JP4482545B2 - Information distribution apparatus and information distribution method - Google Patents

Description

  The present invention relates to an information distribution apparatus and an information distribution method for distributing emergency information related to, for example, a weather disaster or an evacuation instruction to a plurality of terminal devices via an IP (Internet Protocol) network.

  In general, the announcement broadcasting system introduced in the regional network, etc. has an announcement broadcast facility installed at the center side and a dedicated announcement broadcast receiving terminal device installed at the subscriber's house, and between these facilities and the receiving terminal device. Various notification broadcasts by voice are performed from the center side to each subscriber's terminal device by connecting via a CATV (Cable Television) network or the like. In addition to emergency broadcasts that require urgency, such as evacuation warnings in the event of disasters, announcement broadcasts include broadcasts that do not require urgency for the purpose of providing simple information such as information on events.

  Conventionally, as this type of notification broadcasting system, a notification broadcasting server provided on the center side and a plurality of terminal devices provided on the subscriber side are connected via a communication network and input by a microphone. A system has been proposed in which an audio signal is packetized by an announcement broadcast server, transmitted to a plurality of terminal devices as distribution destinations by multicast, and each audio signal is received and reproduced by each terminal device (for example, Patent Documents). 1).

JP 2002-164925 A

  However, in this conventionally proposed system, announcement broadcasting is performed by multicast. For this reason, it is necessary that all transmission apparatuses intervening on the network between the server on the center side and the terminal apparatus provided on the subscriber side are multicast-compatible dedicated apparatuses. As a result, if a transmission device such as a router or gateway arranged on the network does not support multicasting, it cannot be used. For this reason, there is a problem that it is expensive to construct and operate the system.

  The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide an information distribution apparatus and information capable of constructing and operating a system at a low cost without installing a dedicated transmission apparatus on the network. It is to provide a delivery method.

In order to achieve the above object, according to one aspect of the present invention, in an information distribution device connectable to a plurality of terminal devices via a communication network, first, information that prompts the plurality of terminal devices to transmit a distribution request; A trigger packet describing information indicating an access method for the notification information is generated, and the generated trigger packet is transmitted to the plurality of terminal devices via the communication network. Next, the distribution request transmitted from the destination terminal device in response to the trigger packet is received via the communication network, and the notification information corresponding to the received distribution request is read from the notification information storage means. , To the request source terminal device via the communication network. Further, based on the reception result of the notification information distribution request, it is determined whether or not the trigger packet is delivered to each terminal device of the transmission destination, and the trigger packet is not delivered based on the determination result of whether or not the trigger packet is delivered. The terminal packet is extracted, and the trigger packet is retransmitted to the extracted undelivered terminal device . In this retransmission, the extracted undelivered terminal devices are grouped into a plurality of groups based on the information amount of the notification information to be distributed, the number of terminal devices of the distribution destination, and the distribution processing capability of the information distribution device of the self. The trigger packet is retransmitted at different times for each of the divided groups .

Therefore, it is possible to distribute the notification information to a plurality of terminal devices by the unicast method. For this reason, there is no need to provide a dedicated transmission device for multicast on the network, and a general-purpose transmission device can be used as it is, which has the advantage that the construction cost of the system can be reduced. In addition, it is possible to grasp the presence or absence of trigger packet delivery for each terminal device that is a delivery destination in the information delivery device, whereby the trigger packet can be retransmitted to an undelivered terminal device. For this reason, even when the deterioration of the network environment occurs, the notification information can be distributed to as many terminal devices as possible, thereby increasing the distribution completion rate. Furthermore, when the trigger packet is retransmitted, the undelivered terminal devices are divided into a plurality of groups based on the amount of notification information to be distributed, the number of terminal devices as distribution destinations, and the distribution processing capability of the own information distribution device. Since the trigger packet is retransmitted at different times for each of the divided groups, it is possible to increase the processing capacity of the information distribution apparatus or increase the processing load on the information processing apparatus even during retransmission. Therefore, it is possible to smoothly distribute information.

  On the other hand, another aspect of the present invention provides a plurality of content distribution servers that store the same notification information and an information distribution device that can be connected to a plurality of terminal devices that are distribution destinations of the notification information via a communication network. The plurality of terminal devices are divided into a plurality of groups based on the amount of notification information to be distributed, the number of distribution destination terminal devices, and the distribution processing capabilities of the plurality of content distribution servers. The processing load of the plurality of content distribution servers is monitored for each group, and a content distribution server having a processing load equal to or lower than a predetermined condition is selected as a transmission destination of the distribution request. And generating a trigger packet describing information prompting the plurality of terminal devices to transmit a distribution request and information indicating an access method to the notification information stored in the selected content distribution server, and generating the generated trigger packet The packet is transmitted to the terminal devices belonging to the group via the communication network.

  Accordingly, since the notification information is distributed from the content distribution server to the terminal device, the processing load on the information distribution device is reduced. Further, a plurality of content distribution servers are provided, and the distribution process of the notification information to the terminal device is performed by the plurality of content distribution servers in a distributed manner. For this reason, the processing load of the content distribution server is also distributed. In addition, a plurality of terminal devices are grouped, and for each of these groups, a content distribution server having a processing load equal to or lower than a predetermined condition is selected from among the plurality of content distribution servers. Notification information is distributed to the terminal devices belonging to the group. That is, distributed control is performed so that the processing load of each content distribution server is always in an optimal state. For this reason, it is possible to efficiently distribute the notification information to a large number of terminal devices.

  The plurality of terminal devices include means for receiving a trigger packet transmitted from an information distribution device and transmitting the distribution request to a corresponding content distribution server based on information indicating an access method described in the trigger packet. And, when the plurality of content distribution servers receive a distribution request transmitted from the terminal device, means for transmitting notification information corresponding to the distribution request to the requesting terminal device via a communication network; In the case of providing with means for generating information indicating the presence or absence of delivery of the trigger packet in each destination terminal device based on the reception result of the notification information delivery request, from the plurality of content delivery servers, Information indicating the presence or absence of delivery of the trigger packet in each terminal device is acquired, and the trigger is based on the acquired information. Packet is then extracts the terminal device undelivered, retransmits the trigger packet to the terminal device of the extracted undelivered.

  In this case, even if the information distribution device that distributes the trigger packet is provided separately from the content distribution server that distributes the notification information, the trigger packet is delivered to each terminal device that is the distribution destination in the information distribution device. The trigger packet can be retransmitted to an undelivered terminal device. For this reason, even when the deterioration of the network environment occurs, the notification information can be distributed to as many terminal devices as possible, thereby increasing the distribution completion rate.

  In short, according to the present invention, by adopting the unicast method as the one-to-n notification information distribution method, it is possible to construct and operate the system at a low cost without using all the transmission devices on the network as dedicated devices. An information distribution apparatus and an information distribution method can be provided.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an announcement information distribution system provided with an information distribution apparatus according to the first embodiment of the present invention.
This system connects an IP (Internet Protocol) between a notification distribution server SV as an information distribution apparatus installed in a disaster prevention center of a local government and a plurality of terminal apparatuses TM1 to TMn installed in a subscriber's house such as a resident. ) Connection is possible via the network NW.

  The IP network NW includes, for example, the Internet and a plurality of access networks for accessing the Internet. As the access network, for example, a mobile communication network, a DSL (Digital Subscriber Line), a wired subscriber network using an optical transmission line, a LAN (Local Area Network), a wireless LAN, and a CATV (Cable Television) network are used.

The notification distribution server SV has both a function of distributing content representing notification information and a function of distributing a trigger packet that prompts the terminal devices TM1 to TMn to transmit a distribution request for notification information. Composed. FIG. 2 is a block diagram showing the configuration.
That is, the notice distribution server SV includes a control unit 10A, a storage unit, an information input / output interface unit, and a communication interface 41.

  The storage unit includes a non-volatile memory using, for example, a hard disk or a NAND flash memory as a storage medium, a content database (content DB) 21, a terminal / group management database (terminal / group management DB) 22, a delivery / response A management database (delivery / response management DB) 23 is provided.

  The information input / output interface unit includes a distribution content input unit 31 and a terminal / group information input unit 32. The distribution content input unit 31 reads content constituting the notification information from an external memory such as a memory card or other information devices, and stores the content of the read notification information in the content DB 21. The content is composed of, for example, audio data, image data, and character data.

  The terminal / group information input unit 32 captures identification information and attribute information of the terminal devices TM1 to TMn input by the operator using, for example, a key input device, and stores the captured information in the terminal / group management DB 22. The attribute information includes address information of the terminal device, information indicating the owner, information indicating the priority when distributing emergency information, and the like. In addition, when the plurality of terminal devices TM1 to TMn to be distributed are classified into a plurality of groups by the operator, information indicating the belonging group is also included.

  The communication interface 41 transmits and receives packets to and from the terminal devices TM1 to TMn under the control of the control unit 10A. As the communication protocol, TCP / IP (Transmission Control Protocol / Internet Protocol) or UDP / IP (User Datagram Protocol / Internet Protocol) used on the IP network NW is used.

  As a control processing function according to the present invention, the control unit 10A includes a terminal grouping management unit 11, a UDP packet generation unit 12, a UDP packet transmission unit 13, a request reception unit 14, a content transmission unit 15, and a delivery confirmation management. Unit 16 and response management unit 17. All of these functions are realized by causing an application program to be executed by a central processing unit (CPU).

  When the terminal grouping management unit 11 distributes trigger packets to be described later to the terminal devices TM1 to TMn, the terminal grouping management unit 11 stores the number of terminal devices TM1 to TMn serving as distribution destinations stored in the terminal / group management DB 22 and the content DB 21. Based on the information amount of the stored notification information content and the distribution processing capability of the own notification distribution server SV, the terminal devices TM1 to TMn serving as the distribution destinations can be processed in units that can be processed by the own notification distribution server SV. Divide into multiple groups. In addition, the terminal grouping management unit 11 also determines the number of retransmission destination terminal devices, the number of distribution content information, and the distribution processing of the notification distribution server SV when the trigger packet is retransmitted to an undelivered terminal device. Based on the capability, it is divided into a plurality of groups in units that can be processed by its own notification delivery server SV.

  For each group divided by the terminal grouping management unit 11, the UDP packet generation unit 12 generates a trigger packet that prompts a terminal device belonging to the group to transmit a distribution request. This trigger packet is configured by a UDP (User Datagram Protocol) packet. In the header of the UDP packet, address information of each terminal device as a transmission destination is inserted as a destination address. The address information of the terminal device is read from the terminal / group management DB 22. In the information part of the UDP packet, a URL (Uniform Resource Locator) for accessing the content of the notification information stored in the content DB 21 is described.

  The UDP packet transmission unit 13 causes the UDP packet generated by the UDP packet generation unit 12 to be transmitted from the communication interface 41 to the IP network NW toward the terminal device.

  The request receiving unit 14 receives the distribution request (http request) of the notification information content transmitted from the terminal device that has received the UDP packet via the communication interface 41. In response to the http request received by the request reception unit 14, the content transmission unit 15 reads out the corresponding notification information content from the content DB 21. Then, the read notification information content is transmitted from the communication interface 41 to the requesting terminal device.

  Based on the reception result of the http request received by the request reception unit 14, the delivery confirmation management unit 16 determines whether or not a UDP packet is delivered to each terminal device belonging to the group for each group. The determination result is stored in the delivery / response management DB 23 as delivery confirmation information.

  The response management unit 17, for each group, belongs to the group based on the reception result of the notification response message (post data of the http request) returned from the terminal devices TM <b> 1 to TMn in response to the transmission of the notification information content. It is determined whether or not the notification information content is received in the terminal device. The determination result is stored in the delivery / response management DB 23 as response confirmation information.

On the other hand, each of the terminal devices TM1 to TMn includes a personal computer, a mobile terminal such as a mobile phone or a PDA (Personal Digital Assistant), and is configured as follows. FIG. 3 is a block diagram showing the configuration.
That is, the terminal devices TM1 to TMn include a control unit 50, a communication interface 51, and an input / output interface unit 57. The communication interface 51 transmits and receives packets to and from the notification distribution server SV under the control of the control unit 50. As a communication protocol, TCP / IP or UDP / IP used on the IP network NW is used.

  The input / output interface unit 57 includes a content display unit 55, a response input unit 56, and a microphone and a speaker (not shown) for inputting and outputting audio. The content display unit 55 includes, for example, a liquid crystal display and is used to display image data and character data included in the notification information content distributed from the notification distribution server SV. The response input unit 56 includes a key input unit, and is used by the user to input a response instruction for receiving the notification information content.

The control unit 50 includes a UDP packet receiving unit 52, a packet analyzing unit 53, and a request transmitting unit 54. All of these functions are realized by causing the CPU to execute an application program.
The UDP packet receiving unit 52 receives a UDP packet transmitted from the notification distribution server SV via the communication interface 51. The packet analysis unit 53 analyzes the received packet and determines whether or not the packet is a UDP packet that prompts transmission of a distribution request. If it is a UDP packet that prompts transmission of a distribution request, the request transmission unit 54 is instructed to transmit the distribution request.

  In response to the delivery request transmission instruction from the packet analysis unit 53, the request transmission unit 54 transmits an http request according to the URL described in the received UDP packet. Further, when the user inputs a response instruction for reception of the notification information content at the response input unit 56, the request transmission unit 54 returns a response message (post data of the http request) to the notification distribution server SV.

  Next, the operation of the notification distribution server SV configured as described above will be described in association with the operations of the terminal devices TM1 to TMn. FIG. 4 is a flowchart showing the processing procedure and processing contents of the notice delivery server SV, and FIG. 5 is a sequence diagram showing data exchange between the notice delivery server SV and the terminal devices TM1 to TMn.

  Prior to the distribution of the notification information content, the control unit 10A of the notification distribution server SV first acquires the notification information content to be distributed from the external memory or other information devices via the distribution content input unit 31 in step S41. The notification information content is stored in the content DB 21.

  In step S42, the control unit 10A takes in the identification information of the terminal device designated as the distribution destination by the operator from the terminal / group information input unit 32, and stores this identification information in the terminal / group management DB 22. Here, a case where all terminal devices TM1 to TMn are targeted for distribution will be described as an example.

  Next, the control unit 10A moves to step S43, and the terminal grouping management unit 11 notifies the number of terminal devices TM1 to TMn serving as distribution destinations stored in the terminal / group management DB 22 and the notification stored in the content DB 21. Based on the information amount of the information content and the distribution processing capability of its own server SV, the terminal devices TM1 to TMn serving as the distribution destinations are divided into a plurality of groups in units that can be processed by the own server SV.

  For example, the information amount of the content to be distributed is 1 Mbyte, the number of distribution destination terminal devices is 2000, and the notification distribution server SV has the ability to process 500 Mbytes of content at a time (unit time). Suppose you were. In this case, the control unit 10A divides the 2000 terminal devices into four groups of 500 each.

  When the distribution preparation is completed, the control unit 10A first proceeds to step S44, and the UDP packet generation unit 12 selects one of the divided groups. Then, a UDP packet for urging the terminal device belonging to the selected groove to transmit a distribution request is generated. In the header H of this UDP packet, the address information of each terminal device belonging to the selected group is read from the terminal / group management DB 22 and inserted. Further, a URL for accessing the notification information content stored in the content DB 21 is inserted into the information portion of the UDP packet. For example, as shown in FIG. 6, security authentication information P1, message IDP2, display priority P4, and screen transition control parameter P5 are also inserted in the information portion of the UDP packet.

  When the UDP packet is generated, the control unit 10A proceeds to step S45, and the UDP packet transmitting unit 13 transmits the generated UDP packet from the communication interface 41 to the IP network NW. Thus, the UDP packet is transmitted from the notification distribution server SV to each terminal device of the selected group as shown in FIG.

  On the other hand, when the terminal device receives the packet addressed to itself by the UDP packet receiving unit 52, the terminal analyzing unit 53 analyzes the received packet to determine whether the packet is a UDP packet that prompts transmission of a distribution request. . If it is a UDP packet that prompts transmission of a distribution request, the request transmission unit 54 generates an http request, and the http request is sent from the communication interface 51 to the notification distribution server according to the URL described in the received UDP packet. Transmit to the SV as shown in FIG.

  When the transmission of the UDP packet is completed, the control unit 10A of the notification distribution server SV moves to step S46, and the request reception unit 14 receives the http request transmitted from the destination terminal device. Then, the process proceeds to step S47, and the corresponding notification information content is read from the content DB 21 by the content transmission unit 15. Then, after the notification information content is packetized, it is transmitted as an http response to the requesting terminal device as shown in FIG.

  At this time, the control unit 10A of the notification delivery server SV uses the delivery confirmation management unit 16 to deliver a UDP packet for each terminal device belonging to the group selected as the transmission target based on the reception result of the http request. The presence or absence of is determined. Then, information representing the determination result is stored in the delivery / response management DB 23.

  On the other hand, when the notification information content is received, the terminal device decodes and outputs the received notification information content. For example, if the notification information content includes image data or character data, these are decoded and displayed on the content display unit 55, and if the notification information content includes audio data, this is decoded and output from the speaker. Output loudly.

  At the same time, the terminal device returns a notification response message (post data of the http request) to the notification distribution server SV as shown in FIG. On the other hand, the control unit 10A of the notification distribution server SV determines whether or not the notification information content is received for each terminal device based on the reception result of the notification response message by the response management unit 17. And the response confirmation information showing the determination result is memorize | stored in the said delivery / response management DB23. Further, upon receiving the notification response message, the control unit 10A of the notification distribution server SV returns a response confirmation message (http response) to the transmission source terminal device as shown in FIG.

When the transmission of the notification information content ends, the control unit 10A of the notification distribution server SV determines whether or not there remains a group that has not yet transmitted the UDP packet in step S48. As a result of this determination, if an untransmitted group remains, the process returns to step S43 to select an untransmitted group, and a UDP packet is generated in step S44 and is transmitted to each terminal device belonging to the group in step S45. Send to. In response to this, when an http request is sent from the terminal device, the process proceeds from step S46 to step S47, where the content DB 21 to the corresponding notification information content are read and transmitted to the requesting terminal device.
Thereafter, similarly, each time an untransmitted group is selected, a UDP packet is transmitted to each terminal device. If an http request is received from the terminal device, the corresponding notification information content is the requesting terminal device. Delivered to each.

  When the processing from the transmission of the UDP packet to the transmission of the notification information content is completed for all the groups, the control unit 10A of the notification distribution server SV moves to step S49, where the delivery / response management is performed. Based on the delivery confirmation information stored in the DB 23, all terminal devices to which no UDP packet has been delivered are extracted. If the number of extracted undelivered terminal devices exceeds the number that can be processed by the notification distribution server SV at one time, the undelivered terminal devices are grouped in step S43. Then, in steps S44 to S47, for each divided group, processing from transmission of the UDP packet to transmission of the notification information content is executed for each terminal device belonging to the group. That is, the UDP packet retransmission process for undelivered terminal apparatuses is also performed for each group.

  Here, the upper limit number of times of retransmission processing of the UDP packet for one terminal device is defined in advance. The controller 10A monitors in step S50 whether or not the retransmission process has reached the upper limit number. Then, when the number of retransmissions reaches the upper limit number, subsequent distribution processing for the terminal device is stopped.

  As described above, in the first embodiment, when the notification distribution server SV distributes the notification information content to the plurality of terminal devices TM1 to TMn, the URL for accessing the notification information content is described first. A UDP packet is generated and transmitted to the terminal devices TM1 to TMn. In response to this, when an http request for requesting distribution of notification information content arrives from the terminal devices TM1 to TMn, the corresponding notification information content is transmitted to the requesting terminal devices TM1 to TMn.

  Therefore, it is possible to distribute the notification information content to the plurality of terminal devices TM1 to TMn by the unicast method. For this reason, it is not necessary to provide a dedicated multicast device as a transmission device such as a router or gateway installed on the IP network NW, and a general-purpose transmission device can be used as it is. Can be made operational.

  In this embodiment, when the UDP packet is transmitted, the number of terminal devices TM1 to TMn as distribution destinations, the amount of information constituting the notification information stored in the content DB 21, and the own notification distribution server Based on the distribution processing capability of the SV, the terminal devices TM1 to TMn serving as the distribution destinations are divided into a plurality of groups in units that can be processed by the own server SV. Then, UDP packets are transmitted at different times for each of these groups. For this reason, it is possible to smoothly perform the distribution processing of the notification information content without increasing the distribution processing capability of the notification distribution server SV and without applying an excessive processing load to the notification distribution server SV.

  Furthermore, in this embodiment, the presence or absence of UDP packet delivery in each of the terminal devices TM1 to TMn is determined based on the reception result of the http request coming from the terminal devices TM1 to TMn. Then, based on the determination result of whether or not the UDP packet is delivered, a terminal device to which the UDP packet has not been delivered is extracted, and the UDP packet is retransmitted to the extracted undelivered terminal device.

  In this way, it is possible to determine whether or not the UDP packet has been delivered to each of the terminal devices TM1 to TMn that are the delivery destinations in the notification delivery server SV, thereby retransmitting the UDP packet to the undelivered terminal device. be able to. For this reason, even when line quality degradation or the like occurs in the IP network NW, it is possible to distribute notification information content to as many terminal devices as possible, thereby transmitting important information such as emergency information as much as possible. It becomes possible.

  Furthermore, when retransmitting the UDP packet, the terminal device to be retransmitted is divided into a plurality of groups in units that can be processed by the notification distribution server SV, and the UDP packet is retransmitted at different times for each group. I have to. For this reason, it is possible to smoothly perform the distribution processing of the notification information content without increasing the distribution processing capability of the notification distribution server SV and without applying an excessive processing load to the notification distribution server SV.

  Further, in this embodiment, in addition to the URL indicating the access method to the notification information content, the UDP packet is transmitted including information indicating the security authentication information and the display priority. For this reason, it is possible to prevent information leakage, spoofing, and the like, and it is possible to remotely control the display priority of notification information in the notification distribution server SV according to the urgency level of the notification information.

(Second Embodiment)
FIG. 7 is a schematic configuration diagram of a notification information distribution system including a notification distribution server according to the second embodiment of the present invention. This system separately provides a notice delivery server SVC having a trigger packet delivery function and a plurality of content delivery servers SVS1 to SVSm having a notice information content delivery function, and these notice delivery server server SVC and content delivery server The SVS1 to SVSm and the plurality of terminal devices TM1 to TMn can be connected via the IP network NW.

The notification distribution server SVC is configured as follows. FIG. 8 is a block diagram showing the configuration. In the figure, the same parts as those in FIG.
That is, the storage unit newly includes a content distribution server management database (content distribution server management DB) 24 in addition to the content DB 21, terminal / group management DB 22, and delivery / response management DB 23. The content distribution server management DB 24 stores management information of notification information contents distributed to the content distribution servers SVS1 to SVSm in association with the identification information of the plurality of content distribution servers SVS1 to SVSm. In addition, information representing the processing load of each of the content distribution servers SVS1 to SVSm acquired by the content distribution server load management unit 18 described later is also stored.

  The control unit 10B includes, as control processing functions according to the present invention, a terminal grouping management unit 11, a UDP packet generation unit 12, a UDP packet transmission unit 13, a content distribution server load management unit 18, a content distribution unit 19, And a delivery response management unit 20. All of these functions are realized by causing the CPU to execute an application program.

The content distribution server load management unit 18 communicates with each of the content distribution servers SVS1 to SVSm via the communication interface 41 periodically or when necessary, so that the processing load from the content distribution servers SVS1 to SVSm is changed from time to time. Get information representing.
Prior to the distribution of the notification information content, the content distribution unit 19 transfers the notification information content stored in the content DB 21 from the communication interface 41 to each content distribution server SVS1 to SVSm via the IP network NW.

  The terminal grouping management unit 11 serves as a distribution destination stored in the terminal / group management DB 22 when distributing UDP packets that prompt the terminal apparatuses TM1 to TMn to transmit distribution requests to the terminal apparatuses TM1 to TMn. The number of TM1 to TMn, the amount of content constituting the notification information stored in the content DB 21, the number of content distribution servers SVS1 to SVSm, and the content distribution server SVS1 acquired by the terminal grouping management unit 11 The terminal devices TM1 to TMn serving as the distribution destinations are divided into a plurality of groups based on information representing the load of SVSm.

  Further, the terminal grouping management unit 11 also determines the number of retransmission destination terminal devices, the number of pieces of information of the distribution content, the content when the UDP packet is retransmitted to a terminal device to which the UDP packet has not been delivered. The distribution servers SVS1 to SVSm are divided into a plurality of groups based on the number and the load thereof.

For each group divided by the terminal grouping management unit 11, the UDP packet generation unit 12 generates a trigger packet that prompts a terminal device belonging to the group to transmit a distribution request. This trigger packet is configured by a UDP (User Datagram Protocol) packet. At this time, the UDP packet generation unit 12 selects the content distribution server having the smallest load at that time based on the information representing the load of each of the content distribution servers SVS1 to SVSm acquired by the terminal grouping management unit 11. To do. Then, the selected content distribution server is determined as the access destination of the group. That is, a URL (Uniform Resource Locator) for accessing the content distribution server assigned as the access destination is described in the information part of the UDP packet.
The UDP packet transmission unit 13 causes the UDP packet generated by the UDP packet generation unit 12 to be transmitted from the communication interface 41 to the IP network NW toward the terminal device.

  The delivery / response management unit 20 acquires information representing the delivery confirmation of the UDP packet in the terminal devices TM1 to TMn from the content distribution servers SVS1 to SVSm after transmitting the UDP packet, and delivers the information representing the delivery confirmation to the delivery / response. It is stored in the management DB 23. Further, the delivery / response management unit 20 transmits information indicating the notification information content in the terminal devices TM1 to TMn after each content distribution server SVS1 to SVSm transmits the notification information content to the terminal devices TM1 to TMn. (Response information) is acquired from each of the content distribution servers SVS1 to SVSm, and this response information is stored in the delivery / response management DB 23.

On the other hand, the content distribution servers SVS1 to SVSm are configured as follows. FIG. 9 is a block diagram showing the configuration.
That is, the content distribution servers SVS <b> 1 to SVSm include a communication interface 61, a content database (content DB) 71, and a control unit 80. The communication interface 61 performs packet communication between the notification delivery server SVC and the terminal devices TM1 to TMn under the control of the control unit 80. The content DB 71 is used for storing the notification information content transferred from the notification distribution server SVC.

  The control unit 80 includes a content reception unit 81, a content transmission unit 82, a request reception unit 83, a delivery / response management unit 84, and a load status confirmation unit 85 as functions related to the present invention. All of these functions are realized by causing the CPU to execute an application program.

  The content receiving unit 81 receives the notification information content transferred from the notification distribution server SVC via the communication interface 61 and stores it in the content DB 71. The request receiving unit 83 receives a distribution request (http request) transmitted from the terminal devices TM1 to TMn via the communication interface 61. In response to the received http request, the content transmission unit 82 reads out the corresponding notification information content from the content DB 71 and transmits the read notification information content from the communication interface 61 to the requesting terminal device. .

  The delivery / response management unit 84 determines whether the UDP packet is delivered to the terminal device based on the reception result of the http request received by the request reception unit 83. Then, the determination result is transmitted as delivery confirmation information from the communication interface 61 to the notification distribution server SVC. Further, the delivery / response management unit 84 receives a notification response message returned from the transmission destination terminal device after the notification information content is transmitted. Then, the reception result is transmitted as response information from the communication interface 61 to the notification distribution server SVC.

  Next, the operation of the notification distribution server SVC configured as described above will be described in association with the operations of the content distribution servers SVS1 to SVSm and the terminal devices TM1 to TMn. FIG. 10 is a flowchart showing a processing procedure and processing contents of the notice delivery server SVC, and FIG. 11 is a sequence diagram showing data exchange among the notice delivery server SV, the content delivery servers SVS1 to SVSm, and the terminal devices TM1 to TMn.

Prior to the distribution of the notification information content, the control unit 10B of the notification distribution server SVC first captures the notification information content to be distributed from the external memory or other information devices via the distribution content input unit 31 in step S101, and captures this content. The notification information content is stored in the content DB 21.
Further, in step S102, the control unit 10B takes in the identification information of the terminal device designated as the distribution destination by the operator from the terminal / group information input unit 32, and stores this identification information in the terminal / group management DB 22.

  Next, the control unit 10B of the notification distribution server SVC moves to step S103, and the content distribution unit 19 transfers the notification information content stored in the content DB 21 from the communication interface 41 to each of the content distribution servers SVS1 to SVSm. Each of the content distribution servers SVS1 to SVSm receives the notification information content by the content receiving unit 81, and stores the received notification information content in the content DB 71.

  When the distribution timing of the notification information content comes, the control unit 10B of the notification distribution server SVC first proceeds to step S104, and the terminal grouping management unit 11 uses the terminal device TM1 serving as the distribution destination stored in the terminal / group management DB 22. Based on the number of TMn, the amount of notification information content to be distributed, the number of content distribution servers SVS1 to SVSm, and the information indicating the load on the content distribution servers SVS1 to SVSm The terminal devices TM1 to TMn are divided into a plurality of groups.

Then, one of the plurality of divided groups is selected, the process proceeds to step S105, and information indicating the processing load at this time is obtained from each of the content distribution servers SVS1 to SVSm by the content distribution server load management unit 18. get. And it transfers to step S106, the server with the lightest load at this time is selected by comparing the load of each of the acquired content distribution servers SVS1 to SVSm, and this selected server is selected as the access destination of the selected group. Determine as.
For example, if the group G1 among the groups G1 to Gm is selected and the load on the content distribution server SVS1 is the smallest, this content distribution server SVS1 is determined as the access destination of the group G1.

  Next, the control unit 10B proceeds to step S107, and the UDP packet generation unit 12 generates a UDP packet for prompting the terminal device (for example, TM1) belonging to the selected groove G1 to transmit a distribution request. Address information of the terminal device TM1 belonging to the selected group G1 is read from the terminal / group management DB 22 and inserted into the header H of the UDP packet. In addition, a URL for accessing the notification information content stored in the content distribution server SVS1 determined as the access destination is inserted into the information portion of the UDP packet. For example, as shown in FIG. 6, security authentication information P1, message IDP2, display priority P4, and screen transition control parameter P5 are also inserted into the information portion of the UDP packet.

  When the UDP packet is generated in this way, the control unit 10B proceeds to step S108, and the UDP packet transmission unit 13 transmits the generated UDP packet from the communication interface 41 to the IP network NW. Thus, the UDP packet is transmitted from the notice distribution server SVC to the terminal device TM1 belonging to the selected group G1, as shown in FIG. If the terminal device other than the terminal device TM1 is included in the group G1, the UDP packet is transmitted to this terminal device.

  On the other hand, when receiving the packet addressed to itself by the UDP packet receiving unit 52, the terminal device TM1 analyzes the received packet by the packet analyzing unit 53 and determines whether or not the packet is a UDP packet that prompts transmission of a distribution request. To do. If it is a UDP packet that prompts transmission of the distribution request, the request transmission unit 54 generates a distribution request (http request), and the http request is transmitted to the content distribution server according to the URL described in the received UDP packet. It transmits toward SVS1 as shown in FIG.

  When the content receiving server SVS1 receives the http request transmitted from the terminal device TM1 by the request receiving unit 83, the content transmitting unit 82 reads out the corresponding notification information content from the content DB 71. Then, after the read notification information content is packetized, it is transmitted as an http response to the requesting terminal device TM1 as shown in FIG.

  At the same time, when receiving the http request, the content distribution server SVS1 transmits the reception result as delivery confirmation information from the communication interface 61 to the notification distribution server SVC. The notification delivery server SVC receives the delivery confirmation information by the delivery / response management unit 20 and stores it in the delivery / response management DB 23.

On the other hand, when the transmission of the UDP packet to the group G1 is completed, the control unit 10B of the notification distribution server SVC determines whether or not there remains a group that has not yet transmitted the UDP packet in step S109. As a result of this determination, if an untransmitted group remains, the process returns to step S104 to select an untransmitted group. In step S105, information representing the load on each of the content distribution servers SVS1 to SVSm is acquired, and in step S106, the acquired load on each of the content distribution servers SVS1 to SVSm is compared. select. Then, the selected server is determined as the access destination of the selected group.
For example, if the group G2 among the groups G1 to Gm is selected and the load on the content distribution server SVS2 is the smallest, this content distribution server SVS2 is determined as the access destination of the group G2.

  Then, the control unit 10B proceeds to step S107, and the UDP packet generation unit 12 generates a UDP packet for prompting the terminal device (for example, TM2) belonging to the selected groove G2 to transmit a distribution request. At this time, the address information of the terminal device TM2 belonging to the selected group G2 is read from the terminal / group management DB 22 and inserted into the header H of the UDP packet. Also, a URL for accessing the notification information content stored in the content distribution server SVS2 determined as the access destination is inserted into the information portion of the UDP packet.

  When the UDP packet is generated in this way, the control unit 10B proceeds to step S108, and the UDP packet transmission unit 13 transmits the generated UDP packet from the communication interface 41 to the IP network NW. Thus, the UDP packet is transmitted from the notice distribution server SVC to the terminal device TM2 belonging to the selected group G2, as shown in FIG.

  Thereafter, similarly, each time an untransmitted group (for example, Gm) is selected, the content distribution server (for example, SVSm) having the smallest load at that time is selected. Then, a UDP packet in which a URL for accessing the content distribution server SVSm is inserted is generated and transmitted to the terminal devices (for example, TMn) belonging to the group Gm.

  When the UDP packet transmitted from the notification distribution server SVC is received by the terminal device, a distribution request (http request) is transmitted from the terminal device to the content distribution server specified by the URL, and in response to the distribution request, The operation of distributing the notification information content from the content distribution server to the requesting terminal device is the same as that of the group G1 described above as shown in FIG.

  When an http request is received, delivery confirmation information is transmitted from the content distribution servers SVS2 to SVSm to the notification distribution server SVC and stored in the delivery / response management DB 23 of the notification distribution server SVC as shown in FIG. The operation is the same as that of the group G1 described above.

  When the notification information content is distributed, each of the terminal devices TM1 to TMn decodes and reproduces the notification information content. For example, if the notification information content includes image data or character data, these are decoded and displayed on the content display unit 55, and if the notification information content includes audio data, this is decoded and output from the speaker. Output loudly.

  At the same time, the terminal devices TM1 to TMn return a notification response message (post data of the http request) as shown in FIG. 11 to the content distribution servers SVS1 to SVSm of the content distribution source. On the other hand, the content distribution servers SVS1 to SVSm receive the notification response message by the delivery / response management unit 84, and transmit the reception result from the communication interface 61 to the notification distribution server SVC as response information.

  When the processing from the transmission of the UDP packet to the transmission of the notification information content is completed for all the groups G1 to Gm, the control unit 10B of the notification distribution server SVC moves to step S109 and is delivered here. Based on the delivery confirmation information stored in the response management DB 23, all terminal devices to which no UDP packet has been delivered are extracted. Then, after the undelivered terminal devices are grouped in step S104, the load of each of the content distribution servers SVS1 to SVSm is detected in step S105 for each of these groups, and the content distribution server with the smallest load at this time is selected. In step S106, the selected server is determined as the access destination of the undelivered group.

In step S107, a UDP packet for prompting the terminal device belonging to the undelivered groove to transmit a distribution request is generated, and the UDP packet is transmitted to the terminal device in step S108. Also in this case, the address information of the terminal devices belonging to the selected group is read from the terminal / group management DB 22 and inserted into the header H of the UDP packet. In addition, a URL for accessing the notification information content stored in the content distribution server determined as the access destination is inserted into the information portion of the UDP packet.
That is, UDP packet retransmission processing for undelivered terminal devices is also performed for each group, and the access destination of each group is set to the content distribution server with the smallest load at that time.

  In addition, the upper limit number of times of the UDP packet retransmission processing for one terminal device is defined in advance. The control unit 10B monitors whether or not the retransmission process has reached the upper limit number in step S111. Then, when the number of retransmissions reaches the upper limit number, subsequent distribution processing for the terminal device is stopped.

  As described above, in the second embodiment, a plurality of content distribution servers SVS1 to SVSm are provided in addition to the notification distribution server SVC, and the notification distribution server SVC is a content distribution server that is an access destination for the terminal devices TM1 to TMn. A UDP packet in which the URL is described is transmitted so that a distribution request is transmitted from the terminal devices TM1 to TMn to the content distribution servers SVS1 to SVSm, and the content distribution server responds to the distribution request to the requesting terminal devices TM1 to TMn. Notification information content is distributed.

  Therefore, it is not necessary to provide a multicast-compatible dedicated device as a transmission device on the IP network NW, and the system construction cost can be reduced. Furthermore, since the notification information content is distributed from the content distribution servers SVS1 to SVSm to the terminal devices TM1 to TMn, the processing load on the notification distribution server SVC is reduced.

  Moreover, when the notification distribution server SVC transmits a UDP packet, the number of terminal devices TM1 to TMn, the amount of notification information content, the number of content distribution servers SVS1 to SVSm, and the content distribution servers SVS1 to SVSm Based on the information indicating the load, the terminal devices TM1 to TMn serving as the distribution destinations are divided into a plurality of groups, and UDP packets are distributed for each of these groups. For this reason, the processing load of the notice distribution server SVC and the content distribution servers SVS1 to SVSm can be distributed and further reduced.

  Further, when transmitting a UDP packet, the content distribution server having the smallest load at that time is determined as an access destination for each divided group, and the UDP packet is transmitted. For this reason, it is possible to distribute the load so that the distribution process does not concentrate on a specific content distribution server, and thereby it is possible to efficiently distribute the notification information content to a large number of terminal devices.

  Further, the notice distribution server SVC acquires information representing the reception result of the http request transmitted from the terminal devices TM1 to TMn in response to the UDP packet from the content distribution servers SVS1 to SVSm, and each terminal device is based on this information. The presence or absence of UDP packet delivery in TM1 to TMn is determined. Then, based on the determination result of whether or not the UDP packet is delivered, a terminal device to which the UDP packet has not been delivered is extracted, and the UDP packet is retransmitted to the extracted undelivered terminal device.

  In this way, it is possible to determine whether or not the UDP packet has been delivered to each of the terminal devices TM1 to TMn that are the delivery destinations in the notification delivery server SV, thereby retransmitting the UDP packet to the undelivered terminal device. be able to. For this reason, even when line quality degradation or the like occurs in the IP network NW, it is possible to distribute notification information content to as many terminal devices as possible, thereby transmitting important information such as emergency information as much as possible. It becomes possible.

  Further, when retransmitting this UDP packet, the terminal device to be retransmitted is divided into a plurality of groups, and the content distribution server having the smallest load at that time is determined as the access destination for each of the divided groups, and the UDP is determined. The packet is resent. For this reason, even when the UDP packet is retransmitted, it is possible to efficiently distribute the notification information content so that the distribution processing is not concentrated on the specific content distribution server.

  Also in this second embodiment, information is leaked, spoofed, etc. by sending the UDP packet including information indicating the security authentication information and the display priority in addition to the URL indicating the access method to the notification information content. In addition, it is possible to remotely control the display priority of the notification information in the notification distribution server SV according to the urgency level of the notification information.

(Other embodiments)
In each of the above-described embodiments, a case where one notification distribution server is used has been described as an example. However, a plurality of notification distribution servers may be provided, and distribution processing of UDP packets and the like may be distributed by these servers. In the second embodiment, a plurality of content distribution servers are provided independently. However, the functions of the plurality of content distribution servers may be provided on a single distribution server.

  In the second embodiment, when the UDP packet is transmitted, the content distribution server with the smallest load at that time is determined as the access destination for each divided group. However, the content distribution server with the smallest load is not necessarily selected. There is no need to select any server, and an arbitrary server may be selected from the content distribution servers whose load is equal to or less than a preset threshold value.

  Further, in each of the embodiments, an undelivered terminal device is extracted based on delivery confirmation information indicating whether or not a UDP packet is delivered, and the UDP packet is retransmitted to the extracted terminal device. However, in addition to this, a terminal device to which content has not been delivered may be extracted based on information indicating the presence / absence of a response to transmission of notification information content, and a UDP packet may be retransmitted to the extracted terminal device. In this way, it is possible to extract the terminal device that has received the UDP packet but has not received the notification information content, and retransmits the UDP packet to the extracted terminal device to deliver the notification information content. It becomes. As a result, the content distribution completion rate can be further increased.

In addition, the configurations of the notification distribution server and the content distribution server, the processing procedure and processing contents of these servers, the types and configurations of the notification information, and the like can be variously modified without departing from the gist of the present invention.
In short, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

It is a schematic block diagram of the system using the notification delivery server concerning 1st Embodiment of this invention. It is a block diagram which shows the structure of the notification delivery server concerning 1st Embodiment of this invention. It is a block diagram which shows the structure of the terminal device used with the system shown in FIG. It is a flowchart which shows the process sequence and process content by the notification delivery server shown in FIG. It is a figure which shows the transmission / reception sequence of the data between the notification delivery server and terminal device of the system shown in FIG. It is a figure which shows the format of the UDP packet produced | generated in the notification delivery server shown in FIG. It is a schematic block diagram of the system which uses the notification delivery server concerning 2nd Embodiment of this invention. It is a block diagram which shows the structure of the notification delivery server concerning 2nd Embodiment of this invention. It is a block diagram which shows the structure of the content delivery server used with the system shown in FIG. It is a flowchart which shows the process sequence and process content by the notification delivery server shown in FIG. It is a figure which shows the transmission / reception sequence of the data between the notification delivery server of the system shown in FIG. 7, a content delivery server, and a terminal device.

Explanation of symbols

  SV, SVC ... notification distribution server, TM1 to TMn ... terminal device, NW ... IP network, SVS1 to SVSm ... content distribution server, 10A, 10B ... control unit of notification distribution server, 11 ... terminal grouping management unit, 12 ... UDP packet Generation unit, 13 ... UDP packet transmission unit, 14 ... request reception unit, 15 ... content transmission unit, 16 ... delivery confirmation management unit, 17 ... response management unit, 18 ... content distribution server load management unit, 19 ... content distribution unit, DESCRIPTION OF SYMBOLS 20 ... Delivery / response management part, 21 ... Content database, 22 ... Terminal / group management database, 23 ... Delivery / response management database, 24 ... Content delivery server management database, 31 ... Delivery content input part, 32 ... Terminal / group information Input unit, 41 ... Communication interface of notification distribution server , 50 ... control unit of terminal device, 51 ... communication interface of terminal device, 52 ... UDP packet receiving unit, 53 ... packet analysis unit, 54 ... request transmission unit, 55 ... content display unit, 56 ... response input unit, 57 ... Input / output interface unit, 61 ... Communication interface of content distribution server, 71 ... Content database, 80 ... Control unit of content distribution server, 81 ... Content input unit, 82 ... Content transmission unit, 83 ... Request reception unit, 84 ... Delivery Response management unit, 85... Load status confirmation unit.

Claims (4)

In an information distribution device connectable to a plurality of terminal devices via a communication network,
Notification information storage means for storing notification information to be distributed;
Generating a trigger packet describing information for prompting the plurality of terminal devices to transmit a distribution request and information indicating an access method for the notification information, and transmitting the generated trigger packet to the plurality of terminal devices in the communication network; Means for transmitting via,
Means for receiving, via the communication network, the distribution request transmitted from a destination terminal device in response to the trigger packet;
When the distribution request is received, the notification information corresponding to the distribution request is read from the notification information storage unit, and the read notification information is transmitted to the requesting terminal device via the communication network. Means,
Means for determining the presence or absence of delivery of the trigger packet in each destination terminal device based on the reception result of the distribution request;
Based on the determination result of whether or not the trigger packet is delivered, the terminal device that has not been delivered to the trigger packet, and a retransmission unit that retransmits the trigger packet to the terminal device that has not been delivered ,
The retransmission means includes
Means for dividing the extracted undelivered terminal devices into a plurality of groups based on the information amount of the notification information to be distributed, the number of terminal devices of the distribution destination, and the distribution processing capability of the information distribution device of its own; ,
Means for resending the trigger packet at different times for each of the divided groups;
Information distribution apparatus, characterized in that it comprises a. In an information distribution device connectable via a communication network to a plurality of content distribution servers that store the same notification information and a plurality of terminal devices that are distribution destinations of the notification information,
Based on the information amount of the notification information to be distributed, the number of terminal devices to be distributed, the number of the plurality of content distribution servers, and the distribution processing capability of the content distribution servers, Means to divide into
Means for monitoring the processing load of the plurality of content distribution servers for each group and selecting a content distribution server having a processing load equal to or lower than a predetermined condition as an access destination;
Generating a trigger packet describing information prompting the plurality of terminal devices to transmit a distribution request and information indicating an access method to the notification information stored in the selected content distribution server, and generating the generated trigger packet Means for transmitting to the terminal devices belonging to the group via the communication network. Means for receiving a trigger packet transmitted from the information distribution device and transmitting the distribution request to a corresponding content distribution server based on information representing an access method described in the trigger packet; Prepared,
And when the plurality of content distribution servers receive a distribution request transmitted from the terminal device, means for transmitting notification information corresponding to the distribution request to the requesting terminal device via the communication network; And a means for generating information indicating the presence or absence of delivery of the trigger packet in each destination terminal device based on the reception result of the distribution request for the notification information,
Means for acquiring from the plurality of content distribution servers, via the communication network, information indicating presence / absence of delivery of the trigger packet in each terminal device as a transmission destination;
And further comprising: retransmission means for extracting a terminal device to which the trigger packet has not been delivered based on the acquired information, and retransmitting the trigger packet to the extracted undelivered terminal device. The information distribution apparatus according to claim 2 . In an information distribution method used in an information distribution device connectable via a communication network to a plurality of content distribution servers each storing the same notification information and a plurality of terminal devices to which the notification information is distributed,
A process of dividing the plurality of terminal devices into a plurality of groups based on the amount of notification information to be distributed, the number of terminal devices of distribution destinations, and the distribution processing capability of the plurality of content distribution servers;
For each group, monitoring the processing load of the plurality of content distribution servers and selecting a content distribution server having a processing load equal to or lower than a predetermined condition as an access destination;
Generating a trigger packet describing information prompting the plurality of terminal devices to transmit a distribution request and information indicating an access method to the notification information stored in the selected content distribution server, and generating the generated trigger packet And a step of transmitting via the communication network to terminal devices belonging to the group.

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