JP6135499B2 - Information registration search system, method, and program - Google Patents

Description

  The present invention relates to a communication method used when an end node accesses a relay node constituting a distributed database to register or search information.

  A technique for constructing a distributed database using a plurality of mobile nodes such as in-vehicle wireless communication devices has been studied (Patent Document 1). Each node (referred to as a relay node) constituting the distributed database can widely propagate information registered in a certain node by exchanging the data held with the surrounding nodes.

  An end node such as a portable information terminal can register or search for information with respect to the relay node. In the case of information search, if all relay nodes have the same data, a complete result can be obtained by searching for one relay node. However, if the data held by each relay node is different, it is desirable to repeat the search every time communication with a new relay node becomes possible. Also, regarding information registration, when information propagation between relay nodes is slow, it is desirable to repeat information registration every time communication with a new relay node becomes possible.

  However, it is not convenient to allow the user to perform operations for registration and retrieval of information every time communication with a new relay node becomes possible. If a program for accessing the relay node is installed in the end node in advance, resources may be consumed even when the node is not used, or it may not be possible to cope with the program update. In addition, an end node that is not installed with a program in advance needs to access the relay node after being installed, which impairs user convenience.

JP 2012-146034 A

  An object of the present invention is to improve the convenience of a user when an end node operated by a user accesses a relay node constituting a distributed database to perform information registration or search.

The present invention is an information registration search system in which an end node accesses a relay node constituting a distributed database by wireless communication to register or search information, and the end node, a plurality of relay nodes constituting a distributed database, A distribution node that distributes the program to the end node. Each of the plurality of relay nodes includes an information storage unit that stores information, a reception unit that receives a request from the end node, a processing unit that performs processing on the information storage unit in accordance with a request from the end node, Is provided. The distribution node includes program storage means for storing a program, and distribution means for distributing the program to the end node. The end node includes an acquisition unit that acquires the program from the distribution node, and a program execution unit that executes the program. The program includes an input function for acquiring registration information or a search condition from a user, a transmission function for transmitting a request to the relay node based on the registration information or the search condition in response to an input from the user, A retransmission function for transmitting the request to the new relay node when a connection with the new relay node is detected after the transmission of the request by the transmission function.

  In this way, if the end node connects to a new relay node after the user has entered registration information and search conditions once, the program automatically sends a request to the new relay node, saving the user trouble. Convenience.

  Furthermore, since the program is acquired from the distribution node and executed, it is not necessary to install the program in advance, and the latest program can always be executed.

  In the present invention, it is also preferable that the distribution means of the distribution node is a web server, and distributes the program as the web content to the end node. It is also preferable that the program execution means included in the end node is an HTML rendering engine.

  In this way, acquisition and execution of the program in the end node can be performed easily. There is also an advantage that the program can be executed without depending on hardware or OS by executing the program on the HTML rendering engine.

  In the present invention, the distribution node does not have to be a node independent of the relay node, and the distribution node may also serve as the relay node. Note that all relay nodes may have a function as distribution nodes, or only some of the relay nodes may have a function as distribution nodes. However, since all the relay nodes have a function as a distribution node, it is ensured that a program can always be acquired when the relay node is accessible.

  In the present invention, it is preferable that the plurality of relay nodes provide wireless LAN access using the same ESSID, and the receiving means is a web server accessible by the same URL.

  In this way, the end node program can be recognized as virtually accessing the same node even when accessing different relay nodes. That is, a plurality of relay nodes can be regarded as one system.

  In the present invention, the program receives a response to the transmission of the request by the retransmission function from the relay node, stores the response, and presents the stored response at a timing instructed by the user. It is also preferable. As the presentation of the response, it is conceivable to display data that matches the search condition or display how many relay nodes the information has been registered.

  If it does in this way, the result of the processing which the program performed automatically can be checked at the timing which a user desires. A configuration may be adopted in which a response is presented to the user each time a response is obtained by the retransmission function.

The present invention can also be understood as an information registration / retrieval system comprising at least a part of the above means, or as a relay node, distribution node, or end node. The present invention can also be understood as an information registration search method for executing at least a part of the above-described processing. The present invention can also be understood as a computer program for causing a computer to execute this method, or a computer-readable storage medium in which this computer program is stored non-temporarily. Each of the above means and processes can be combined with each other as much as possible to constitute the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the convenience of a user when accessing the relay node which comprises a distributed database from the end node which a user operates, and registering and searching is improved.

It is a figure which shows the outline | summary of a safety information transmission system. It is a figure which shows the function structure of a portable information terminal (end node) and a vehicle-mounted terminal (relay node). The figure which shows the example of the display screen of a registration / search program. The figure which shows the outline | summary of an information registration process. The figure which shows the sequence of an information registration process. The figure which shows the outline | summary of an information search process. The figure which shows the sequence of an information search process.

<Overview>
An embodiment of the present invention is a safety information transmission system (information registration search system) that uses an in-vehicle wireless communication device (in-vehicle terminal) as a relay node. FIG. 1 shows an overview of a safety information transmission system according to the present embodiment. For example, a victim in a disaster area registers and searches a message from the portable information terminal 100 to the in-vehicle terminal 200. The in-vehicle terminal 200 moves in a disaster area, a refuge, or the like, and further exchanges the retained message with a surrounding in-vehicle terminal, so that the message registered by the victim is spread over a wide geographical area. A disaster victim or other users can obtain a message registered by a disaster victim in a remote disaster area by accessing the in-vehicle terminal. In addition, when the in-vehicle terminal 200 can be connected to a wide area communication network (such as the Internet) such as a mobile base station 300 or a wireless LAN access point, the in-vehicle terminal 200 uploads the message it holds to the server, Users can also search for disaster information.

  The safety information transmission system according to the present embodiment can be regarded as a distributed database system in which the portable information terminal 100 is an end node and the in-vehicle terminal 200 is a relay node. The end node means a node that performs information registration (information generation) and information search (information use). The relay node means a node that relays information. There may be nodes that serve as both end nodes and relay nodes, but such cases are not considered below for the sake of simplicity.

  In the safety information transmission system, if the information held by all in-vehicle terminals 200 (relay nodes) is always synchronized, information registration and search from the portable information terminal 100 (end node) may be performed once. However, in the configuration of the present embodiment, it is not expected that the information held by all the in-vehicle terminals 200 is immediately synchronized. Therefore, every time the user can communicate with the new in-vehicle terminal 200, the portable information It is necessary to register and search information from the terminal 100.

  An object of the present embodiment is to reduce a user's trouble when performing registration and search of information every time communication from an end node (mobile information terminal 100) to a relay node (in-vehicle terminal 200) becomes possible. By reducing the burden on the user, information can be registered and searched effectively, and a large amount of information is expected to be distributed in the system.

  In the following description, the terms “end node” and “portable information terminal” are used interchangeably. Similarly, the terms “relay node” and “vehicle terminal” are also used interchangeably.

<Configuration>
[Portable information terminal (end node)]
The portable information terminal 100 is a portable computer device such as a mobile phone, a smartphone, a notebook computer, or a tablet computer. The configuration of the portable information terminal 100 will be described with reference to FIG. The portable information terminal 100 includes a wireless communication unit 110, a control unit 120, a storage unit 130, and an input / output unit 140.

  The wireless communication unit 110 is a functional unit that performs wireless communication with the in-vehicle terminal 200. The wireless communication method may be arbitrary, but in the present embodiment, it is assumed that communication is performed using a wireless LAN (IEEE 802.11 standard).

The control unit 120 includes a general-purpose processor such as a CPU or MPU, and provides functions such as the wireless LAN client 121 and the web browser 122 by executing a program stored in a memory or the like. The wireless LAN client 121 has a function of establishing a connection and communicating with the wireless LAN access point 221 of the in-vehicle terminal 200. The web browser 122 includes an HTML rendering engine, and is a program that obtains and interprets web content described in HTML5 and calculates characters and images to be displayed. Examples of HTML rendering engines include WebKit, Blink, Gecko, Trident and the like. The web browser 122 corresponds to an acquisition unit and a program execution unit in the present invention.

  The storage unit 130 includes an input information storage unit 131 and a response result storage unit 132. Both can be realized by the WebStorage API of HTML5. The input information storage unit 131 is a functional unit that stores registration information and search conditions input by the user for registration and search of information with respect to the in-vehicle terminal 200. The response result storage unit 132 is a functional unit that stores a response from the in-vehicle terminal 200 in response to a request for information registration or search.

  The input / output unit 140 includes an input device such as a keyboard and a touch panel, and an output device such as a display and a speaker.

  In addition to the above functions, the portable information terminal 100 preferably provides functions such as a wireless LAN authentication client, a DHCP client, and a DNS client according to functions provided by the in-vehicle terminal 200.

[In-vehicle terminal (relay node)]
The configuration of the in-vehicle terminal 200 will be described with reference to FIG. The in-vehicle terminal 200 includes a wireless communication unit 210, a control unit 220, a storage unit 230, and an input / output unit 240.

  The wireless communication unit 210 is a functional unit that performs wireless communication with other in-vehicle terminals 200 and portable information terminals 100. In the present embodiment, it is assumed that communication by a wireless LAN (IEEE 802.11 standard) is performed. However, in addition to the wireless LAN, any wireless communication method such as millimeter wave communication or DSRC (dedicated area communication) can be adopted. Also, a plurality of methods can be combined, or inter-vehicle communication and communication with a portable information terminal. Different schemes may be adopted. Furthermore, it is also preferable to employ cognitive communication that performs communication using an available frequency band such as white space communication.

The control unit 220 is composed of a general-purpose processor such as a CPU or MPU, and executes a program stored in a memory or the like, whereby a wireless LAN access point 221, a wireless LAN client 222, a web server 223, a database management unit 224, The function of the safety information exchange unit 225 is provided.

The wireless LAN access point 221 is a function that provides a wireless LAN access point, and provides connection to the portable information terminal 100 and other in-vehicle terminals 200. In the present embodiment, the wireless LAN access point 221 is realized by software (for example, hostapd).

  The wireless LAN client 222 is a function for connecting to a wireless LAN access point, and is used to connect to another in-vehicle terminal 200 or other station node that provides the wireless LAN access point. Information registered by the user is exchanged between in-vehicle terminals via the wireless LAN client 222. In the present embodiment, the wireless LAN client is realized by software (for example, wpa_supplicant).

The web server 223 provides the web content stored in the web content storage unit 231 to a client (such as a web browser of the portable information terminal 100) having HTTP access. As will be described later, the web content includes a safety information registration / search program that can be executed on the web browser (HTML rendering engine). The web server 223 is realized by software (for example, httpd). The web server 223 and the web content storage unit 231 correspond to distribution means and program storage means in the present invention, respectively.

  The database management unit 224 receives a safety information registration / search request from the portable information terminal 100 via a safety information registration / search program, and performs an operation on the safety information storage unit 232 in response to the request. As the database management unit 224, any existing database management system can be adopted. The database management unit 224 corresponds to a receiving unit and a processing unit in the present invention.

  The safety information exchange unit 225 is a functional unit that exchanges the safety information stored in the safety information storage unit 232 with other in-vehicle terminals. When the safety information exchanging unit 225 can communicate with other in-vehicle terminals, the safety information exchanging unit 225 selects and transmits the safety information according to a predetermined algorithm. Further, when safety information is received from another in-vehicle terminal, it is stored in the safety information storage unit 232. The safety information storage unit 232 corresponds to the information storage means in the present invention. The method for exchanging safety information is not particularly limited in the present invention, and any conventional method can be employed.

In addition, in the in-vehicle terminal 200, it is also preferable to provide functions such as a wireless LAN authentication server, an SSL daemon, a DHCP server, and a DNS server in addition to the above functions. The wireless LAN authentication server is a function for performing authentication and encryption of wireless LAN connection, for example, radiusd
Can be realized. The SSL daemon is a function for performing authentication and encryption of access to the web server, and can be realized by, for example, mod_ssl. DHCP server is a wireless LAN
This is a functional unit that assigns a local IP address to an end node connected to the access point 221, and can be realized by, for example, dhcpd. The DNS server has a function of converting a URL to the IP address of the relay node when the end node accesses the web server in the relay node with the URL. The DNS server can be realized by bind, for example.

The storage unit 230 includes a web content storage unit 231 and a safety information storage unit 232. The web content storage unit 231 stores information to be provided to a web client that has accessed the web server 223. The web content storage unit 231 also includes a program executed in the web browser (HTML rendering engine) of the end node. In this embodiment, a program written in HTML5 is used. This web content includes a script language such as JavaScript, and provides a dynamic user interface in response to a user input. In this specification, HTML5 terms are used in a broad sense including WebSocket API, WebStorage API, Geolocation API, XML HttpRequest Level 2, and the like.

  The safety information storage unit 232 stores safety information registered by the user. The data format of the safety information may be arbitrary. For example, the safety information includes a user name (name), a telephone number, message content (arbitrary text), registration date and time, and the like. It is also preferable for the safety information to include information such as the registration location, the reception date / time, the reception location, and the most recent transfer date / time in order to improve the efficiency of the exchange of the safety information between the in-vehicle terminals.

  The input / output unit 240 includes an input device such as a keyboard and an output device such as a display and a speaker.

[Web content (registration / search program)]
Of the web contents stored in the web content storage unit 231, web contents for performing information registration and information retrieval from the end node will be described. This web content is executed by the web browser 122 of the end node, a user interface function for information registration to the relay node and information retrieval, a function for transmitting a registration request to the relay node and a search request, and a function for receiving a response result Etc. Hereinafter, this web content is also referred to as a “registration / search program” in order to distinguish it from other web content. The registration / search program is HTML5 content including a script such as JavaScript, and the following functions are provided by interpretation and execution by a web browser (HTML rendering engine).

  As shown in FIG. 3, the registration / retrieval program provides an interface for the user to input the contents of information to be registered, information retrieval conditions, and the like (input function). In the case of information registration, a name 81, a telephone number 82, and a message 83 can be input. By selecting a registration button 84, the input information is registered. The format of the registration information may be arbitrary. For example, information such as age and current location may be input in addition to the above. In the case of information search, a name 85 and a telephone number 86 can be input. By selecting a search button 87, a search under the input conditions is executed. Note that the interface in FIG. 3 is merely an example. For example, the input items and the input method may be other than those shown in FIG. 3, or the information registration and information search pages may be different. Good.

When the registration button 84 is selected and information registration is executed, the registration / search program transmits an information registration request to the relay node using the WebSocket API (transmission function). This information registration request is processed by the database management unit 224 of the relay node, and the registration information input by the user is stored in the safety information storage unit 232. When the registration / retrieval program receives a registration completion notification from the relay node, the registration / retrieval program provides the user with an indication that the registration is complete (for example, a “registration complete” indication). Also, the number of relay nodes registered with the registration information input by the user is stored in the environment of the web browser 122 using the WebStorage API.

When the search button 87 is selected and information search is executed, the registration / search program transmits an information search request to the relay node using the WebSocket API (transmission function). This query request is processed by the database management unit 224 of the relay node, and the safety information that matches the search condition is extracted from the safety information storage unit 232 and transmitted to the end node. When the registration / search program receives a notification of the search result from the relay node, it is preferable to present the content of the search result (for example, “Taro Yamada: I am in the evacuation center A”) to the user. Further, the search condition input by the user is stored in the environment of the web browser 122 using the WebStorage API together with the search result.

  When the connection with the currently connected relay node is disconnected and the connection with the new relay node is detected, the registration / search program requests registration information and search conditions stored in the WebStorage API. The search request is automatically transmitted to the new relay node (retransmission function). Responses from the relay node to the registration request and the search request are stored in the environment (local database) of the web browser 122 using the WebStorage API. For example, the number of registered relay nodes and search results are stored in the local database.

  A connection with a new relay node and a detection method thereof will be described. By using a common ESSID (network ID) for all relay nodes, the portable information terminal 100 can automatically establish a radio link with a new relay node by applying the previous record in general. It is. The registration / retrieval program can detect a new connection by periodically confirming whether a wireless link has been established or receiving an event notification from the control unit 220 of the portable information terminal 100 when a wireless link is established. When a new connection is detected, the registration / retrieval program checks the ESSID using the SystemInfo API, and if the ESSID is commonly used in the relay node, the registration / retrieval program detects that it has connected to the new relay node. it can.

  The registration / search program has a function of displaying a registration record related to information registration and a search result related to information search in accordance with an instruction from the user. This can be done by displaying information stored in the WebStorage API in association with registration information and search conditions. The registration record is, for example, information indicating how many relay nodes the information registration has been completed. The search result is, for example, registration information that matches the search condition. Further, information such as how many relay nodes information search has been performed may be displayed.

  In addition to the above, the registration / retrieval program has a function for changing the contents of registered information and search conditions that have already been entered, and a function for pausing, resuming, and terminating automatic execution of information acquisition and information retrieval. It is also preferable to provide

<Example of network interface implementation>
All relay nodes 200 are preferably designed to have the same ESSID and the same URL. By making the ESSIDs the same, the end node can automatically connect using the previous connection record. In addition, since it can be accessed by the same URL (more specifically, an origin consisting of a scheme, a domain, and a port number), the end node can recognize that it is accessing the same node, and the relay node of the connection destination is changed. Session can be continued. In addition, since the name space of WebStorage API is divided by origin, the information acquired from each relay node can be unified and managed in the same database.

  In addition, it is preferable that the relay node 200 is configured to receive an HTTP request from the end node and to redirect to a page that prompts the user to download the registration / search program when it is the first access. By doing so, the registration / search program can be acquired without the user knowing the address for acquiring the registration / search program. Although the redirect destination may be a page for distributing the registration / search program, it is preferable that the registration / search program is downloaded after obtaining the user's confirmation as described above from the viewpoint of usability.

<Processing flow>
[Information registration process]
Hereinafter, the flow of processing when registering or retrieving information from an end node to a relay node will be described with reference to the drawings. First, the information registration process will be described. FIG. 4 is a diagram for explaining an outline of the flow of information registration processing, and FIG. 5 is a diagram showing a sequence of information registration processing.

  When the end node approaches the relay node A, a connection is established between the wireless LAN access point 221 of the relay node A and the wireless LAN client 121 of the end node (S101). When the connection is established, the DHCP server of the relay node A assigns an IP address to the end node (S102).

  When the user activates the web browser 122 and accesses the distribution page of the relay node registration / search program by specifying the URL (processing 1 in FIG. 4), the processing in steps S104 to S107 in FIG. 5 is performed. That is, the IP address corresponding to the URL is obtained by name resolution in the DNS server (S104). Then, the web browser 122 transmits an HTTP request to the IP address (S105), and receives an HTTP response from the web server (S106). The HTTP response includes a registration / search program, and this program content is downloaded to the end node (S107, process 2 in FIG. 4). The access to the distribution page of the registration / search program may be directly input by the user, or the web browser 122 may store the address in advance.

  In this example, the URL for accessing the registration / search program distribution page is described. However, when the end node accesses for the first time via the wireless LAN access point 221, the relay node designates the distribution page. It is preferable to redirect to the download page of the registration / search program regardless of the registered address. In this case, the registration / search program is downloaded when the user selects the start of download.

  When the web browser 122 acquires the registration / search program, the contents are interpreted and a screen as shown in FIG. 3 is presented. Here, it is assumed that the registration process is started by inputting registration information in order for the user to register information in the relay node (S108, process 3 in FIG. 4). Then, the registration / retrieval program stores the input registration information in the local database (WebStorage API) and sends a request (registration request) for registering this information to the relay node database to the relay node A. Transmit (S109, process 4 in FIG. 4). Upon receiving this registration request, the database management unit 224 of the relay node A registers (stores) the registration information in the safety information storage unit 232 (process 5 in FIG. 4).

  Although not shown in the figure, when information registration is completed, a notification to that effect is transmitted from the relay node to the end node, and the end node displays information registration completion.

  Here, it is assumed that the relay node A moves or the like, the wireless link between the end node and the relay node A is disconnected (S110), and the end node and the relay node B can communicate thereafter. When the end node and the relay node B approach each other, a connection is established between the wireless LAN access point 221 of the relay node B and the wireless LAN client 121 of the end node (S111). When the connection is established, the DHCP server of the relay node B assigns an IP address to the end node (S112).

When the registration / retrieval program detects the connection to the new relay node B, the registration information input from the user in step S108 is automatically sent to the relay node B (a user's explicit instruction). Without transmission) (S114, process 6 in FIG. 4). In response to this registration request, the relay node B registers (stores) the information transmitted to the safety information storage unit 232 via the database management unit 224 (process 7 in FIG. 4).

  By performing such processing, the user only needs to input information to be registered once, and the registration / search program automatically registers information each time a connection with a new relay node is established. It is possible to register information for many relay nodes without burdening the network.

[Information search processing]
Next, the information search process will be described. FIG. 6 is a diagram for explaining the outline of the flow of information search processing, and FIG. 7 is a diagram showing a sequence of information search processing. Since the processes (steps S201 to S207, processes 1 and 2 in FIG. 6) from the establishment of the wireless LAN connection to the acquisition of the web content (registration / search program) are the same as those in the information registration process, the explanation will be given. Omitted.

  When the web browser 122 acquires the registration / search program, the contents are interpreted and a screen as shown in FIG. 3 is presented. Here, it is assumed that the search process is started by inputting a search condition in order for the user to acquire registration information (safety information) from the relay node (S208, process 3 in FIG. 6). In this case, the registration / search program transmits a search request based on the input search condition to the relay node (S209, process 4 in FIG. 6). Upon receiving this search request, the database management unit 224 of the relay node A searches the safety information storage unit 232 with the conditions included in the search request, acquires data that matches the search conditions, and transmits the data to the end node (S210). Process 5 in FIG. Upon receiving the search result, the end node stores the contents in the local database (WebStorage API) (process 6 in FIG. 6). In addition, the search result stored in the local database is acquired, and a screen for displaying the search result is presented to the user (step S211, processes 7 to 8 in FIG. 6).

  Since the processing (S212 to S215) from when the connection between the end node and the relay node A is disconnected until the end node starts to connect with the relay node B is the same as that in the information registration processing, the description thereof is omitted.

  When the registration / search program detects a connection to the new relay node B, it automatically sends a search request based on the search condition input by the user in step S208 to the relay node B (without an explicit instruction from the user). ) (S216, process 9 in FIG. 6). In response to this search request, the relay node B searches the safety information storage unit 232, acquires data that matches the search condition, and transmits the data to the end node (S217, process 10 in FIG. 6). Upon receiving the search result, the end node stores the contents in the local database (WebStorage API) (process 11 in FIG. 6).

  After that, when the user instructs to update (reload) the display of the search result at an arbitrary timing (S218, processing 12 in FIG. 6), the registration / search program acquires information registered in the local database, A screen for displaying all the search results is presented to the user (S219, processes 13 to 14 in FIG. 6).

  By performing such a process, the user only has to input the search condition once, and the registration / search program automatically searches for information every time a connection with a new relay node is established. It is possible to retrieve information from many relay nodes without spending time.

The processing described here is only an example. For example, if the registration / search program is already read into the web browser 122, the information registration and information search processing may be started without acquiring the registration / search program from the relay node. In the above description, only one process of information registration or information search is described as being automatically performed. However, a plurality of information registrations, a plurality of information searches, or a combination of information registration and information search is automatically performed. May be executed automatically. That is, the user may request a registration / search program for a plurality of registration processes and search processes, and the program may send the plurality of processing requests to the new relay node each time it can communicate with the new relay node. . It is also preferable that the user can instruct the automatic execution to be paused, resumed, or terminated for each information registration or information retrieval.

  In addition, when the end node transmits a request to the relay node via the registration / search program, it is preferable to notify the version of the registration / search program. The relay node preferably confirms the version of the registration / retrieval program of the request transmission source, and if it is not the latest version, it is preferable to prompt the end node to obtain the latest version program. In this way, registration and retrieval of information can always be performed based on the latest program. Here, updating the program includes updating the setting file referred to by the program in addition to updating the entire program.

<Advantageous Effects of Embodiment>
According to the present embodiment, it is not necessary to perform input for information registration or information search every time the user can communicate with the in-vehicle terminal, and the user's labor is reduced. In addition, it is not necessary to previously install a program for information registration or information retrieval in the portable information terminal, and this program can be acquired by simple web access. By reducing the effort of the user in this way, the number of times the user is used is increased, and more information is expected to be distributed in the system.

  In addition, since the program for information registration and information retrieval is in the form of web content that runs on a web browser, if the program is written according to the HTML standard, it can be used on any terminal without depending on hardware or OS. Execution is possible. In addition, by adopting such a program distribution form, there is an advantage that resources of the portable information terminal are not consumed when the program is not used.

<Modification>
The above description exemplifies the embodiment of the present invention. The present invention should not be construed as being limited to the above embodiment, and various modifications can be made within the scope of the technical idea of the present invention. Deformation is possible.

  In the above embodiment, all relay nodes (in-vehicle terminals) have been described as having a function for distributing a registration / search program. However, only some relay nodes may have a program distribution function. . Also, the relay node that functions as a distributed database and the distribution node that distributes the registration / search program may be separated. That is, the relay node may perform only information registration and search processing, and the distribution node may perform only registration / search program distribution processing. In this way, it is assumed that the chance that the end node can acquire the registration / search program is reduced, but the security can be improved because only the node whose security is ensured can be distributed.

In the above embodiment, a URL is used when accessing a web server from a web browser. However, an IP address may be designated for access. In this case, since the name space of the local database in the web browser is divided according to the IP address, all the relay nodes have the same IP address in order to regard all the relay nodes as virtually the same distributed database. It is necessary to. Even if it does in this way, the effect similar to the above can be acquired.

  When the distribution node and the relay node are separated, it is desirable that the ESSID (network ID) is common and fixed at least for the distribution node. This is because the end node needs to acquire a program (web content). The URL of the program distribution address of the distribution node may be common and fixed, or may be redirected to that address at the first access. In addition, although the ESSID and URL (or IP address) of the relay node may be fixed, they are different from each other, and the distribution node distributes the ESSID and URL (or IP address) for accessing the relay node (group). ) May be described. Thus, by designating ESSID, URL, etc. from the program, it is possible to cope with the case where the relay node also has a plurality of independent information registration / retrieval systems.

  Moreover, although the above embodiment is a safety information transmission system at the time of a disaster, application of a distributed database system including a plurality of relay nodes may be arbitrary. For example, information relay in a sensor network, load distribution of a center database, and the like can be assumed as application examples. In any system, the mechanism for information registration and information search between the end node and the relay node described in the above embodiment can be applied. Further, the relay node does not have to be an in-vehicle terminal, and may be an arbitrary movable wireless communication device. The movable wireless communication device is a wireless communication device provided in a vehicle, a ship, an aircraft, or the like, or a wireless communication device that can be carried by a user, such as a notebook computer, a slate computer, or a mobile phone. However, it is not essential that the relay node is movable, and the present invention can also be applied to a system (such as a sensor network) including a fixed wireless communication device.

100: Personal digital assistant (end node)
120: Control unit 121: Web browser 130: Storage unit 131: Input information storage unit 132: Response result storage unit 200: In-vehicle terminal (relay node)
220: Control unit 223: Web server 224: Database management unit 225: Safety information exchange unit 230: Storage unit 231: Web content storage unit 232: Safety information storage unit

Claims (11)

An information registration / retrieval system in which an end node accesses a relay node constituting a distributed database by wireless communication to register or retrieve information,
An end node, a plurality of relay nodes that constitute a distributed database, and a distribution node that distributes a program to the end node;
Each of the plurality of relay nodes includes an information storage unit that stores information, a reception unit that receives a request from the end node, a processing unit that performs processing on the information storage unit in accordance with a request from the end node, With
The distribution node includes program storage means for storing a program, and distribution means for distributing the program to the end node,
The end node includes an acquisition unit that acquires the program from the distribution node, and a program execution unit that executes the program.
The program includes an input function for acquiring registration information or a search condition from a user, a transmission function for transmitting a request to the relay node based on the registration information or the search condition in response to an input from the user, A retransmission function for transmitting the request to the new relay node when a connection with the new relay node is detected after transmission of the request by the transmission function;
Information registration search system. The distribution means of the distribution node is a web server, and distributes the program to the end node as web content.
The information registration search system according to claim 1. The program execution means is an HTML rendering engine.
The information registration search system according to claim 2. The delivery node also serves as the relay node;
The information registration search system according to any one of claims 1 to 3. The plurality of relay nodes provide wireless LAN access using the same ESSID, and the receiving means is a web server accessible by the same URL.
The information registration search system according to any one of claims 1 to 4. The program receives and stores a response to the transmission of the request by the retransmission function from the relay node, and presents the stored response to the user at a timing instructed by the user.
The information registration search system according to any one of claims 1 to 5. An information registration search method in an information registration search system comprising an end node, a plurality of relay nodes constituting a distributed database, and a distribution node for distributing a program to the end node,
An acquisition step in which the end node acquires the program from the distribution node;
A program execution step in which the end node executes the program;
An input step in which the program executed by the end node acquires registration information or search conditions from a user;
A transmission step in which the program executed by the end node transmits a request to the relay node based on the registration information or the search condition input by a user;
A retransmission step for transmitting the request to the new relay node when the program executed by the end node detects a connection with the new relay node after the transmission step;
Including information registration and retrieval method. In the acquisition step, the program is acquired as web content from the web server of the distribution node.
The information registration search method according to claim 7. In the program execution step, the program is executed using an HTML rendering engine.
The information registration search method according to claim 8. The program of the end node receives and stores a response to the transmission of the request in the retransmission step from the relay node;
The program of the end node presents to the user the response stored at the timing of the instruction from the user;
The information registration search method according to any one of claims 7 to 9, further comprising: A program for accessing or registering information by wireless communication to a relay node constituting a distributed database,
An input step for obtaining registration information or search conditions from the user;
A transmission step of transmitting a request to the relay node based on the registration information or the search condition input by a user;
A retransmission step for transmitting the request to the new relay node when a connection with the new relay node is detected after the transmission step;
A program that causes a computer to execute.

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