JP2006050467A - Network system that manages content in a distributed manner - Google Patents

Abstract

【Task】
In a network system that manages information in a distributed manner, when a terminal tries to acquire content held by another terminal, if both terminals do not exist in an area with good communication, there is a high possibility that content acquisition will fail. .
[Solution]
When a terminal that manages content belonging to a certain community checks the communication status of each content owner terminal and detects a deterioration in the communication status, it determines the destination terminal of the content and moves the content to the content owner. Request.
[Selection] Figure 4

Description

  The present invention relates to a communication system that manages information in a distributed manner, and more particularly to a technology that provides an environment in which data can be easily accessed even if a terminal belonging to the communication system moves.

  In the network communication field, peer-to-peer enables personal terminals to exchange files directly without going through a server, or to perform complex scientific computations by linking many computers distributed around the world. (Peer-to-Peer: hereinafter referred to as P2P) type network technology is being put into practical use. Even in ordinary households, broadband has become popular with ADSL and FTTH, and a large amount of multimedia data can be exchanged. Today, P2P networks do not become a bottleneck due to the concentration of traffic to server computers. It is effective as a communication means in a highly fluid ubiquitous communication environment in which a large number of terminals move or join / leave a network.

  As a system for sharing information and communicating between terminals connected by a P2P network, a system using an ID tag has been studied (for example, see Non-Patent Document 1). The ID tag is one of the technologies for connecting the real world where people live and work and the virtual world that is perceived and recognized through information communication means, and standardization is being promoted. The ID tag itself is used to associate an identifier with an object existing in the real world.

  In the system disclosed in the above document, an ID tag is used as a trigger, and terminals having the same ID read from the tag freely form a community and share information (for example, content). Each content is stored in the created terminal to construct an information distribution environment.

Takeshi Ishizaki, 3 others, “Development of distributed information sharing technology using ID tag and P2P network”, [online], search on July 17, 2004, Information processing promotion business association 2002 results report collection, Internet <URL : Http://www.ipa.go.jp/SPC/report/02fy-pro/report/1497/paper.pdf>

  In the case of non-patent document 1, the original of each content is held by the creation terminal. If another terminal acquires the content once, it is held in the terminal that acquired the content. However, when a content acquisition request is received from another terminal, the content is transmitted only to the created terminal It is. When a network is configured with non-moving terminals that are always connected in the home, content distribution by holding the content creation terminal is effective to avoid concentration of access to one terminal. It is.

  However, in a network environment in which a terminal frequently enters and exits the network as in an ad hoc network and routing is frequently updated as each terminal moves, a terminal that holds information (for example, content) is fixed. That is not always effective. For example, when a certain terminal tries to acquire content possessed by another terminal and both terminals are not in an area with good communication status, there is a high possibility that content acquisition will fail.

  The present invention provides an information management service for storing information in a network system that manages information in a distributed manner in consideration of the communication state of the terminal of the information creator.

  According to one aspect of the network system for distributedly managing content of the present invention, a plurality of mobile terminals are connected using a wireless communication network, and the network system is configured to distribute and manage content with a plurality of mobile terminals, For example, it comprises a mobile terminal that manages the system, a mobile terminal that holds content, and other mobile terminals.

  Furthermore, when the mobile terminal to be managed determines that the communication status between the mobile terminal holding the content and the other mobile terminal is inferior and the communication status of the mobile terminal holding the content is poor as a result of the inspection, Means for determining a destination terminal, means for requesting the mobile terminal holding the content to move the content to the destination terminal, means for updating the content list when the content is moved to the destination terminal, It is characterized by providing.

  Furthermore, when other mobile terminals request content, the mobile terminal that manages them requests and acquires a content list indicating the content address, and selects the content selected based on the acquired content list. And a mobile terminal that manages the content may be provided with a means for transmitting the requested content list to other mobile terminals.

  Furthermore, the mobile terminal to be managed may activate a means for inspecting the communication status when the content list is requested or when the routing table of the wireless communication network is updated.

  Furthermore, means for inspecting the communication status includes means for acquiring the number of transfer hops in the wireless communication network between the mobile terminal that requested the content acquisition and the mobile terminal that holds the content, and the mobile terminal that holds the content. Means for transmitting an inspection packet and measuring a response time to the inspection packet may be provided.

  Further, the means for requesting the movement of the content includes a means for acquiring an access frequency to the content, a means for determining whether to copy the content based on the access frequency instead of moving, a copy generation of the content, And means for instructing transmission of the content to the destination terminal.

  Furthermore, the mobile terminal that holds the content may be provided with means for notifying the mobile terminal to be managed of a movement request for the content to be held when the mobile terminal leaves the wireless communication network.

  ADVANTAGE OF THE INVENTION According to this invention, in the network system which distributes and manages a content, the situation where another terminal cannot acquire a content can be reduced by moving a content according to the communication state of a content owner terminal.

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a configuration example of a network system that distributes and manages information related to an embodiment of the present invention.

  In FIG. 1, a packet network (also referred to as a packet network) 1 and a plurality of mobile terminals 2-1 to 2-9 and relay terminals 3-1 to 3-3 are connected to the packet network 1. The packet network 1 may be either wireless or wired, but each relay terminal 3 has a wireless communication processing unit. The mobile terminal 2 has a wireless communication processing unit, and can connect to other mobile terminals 2 or relay terminals 3 while moving. When the packet network 1 is an ad hoc network in which the mobile terminal 2 and the relay terminal 3 are connected to each other and communicate without passing through another access point, each mobile terminal 2 and each relay terminal 3 has a packet data routing function. It also has. Hereinafter, the configuration and processing when the packet network 1 is an ad hoc network will be described. The connection topology of each mobile terminal 2 and relay terminal 3 is updated as the mobile terminal 2 moves.

  FIG. 2 shows the internal configuration of the mobile terminal 2 and the relay terminal 3.

  The mobile terminal 2 includes a memory 10 in which a community program 16 is stored, a CPU 11 that performs processing based on the program in the memory 10, a storage device 12, an input device 13 such as a camera, a microphone, and an ID tag reader, and a recording medium And a packet network interface 15 for communication with the packet network 1 and an output device 14 such as a speaker and a display. Each module is connected by an internal communication line such as a bus.

  The input device 13 is not necessarily required when all inputs such as data and events are performed via the packet network 1. Furthermore, the input device 13 is an input support function that, when inputting setting information or the like from the user interface, for example, when a certain character is input, displays a keyword that has been input in the past and saves input time. May be included.

  The community program 16 developed in the memory 10 manages the routing table of the ad hoc network and connects the ad hoc routing processing unit 17 that performs packet data routing processing and the connection status of other mobile terminals 2 that operate the community program. A connection terminal management processing unit 18 that manages the content, a content transfer / acquisition processing unit 19 that transfers and acquires content for which the own terminal or other mobile terminal 2 is the owner, and the own terminal or other mobile terminal 2 is the owner. A content management processing unit 20 for managing a certain content, a communication management processing unit 21 for monitoring a communication status with other mobile terminals 2 and relay terminals 3, and a community management for managing a community in which the terminal is participating A processing unit 22 and an ID tag reader interface that performs ID tag reading processing The case 23 and the user interface 24 are composed of programs that are realized by the processing of the CPU 11. In this embodiment, the ID tag reader interface 23 is used as a community participation / generation trigger, but other processing units may be used.

  Hereinafter, a case where a user of each mobile terminal plays a treasure hunting game will be described as an embodiment of the present invention.

  First, an outline of the treasure hunt game will be described with reference to FIG.

  Assume that a packet network 1 is constructed by a mobile terminal 2 and a relay terminal 3 in a certain amusement park. The mobile terminal 2 and the relay terminal 3 operate the community program 16. A plurality of ID tags are pasted in the park, and the user searches for the ID tag with the mobile terminal 2 equipped with the ID tag reader, and if found, the ID assigned to the ID tag is read into the mobile terminal 2.

  There are a plurality of types of ID tags, such as “team ID”, “treasure ID”, and “attraction ID”, which are necessary for playing a treasure hunting game. A treasure hunting game is performed by exchanging information (contents) between the mobile terminal 2 and the relay terminal 3 using a value registered in each ID tag as a trigger.

  When the read ID tag is “treasure ID”, the information of the “treasure ID” is notified to all mobile terminals 2 that have read the same “team ID” (that is, belong to the same team).

  When the read ID tag is “Attraction ID”, the attraction community receives hint information that is a type of content.

  Each mobile device searches for a “treasure ID” based on the hints received, notifies other team members with the same “team ID” that the hint information is available, and asks and answers The treasure ID is searched by exchanging as a kind of content.

  FIG. 4 shows an example of the behavior of the mobile terminal 2 and the relay terminal 3.

  The relay terminal 3 operates the community program 16, but is not carried by the user.

  In addition, each mobile terminal 2, the relay terminal 3, and the information held by each terminal are provided with addresses that are uniquely determined in the network system of the present embodiment.

  If the mobile terminal 2-1 reads “attraction ID” and the value (ID) assigned to the read ID tag is 1, the mobile terminal 2-1 determines the owner of the ID tag having ID: 1 as Search by the following steps.

  When the community program 16 is activated, the community program 16 acquires an identifier of another terminal that operates the community program 16 and generates a participating terminal list. In order to find the owner of the ID tag, a discovery request is issued based on the participating terminal list.

  Each mobile terminal 2 that has received the ID tag owner discovery request of ID: 1 checks whether or not the terminal is the owner, and if it is the owner, the community belonging to the ID tag (for example, an official information community, a word-of-mouth information community, etc.) (Here, the mobile terminal 2-5 is the owner with ID: 1).

  The mobile terminal 2-1 that has acquired the community list from the ID tag owner of ID 1 selects a community (for example, community 1) that the user wants to participate in, and provides content to the owner of the community 1 (here, mobile terminal 2-4). Issue a list acquisition request.

  The mobile terminal 2-4, which is the owner of the community 1, searches the result of monitoring the communication status of the owner of each content by the communication management processing unit based on the content list of the community 1 managed by the terminal, and connects to the network 1. Whether to move the content is determined from the presence / absence, the number of hops with respect to the threshold, the inspection response time, the access frequency to the content, and the like. Instead of moving content, it may be copied to distribute access to one content.

  When it is determined that the communication status of the mobile terminal 2-9 that is one of the content owners is poor, the mobile terminal 2-4 that is the community 1 owner issues a content transfer request to the content owner 2-9. At this time, the destination terminal (here, relay terminal 3-1) is notified. Upon receiving the content movement request, the mobile terminal 2-9 moves the corresponding content to the designated destination relay terminal 3-1.

  The relay terminal 3-1 that has received the mobile content updates the content management information managed by the local terminal and issues a content movement completion notification including the content storage address to the mobile terminal 2-4 that is the owner of the community 1. .

  Upon receiving the content movement completion notification, the mobile terminal 2-4 updates the content management list of the community 1, and responds to the mobile terminal 2-1 that has requested the content list with the latest list.

  The mobile terminal 2-1 that has acquired the content list issues a content acquisition request directly to the new content owner (here, the relay terminal 3-1) based on the list and acquires the content.

  FIG. 5 shows a flow of commands exchanged between the mobile terminal 2 and the relay terminal 3.

  In FIG. 5, when the mobile terminal 2-1 newly starts the community program 16 (step 30), it broadcasts a participating terminal discovery request command “Join_REQ” (step 31). The command may not be broadcast but issued individually to all terminals or a plurality of terminals in the ad hoc routing table.

  The other mobile terminals 2-5, 2-4, 2-9, and the relay terminal 3-1 that have received “Join_REQ” directly or via other mobile terminals each include their own participating terminal lists. A “Join_ACK” command is returned (step 32). The mobile terminal 2-1 generates a newest participating terminal list by combining a plurality of participating terminal lists acquired from other mobile terminals directly or via other mobile terminals (step 33).

  When the mobile terminal 2-1 reads an ID tag (step 34), it issues a “Discovery” command for inquiring about the owner of the ID tag based on the participating terminal list (step 35). The “Discovery” command is issued to the top n of the participating terminal list. The number n of issue destination terminals may be determined in advance or may be appropriately changed according to the communication status.

  When the mobile terminal 2-5 that is the owner of the ID tag receives the "Discovery" command, the mobile terminal 2-5 responds with a "Discovery_ACK" command including the community list (step 36). The mobile terminal 2-1 displays the community list and waits for an operation from the user (step 37).

  When the user selects community 1 from the community list (step 38), the mobile terminal 2-1 sends the content list acquisition request “CLIST_REQ” command belonging to community 1 to the owner 1 movement of community 1 recorded in the community list. It is issued to the terminal 2-4 (step 39).

  The mobile terminal 2-4 that has received the “CLIST_REQ” command acquires the communication status of the owner of each content belonging to the community 1, and determines whether or not the content is moved (step 40). For example, when the mobile terminal 2-9 decides to move the content that is the owner to the relay terminal 3-1, a content movement request “CMOVE_REQ” command is issued to the mobile terminal 2-9 (step 41). .

  The mobile terminal 2-9 that has received the “CMOVE_REQ” command moves the corresponding content to the designated destination relay terminal 3-1 using the “CMOVE” command (step 42).

  The relay terminal 3-1 that has received the “CMOVE” command stores the content included in the command and updates the content management information (step 43). The relay terminal 3-1 issues a content movement completion command “CMOVE_ACK” to the mobile terminal 2-4 that is the owner of the community 1 (step 44).

  The mobile terminal 2-4 updates the content list with the new address of the content included in the “CMOVE_ACK” command (step 45) and includes the content list in the “CLIST_ACK” command, and the mobile terminal 2-1 that issued the “CLIST_REQ” command (Step 46).

  The mobile terminal 2-1 displays the content list included in the “CLIST_ACK” command (step 47). When the user of the mobile terminal 2-1 selects the content 1 from the content list and issues a display event (step 48), the relay terminal 3-1 that is the owner of the content 1 from the content list (if there is a plurality, from the list) Address is selected (step 49), and a content acquisition request “CGET_REQ” command is issued (step 50).

  The relay terminal 3-1 that has received the “CGET_REQ” command responds with the “CGET_ACK” command including the corresponding content (step 51).

  In steps 40 to 44, whether or not the content is to be moved, that is, whether or not the content list is to be updated, is triggered by reception of the content list request. Independently of receiving the request, it may be performed repeatedly (eg, periodically).

  6 to 17 show the processing flow of the mobile terminal 2 and the relay terminal 3. However, since the relay terminal 3 does not accept an event from the user, the ID tag reading, community, content selection processing, and the like are not performed.

  18 shows the community and content list belonging to the ID tag, FIG. 19 shows the participating terminal communication monitor table, FIGS. 20 to 22 show the format of each command exchanged between the mobile terminal 2 and the relay terminal 3, and FIG. An example of the user interface is shown.

  In FIG. 6, each mobile terminal 2 and relay terminal 3 perform initial settings such as reading an ad hoc routing table and securing each list use memory when the community program 16 is activated (step 60). When each mobile terminal 2 reads an ID tag by an ID tag reader by a user operation (yes in step 61), community participation processing such as acquisition of community information associated with the ID tag is performed (step 62).

  When a participation terminal discovery request command “Join_REQ” is received from another mobile terminal 2 (yes in step 63), a response command “Join_ACK” including a participation terminal list held in the own terminal is returned (step 64). .

  When “Join_ACK” is received, the participating terminal list included in the command is used, and when “Join_ACK” is similarly received from other terminals, the participating terminal list included in each command is merged to obtain the latest participating terminal list. Generate (step 65).

  When an ID tag owner discovery request command “Discovery” is received from another mobile terminal 2 (yes in step 66), Discovery incoming processing is performed to search and respond to whether or not the own terminal is the owner of the ID tag (step 67).

  If any of the mobile terminals 2 issues an end request event for the community program 16 by the user's operation (yes in step 68), “Leave” indicating the saving of each list held by the own mobile terminal and the departure from the community Termination settings such as command transmission and communication interface disconnection processing are performed (step 69).

  If all the above steps 61, 63, 66 are no, the process proceeds to A of FIG.

  In FIG. 7, when each mobile terminal 2 or relay terminal 3 receives a “CLIST_REQ” command from another mobile terminal 2 (yes in step 70), the mobile terminal 2 or the relay terminal 3 performs a list transmission process of the corresponding content held by itself (step 70). 71).

  When the “CGET_REQ” command is received (yes in step 72), the corresponding content held by the terminal is transmitted (step 73).

  When the “CMOVE_REQ” command is received (yes in step 74), a content moving process for transmitting the corresponding content to the designated mobile terminal 2 is performed (step 75).

  When the “CMOVE” command is received (yes in step 76), a moving content management process for holding the content included in the command in its own terminal is performed (step 77).

  When a new content generation event is received from the user (yes in step 78), content generation processing is performed (step 79).

  If the routing table of the ad hoc network has been updated (yes in step 80), a communication monitor process for inspecting the communication status of other terminals is performed (step 81).

  When each processing of FIG. 7 is completed and when all of Steps 70, 72, 74, 76, 78, and 80 are no, the process returns to B of FIG.

  FIG. 8 shows the flow of the community participation process in step 62 of FIG.

  Whether or not the ID tag value read in step 61 is in the own terminal is searched. If the ID tag has already been read (yes in step 90), information on the community list associated with the ID tag is displayed ( Step 91).

  At this time, in order to obtain the latest information, a “Discovery” command may be transmitted to the owner of the ID tag, or each mobile terminal that has accessed the ID tag when a new community is generated from the owner of the ID tag 2 may be notified of the latest list.

  When the user performs an operation of selecting a community from the displayed community list (yes in step 92), the address of the owner of the community is acquired from the community list and a content list acquisition request command “CLIST_REQ” is issued. (Step 93).

  When a “CLIST_ACK” command is received from the community owner and a content list is acquired, a content acquisition event in the content list from the user is waited for and content acquisition processing is performed (step 94).

  If a community end event is received from the user after displaying the community list in step 91 (yes in step 95), the community list display screen is closed and the community participation process is ended.

  When the information related to the ID tag read in step 61 does not exist in the own terminal (no in step 90), the issuer of the owner discovery request command “Discovery” of the ID tag is acquired from the participating terminal list (step 96). A “Discovery” command is issued (step 97).

  When the “Discovery_ACK” command is received (yes in step 98), the community list included in the “Discovery_ACK” command is displayed (step 91). When there is no response from each mobile terminal 2 that is the destination of the “Discovery” command issuance (No in Step 98), a process for creating a new community is performed (Step 99).

  FIG. 9 shows the flow of content acquisition processing in step 94 of FIG.

  When a certain content is selected from the displayed content list and there is a display request event (yes in step 100), the address information of the content is acquired from the content list (step 101).

  When there are a plurality of address information (yes in step 102), the mobile terminal 2 or the relay terminal 3 having a good communication state is selected from the communication status list (step 103), and a content acquisition request command “CGET_REQ” is issued (step 104). .

  When the “CGET_ACK” command is received from the counterpart terminal 2 or the relay terminal 3 (yes in step 105), the content included in the command is displayed (step 106).

  If there is a response to the content displayed by the user or a new content generation event (yes in step 107), the content generation processing in step 79 is performed.

  If there is no response to the “CGET_REQ” command and a time-out occurs (yes in step 108), a “CGET_REQ” command issuance process is performed to another mobile terminal 2 having the content.

  If there is no other mobile terminal 2 having the content (No in Step 102), the user is informed that the content cannot be acquired and waits for an event from the user (Step 109).

  If no in steps 100 and 107, or after step 109, the process of step 94 in FIG.

FIG. 10 shows the flow of the Discovery incoming process in FIG. 6 and step 67. In FIG. 10, the ID tag management list in which the terminal is the owner is searched from the ID tag value included in the received “Discovery” command (step 120).

  If the ID tag information exists (yes in step 121), a “Discovery_ACK” command including the community list of the ID tag is generated and returned to the requesting mobile terminal 2, and the request source information (identifier and address) ) Is added to the ID tag management list (step 122).

  If the own terminal is not the owner of the ID tag (no in step 121), but there is the transfer destination mobile terminal 2 from the participating terminal list (yes in step 123), the received "Discovery" command is transferred (step 124). If there is no transfer destination mobile terminal 2, the process is terminated as it is (no in step 123).

  FIG. 11 shows the flow of the new community creation process in step 99 of FIG.

  In FIG. 11, the mobile terminal 2 displays a new ID tag owner registration screen (step 130).

  When the user inputs an ID tag name (yes in step 131), a new community registration screen is displayed (step 132).

  If the user inputs community information (yes in step 133), a new community screen is displayed (step 134) and a user event is awaited.

  When the user requests a new content generation event (yes in step 135), the content generation process in step 79 is performed (step 136).

  When the user notifies a community information display end event (no in step 135, yes in step 136), the new community generation process is ended.

  In the new community registration screen display of step 132, when the user notifies an end event (no in step 133, yes in step 137), the new community generation process is terminated.

  In the new ID tag owner registration screen display of step 131, when the user notifies the event of ending the process without becoming the owner of the ID tag (no in step 131, yes in step 138), this process is ended.

  FIG. 12 shows the flow of content generation processing in step 79 of FIG.

  If there is a transmission request for content input by the user (yes in step 140), the mobile terminal 2 acquires the input content (step 141), and acquires address information of the owner of the community to which the content belongs from the community list. Then, “CPUT_REQ” including the title of the input content and the storage location information of the content is transmitted to the community owner (step 143).

  When the “CPUT_ACK” command is received from the community owner (yes in step 144), new content information is added to the content management list for which the terminal is the owner and updated (step 145).

  If there is no response from the community owner (No in step 144), the user is notified that the created content cannot be registered (step 146) and waits for an event from the user. If there is a retransmission request from the user (yes in step 147), the processing from step 143 is repeated. If there is no retransmission request (no in step 147) or a content generation process end event is received from the user (yes in step 148), this process ends.

  FIG. 13 shows the flow of the content list transmission process in step 71 of FIG.

  The mobile terminal 2 acquires the address information of the transmitting terminal from the “CLIST_REQ” command (step 150). Subsequently, the requested content list included in the command is acquired from the content management list stored in the terminal (step 151).

  In order to inspect the communication status of each content owner from the content list and determine whether or not the content can be moved, the counter i of the inspection loop is initialized (step 152). If the loop counter i is less than the number of contents (yes in step 153), the communication status of the i-th content owner in the content list is acquired from the communication status list (step 154).

  It is determined whether or not the content needs to be moved by using the acquired list. For example, if the number of hops from the content requesting terminal to the content owner is greater than or equal to a predetermined threshold, the inspection response time from the content owner is long, or the access frequency to the content is high, the content is moved or copied If it is determined that the mobile terminal 2 or the relay terminal 3 is to be moved or copied from the communication status management table (step 156). If it is determined that neither movement nor copying is performed, the process proceeds to step 160.

  “CMOVE_REQ” including the address of the destination terminal is issued to the content owner (step 157), and the reception of the “CMOVE_ACK” command from the destination terminal is awaited (step 158). When the “CMOVE_ACK” command is received, the content list is updated (step 159), and the inspection loop counter is incremented (step 160).

  When the inspection loop counter value reaches the number of contents (no in step 153), a “CLIST_ACK” command including the content list for which update processing has been completed is returned to the “CLIST_REQ” command transmission terminal (step 161).

  FIG. 14 shows the flow of the content transmission process in FIG.

  The mobile terminal 2 or the relay terminal 3 acquires the corresponding content held in its own terminal from the content address information included in the “CGET_REQ” command (step 170). The address information of the “CGET_REQ” command sender is acquired (step 171), and the “CGET_ACK” command including the requested content is transmitted to the address (step 172).

  FIG. 15 shows the flow of the content movement process in FIG.

  The mobile terminal 2 or the relay terminal 3 acquires the corresponding content held in its own terminal from the content address information included in the “CMOVE_REQ” command (step 180). Further, the destination address information included in the “CMOVE_REQ” command is acquired (step 181), and the “CMOVE” command including the requested content is transmitted to the address (step 182).

  FIG. 16 shows the flow of the moving content management process in step 77 of FIG.

  The mobile terminal 2 or the relay terminal 3 acquires the content and the address of the community owner included in the received “CMOVE” command (step 190). The received content is additionally stored in the content management list held by the terminal (step 191), and a “CMOVE_ACK” command including content storage location information is issued to the community owner (step 192).

  FIG. 17 shows a flow of the communication monitoring process in FIG.

  The mobile terminal 2 or the relay terminal 3 acquires a participating terminal list (step 200). Based on the routing table of the ad hoc network, the number of hops to each terminal registered in the participating terminal list is updated (step 201).

  Next, a “Test” packet is issued to the terminal whose routing has been changed, and the response time is measured (step 202). If the value calculated based on the number of hops or the response time of the “Test” packet is equal to or greater than the threshold (step 203), the order of the participating terminal list is changed, and the terminal having a good communication state is positioned higher in the participating terminal list ( Step 204).

  Further, when the terminal having poor communication status is the content owner of the community in which the own terminal is the owner (yes in step 205), the movement request command “CMOVE_REQ” for the corresponding content is issued (step 206). The command includes address information of the content transfer destination terminal. When the “CMOVE_ACK” command is received from the destination terminal of the relevant content (yes in step 207), the content list to which the relevant content belongs is updated (step 208).

  FIG. 18 shows examples of various tables held by the mobile terminal 2 and the relay terminal 3.

  210 is a community list of ID tags, 213 is a table showing community information, and 218 is a content list. Reference numeral 211 denotes an ID tag value, and 212 denotes a community identifier associated with the ID tag and an address of the community information table. Reference numeral 214 denotes an ID tag identifier (same as 211), 215 denotes the number of contents associated with the community, 216 denotes the latest update date of the community, and 217 denotes the head address of the contents list. 219 indicates the address where the content is stored, 220 indicates the frequency of access to the content, 221 indicates the number of copies of the content, and 222-224 indicate the copy destination addresses when the content is copied. List several minutes.

  FIG. 19 shows an example of a participating terminal list.

  230 indicates the ID of the participating terminal, 231 indicates the address of the participating terminal, 232 indicates the number of hops to the terminal, and 233 indicates the response time of the “Test” packet with the terminal.

  20 to 22 show examples of various command formats. The commands include "Join_REQ" "Join_ACK" "Leave" "Test" "Test_ACK" "Discovery" "Discovery_ACK" "CPUT_REQ" "CPUT_ACK" "CGET_REQ" "CGET_ACK" "CLIST_REQ" "CLIST_ACK" "CMOVE_REQ" "CMOVE_ACK" CMOVE "etc.

  Hereinafter, it explains according to the element which constitutes each command.

  20 to 22, 240 and 241 common to each command indicate a communication header such as IP / TCP / UDP, and a command type, respectively.

  242 included in each command excluding “CMOVE_REQ” indicates an identifier of the mobile terminal 2 or the relay terminal 3 that is the command transmission source.

  Reference numerals 243 included in commands excluding “Join_REQ”, “Join_ACK”, “Leave”, “Test”, and “Test_ACK” indicate values assigned to the ID tags.

  244, 245, included in the “Join_ACK” command indicate a set of identifiers and address information of participating terminals, respectively.

  246, 247, included in the “Discovery_ACK” command indicate community list information attached to the tag ID indicated by 243, and each list information is a combination of a community identifier of 248 and a head address of the community information list of 249. Including.

  The community identifier 248 is also included in each command shown in FIGS. In each command shown in FIGS. 21 and 22, 250 indicates a content identifier.

  251 included in the “CMOVE_REQ” command indicates address information of a content transfer destination terminal.

  Reference numeral 252 included in the “CMOVE_ACK”, “CPUT_REQ”, and “CLIST_ACK” commands indicates address information of an area in which content is stored.

  253, which is included in the “CLIST_ACK” command, is information on each content in the content list, 250 content identifiers, 252 content storage location address, 254 copy number of the content, 256, 256, copy destination. It consists of an address.

  In the “CGET_ACK” and “CMOVE” commands shown in FIG. 22, 260 indicates content information.

  FIG. 23 shows an example of a screen when the system according to the present embodiment is applied to a “treasure hunting game” at an amusement park as an example of a user interface.

  In FIG. 23, 270 is a top screen of the “treasure hunting game”, 273 is a “communication” button used when communicating with terminals that have read the same ID tag. Is displayed.

  274 is a button for jumping to a community of real-time still images taken around the place where the treasure ID is pasted in order to provide a hint for a treasure hunting game. A button 276 is pressed when reading the found ID tag.

  Reference numeral 271 denotes an example of a content generation screen displayed when creating new content. 277 is a title of the content to be generated, 278 is an identifier of the content creator, 279 is a button for displaying a fixed phrase of a question, and 280 is a button for displaying a fixed phrase for creating a “teach” message 281 is a content to be created, 282 is a button for notifying the community owner of information of the created content 281, 283 is a button for deleting the created content 281, title 277, etc. 284 is the previous screen Indicates a button to return to.

  272 is a treasure acquisition status display screen displayed when the button 275 is pressed, 285 is an area for displaying the treasure information acquired so far, 286 is a button for returning to the top screen of 270, and 287 is a communication Indicates a button for returning to the display screen.

  288 is an example of a card-type ID tag indicating “treasure”, and each mobile terminal acquires a preset ID from the ID tag 288.

1 is an overall configuration diagram of a network system that performs distributed management according to an embodiment. FIG. It is an example of an internal block diagram of a mobile terminal and a relay terminal. It is a utilization image at the time of applying the network system which carries out distributed management according to an embodiment to an amusement park or the like. It is an example of the whole flow of this system. It is an example of the whole flow at the time of making a user event a trigger. It is an example of the processing sequence of a mobile terminal and a relay terminal. It is an example of the processing sequence of a mobile terminal and a relay terminal. It is an example of the sequence of a community participation process. It is an example of the sequence of a content acquisition process. It is an example of the sequence of a Discovery process. It is an example of the sequence of a new community creation process. It is an example of the sequence of a content generation process. It is an example of the sequence of a content list transmission process. It is an example of the sequence of a content transmission process. It is an example of the sequence of a content movement process. It is an example of the sequence of a moving content management process. It is an example of the sequence of a communication monitor process. It is an example of the community list of ID tag used in this system, a community information table, and a content list. It is an example of the communication monitor list | wrist of the participating terminal used by this system. It is an example of the format of the command used by this system. It is an example of the format of the command used by this system. It is an example of the format of the command used by this system. It is an example of the user interface used by this system.

Explanation of symbols

1: packet network, 2: mobile terminal, 3: relay terminal, 17: ad hoc routing processing unit, 18: connected terminal management processing unit, 19: content transfer / acquisition processing unit, 20: content management processing unit, 21: communication management Processing unit 22: Community management processing unit 23: ID tag reader interface 23

Claims (14)

A network system in which a plurality of mobile terminals are connected using a wireless communication network and content is distributed and managed by the plurality of mobile terminals,
A mobile terminal that manages the system, a mobile terminal that holds content, and other mobile terminals,
Each of the mobile terminals has communication means using the wireless communication network with the other mobile terminals,
The mobile terminal to be managed is
Means for inspecting the communication status between the mobile terminal holding the content and the other mobile terminal;
Means for determining a destination terminal of the content when the inspection determines that the communication status of the mobile terminal holding the content is poor;
Means for requesting the mobile terminal holding the content to move the content to the destination terminal;
And a means for updating the content list when the content is moved to the destination terminal. A network system for managing the information according to claim 1 in a distributed manner,
Means for requesting and obtaining a content list indicating an address of the content from the mobile terminal to be managed when the other mobile terminal requests the content;
Means for requesting the content selected based on the acquired content list to the mobile terminal holding the selected content,
The managed mobile terminal comprises means for transmitting the requested content list to the other mobile terminal,
A network system for managing distributed information. A network system for managing the information according to claim 2 in a distributed manner,
The network system for distributed management of information, characterized in that the mobile terminal to be managed comprises means for starting the means for checking the communication state when the content list is requested. In the network system which carries out the distributed management of the information of Claim 1,
The mobile terminal to be managed is
A network system for distributedly managing information, characterized by comprising means for starting means for inspecting the communication status when updating a routing table of the wireless communication network. A network system for managing the information according to claim 1 in a distributed manner,
The means for checking the communication status of the mobile terminal to be managed is:
Means for acquiring the number of transfer hops in the wireless communication network between the mobile terminal that has requested content acquisition and the mobile terminal that holds the content;
A network system for distributing and managing information, comprising: means for transmitting an inspection packet to the mobile terminal holding content and measuring a response time to the inspection packet. A network system for managing the information according to claim 1 in a distributed manner,
The means for requesting movement of the content is:
Means for obtaining an access frequency to the content;
Means for determining whether to generate a copy of the content instead of moving based on the access frequency;
A network system for distributing and managing information, comprising: means for instructing copy generation of the content and transmission of the content to the destination terminal. A network system for managing the information according to claim 1 in a distributed manner,
When the mobile terminal that holds the content leaves the wireless communication network, the mobile terminal that manages the information is distributedly managed to notify the mobile terminal that manages the content to move Network system. A mobile terminal for managing the content used in a network system in which a plurality of mobile terminals are connected using a wireless communication network and the content is distributed and managed by the plurality of mobile terminals,
Communication means using the wireless communication network with other mobile terminals;
Means for inspecting the communication status between the mobile terminal holding the content and the other mobile terminal;
Means for determining a destination terminal of the content when the inspection determines that the communication status of the mobile terminal holding the content is poor;
A mobile terminal that manages content, comprising: means for requesting the mobile terminal that holds the content to move the content to the destination terminal. A mobile terminal for managing content according to claim 8,
A mobile terminal for managing content, comprising: means for transmitting to the other mobile terminal when a list of the content is requested from another mobile terminal. A mobile terminal for managing content according to claim 8,
A mobile terminal for managing content, comprising: means for activating the means for checking the communication state when the content list is requested. A mobile terminal that manages the content according to claim 8,
A mobile terminal for managing content, comprising: means for activating means for inspecting the communication status when updating a routing table of the wireless communication network. A mobile terminal for managing content according to claim 8,
The means for checking the communication status is:
Means for acquiring the number of transfer hops in the wireless communication network between the mobile terminal that requested content acquisition and the mobile terminal that holds the content;
A mobile terminal for managing content, comprising: means for transmitting an inspection packet to the mobile terminal holding the content and measuring a response time to the inspection packet. A mobile terminal for managing content according to claim 9,
The means for requesting movement of the content is:
Means for obtaining an access frequency to the content;
Means for determining whether to generate a copy of the content instead of moving based on the access frequency;
A mobile terminal for managing content, comprising: means for instructing a terminal that holds the content to generate a copy of the content and to transmit the content to the destination terminal. A mobile terminal for managing content according to claim 8,
A mobile terminal for managing content, comprising: means for receiving a movement request for content held from the mobile terminal holding the content when the mobile terminal holding the content leaves the wireless communication network.

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