JP2007228085A - Presence estimate apparatus and method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a presence estimate apparatus, a presence estimate method, and a program for estimating a state of a user of a terminal and informing of the state as state information. <P>SOLUTION: The presence estimate apparatus 30 includes: a communication control means 32 for controlling transmission reception via a wireless network; a condition storage means 36 for registering identification information and presence information of the terminal in cross reference with each other; a terminal apparatus registration means 22 for registering a unique identification value of the terminal taking part in the wireless network; and an estimate means 38 for acquiring the unique identification value from registered data in the terminal apparatus registration means 22, searching the condition storage means 36 and estimating a presence state of the user to the terminal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to notification of user status information, and more particularly to a presence estimation device, a presence estimation method, and a program for estimating the status of a user of a terminal device and notifying the status information.

  In recent years, information processing apparatuses are interconnected not only by a wired network but also by a wireless network such as a wireless network or an infrared network, so that portability is improved and a flexible network can be constructed. FIG. 9 shows the generation of a network system in a conventional wireless network. The wireless network 100 is configured around an access point 102, and a cell 104 is formed within a certain range from the access point 102.

  The access point 102 periodically transmits a beacon frame 108 by broadcasting. Further, the terminal device 106 periodically broadcasts a probe request frame 110 and performs handshake / handoff processing in the cell 104 of the terminal device 106 that can be connected to the wireless network 100. Examples of the terminal device 106 include a notebook personal computer, a mobile phone, a smartphone, and a PDA.

  For example, if the wireless network 100 uses an active scanning protocol, when the access point 102 receives the probe request frame 110 from the terminal device 106, it transmits a probe response frame and connects according to the handshake protocol. Is established. At this time, the access point 102 acquires the unique identification value (MAC address) of the terminal device 106 and registers it in a terminal registration unit that stores an address table as a destination of subsequent transactions.

  The access point 102 is connected to the router 114 via a wired network 112 such as Ethernet (registered trademark). The router 114 has a function such as NAT or IP masquerade for mutual conversion of an Internet connection request from the terminal device 106 or a transaction from a server (not shown) to the terminal device 106. The router 114 connects the terminal device 106 and the terminal device 116 to a public network 118 such as the Internet or a public telephone network. At the same time, the router 114 can transmit data to and from the terminal device 116 such as a personal computer via a wired network.

  The access point 102 checks whether the terminal device 106 exists in the cell according to the protocol described above. Therefore, the access point 102 can efficiently provide the presence information of the terminal device 106. If the information generated by the access point 102 is effectively used, the presence information of the user of the terminal device 106 is obtained. It is thought that efficient updating of the system will be possible.

  Until now, an apparatus for registering status information of a user who uses an information processing apparatus has been proposed. For example, Japanese Patent Laid-Open No. 2004-64647 (Patent Document 1) stores current presence information including schedule information. There is disclosed a presence updating device that includes presence storage means and updates current presence information in the presence storage means in response to presence selection by a user. Japanese Patent Laying-Open No. 2004-23374 (Patent Document 2) discloses a state notification device that detects an operation in response to an operation of a communication terminal and transmits a presence state.

The presence update apparatus described in Patent Document 1 has a problem that it cannot update the status information responding to the user status in real time because it determines the status of the user from the schedule information. In addition, since the status notification device described in Patent Document 2 updates presence information in response to a specific operation such as a mobile phone by a user, the terminal device such as a mobile phone is operated during a conference or otherwise. In an environment where this is not possible, there is a problem that state information cannot be notified or updated. In addition, problems such as inaccuracy of the presence state occur due to the user's forgetting operation.
JP 2004-64647 A JP 2004-23374 A

  The present invention has been made in view of the above-described prior art. Until now, when a user changes the state of the information processing apparatus, the user's state can be changed without requiring any special operation. It was necessary to update the state and infer its state.

  The present invention has been made in view of the above problems, and manages the state of a user in a wireless network environment in relation to an access point, predicts the state, and stores the presence data of the user. Update. In the present invention, when it is determined that the terminal device has departed from the cell formed by the access point, the information processing device selects the user state from the reservation states registered in advance, and estimates the presence state. To do. For this reason, when a user leaves or joins a cell, the user can update his / her presence status without performing any special operation, and the presence information is more flexible and accurate. Can be provided.

That is, according to the present invention, a presence estimation device for estimating the presence status of a user of a terminal device,
A communication control means for controlling transmission / reception via the wireless network;
Condition storage means for registering terminal device identification information and presence information correspondingly,
Terminal device registration means for registering a unique identification value of the terminal device participating in the wireless network;
There is provided a presence estimation device comprising: an estimation unit that acquires the unique identification value from registration data of the terminal device registration unit, searches the condition storage unit, and estimates the presence state of the user of the terminal device. The

  The present invention can further include a transmission / reception data processing unit for transmitting the estimated presence status to the outside via a wired network. In the present invention, the condition storage means stores the device type data of the terminal device, and the estimation means estimates the presence state by counting the number of the terminal devices having the same device type data. Counting means. In the present invention, the wireless network may be a wireless network conforming to the Bluetooth or IEEE 803.11.

According to the present invention, there is a presence estimation method for causing an information processing apparatus to execute a method of estimating the presence state of a user of a terminal device,
Obtaining a unique identification value of the terminal device participating in the wireless network via the communication control means;
Searching registration data of the terminal registration means, and specifying the unique identification value of the terminal device that may have changed the participation state in the wireless network;
The present invention provides a presence estimation method comprising: searching a condition storage means using the identified unique identification value of the identified terminal device as a search key, and generating an estimated result in a presence state corresponding to the unique identified value.

  The present invention may further include a step of transmitting the estimated presence status to the outside via a wired network. The present invention can include a step of acquiring device type data of the terminal device and a step of estimating the presence state by counting the number of the terminal devices having the same device type data. The present invention may include a step of periodically requesting an acknowledgment from the terminal device. In the present invention, the unique identification corresponding to the difference between the step of storing the unique identification value of the terminal device registered immediately before, the stored unique identification value, and the unique identification value acquired thereafter Obtaining a value, and obtaining a presence state corresponding to the unique identification value corresponding to the difference and updating the estimation result.

  In the present invention, an apparatus-executable program for causing an information processing apparatus to execute any one of the methods described above is provided.

  Hereinafter, the present invention will be described with the embodiments of the present invention shown in the drawings, but the present invention is not limited to the embodiments shown in the drawings.

  FIG. 1 shows a presence notification system 10 including the presence inference device of the present invention. The presence notification system 10 of the present invention includes a wired network 12 such as Ethernet (registered trademark). The switch 14 also connects a plurality of information processing apparatuses. In the embodiment shown in FIG. 1, the switch 14 interconnects an access point 16, a plurality of personal computers 18, a presence server 20, etc. that form a wireless network defined by Bluetooth or IEEE 802.11. is doing.

  The access point 16 periodically transmits a beacon frame to notify the existence of the access point 16 to a terminal device (not shown) such as a personal computer, a PDA, or a mobile phone existing in the cell. ing. In addition, the terminal device transmits a probe request frame to request a handshake with the access point 16. When the wireless network of the present invention uses an active scanning protocol, when the access point 16 receives a probe request frame from a terminal device, the access point 16 transmits a probe response frame to perform an association request / association. -Establish a connection using the response protocol.

  When the wireless network of the present invention uses the passive scanning protocol, the terminal device identifies a cell participating in the wireless network in response to receiving the beacon frame, and performs a handshake process. To start. The access point 16 enters the unique identification value (MAC address) of the terminal device that has established the connection as registration data in the address table of the terminal device registration means 22, and manages it as a destination for polling during data transmission processing. ing.

  In another embodiment of the present invention, an appropriate information processing means such as the access point 16 or another information processing apparatus, for example, the server 20, periodically stores the unique identification value stored in the access point 16. By copying and creating registration data and comparing with the immediately preceding terminal device registered in the access point 16, the association between the terminal device and the cell can be determined.

  The access point 16 is further connected to the wired network 12 and is further connected to the switch 14 having at least a layer 2 level function via the wired network 12. On the other hand, the switch 14 includes an address table 24 and registers the addresses of the personal computer 18 and the server 20 connected to the wired network 12. The switch 14 has at least a layer 2 level function and processes a transaction in the wired network 12.

  The wired network 12 is connected to the router 26 via the switch 14. The router 26 can transmit and receive transactions such as FTP requests, HTTP requests, mails, and facsimiles of terminal devices, personal computers 18, and servers 20 connected to the wireless network via the Internet, public telephone network, or the like.

  FIG. 2 is a block diagram of the presence estimation apparatus 30 of the present invention. The presence inference device 30 of the present invention may be a module of the access point 16 in a specific embodiment of the present invention. In this case, if the presence estimation device 30 of the present invention is a module of the access point 16, it periodically polls the terminal device and monitors a response such as an ACK (acknowledgment response) from the terminal device. Then, the status of the terminal device in the cell is determined from a response timeout or the like, and processing for deleting the registration from the terminal device registration means 22 is performed. In the specific embodiment of the present invention, the polling interval is shorter than the interval at which the terminal device registration unit 22 automatically deletes the unique identification value.

  For this reason, the terminal device registration means 22 is configured to enter a unique identification value of a terminal device existing in the cell without performing data transmission through the access point. Further, when the presence estimation device 30 of the present invention is provided as a module such as the server 20, when the similar function is a module of the server 20, the server 20 periodically performs a terminal device of the wireless network. Can be polled and its status can be grasped.

  The presence inference device 30 of the present invention will be described in more detail. The presence inference device 30 is transmitted and received between the communication control means 32 that performs processing for transmitting a frame or a packet to the network, and the communication control means 32. And a transmission / reception data processing unit 34 for generating a frame or a packet. The communication control means 32 can be generally constituted by functions referred to as a network interface card (NIC), and executes processing based on a physical layer protocol in the OSI basic reference model.

  The transmission / reception data processing unit 34 has a function of extracting data from a frame or packet and adding data to the frame or packet. It is in charge. The presence inference device 30 of the present invention can receive a condition set by a user via a network and execute a process of registering it as condition data in the condition storage means 36 so that the inference state can be inferred by the inference means 38. And The estimation means 38 is configured as application software, and uses the data of the condition storage means 36 stored in an appropriate memory or the like and the data of the terminal device registration means 22 similarly stored in an appropriate memory, so that the terminal device Guess the state of users.

  The estimated result is converted into a transmission packet or a transmission frame by the transmission / reception data processing unit 34 and then transmitted to the network through the communication control unit 32. The estimation result sent to the network is used, for example, to update the presence information related to the corresponding user of the server 20.

  In another embodiment of the present invention, when the presence estimation device 30 is a module of the server 20, the presence estimation device 30 of the present invention uses the terminal device registration means 22 for the access point 16. It has a function of querying registered registration data or copied registration data.

  In the case of the embodiment described above, the presence inference device 30 periodically acquires the unique identification value data of the terminal device registration means 22 of the access point 16 and registers the terminal device in an appropriate storage area such as the server 20. A copy of the registered data in the means 22 is stored. By performing this process, if the terminal device registration means 22 performs a process of automatically updating the unique identification value, the registration data used for the estimation and the next registration are performed without polling each terminal device. The difference data between the registered data and the registered data can be generated accurately.

  In still another embodiment of the present invention, the presence inference device 30 can accept an inquiry for presence information about a specific user from the outside. In this embodiment, the presence inference device 30 receives an inquiry about the information of a specific user via the network, searches the inquiry source for the data of the user, and at that time The estimated presence status may be notified.

  FIG. 3 is a diagram showing an embodiment of the terminal device registration means 22 included in the access point 16 in the present invention. FIG. 3 (a) shows an embodiment of the terminal device registration means 22 when the wireless network is constructed by IEEE 802.11 or the like, and FIG. 3 (b) shows a standard in which the wireless network is Bluetooth or the like. An embodiment in the case of being constructed in the above. In the embodiment shown in FIG. 3A, the terminal device registration unit 22 includes a field 40 for entering a port_id that is a port identification value of the access point 16, and a unique identification value managed by the port. And a field 42 for entering. The access point 16 has a unique identification value AB. CD. EF. GH. IJ. When a frame including a KL destination is received, port_id is searched, and the frame is transferred to the corresponding port, thereby communicating with the target terminal device.

  In addition, in the embodiment shown in FIG. 3B, in addition to the field 40 and the field 42, a field 44 for registering an 11-bit device code defined in, for example, Bluetooth is included. The device code is terminal device type data, and a unique device code is assigned to the terminal device type. This code can be a binary code or a text code. In the embodiment of FIG. 3 (b), the access point 16 can use the device code in the field 44 to predict the presence state.

  FIG. 4 is a diagram showing a condition table 46 managed by the condition storage means 36 of the presence inference device. The condition table 46 shown in FIG. 4 is generated when the server 20 or the access point 16 receives a condition input from the terminal device by the user of the terminal and enters the condition storage means 36. The condition table 46 includes a field 48 for identifying a condition, a field 50 for registering terminal data used for condition determination, a field 52 for registering a determination condition used for determination, and a field 52 used for the determination. The field 54 for registering the search result of the terminal device registration means 22 to be entered is entered.

  In addition, when making a guess using a device code in the present invention, a field 56 for registering other conditions such as designation of the number of devices is provided. As the condition of the field 56, when the user uses a predetermined number of devices, a value serving as a reference for the determination is registered. In the embodiment shown in FIG. 4, when three or more predetermined devices are detected by a specific access point, the presence status is “in meeting” as defined in the field 58. Instruct. In the field 58, states such as “meal” and “working” for specifying the presence state of the user are registered. In the present invention, the condition data shown in FIG. 4 can be used for all the users as a whole, or a different table for each user so that a plurality of conditions can be set for each user. Can be offered as.

  The estimation process of the presence estimation apparatus 30 of the present invention is executed as follows. The presence estimation device 30 periodically looks up the terminal device registration means 22 and acquires the unique identification value of the terminal device registered at that time. Thereafter, for the condition data registered corresponding to all the unique identification values looked up, the presence determination is executed, and the process of acquiring the presence state is executed.

  Further, in the second embodiment of the present invention, when a copy of the terminal device registration unit 22 is generated, the unique identification value obtained by the lookup of the terminal device registration unit 22 is copied the previous time. The difference data is generated by comparing with the unique identification value of the obtained data, and the presence status update process is executed only for the difference data. In this case, it is not necessary to collectively perform the presence state determination process for all the unique identification values registered at that time, so that an efficient estimation process is possible.

  The presence inference device 30 looks up the condition table in the condition storage means 36 using all the unique identification values or the difference data that could be looked up at that time as search keys. Thereafter, the presence inference device 30 refers to the judgment data such as the system timer at that time, and acquires the date and time, or the device code if specified by the user, respectively, and the variables c_time and Set to variable device_id. Thereafter, the presence inference device 30 looks up the presence data registered in the field 54 of the condition table, obtains time range data (set_time_1, set_time_2) and presence status values (status), and acquires a specific uniqueness. With reference to the condition data having the identification value, the determination process indicated by the following pseudo code is executed. The definition of each variable is as follows.

c_time: Time when the estimation process is executed
device_code: Device code of the terminal device
device_id: Code or name of the specific device specified by the user
device_number: Number of terminal devices with a specific device code
set_time_1: Start time of the time range registered by the user
set_time_2: End time of the time range registered by the user
status: Value of presence status registered in the condition data
lunch
current_status: A variable that stores the estimated presence status value
in_business: Business
port (i): Port number in the terminal device registration means
meeting: Meeting
no_meeting: Not in a meeting
absent or
private_holiday: off or on vacation
^* socketaddr: Pointer indicating the socket address
destination_addr: Destination address (IP address or unique address)
current_statusLen: Estimated presence status byte length

  In the present invention, similar determination processing can be executed using different conditions, and the presence status of the user can be updated. In the above-described pseudo code, a predetermined user registers a plurality of condition data such as year / month / day: time, year / month / day: time & number of units, and the presence inference device 30 applies all the condition data of the corresponding user. In the present invention, the same estimation process can be individually processed for each condition data here.

  FIG. 5 is a flowchart of processing in which the terminal device transmits condition data to the presence estimation device 30 of the present invention. The terminal device starts the condition data input process from step S100, and in response to the user input in step S101, accepts the input of the user identification value (for example, the terminal name) and the determination condition and stores them in the buffer memory or the like. To do. In step S102, the unique identification value of the user is acquired and similarly stored in a buffer memory or the like. In step S103, the user identification value, determination condition, and unique identification value stored in the buffer memory are sent to the access point 16 or the server 20 in an appropriate protocol, for example, IEEE803.11, Bluetooth, or IEEE803.2 frame. The packet of the protocol suite such as IPv4 or IPv6 is superimposed and transmitted. Thereafter, the input process from the terminal device ends in step S104. In the specific embodiment of the present invention, the device code of the terminal device can be transmitted when the device code is allowed regardless of the user's input.

  FIG. 6 shows a flowchart of processing executed by the presence estimation apparatus 30 of the present invention. FIG. 6A shows a process in which the presence estimation device 30 of the present invention performs polling to detect the presence of a terminal device. In the process of FIG. 6A, in step S200, the terminal device existing in the cell is periodically polled separately from the data communication. As a command that can be used at this time, any type of command can be used, and any command that returns a response message such as ACK (acknowledgment response) in response to the terminal device receiving the command is used. can do. If the terminal device has an IP address at the same time, for example, a PING command (response message is ICMP) can be used, or an ARP command (response message is ARP reply) or the like can be used. You can also In the present invention, any command having a similar function can be used in addition to these commands.

  In step S201, the presence inference device 30 monitors a response message from the terminal device, and determines whether or not a timeout has elapsed in step S202. If the response message is not returned before the timeout elapses (yes), it is determined that the terminal device does not exist in the cell, and the unique identification value of the corresponding address of the terminal device registration means 22 is deleted, The terminal device registration means 22 is updated, and the process of step S200 is repeated again.

  FIG. 6B is an embodiment in the case where the presence inference device 30 of the present invention executes a process of generating a copy of registration data of the terminal device registration means 22. In the process shown in FIG. 6B, in step S210, the unique identification value of the terminal device registration means 22 of the access point 16 is inquired. In step S211, the presence inference device 30 requests the unique identification value registered in the terminal device registration unit 22, acquires at least the unique identification value in the terminal device registration unit 22 in step S212, and copies the unique identification value. And store it in the appropriate memory. In step S213, the process waits for expiration of the timer for copying the unique identification value. When the timer expires, the process from step S210 to step S212 is used again to copy the value of the unique identification value registered in the terminal device registration means 22. Then, the unique identification value update process is executed. The list of unique identification values generated at this time is used for lookup by the estimation means described later.

  FIG. 7 shows a flowchart of the presence estimation process executed by the presence estimation apparatus 30 of the present invention. In step S300, the input user identification value, determination condition, unique identification value, etc. are received and registered as a new record of condition data, condition #N. In step S301, the presence inference device 30 looks up the address table of the terminal device registration means 22 to obtain all registered unique identification values, or compares the unique identification values with a copy of the unique identification values. Get difference data between values.

  In step S302, the condition table is looked up using the acquired unique identification value or difference data as a search key, presence information corresponding to the unique identification value is acquired, and the value is set in the above-described variable current_status as an estimation result. To do. In step S303, the value is transmitted to, for example, a server connected via a wired network, and the corresponding user field of the presence server is updated. In step S304, the timer is started, the timer (10 minutes in the specific embodiment of the present invention) is waited for expiration, and when the timer expires (yes), the process is branched again to step S302, and the user Presence information estimation processing is executed. Note that the timer used in this case can be shared with the timer shown in FIG.

  FIG. 8 is a diagram showing an embodiment of frames and packets when data is transmitted from the presence estimation device to the externally connected server 20, for example, according to the present invention. FIG. 8A shows an embodiment of the frame 60 in the case where the presence estimation device transmits an estimation result to the server 20 connected via the wired network 12, and FIG. 8B shows, for example, a router. 26 is an embodiment of an IP packet for transmitting an estimation result from a server 26 to a server connected via a public network. The frame 60 shown in FIG. 8A has a frame format defined in, for example, IEEE 802.3, and includes a destination unique identification value 62, a source unique identification value 64, a data length or type 66, data 68, , Checksum 70.

  The destination unique identification value 62 describes the unique identification value of the server 20, and the transmission source unique identification value 64 describes the unique identification value of the presence estimation device. The data length or type 66 describes the length of data to be transmitted, the type of frame, and the like, and further describes data 68 including a user identification value and a determined presence state. The check sum 70 is used to determine the validity of the received data.

  The IP packet 72 shown in FIG. 8B describes data 78 including a destination IP address 74, a source IP address 76, a user identification value, determined state information, and the like. The presence inference device generates the IP packet shown in FIG. 8B for the presence server installed via the public network, and passes the route of switch-router-public network-destination router-presence server. After that, the estimation result is transmitted. The packet shown in FIG. 8B can also be used when a private address is assigned in the wired network.

  Further, the present invention can be applied not only to IEEE 802.11 as a wireless network but also to a security-compatible wireless network such as IEEE 802.11i and IEEE 802.1X.

  The above functions of the present invention are described in object-oriented programming languages such as C ++, Java (registered trademark), Java (registered trademark) Beans, Java (registered trademark) Applet, Java (registered trademark) Script, Perl, and Ruby. It can be realized by a program executable by the apparatus, and can be stored in a device-readable recording medium and distributed.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. It can be changed within the range that can be conceived by a trader, and any embodiment is included in the scope of the present invention as long as the effects and effects of the present invention are exhibited.

The figure which showed the presense notification system containing the presence estimation apparatus of this invention. The block diagram which shows the structure of the presence estimation apparatus of this invention. The figure which showed embodiment of the terminal device registration means 22 which an access point contains in this invention. The figure which showed the condition table which the condition memory | storage means of a presence estimation apparatus manages. The flowchart of the process which a terminal device transmits condition data to the presence estimation apparatus of this invention. The flowchart of the process which the presence estimation apparatus of this invention performs. The figure which showed embodiment of the flame | frame and packet in the case of transmitting the input data transmitted to the server 20 from a presence estimation apparatus by this invention. The figure which showed embodiment of the flame | frame and packet in the case of transmitting data to the exterior from a presence estimation apparatus by this invention. 1 is a schematic diagram of a network system that includes a conventional wireless network.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Presence notification system, 12 ... Wired network, 14 ... Switch, 16 ... Access point, 18 ... Personal computer, 20 ... Server, 22 ... Terminal device registration means, 24 ... Address table, 26 ... Router, 30 ... Presence estimation device, 32 ... Communication control means, 34 ... Transmission / reception data processing section, 36 ... Condition storage means, 38 ... Estimation means, 46 ... Condition table, 60 ... Frame, 72 ... IP packet

Claims (10)

A presence estimation device for estimating the presence status of a user of a terminal device,
A communication control means for controlling transmission / reception via the wireless network;
Condition storage means for registering terminal device identification information and presence information correspondingly,
Terminal device registration means for registering a unique identification value of the terminal device participating in the wireless network;
A presence estimation device comprising: an estimation unit that acquires the unique identification value from registration data of the terminal device registration unit, searches the condition storage unit, and estimates the presence state of the user of the terminal device.   The presence estimation device according to claim 1, further comprising a transmission / reception data processing unit for transmitting the estimated presence status to the outside via a wired network.   The condition storage means stores device type data of the terminal device, and the estimation means counts the number of the terminal devices having the same device type data and estimates the presence state. The presence estimation apparatus according to claim 1, comprising:   The presence inference device according to claim 3, wherein the wireless network is a wireless network conforming to the Bluetooth or IEEE 803.11 standard. A presence estimation method for causing an information processing apparatus to execute a method of estimating a presence state of a user of a terminal device,
Obtaining a unique identification value of the terminal device participating in the wireless network via the communication control means;
Searching registration data of the terminal registration means, and specifying the unique identification value of the terminal device that may have changed the participation state in the wireless network;
Searching condition storage means using the identified unique identification value of the identified terminal device as a search key, and generating an estimated result in a presence state corresponding to the unique identified value.   6. The method of claim 5, further comprising transmitting the inferred presence status to the outside via a wired network. Obtaining device type data of the terminal device;
The method according to claim 5, further comprising: counting the number of the terminal devices having the same device type data to estimate the presence state.   The method of any one of Claims 5-7 including the step which requests | requires a confirmation response periodically with respect to the said terminal device. Storing the unique identification value of the terminal device registered immediately before;
Obtaining a unique identification value corresponding to a difference between the stored unique identification value and a subsequently obtained unique identification value;
The method according to claim 5, further comprising: obtaining a presence state corresponding to the unique identification value corresponding to the difference and updating the estimation result.   An apparatus-executable program for causing an information processing apparatus to execute the method according to claim 5.

Images