of the wireless terminal 500-1 with the connection base station information already registered in the terminal information storage unit 150. If these pieces of base station information are the same, the process ends here. If they are different, it is determined that the connected base station is changed, and the process proceeds to step C1604.

  In Step C1604, the new connection base station information acquired in Step C1601 and the position acquisition base station information originally registered in the terminal information storage unit 150 acquired in Step C1602 are combined with the terminal identification information of the wireless terminal 500-1. The terminal movement detection unit 140 is notified.

  Next, the processing of the terminal movement detection unit 140 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  The terminal movement detection unit 140 according to the present embodiment starts the process by acquiring the notification from the terminal information acquisition unit 160 in step C4 of FIG. 16 (step C1401).

  Receiving the notification of these base station information in step C4, the terminal movement detection unit 140 next searches the base station installation position database unit 120 for adjacent base station information of the position acquisition base station information acquired in step C1401. (Step C1402).

  Then, it is confirmed whether or not the adjacent base station information acquired in step C1402 includes the new base station information acquired in step C1401 (step C1403). If the adjacent base station information acquired in step C1402 includes the newly connected base station information acquired in step C1401, the process ends without determining that the terminal has moved. On the other hand, if it is not included, it is determined that the terminal has moved, and the process proceeds to the next step C1404.

  In step 1404, the location detection processing unit 130 is notified together with the terminal identification information that the wireless terminal 500-1 has moved, and the location acquisition base station information of the wireless terminal 500-1 in the terminal information storage unit 150 is updated in step C1401. Update to the newly connected base station information.

  As described above, in the third embodiment, when the wireless terminal changes the connection base station, the wireless terminal after the change can be handed over from the originally connected wireless base station (adjacent base station). If the wireless terminal is connected to a wireless base station other than the adjacent base station beyond the threshold, it is determined that the wireless terminal has moved.

  The present embodiment can be applied even in the case of a wireless system in which the load distribution control unit of the wireless base station or the wireless terminal does not have an interface for providing information on the presence / absence of load distribution to the outside.

  In addition, even if the wireless terminal does not move to a distance at which it can no longer communicate with the wireless base station to which it originally connected, if the terminal moves to a certain distance (away from the adjacent base station), the terminal moves. Therefore, it is possible to determine the terminal movement more quickly.

  Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings.

  In the present embodiment, when the connection base station of the wireless terminal changes, the connection base station changes due to load distribution control or the wireless terminal moves by looking at the change in the radio field intensity of the base station that was originally connected. It is characterized in that it is determined whether or not the connected base station changes.

  First, FIG. 19 shows a configuration example of the terminal information storage unit 150 in the present embodiment. 19 is different from the configuration example of the terminal information storage unit 150 in the first embodiment shown in FIG. 6 in that a parameter for recording the radio field intensity of the connection base station is added together with the connection base station information. Part.

  Next, the entire operation flow in the present embodiment will be described in detail with reference to FIG.

  First, in step D0 of FIG. 20, similarly to step A0 of the first embodiment, between the wireless terminal 500-1 and the wireless base station 400-1, load distribution processing or handover processing accompanying terminal movement is performed. A connection base station change process is performed.

  Next, in the connected base station management unit 520, the wireless terminal 500-1 uses the connected base station information that is the currently connected base station information and the base station information that was connected before changing the connected base station. The connection base station information, the radio wave intensity from the currently connected base station, and the radio wave intensity from the previous connection base station after the change of the connection base station are notified to the positioning server 100 together with the terminal identification information (step D1). The process of step D1 may be performed periodically regardless of the process of step D0, or may be performed when connection to the radio base station is started or when the connection base station changes. is there.

  Moreover, the time of measurement of each radio wave intensity can be, for example, the time of notification to the positioning server 100.

  Next, on the positioning server 100 side, in the terminal information acquisition unit 160, identification information of the wireless terminal 500-1 from the wireless terminal 500-1, connected base station information, previous connected base station information, and radio waves from these base stations. Receive strength. Then, the terminal information storage unit 150 is searched, and the connection base station information and the radio wave intensity registered in the entry of the wireless terminal 500-1 are acquired (steps D2 and D3).

  Next, it is determined whether or not the connection base station has been changed. If the connection base station has changed, the terminal identification information of the wireless terminal 500-1 and the connection base acquired from the terminal information storage unit 150 in step D3. The radio wave intensity of the station information and the radio wave intensity of the previously connected base station information notified from the wireless terminal 500-1 in step D1 are transmitted to the terminal movement detection unit 140 (step D4). However, if it is determined that the connected base station has not changed, the process of step D4 is not performed.

  The terminal information acquisition unit 160 then connects the connection base station information and the radio wave intensity of the entry of the wireless terminal 500-1 in the terminal information storage unit 150 to the currently connected connection base station notified from the wireless terminal 500-1 in step D1. Information and its radio field intensity are updated (step D5).

  In the terminal movement detection unit 140 that detects the change of the connection base station in step D4 and receives the notification from the terminal information acquisition unit 160, the radio field intensity of the previous connection base station information notified from the wireless terminal 500-1 in step D1. Are compared with the radio field intensity of the connection base station information acquired from the terminal information storage unit 150 in step D3, and acquired in step D1 (change in connection base station) from the radio field intensity acquired in step D3 (before the connection base station is changed). When the latest radio field intensity from the same base station is decreased, it is determined that the wireless terminal 500-1 has moved, and a terminal movement notification is transmitted to the position detection processing unit 140. However, if the radio field intensity has not decreased, it is not determined that the terminal has moved, and the terminal movement notification is not performed (steps D6 and D7).

  Also, with regard to this terminal movement determination method, a certain range is set for the magnitude of the change in the radio field intensity so that the radio terminal 500-1 determines that the radio terminal 500-1 has moved when the decrease range of the radio field intensity is a certain value or more. You can make it.

  The reason why such movement determination is possible is as follows.

  The radio wave intensity of the connected base station information corresponding to the entry of the wireless terminal 500-1 stored in the terminal information storage unit 150 is recognized after the base station change is recognized and the terminal movement determination process is transferred to the terminal movement detection unit 140. Since it is updated, the information in the terminal information storage unit 150 used in the terminal movement determination process in the terminal movement detection unit 140 is information before the update. That is, the radio field intensity stored in the terminal information storage unit 150 is the radio field intensity from the connected base station before the change at the time before the base station is changed.

  On the other hand, the radio field intensity of the previous connection base station notified from the radio terminal 500-1 is the radio field intensity at the time after the base station of the same base station is changed.

  For this reason, when the base station to be connected is changed by load distribution processing or the like even though the wireless terminal 500-1 is not moving, both radio field intensities are not changed. This is because when the base station to be connected due to movement is changed, there is a difference between the two radio wave intensities.

  Note that the processing performed by the position detection processing unit 130 after receiving the terminal movement notification in step D7 is the same as the processing in steps A9, A10, and A11 in the first embodiment, and thus the description thereof is omitted.

  Next, the processing of the terminal information acquisition unit 160 in this embodiment will be described in detail with reference to the flowchart of FIG.

  In step D1 of FIG. 20, the terminal information acquisition unit 160 in the present embodiment obtains the terminal identification information from the wireless terminal 500-1, the connection base station information, the previous connection base station information, and the radio wave intensity from these base stations. By receiving, the process is started (step D1601).

  Next, in step D1602, the terminal information storage unit 150 is searched, and the connection base station information and the radio wave intensity registered in the entry of the wireless terminal 500-1 are acquired (step D1602).

  In step D1603, it is confirmed whether or not the connected base station has changed. If not, the process of step D1604 is omitted and the process proceeds to step D1605.

  On the other hand, if the connected base station has changed, the process proceeds to step D1604, the terminal identification information of the wireless terminal 500-1, the radio field intensity of the connected base station information acquired from the terminal information storage unit 150 in step D1602, In step D1601, the radio field strength of the previous connection base station information notified from the wireless terminal 500-1 is transmitted to the terminal movement detection unit 140.

  Next, in step D1605, the connection base station information 153-2 and the radio wave intensity 153-3 of the corresponding entry of the wireless terminal 500-1 in the terminal information storage unit 150 are the new connection base station information acquired in step D1601 and the radio wave intensity thereof. Update to

  Next, processing of the terminal movement detection unit 140 in the present embodiment will be described in detail with reference to the flowchart of FIG.

  The terminal movement detection unit 140 according to the present embodiment receives the notification from the terminal information acquisition unit 160 in step D4 of FIG. 20 and starts its processing (step D1401).

  Next, in step D1402, the radio field intensity of the previous connection base station of the wireless terminal 500-1 acquired in step D1401 is compared with the radio field intensity of the connection base station information acquired from the terminal information storage unit 150. Here, it is confirmed whether or not the radio field intensity of the previous connection base station acquired from the wireless terminal 500-1 is lower than the radio field intensity of the connection base station information acquired from the terminal information storage unit 150 (step D1402). The radio field intensity to be compared here is the radio field intensity before and after the connection change for the same radio base station. Therefore, when it is confirmed that the radio field intensity has decreased, it is determined that the wireless terminal 500-1 has moved, and the process proceeds to step D1403. Also, with regard to this terminal movement determination method, a certain range is set for the magnitude of the change in the radio field intensity so that the radio terminal 500-1 determines that the radio terminal 500-1 has moved when the decrease range of the radio field intensity is a certain value or more. You can make it.

  In step D1403, a terminal movement notification is transmitted to the position detection processing unit 130, and the process ends. On the other hand, if it is not possible to confirm in step D1402 that the radio field intensity has decreased (greater than a certain value), it is not determined that the terminal has moved, and the process of step D1403 is omitted and the process ends.

  As described above, in the fourth embodiment, when the wireless terminal changes the connection base station, the radio wave intensity before the change from the radio base station before the change is compared with the radio wave intensity after the change. . Then, when the radio wave intensity at the time after the change is lower than the radio wave intensity at the time before the change, it is determined that the wireless terminal has moved.

  In the above description, when the wireless terminal changes the connection base station, an example is shown in which all processing for viewing the change in radio field strength of the wireless base station that was originally connected is performed on the positioning server side. A method of performing this process on the wireless terminal side is also applicable.

  As described above, in the present invention, when the wireless base station to which the wireless terminal is connected is changed using the various methods described in the first to fourth embodiments, the change is caused by the movement of the wireless terminal. It is determined whether it is caused by load distribution processing or the like, that is, a factor for changing the connected base station is obtained.

  Further, in the above description, the processing in the wireless terminal and the positioning server is described as being realized by hardware, but these processing may be realized by a program.

It is a figure which shows the system configuration example of this invention. It is a figure which shows the structural example of the radio | wireless terminal of this invention. It is a figure which shows the structural example of the wireless base station of this invention. It is a figure which shows the structural example of the positioning server of this invention. It is a figure which shows the structural example of the radio base station installation position database part of the 1st Embodiment of this invention. It is a figure which shows the structural example of the terminal information storage part of the 1st Embodiment of this invention. It is a sequence chart which shows the whole operation | movement in the 1st Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal information acquisition part of the 1st Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal movement detection part of the 1st Embodiment of this invention. It is a figure which shows the structural example of the terminal information storage part of the 2nd Embodiment of this invention. It is a sequence chart which shows the whole operation | movement in the 2nd Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal information acquisition part of the 2nd Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal movement detection part of the 2nd Embodiment of this invention. It is a figure which shows the structural example of the terminal information storage part of the 3rd Embodiment of this invention. It is a figure which shows the structural example of the radio base station installation position database part of the 3rd Embodiment of this invention. It is a sequence chart which shows the whole operation | movement in the 3rd Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal information acquisition part of the 3rd Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal movement detection part of the 3rd Embodiment of this invention. It is a figure which shows the structural example of the terminal information storage part of the 4th Embodiment of this invention. It is a sequence chart which shows the whole operation | movement in the 4th Embodiment of this invention. It is a figure which shows the structural example of the terminal information storage part of the 4th Embodiment of this invention. It is a figure which shows the operation | movement flow of the terminal movement detection part of the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Positioning server 200 Application server 300 Network 400-1, 400-2 Wireless base station 500-1, 500-2, 500-3 Wireless terminal

Claims (20)

A connected base station change detecting means for detecting presence or absence of a change in a base station to which the terminal is connected;
When detecting a change of the base station to which the terminal is connected by the connected base station change detection means, determine whether this change is caused by load distribution processing, and when it is determined not to be caused by load distribution processing, Terminal movement determining means for determining that the terminal has moved;
When it is determined by the terminal movement determination means that the terminal has moved, position information update processing means for obtaining the position information of the terminal based on the position of the base station connected after the movement;
A positioning server comprising:   The determination as to whether or not the terminal movement determination means is caused by load balancing confirms whether load balancing processing is performed based on information from a terminal or a base station. When load balancing processing is not performed, the change is load balancing. The positioning server according to claim 1, wherein the positioning server is determined not to be caused by processing. The connected base station change detecting means detects whether or not there is a change in a surrounding base station that can be sensed by the terminal, in addition to detecting whether or not the base station to which the terminal is connected is changed,
When the determination as to whether or not the terminal movement determination means is caused by load distribution detects a change in a connected base station or a change in a neighboring base station that can be sensed by the connected base station change detection means, The positioning server according to claim 1, wherein when the base station connected to the terminal is not included in the neighboring base station after the change, it is determined that the change is not caused by the load distribution process.   If the base station connected to the terminal after the change is not included in the base station that can be handed over by the base station connected to the terminal after the change, the determination as to whether or not the terminal movement determination means is caused by the load distribution The positioning server according to claim 1, wherein the positioning server is determined not to be caused by processing.   This change occurs when the determination as to whether or not the terminal movement determination means is caused by load distribution is when the radio field intensity from the base station connected to the terminal before the change is lower than the radio field intensity from the base station after the change. The positioning server according to claim 1, wherein the positioning server is determined not to be caused by load distribution processing. A positioning system comprising a terminal, a base station connected to the terminal, and a positioning server connected to the terminal via the base station,
The positioning server is
A connected base station change detecting means for detecting presence or absence of a change in a base station to which the terminal is connected;
When detecting a change of the base station to which the terminal is connected by the connected base station change detection means, determine whether this change is caused by load distribution processing, and when it is determined not to be caused by load distribution processing, Terminal movement determining means for determining that the terminal has moved;
When it is determined by the terminal movement determination means that the terminal has moved, position information update processing means for obtaining the position information of the terminal based on the position of the base station connected after the movement;
A positioning system characterized by comprising:   The determination as to whether or not the terminal movement determination means is caused by load balancing confirms whether load balancing processing is performed based on information from a terminal or a base station. When load balancing processing is not performed, the change is load balancing. The positioning system according to claim 6, wherein the positioning system is determined not to be caused by processing. The connected base station change detecting means detects whether or not there is a change in a surrounding base station that can be sensed by the terminal, in addition to detecting whether or not the base station to which the terminal is connected is changed,
When the determination as to whether or not the terminal movement determination means is caused by load distribution detects a change in a connected base station or a change in a neighboring base station that can be sensed by the connected base station change detection means, The positioning system according to claim 6, wherein when the base station connected to the terminal is not included in the peripheral base station after the change, it is determined that the change is not caused by the load distribution process.   If the base station connected to the terminal after the change is not included in the base station that can be handed over by the base station connected to the terminal after the change, the determination as to whether or not the terminal movement determination means is caused by the load distribution The positioning system according to claim 6, wherein the positioning system is determined not to be caused by processing.   This change occurs when the determination as to whether or not the terminal movement determination means is caused by load distribution is when the radio field intensity from the base station connected to the terminal before the change is lower than the radio field intensity from the base station after the change. The positioning system according to claim 6, wherein the positioning system is determined not to be caused by load distribution processing. A connected base station change detection step for detecting presence or absence of a change in a base station to which the terminal is connected;
When detecting the change of the base station to which the terminal is connected in the connected base station change detection step, determine whether this change is caused by the load distribution process, and when determining that the change is not caused by the load distribution process, A terminal movement determination step for determining that the terminal has moved;
When it is determined that the terminal has moved by the terminal movement determination step, a position information update processing step for obtaining position information of the terminal based on the position of the base station connected after the movement;
A positioning method characterized by comprising:   The determination as to whether or not it is caused by load distribution in the terminal movement determination step confirms the presence or absence of load distribution processing based on information from a terminal or a base station. The positioning method according to claim 11, wherein the positioning method is determined not to be caused by processing. The connected base station change detection step detects whether or not there is a change in a surrounding base station that can be sensed by the terminal in addition to detecting whether or not the base station to which the terminal is connected is changed,
When the determination of whether or not it is caused by load distribution in the terminal movement determination step detects a change in a connected base station or a change in a neighboring base station that can be sensed in the connected base station change detection step, The positioning method according to claim 11, wherein when the base station connected to the terminal is not included in the neighboring base station after the change, it is determined that the change is not caused by the load distribution process.   If the base station connected to the terminal after the change is not included in the base station to which the terminal before the change can be handed over is determined whether the determination of whether or not it is caused by the load distribution in the terminal movement determining step. The positioning method according to claim 11, wherein the positioning method is determined not to be caused by processing.   If the determination as to whether or not it is caused by load distribution in the terminal movement determination step is that the radio field intensity from the base station connected to the terminal before the change is lower than the radio field intensity from the base station after the change, this change The positioning method according to claim 11, wherein the positioning method is determined not to be caused by the load distribution process. Connection base station change detection processing for detecting whether or not the base station to which the terminal is connected has changed,
When detecting a change in the base station to which the terminal is connected by the connected base station change detection process, determine whether this change is caused by the load distribution process, and when determining that the change is not caused by the load distribution process, A terminal movement determination process for determining that the terminal has moved;
When it is determined that the terminal has moved by the terminal movement determination process, the position information update processing step for obtaining the position information of the terminal based on the position of the base station connected after the movement;
The program characterized by having.   The determination as to whether or not the load distribution process is caused by load distribution in the terminal movement determination process confirms whether or not the load distribution process is performed based on information from the terminal or the base station. The program according to claim 16, wherein the program is determined not to be caused by processing. The connected base station change detection process detects whether there is a change in a surrounding base station that the terminal can sense, in addition to detecting whether there is a change in the base station to which the terminal is connected,
When the determination as to whether or not it is caused by load distribution in the terminal movement determination process detects a change in a connected base station or a change in a neighboring base station that can be sensed by the connected base station change detection means, The program according to claim 16, wherein when the base station connected to the terminal is not included in the peripheral base station after the change, it is determined that the change is not caused by the load distribution process.   If the base station connected to the terminal after the change is not included in the base station that can be handed over to the terminal before the change, this change is determined by the load distribution in the terminal movement determination process. The program according to claim 16, wherein the program is determined not to be caused by processing. This change occurs when the determination as to whether or not it is caused by load balancing in the terminal movement determination process is lower than the radio field intensity from the base station after the change, from the base station connected to the terminal before the change. The program according to claim 16, wherein the program is determined not to be caused by load distribution processing.

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