JP5326968B2 - Information communication system, support apparatus, support apparatus program, and content acquisition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information communication system for efficiently acquiring content at a predetermined time. <P>SOLUTION: This information communication system is configured of a content distribution center and an edge server SE for relaying the content, and for distributing the content to a user terminal T and a network NW. In order to distribute the content to the terminal T at a predetermined acquisition time, an acquisition list including the content information and acquisition time information is distributed from a management server SM to an edge server SE. The edge server SE acquires the pertinent content from a distribution center to a cache. In order to achieve the efficiency of the acquisition and distribution of the content, the transfer of the content is performed between the edge server SE and the terminal T by using a peer-to-peer network technology so that it is possible to efficiently acquire the content to the terminal T. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a technical field of a peer-to-peer (P2P) type information communication system including a plurality of node devices that can communicate with each other via a network.

  In recent years, a peer-to-peer communication system as disclosed in Patent Document 1 has attracted attention. The peer-to-peer communication system is attracting attention as a new form that replaces the server client system, which is the mainstream form of current content distribution. In this peer-to-peer communication system, content requests to the server device at the center are not concentrated. Therefore, content can be acquired in a short time compared to the server client method. In addition, when the user views the content continuously, a viewing list is created and the content is downloaded in order. For example, Patent Document 2 discloses a technique for making a content viewing reservation.

JP 2006-197400 A JP 2002-152672 A

  By the way, there are cases where there are bases in various places such as a private school, a school, a company, a hotel, etc., and there are a plurality of terminal devices at each base. In this case, generally, a private network such as a LAN (Local Area Network) to which each terminal device is connected is formed in the base. The base is provided with a line connected to a public network such as the Internet or a WAN (Wide Area Network).

  In such a case, it is conceivable that each terminal apparatus has a peer-to-peer communication function as disclosed in Patent Document 1. If it does so, each terminal device will be able to acquire a content also from the terminal device which exists in the same base. Accordingly, there is a case where the terminal device does not need to request content from other bases, so that the traffic on the externally connected line can be reduced.

  However, when the number of contents stored in each terminal device existing in the site is small, the probability of requesting necessary content on the network outside the site increases. In this case, for example, if the number of externally connected lines is small or the bandwidth is narrow, the time required for content acquisition becomes long. For this reason, there is a case where the effect of adopting the peer-to-peer communication system cannot be sufficiently obtained.

  In this case, it may be possible to install an edge server dedicated to storing contents at each site. Then, when the content is stored in the edge server installed in the same base, the terminal device can acquire the content from the edge server in advance. However, every time each terminal device reproduces the content, it is necessary to access the edge server and download the desired content, which causes a considerable waiting time for download.

  Therefore, the present invention has been made in view of the above points. An object of this invention is to provide the information communication system etc. which can acquire a content efficiently.

In order to solve the above-described problem, the invention according to claim 1 is an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices, and the information communication system includes a plurality of internal networks in an external network. A plurality of node devices connected to the same internal network, and a support device connected to the internal network and supporting content acquisition by the node device, for each internal network, the support device time, to obtain a plurality of content information to which the support device itself the respectively identifying a plurality of the content to be reproduced in each said node device connected to the internal network and the same internal network connecting the respective said content To obtain an acquisition list in which the acquisition time information indicating And obtaining a list acquisition means, and the node device information identifying each said node device connected to the same internal network, and the plurality of content information, and transmission time information indicating a transmission time of transmitting the content to the respective node devices Are transmission lists associated with each other, user information for identifying a plurality of users using each of the node devices connected to the same internal network, the node device information of each of the node devices, Obtain a transmission list created based on usage registration information in which content information for identifying content that each user plans to use is associated with playback time information indicating the time at which the content is played back A transmission list acquisition means for performing information on contents whose reproduction time is within a predetermined period from the current time. And the use list acquisition means for acquiring at each predetermined timing, based on the acquired time information has been acquired list acquired by the acquiring list acquisition means comprises, whether led to a time of acquiring the content, predetermined When the acquisition time determination unit and the acquisition time determination unit determine that the content acquisition time has been reached, the free storage capacity of the storage unit that stores the content is less than a predetermined amount. When the free capacity determining means for determining whether or not the free capacity determining means determines that the free storage capacity of the storage means is less than a predetermined amount, the free list is acquired by the use list acquiring means. Content whose playback time is not within a predetermined period from the current time among the content stored in the storage means based on the usage list Is acquired from the storage means, and when the free capacity determination means determines that the free storage capacity of the storage means is not less than a predetermined amount, or after deletion by the deletion means, the acquisition list acquisition a content acquiring means for acquiring contents which the content information is shown corresponding to the acquired time information included in the acquired acquired list by means of other said support device, has been the content acquired by the content acquisition unit in said storage means Storage control means for storing; transmission time determination means for determining whether or not the time for transmitting the content has been reached based on the transmission time information of the transmission list acquired by the transmission list acquisition means; and the transmission time If the determination means determines that the time for transmitting the content has been reached, the transmission The specific node device indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the list acquisition unit acquires the content to be reproduced next from the storage unit and transmits the content to the specific node device. An information communication system comprising: content transmission means .

In order to solve the above-mentioned problem, the invention according to claim 2 is characterized in that the node device specifies content information for specifying content to be reproduced by the node device itself, acquisition time information indicating a time to acquire the content, The acquisition time determination means for determining whether or not the time for acquiring the content has been reached based on the acquisition time information in the acquisition lists respectively associated with the time at which the content is acquired by the acquisition time determination means in the case where it is determined that the led, to the support device connected to the internal network to which the node apparatus itself is connected, at least including content request information the content information for identifying the content that led to the time the acquiring The content request information transmitting means to transmit and the internal network to which the node device itself connects are connected. Content receiving means for receiving content corresponding to the content information from the support device, the support device from any of the node devices connected to the internal network to which the support device itself connects When the content request information including the content information is received, the content transmission unit acquires the content corresponding to the content information included in the content request information from the storage unit, and sends the content request information to the node device that has transmitted the content request information. The information communication system according to claim 1, wherein transmission is performed.

In order to solve the above-mentioned problem, the invention according to claim 3 is a support device provided in an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices, and the information communication system includes an external network. A plurality of node devices connected to the same internal network, and the support device connected to the internal network and supporting acquisition of content by the node device, for each internal network. includes the said support device includes a plurality of content information to which the support device itself the respectively identifying a plurality of the content to be reproduced in each said node device connected to the internal network and the same internal network connecting , Acquisition time information indicating the time at which each content is acquired, Sending an acquisition list acquisition means for acquiring Tagged acquired list, the node device information identifying each said node device connected to the same internal network, and the plurality of content information, the content to the respective node devices Transmission time information indicating a transmission time, a transmission list associated with each of the transmission time information, user information for specifying a plurality of users using each of the node devices connected to the same internal network, and each of the nodes Based on usage registration information in which the node device information of a device, content information for specifying content that each user plans to use, and playback time information indicating a time at which the content is played back are associated with each other. The transmission list acquisition means for acquiring the transmission list created in the above, and the playback time is within a predetermined period from the current time The information of the content as a usage list, and use the list acquiring means for acquiring at each predetermined timing, based on the acquired time information has been acquired list acquired by the acquiring list acquisition means comprises, or has reached the time to acquire the content as to whether or not, and determines acquisition time decision means for each predetermined timing, by the acquisition time determination unit, when it is determined that led to the time of acquiring the content, the free storage capacity of the storage means for storing content When the free capacity determination means for determining whether or not the free storage capacity of the storage means is less than the predetermined amount by the free capacity determination means and the free capacity determination means, the use list acquisition is performed. Based on the usage list acquired by the means, whether the playback time of the content stored in the storage means is the current time When the deletion unit that deletes content not within a predetermined period from the storage unit and the free space determination unit determine that the free storage capacity of the storage unit is not less than a predetermined amount, or the deletion by the deletion unit later, a content acquiring means for acquiring content indicated by the content information corresponding to the acquired time information has been acquired list acquired by the acquiring list acquisition means comprises from another said support device, obtained by the content obtaining unit and storage control means for storing the content in the storage means, on the basis of the transmission time information of the transmission list acquired by the transmission list acquisition unit, the transmission time determination determines whether reached time to transmit the content Means for transmitting the content by the transmission time determining means and the transmission time determining means. If it is determined that the specific node device indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition unit acquires the content to be reproduced next from the storage unit And a content transmission means for transmitting to the specific node device .

In order to solve the above-mentioned problem, the invention according to claim 4 is an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices, and a plurality of internal networks are connected to an external network, and the same The support device in the information communication system comprising a plurality of the node devices connected to the internal network and the support device connected to the internal network and supporting acquisition of content by the node device for each internal network. a computer included in a plurality of content information which the support device itself the respectively identifying a plurality of the content to be reproduced in each said node device connected to the internal network and the same internal network connecting each said content Acquisition time information indicating the time to acquire It transmits the acquired list acquisition step of acquiring Tagged acquired list, the node device information identifying each said node device connected to the same internal network, and the plurality of content information, the content to the respective node devices Transmission time information indicating a transmission time, a transmission list associated with each of the transmission time information, user information for specifying a plurality of users using each of the node devices connected to the same internal network, and each of the nodes Based on usage registration information in which the node device information of a device, content information for specifying content that each user plans to use, and playback time information indicating a time at which the content is played back are associated with each other. The transmission list acquisition step to acquire the transmission list created in the above, and the playback time is a predetermined period from the current time The information of the inner content is as available list, and use a list acquisition step of acquiring at each predetermined timing, based on the acquired time information acquired list obtained by the obtaining list acquisition step comprises acquires the content time If the acquisition time determination step for determining whether or not the content has been reached and the acquisition time determination step determines that the time for acquiring the content has been reached, the storage means for storing the content When the free capacity determination step for determining whether or not the free storage capacity is less than a predetermined amount and the free capacity determination step determines that the free storage capacity of the storage means is less than the predetermined amount, Based on the usage list acquired in the usage list acquisition step, the controller stored in the storage means. Of the content, a deletion step of deleting content whose playback time is not within a predetermined period from the current time from the storage unit and a free space determination step determine that the free storage capacity of the storage unit is not less than a predetermined amount. Or a content acquisition step of acquiring content indicated by the content information corresponding to the acquisition time information included in the acquisition list acquired by the acquisition list acquisition step from another support device after deletion by the deletion step When a storage control step of storing the content obtained by the content obtaining step to said storage means, on the basis of the said transmission time information has been transmitted list acquired by the transmission list acquisition step, the time for transmitting the content The transmission time judgment process for judging whether or not And the node device corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition step when it is determined by the transmission time determination step that the time for transmitting the content has been reached The specific node device indicated by the information acquires the content to be reproduced next from the storage means, and transmits the content to the specific node device .

In order to solve the above problem, the invention according to claim 5 is a content acquisition method in an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices, and the information communication system is connected to an external network. A plurality of node devices connected to the same internal network, and a support device connected to the internal network and supporting content acquisition by the node device are provided for each internal network. and, wherein the support device includes a plurality of content information to which the support device itself the respectively identifying a plurality of the content to be reproduced in each said node device connected to the internal network and the same internal network connecting each Acquisition time information indicating the time at which the content is acquired, respectively. And obtaining a list acquisition step of acquiring acquires list attached response, the node device information identifying each of said node devices, the support apparatus connected to the same internal network, and the plurality of content information, wherein each node device Transmission time information indicating the transmission time at which content is transmitted to each other, and a transmission list associated with each of the transmission time information, and user information for identifying a plurality of users who use each of the node devices connected to the same internal network And the node device information of each node device, content information specifying the content scheduled to be used by each user, and playback time information indicating the time when the content is played back are associated with each other. A transmission list acquisition step of acquiring a transmission list created based on usage registration information; and the support Location is the information of the content reproduction time is within a predetermined time period from the current time as the usage list, and use a list acquisition step of acquiring at predetermined timing, the support device has been acquired by the acquisition list acquisition step Based on the acquisition time information included in the acquisition list, the acquisition time determination step of determining whether or not the time for acquiring the content has been reached at every predetermined timing; and the support device, by the acquisition time determination step, When it is determined that the time for acquiring the content has been reached, a free space determination step for determining whether or not the free storage capacity of the storage unit for storing the content is less than a predetermined amount; When it is determined in the capacity determination step that the free storage capacity of the storage means is less than a predetermined amount Is a deletion step of deleting, from the storage means, contents whose reproduction time is not within a predetermined period from the current time among the contents stored in the storage means based on the use list acquired by the use list acquisition step. The support device is acquired by the acquisition list acquisition step when it is determined by the free space determination step that the free storage capacity of the storage means is not less than a predetermined amount, or after deletion by the deletion step. and a content obtaining step of obtaining content indicated by the content information from another of the support device corresponding to the acquired time information acquisition list includes the support device, the content obtaining the storage means obtained content by step a storage control step of storing in said support Based on the transmission time information of the transmission list acquired by the transmission list acquisition step, the transmission time determination step of determining whether or not the time for transmitting the content has been reached, and the support device, When it is determined by the transmission time determination step that the time for transmitting the content has been reached, the specific node indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition step A content acquisition method comprising: a content transmission step of acquiring the content to be reproduced next by the device from the storage means and transmitting the content to the specific node device .

  According to the present invention, the support device can efficiently acquire the content scheduled to be played by each node device based on the acquisition list.

It is a figure showing an example of outline composition of contents distribution system S concerning one embodiment. It is a figure which shows the construction example of overlay network PW and base network NLm in the content delivery system S which concerns on one Embodiment. It is the conceptual diagram which showed an example of a mode that a content is distributed in the content distribution system S which concerns on one Embodiment. It is an example of a class schedule. (A) is an example of an acquisition list. (B) is an example of a transmission list. It is the conceptual diagram which showed an example of a mode that a content is distributed in the content distribution system S which concerns on one Embodiment. It is an example of use registration information. (A) is an example of an acquisition list. (B) is an example of a transmission list. It is an example of a use content list. This is the usage registration information that is the basis for creating the usage content list of FIG. It is a block diagram which shows the example of a schematic structure of management server SM. It is a block diagram which shows the schematic structural example of edge server SEm. It is a block diagram which shows the example of a schematic structure of user terminal Tm-n. It is a flowchart which shows the process example of the control part 11 in the management server SM which concerns on one Embodiment. It is a flowchart which shows the process example of the control part 21 in edge server SEm which concerns on one Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a content distribution system.

[1. Overview of content distribution system]
First, the schematic configuration of the content distribution system according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a schematic configuration example of a content distribution system S according to the present embodiment.

  As shown in FIG. 1, in the content distribution system S, a distribution center network NS and a plurality of base networks NLm (m = 1, 2, 3,...) Are connected to a network NW. This network NW, distribution center network NS, and each base network NLm are real-world communication networks. The network NW is an example of an external network. The base network NLm is an example of an internal network.

  The network NW is a network for interconnecting the distribution center network NS and each base network NLm. The network NW is, for example, the Internet or a WAN (Wide Area Network). The network NW includes, for example, IX (Internet eXchange), ISP (Internet Service Provider), DSL (Digital Subscriber Line) line provider apparatus, FTTH (Fiber To The Home) line provider apparatus, communication line, etc. Is built by. The network NW may be a network dedicated to the content distribution system S.

  The distribution center network NS is a network constructed in the site of the distribution center. This distribution center network NS is constructed by, for example, a LAN (Local Area Network) or the like.

  The distribution center network NS is connected to server devices such as the input server ST, the management server SM, and the portal server SP, and the management terminal MT. Further, a firewall FW that interconnects the distribution center network NS and the network NW is connected to the distribution center network NS via a communication line LS.

  Each base network NLm is a network constructed in the site of the base m. The bases include, for example, a company, a school, a hospital, and a cram school. This base network NLm is constructed by a LAN or the like, for example. The base network NLm may be a network constructed by interconnecting a plurality of LANs. In this case, the plurality of LANs are connected via a network device such as a router. An example of a network in which a plurality of LANs are interconnected is CAN (Campus Area Network).

  In addition, a plurality of user terminals Tm-n (n = 1, 2, 3...) And an edge server SEm are connected to each base network NLm. Further, each base network NLm is connected to a firewall FW or a broadband router BR that interconnects the distribution center network NS and the network NW via a communication line Lm. Which of the firewall FW and the broadband router BR is installed at the base is arbitrarily determined for each base. The user terminal Tm-n is an example of a node device. The edge server SEm is an example of a support device.

  In the content distribution system S having such a configuration, the functional outline of each device as a component is as follows.

  The input server ST is a server device that inputs content data to a P2P network PW described later. Here, the input of content data refers to placing content data in a state where it can be acquired from the edge server SEm. The content data is referred to as “content”.

  The portal server SP transmits a web page to the user terminal Tm-n in response to a request from the user terminal Tm-n. The Web page transmitted by the portal server SP constitutes a Web site that distributes moving image data as an example of content.

  The management server SM provides a web application for managing the content to be distributed to the management terminal MT. That is, the management server SM transmits a web page for managing content to the management terminal MT. In addition, the management server SM provides the management terminal MT with a Web application for setting the operation mode of each edge server SEm and each user terminal Tm-n. Details of the operation mode will be described later.

  The user terminal Tm-n is a terminal device used by a user at the base m. The user terminal Tm-n acquires a Web page from a Web server such as the portal server SP, and displays the acquired Web page on the screen. In addition, the user terminal Tm-n acquires and stores content from another terminal Tm-n connected to the same base m or the edge server SEm. Furthermore, the user terminal Tm-n reproduces content such as moving image data.

  At least one edge server SEm is installed at each base m. The edge server SEm supports content acquisition by the terminal Tm-n connected to the same base m. Specifically, the edge server SEm acquires content from another edge server SEm or the input server ST as a proxy for the user terminal Tm-n. Then, the edge server SEm transmits the acquired content to the user terminal Tm-n. Further, the edge server SEm stores the acquired content.

[2. Overview of P2P network PW]
Next, an outline of the P2P network PW in the content distribution system S will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a construction example of the P2P network PW and the base network NLm in the content distribution system S according to the present embodiment.

  A P2P network PW and a base network NLm for content distribution are constructed on the network NW.

  The P2P network PW is a logical overlay network constructed on the network NW. The P2P network PW is a network formed by connecting any of a plurality of edge servers SEm among the edge servers SEm constituting the content distribution system S. The input server ST may also be connected to the P2P network PW. Each base network NLm is connected to the network NW via the broadband router BR and the firewall FW. Therefore, the port forwarding is set in the broadband router BR and the firewall FW so that the edge server SEm can perform communication by the peer-to-peer method. For example, in the case of a broadband router BR, it is preferable to set port forwarding automatically using a UPnP (Universal Plug and Play) function or the like.

  Hereinafter, the P2P network PW will be described. A device connected to the P2P network PW is referred to as a “node”. An apparatus corresponding to a node in the P2P network PW is an edge server SEm. Alternatively, the edge server SEm and the input server ST correspond to nodes.

  The P2P network PW in the content distribution system S is realized by a specific algorithm, for example, an algorithm using a DHT (Distributed Hash Table). Each node connected to the content distribution system S is assigned a node ID, which is unique identification information having a predetermined number of digits. The node ID is an example of node device information.

  The node ID is, for example, a value obtained by hashing an IP address, a serial number, or a MAC address (Media Access Control address) individually assigned to each node using a common hash function. The node IDs are arranged in a distributed manner in the ID space. For example, SHA-1 or the like is used as the hash function. The hashed value has a bit length of 160 bits, for example. The node IDs are distributed in the ID space without being distributed. The node ID may be registered for each node by a system administrator, a user, or the like when setting up P2P software for connecting to the P2P network PW. The P2P network PW shown in FIG. 2 shows the ID space of the node ID as a ring. The position of each node shown in the ring-shaped ID space of FIG. 2 corresponds to each node ID.

  The edge server SEm is connected to the P2P network PW. In this case, node IDs are assigned to all nodes so as not to overlap. Connection to the P2P network PW is performed by a node not connected to the P2P network PW transmitting a participation request message indicating a participation request to the content distribution system to any connected node. This participation request message is an example of participation request information. Here, participation in the P2P network PW means that a node is connected to the P2P network PW and can acquire content from the P2P network PW. The arbitrary node is, for example, a contact node that is always connected to the P2P network PW. The contact node in the P2P network PW is, for example, the input server ST.

  Each node holds a routing table using DHT. This routing table defines various message transfer destinations on the content distribution system S. Specifically, a plurality of pieces of node information including node IDs, IP addresses, and port numbers of nodes that are moderately separated in the ID space are registered in this routing table. This node information is an example of address information.

  One node connected to the P2P network PW stores the minimum necessary node information as a routing table. By transferring various messages between the nodes, node information about nodes that do not store node information is acquired.

  Such a routing table using DHT is well known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and will not be described in detail.

  The P2P network PW stores various content replicas having different contents distributed in a plurality of nodes in a predetermined file format. A replica can be used between the nodes. The original of each content is stored in the input server ST. For example, in the P2P network PW, a content cache area of the edge server SE5 stores a movie content replica with the title XXX. On the other hand, the content cache area of the edge server SE3 stores a replica of the movie content whose title is YYY. In this way, the content is distributed and stored in a plurality of nodes. The content cache area is an area for storing and storing content. For example, the actual content cache area is allocated to a specific hard disk included in the node, or is allocated to a specific partition of the hard disk. The storage capacity of the content cache area of the edge server SEm is larger than the storage capacity of the content cache area of the user terminal Tm-n. As an example, the storage capacity of the content cache area of the edge server SEm is about 10 to 100 times the storage capacity of the content cache area of the user terminal Tm-n. When content cannot be stored in the content cache area, new content is stored. For example, the content is deleted from the content cache area in the oldest order. Whether the content is new or old is determined based on, for example, the use date of the content. Hereinafter, a node in which a content replica is stored is referred to as a “content holding node”. In the following description, the original content and the replica are referred to as content without particular distinction.

  Information such as a content name and content ID, which is unique identification information for each content, is added to each content described above. This content ID is generated, for example, by hashing the content name + an arbitrary numerical value with a hash function common to the case of obtaining the node ID. Alternatively, the system administrator may give a unique ID value for each content. The content ID is an example of content information.

  The location of the content that is distributed and stored is stored as index information by a node or the like that manages (stores) the location of the content. Hereinafter, a node that manages (stores) the location of content is referred to as a “root node”. The index information includes a set of node information including the node ID, IP address, and port number of the node that stores the content, and the content ID of the content. Such a root node is determined to be a node having a node ID closest to the content ID, for example. The node ID closest to the content ID is, for example, the node ID with the highest number of upper digits that match.

  For example, in the case of the P2P network PW, the index information about the content of the movie whose title is XXX is managed by the edge server SE1 that is the root node of the content. Further, for example, the index information about the content of the movie whose title is YYY is managed by the edge server SE2 which is the root node of the content.

  When a user of a certain node wants to acquire desired content, the node that desires acquisition of the content generates a message. Hereinafter, a node that the user desires to acquire content is referred to as a “user node”. This message is a content location inquiry message including the content ID of the content desired to be acquired, the IP address of the user node, the port number, and the like. The content location inquiry message is a message for searching for a content holding node. In the following description, the content location inquiry message is referred to as “query”. The query is sent to other nodes according to the DHT routing table acquired by the user node. That is, the user node sends the query toward the root node. As a result, the query finally arrives at the root node by DHT routing using the content ID as a key.

  In each node, attribute information such as content ID of the content is described in the content catalog information. The content attribute information described in the content catalog information includes, for example, a content name, a content ID, a content publication start date and time, a publication end date and time, a valid / invalid flag, and the like. The valid / invalid flag is a flag indicating whether the content is valid or invalid. If this valid / invalid flag indicates invalid, the corresponding content is deleted from the content cache area.

  The content catalog information is distributed from, for example, the input server ST to all edge servers SEm. The distribution of the content catalog information may be performed by, for example, DHT multicast (multicast message transfer processing) disclosed in Japanese Patent Application Laid-Open No. 2007-053662. Further, each edge server SEm may acquire content catalog information by accessing the input server ST periodically. Furthermore, each user terminal Tm-n may acquire content catalog information by accessing the edge server SEm periodically.

  The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that has received the query acquires index information corresponding to the content ID included in the query from the index information cache. The acquired index information is returned to the user node that is the transmission source of the query. The user node that has acquired the index information in this way can download (acquire) the content based on the index information. The user node accesses the content holding node based on the IP address and port number of the content holding node included in the index information. The user node can download the content from the accessed content holding node. The index information may include node information of a plurality of content holding nodes. In this case, the user node selects one content holding node from among the plurality of content holding nodes. Then, the user node can connect to the selected content holding node and download the content.

  Note that the root node transmits a content transmission request message to the content holding node indicated by the IP address and port number included in the index information, whereby the user node transmits the content from the content holding node. Can also be downloaded. In addition, the user node can acquire the index information from a cache node that caches the same index information as that of the root node until the query reaches the root node.

  When the user node acquires and stores content from the content holding node, the stored user node generates a publish message. This publish message is a message for informing the root node that the content has been saved. The publish message includes the content ID of the content and node information of the node device that stores the content. The publish message is sent toward the root node. As a result, the publish message arrives at the root node by DHT routing using the content ID as a key, as in the query. Then, the root node receives the publish message. The root node stores index information including a set of node information and content ID included in the publish message in the index information cache area. Thus, the user node becomes a new content holding node that holds the content.

[3. Overview of content delivery]
Next, an outline of the operation of the content distribution system S when content is distributed will be described. Here, the configuration in which the edge server SEm acquires content according to the lesson schedule and transmits the content to each user terminal Tm-n connected to the same base will be described as an example.

  FIG. 3 is a conceptual diagram showing an example of how content is distributed in the content distribution system S according to the present embodiment.

  First, the system administrator operates the management terminal MT to register the content to be distributed (FIG. 3 (1)). Specifically, the system administrator designates the file name and content name of the content on the Web application. Then, the management terminal MT transmits the content specified by the file name to the management server SM.

  The management server SM transmits the received content to the input server ST and instructs distribution of the content ((2) in FIG. 3). The input server ST assigns a new content ID to the received content and stores the content. The input server ST returns the content ID assigned to the content to the management server SM. When receiving the content ID, the management server SM updates the Web page distributed by the portal server SP. Specifically, the management server SM adds a tag describing the assigned content ID and content name to an HTML (Hyper Text Markup Language) document constituting the Web page. As a result, new content can be selected as reproducible content.

  The input server ST inputs the content received from the management server SM into the P2P network PW (FIG. 3 (3)). Specifically, the input server ST transmits the content to one or a plurality of arbitrary edge servers SEm. If the input server ST is a node connected to the P2P network PW, the input server ST may store the content itself without transmitting the content at this time. Even in this case, content can be acquired from the input server ST when the edge server SEm is required. In this way, a plurality of contents are input to the P2P network PW, and the contents input by each edge server SEm connected to the P2P network PW can be acquired.

  The management server SM transmits the acquisition list and the transmission list to each edge server SEm. The acquisition list and the transmission list are created in advance by the management server SM according to the lesson schedule performed at each base. Specifically, the acquisition list specifies the time at which the edge server SEm acquires content from the P2P network PW. The transmission list is used to specify the time at which the edge server SEm transmits content to each user terminal Tm-n connected to the same base m.

  FIG. 4 is an example of a lesson schedule at the base 1. In the lesson schedule, the date when the lesson is performed, the time when the lesson is performed, the lesson subject, the content name reproduced in the lesson and the content ID thereof are registered in association with each other.

  Each user terminal T1-n at the site 1 reproduces content according to the lesson schedule shown in FIG. Specifically, a Japanese language class is held at each user terminal T1-n from 10:00 to 12:00 on July 29, 2009. The content “National language 1”, the content “National language 2”, and the content “National language 3”. Is played. Accordingly, each user terminal T1-n has to acquire the content “National language 1”, the content “National language 2”, and the content “National language 3” to prepare for reproduction by at least 10:00 on July 29, 2009. Don't be.

  Furthermore, according to the lesson schedule, each user terminal T1-n can complete the acquisition of content before the lesson start time. In other words, the edge server SE1 is a user terminal before the lesson start time at each user terminal T1-n. The edge server SE1 acquires content from the P2P network PW according to the acquisition list and stores it in the content cache area of the edge server SE1 so that the content can be transmitted to T1-n. Then, the edge server SE1 transmits the content stored in the content cache area according to the transmission list to each user terminal T1-n.

  FIG. 5A is an example of an acquisition list received by the edge server SE1. FIG. 5B is an example of a transmission list received by the edge server SE1.

  The edge server SE1 acquires content according to the acquisition list of FIG. Specifically, the edge server SE1 acquires each content of content ID (A) to content ID (H) from the P2P network PW at 00:00 on July 29, 2009, and at 00:00 on July 30, 2009. , Each content of content ID (I) to content ID (M) is acquired from the P2P network PW.

  FIG. 6 is a conceptual diagram illustrating an example of how content is distributed in the content distribution system S.

  First, the edge server SE1 generates a query including the content ID of the content to be acquired. For example, a query including the content ID (A) is generated, and the generated query is transmitted to the root node of the content ID (A) (FIG. 6 (1A), (1B)). The query is transferred to the root node, for example, edge server SE5. The edge server SE5 transmits the index information of the content ID (A) to the edge server SE1 ((2) in FIG. 6). The edge server SE1 transmits a content request message including information on the content ID (A) to the edge server SE2 that is one of the content holding nodes with the content ID (A) ((3) in FIG. 6). The edge server SE2 acquires the content “national language 1” corresponding to the content ID (A) included in the content request message from the content cache area of the edge server SE2 itself, and transmits it to the edge server SE1 (FIG. 6 (4)). )). The edge server SE1 stores the received content “National language 1” in the content cache area of the edge server SE1 itself. In this way, the edge server SE1 acquires content according to the acquisition list.

  Then, the edge server SE1 transmits the content according to the transmission list of FIG. Specifically, at 8:00 on July 29, 2009, each content of content ID (A) to content ID (C) is transmitted to each user terminal T1-n, and at 10:00 on the same day, content ID (D) to content ID Each content of ID (F) is transmitted to each user terminal T1-n. Thereafter, each content is sequentially transmitted according to the transmission list.

  When receiving the content from the edge server SE1, each user terminal T1-n at the site 1 stores it in the content cache area. Thereafter, each user terminal T1-n reproduces the content when the class start time arrives. Specifically, each user terminal T1-n receives the Web page and displays the screen by accessing the portal server SP. Then, on the Web page displayed on the screen, the user instructs playback of a certain content, for example, the content “National Language 1”. Then, the user terminal T1-n starts reproduction of the content “National language 1” stored in the content cache area of the user terminal T1-n itself.

[3-1. When acquisition lists and transmission lists are created based on usage registration information]
One user terminal Tm-n may be shared by a plurality of users. In this case, the management server SM may create an acquisition list and a transmission list based on usage registration information that is a lesson schedule for each user.

  When one user terminal Tm-n is shared by a plurality of users, first, each user registers in advance in the management server SM. Information registered for use is stored in the storage unit of the management server SM as use registration information. The usage registration information includes user information for identifying each user, a node ID of each user terminal Tm-n, a content ID of the content that each user plans to use, and a reproduction indicating the time when the content is reproduced. The time information is associated with each other. The management server SM creates an acquisition list and a transmission list according to the use registration information, and transmits it to the edge server SEm.

  FIG. 7 shows an example of usage registration information. According to the example shown in FIG. 7, in the user terminal T1-1, three users, user1, user2 and user3, have registered for use. In the user terminal T1-2, three users, user4, user5, and user6, have registered for use.

  The edge server SEm acquires content from the P2P network PW according to the acquisition list so that each user terminal Tm-n completes acquisition of the content by the scheduled viewing date and time of each user who has registered for use, and the edge server according to the transmission list. The content is transmitted to each user terminal Tm-n at the site to which the SEm is connected.

  FIG. 8A is an example of an acquisition list received by the edge server SE1. The acquisition list is a list in which the content ID, the acquisition date and time of the content, the node ID of the user terminal Tm-n registered for use, and the user information are associated with each other. The content acquisition date is an example of acquisition time. The edge server SE1 acquires content according to the acquisition list of FIG. Specifically, the edge server SE1 acquires the content of the content ID (A) from the P2P network PW at 2:30 on July 29, 2009, and the content ID (B) at 3:30 on the same day. Content is acquired from the P2P network PW. The content acquisition date is defined to be a predetermined time before the content transmission time.

  FIG. 8B is an example of a transmission list received by the edge server SE1. The transmission list is a list in which content IDs, content transmission dates and times, node IDs of user terminals Tm-n registered for use, and user information are associated with each other. The content transmission date is an example of the transmission time. The edge server SE1 transmits the content according to the transmission list of FIG. The content transmission date and time is defined to be a predetermined time before the content reproduction time. Specifically, at 2:30 on July 29, 2009, the edge server SE1 transmits the content with the content ID (A) to the user terminal T1-1, and sends the content with the content ID (J) to the user. It transmits to terminal T1-2. The user terminal T1-1 and the user terminal T1-2 are examples of specific node devices. When each user terminal T1-n receives content from the edge server SE1, each user terminal T1-n stores it in the content cache area of each user terminal T1-n itself.

  In this way, the edge server SEm acquires content based on the acquisition list created according to the lesson schedule and usage registration information, and transmits it to each user terminal Tm-n based on the transmission list. As a result, each user terminal Tm-n can efficiently acquire at least the content to be reproduced next, which is the content scheduled to be used before the content is reproduced.

[4. Delete content]
Next, an operation in which the user terminal Tm-n and the edge server SEm delete content from the content cache area will be described with reference to FIG. 9 and FIG. When the free storage capacity of the content cache area of the user terminal Tm-n and the edge server SEm becomes less than a predetermined capacity, content that is less likely to be used in the future is preferentially deleted.

  FIG. 9 is an example of a used content list acquired by the edge server SEm at a certain base m. The used content list is a list of contents scheduled to be viewed within a predetermined period from the present at a certain site m. The usage content list is an example of a usage list.

  The management server SM creates a usage content list for each site based on the usage registration information and transmits it to the edge server SEm at that site. Within the predetermined period is, for example, within one week or within one month. FIG. 10 shows the usage registration information that is the basis for creating the usage content list of FIG. Note that the usage registration information shown in FIG. 10 shows only the usage registration information associated with the node ID of the user terminal Tm-n connected to a certain base m for the sake of simplicity of illustration and explanation, and further, the viewing schedule Only the date is listed as the scheduled viewing date.

  The management server SM creates a use content list at a transmission time set in advance by input from the management terminal MT and transmits it to the edge server SEm. For example, when the use content list transmission time arrives at 0 o'clock on August 1, first, the management server SM starts from 0 o'clock on August 1 to 23:59 on August 7 from the use registration information. The content ID of the content used in the process is extracted to create a used content list. Referring to FIG. 10, in each user terminal Tm-n connected to a certain base m, contents scheduled to be used from August 1 to August 7 are content ID (A) to content ID ( F) content. Therefore, the management server SM creates a use content list (FIG. 9) on which content ID (A) to content ID (F) are posted. If the next usage content list transmission time is 0:00 on August 8, one week later, the usage registration information can be updated between August 1 and August 7. There is sex. For example, when the usage content list was created on August 1, there was no plan to view the content ID (J), but on August 2, the usage registration of the content ID (J) was made on August 3. There may be. That is, the longer the period from the creation of the used content list to the next creation, the lower the accuracy as the used content list. Therefore, the management server SM preferably updates the usage content list about once a day based on the usage registration information.

  Each edge server SEm refers to the used content list received from the management server SM when the free storage capacity of the content cache area becomes less than the predetermined capacity. Then, each edge server SEm deletes content not listed in the usage content list so as to make free space in the content cache area.

[5. Configuration and function of each device]
Next, the configuration and function of each device will be described with reference to FIGS. FIG. 11 is a block diagram illustrating a schematic configuration example of the management server SM. FIG. 12 is a block diagram illustrating a schematic configuration example of the edge server SEm. FIG. 13 is a block diagram illustrating a schematic configuration example of the user terminal Tm-n.

[5-1. Configuration and function of management server SM]
As shown in FIG. 11, the management server SM includes a control unit 11 as a computer including a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, and the like. In addition, the management server SM includes a storage unit 12 composed of an HD or the like for storing and storing various data and various programs. Further, the management server SM controls communication of information with the input server ST and the like through the distribution center network NS. Further, the management server SM includes a communication unit 13 for controlling communication of information with the edge server SEm through the network NW or the like. The control unit 11, the storage unit 12, and the communication unit 13 are connected to each other via a bus 14.

  The storage unit 12 stores the node ID, IP address, port number, and the like of each edge server SEm. The storage unit 12 stores an operating system, a lesson schedule program, a usage registration program, an acquisition list and transmission list management program, a usage content list management program, and the like. These programs may be downloaded from a predetermined server on the distribution center network NS, for example. Further, these programs may be recorded on a recording medium and read via a drive of the recording medium, for example.

  The control unit 11 performs overall control of the entire management server SM by reading and executing a program stored in the storage unit 12 or the like by the CPU.

[5-2. Edge server configuration and functions]
As shown in FIG. 12, the edge server SEm includes a control unit 21 as a computer including a CPU having a calculation function, a working RAM, a ROM for storing various data and programs, and the like. In addition, the edge server SEm includes a storage unit 22 composed of an HD (hard disk) for storing and storing various data, various programs, and the like, and a buffer memory 23 for temporarily storing received content and the like. . The storage unit 22 is an example of a storage unit. Furthermore, the edge server SEm includes a decoder unit 24 that decodes encoded video data (video information), audio data (audio information), and the like included in the content. Further, the edge server SEm performs a predetermined drawing process on the decoded video data and the like and outputs it as a video signal, and displays a video based on the video signal output from the video processor 25. And a display unit 26 such as a CRT or a liquid crystal display. The edge server SEm further converts the decoded audio data into an analog audio signal by D (Digital) / A (Analog) conversion, amplifies it by an amplifier, and outputs it, and this audio processing unit. And a speaker 28 that outputs the audio signal output from the sound wave 27 as a sound wave. Furthermore, the edge server SEm controls communication of information with the user terminal Tm-n through the base network NLm, and controls communication of information with other edge servers SEm, input servers ST, etc. through the network NW. The communication part 29 for performing is provided. Furthermore, the edge server SEm includes an input unit (for example, a keyboard, a mouse, a remote controller, an operation panel, or the like) 30 that receives an instruction from a user and gives an instruction signal corresponding to the instruction to the control unit 21. Yes. The control unit 21, the storage unit 22, the buffer memory 23, the decoder unit 24, the communication unit 29, and the input unit 30 are connected to each other via a bus 31. As the edge server SEm, for example, in addition to a dedicated server device, a personal computer or the like can be applied. Note that when the user does not reproduce and use the content on the edge server, the decoder unit 24, the video processing unit 25, the display unit 26, the audio processing unit 27, the speaker 28, and the input unit 30 are unnecessary.

  The storage unit 22 stores a routing table using DHT, index information, content catalog information, an acquisition list, a transmission list, a use content list, and the like. In addition, the storage unit 22 stores the IP address and port number of a contact node as an access destination when participating in the P2P network PW, the IP address and port number of the input server ST, and the like. Further, the storage unit 22 stores the base identification information of the base m where the edge server SEm is installed, and the node ID assigned to the edge server SEm. The base identification information is information for identifying each base, and is unique to each base. A content cache area is allocated to a part of the storage capacity of the storage unit 22. Content is stored in this content cache area. The storage unit 22 stores an operating system, an acquisition list control program, a transmission list control program, a content control program, a used content list control program, P2P software, and the like. The P2P software is software for connecting to the P2P network PW. These programs may be downloaded from the input server ST, for example. Further, these programs may be recorded on a recording medium and read via a drive of the recording medium, for example.

  The control unit 21 reads and executes a program stored in the storage unit 22 or the like by the CPU, whereby an acquisition list acquisition unit, an acquisition time determination unit, a storage control unit, a transmission time determination unit, a content transmission unit, It functions as a transmission list creation unit, a usage list acquisition unit, a free space determination unit, and a deletion unit.

[5-3. Configuration and functions of user terminal]
Next, the configuration and function of the node will be described with reference to FIG.
FIG. 13 is a diagram illustrating a schematic configuration example of the user terminal Tm-n.
As shown in FIG. 13, the user terminal Tm-n includes a control unit 41, a storage unit 42, a buffer memory 43, a decoder unit 44, a video processing unit 45, a display unit 46, an audio processing unit 47, a speaker unit 48, and a communication unit. 49, an input unit 50, and a bus 51. The basic configurations and functions of the control unit 41, the storage unit 42, the buffer memory 43, the decoder unit 44, the video processing unit 45, the display unit 46, the audio processing unit 47, the speaker unit 48, the input unit 50, and the bus 51 are as follows. The control unit 21, storage unit 22, buffer memory 23, decoder unit 24, video processing unit 25, display unit 26, audio processing unit 27, speaker unit 28, input unit 30, and bus 31 in the edge server SEm are the same. For example, a personal computer can be applied as the user terminal Tm-n.

  The communication unit 49 controls communication of information with other user terminals Tm-n and the edge server SEm through the base network NLm, and controls communication of information with the portal server SP and the like through the network NW.

  The input unit 50 receives an instruction from the user and gives an instruction signal corresponding to the instruction to the control unit 41. The input unit 50 is configured by, for example, a keyboard, a mouse, a remote controller, an operation panel, or the like.

  The storage unit 42 stores a routing table using DHT, index information, content catalog information, and the like. Further, the storage unit 42 stores the base identification information of the base m where the user terminal Tm-n is installed, and the node ID assigned to the user terminal Tm-n. In addition, a content cache area is allocated to a part of the storage capacity of the storage unit 42. Content is stored in this content cache area. The storage unit 42 stores an operating system, a content control program, a used content list control program, a Web browser program, a player program, and the like. Note that these programs may be downloaded from, for example, the edge server SEm or the portal server SP. Further, these programs may be recorded on a recording medium and read via a drive of the recording medium, for example.

[6. Operation of content distribution system]
Next, the operation of the content distribution system S according to the present embodiment will be described. Here, an example will be described in which each user performs usage registration, and the management server SM creates an acquisition list, a transmission list, and a usage content list based on the usage registration information and transmits them to the edge server SEm.

  FIG. 14 is a flowchart illustrating a processing example of the management server SM according to the present embodiment. This process is a process that starts when each program of the management server SM is initialized and information can be exchanged with the edge server SEm or the like.

  First, the control unit 11 of the management server SM determines whether or not there is a new usage registration (step S10). If there is a usage registration (step S10: Yes), the usage registration information is updated (step S11). . Thereafter, the process proceeds to step S16.

  On the other hand, when there is no new usage registration (step S10: No), the control unit 11 determines whether or not the transmission times of the acquisition list and the transmission list have arrived (step S12). As a result of the determination, when the transmission time has arrived (step S12: Yes), the control unit 11 creates an acquisition list and a transmission list, transmits them to each edge server SEm (step S13), and proceeds to step S16. .

  On the other hand, when the transmission times of the acquisition list and the transmission list have not arrived (step S12: No), the control unit 11 determines whether or not the transmission time of the usage content list has arrived (step S14). If the transmission time has arrived as a result of the determination (step S14: Yes), the control unit 11 creates a use content list, transmits it to each edge server SEm (step S15), and proceeds to step S16. Note that the transmission times of the acquisition list and the transmission list or the usage content list in steps S12 and S14 may be set uniformly as the transmission times for all edge servers SEm. Further, it may be determined for each of a plurality of edge servers SEm. Further, the transmission time of the usage content list in step S14 may be the same as or different from the transmission times of the acquisition list and the transmission list in step S12. Further, these transmission times may be appropriately changed based on the control of the control unit 11 of the management server SM.

  On the other hand, when the transmission time of the usage content list has not arrived (step S14: No), the process proceeds to step S16.

  In step S16, the control unit 11 determines whether or not the service as the management server SM has ended (step S16). The determination is made based on, for example, whether or not the service termination as the management server SM is instructed from the management terminal MT or the like. When the service end is instructed (step S16: Yes), the process ends. On the other hand, when the service end is not instructed (step S16: No), the process proceeds to step S10, and the processes of steps S10 to S16 are repeatedly executed until the service end is instructed.

  FIG. 15 is a flowchart illustrating a processing example of the edge server SEm according to the present embodiment. This process is a process that is started when initialization processing of each program of the edge server SEm is performed and information can be exchanged with the management server SM, the user terminal Tm-n, and the like.

  First, the control unit 21 of the edge server SEm determines whether an acquisition list and a transmission list are received from the management server SM (step S30). If the acquisition list and the transmission list are received as a result of the determination (step S30: Yes), the control unit 21 stores the received acquisition list and transmission list in the storage unit 22 (step S31). Thereafter, the process proceeds to step S41.

  On the other hand, when the acquisition list and the transmission list are not received (step S30: No), the control unit 21 determines whether or not the use content list is received (step S32). If the use content list is received as a result of the determination (step S32: Yes), the control unit 21 stores the received use content list in the storage unit 22 (step S33). Thereafter, the process proceeds to step S41. On the other hand, when the usage content list has not been received (step S32: No), the control unit 21 refers to the transmission list in the storage unit 22 and determines whether or not the content transmission date has arrived (step S32). S34). As a result of the determination, when the transmission date / time of the content has arrived (step S34: Yes), the control unit 21 refers to the transmission list and acquires the content corresponding to the transmission date / time from the storage unit 22. And the control part 21 transmits to user terminal Tm-n corresponding to a transmission date (step S35). The user terminal Tm-n corresponding to the transmission date and time is an example of a specific node device. Thereafter, the process proceeds to step S41.

  When the content transmission date / time has not arrived (step S34: No), the control unit 21 refers to the acquisition list in the storage unit 22 and determines whether or not the content acquisition date / time has arrived ( Step S36). If the control unit 21 determines that the content acquisition date has not arrived (step S36: No), the control unit 21 proceeds to step S41.

  On the other hand, when the content acquisition date and time has arrived (step S36: Yes), the control unit 21 determines whether or not the free storage capacity of the content cache area of the storage unit 22 is less than the predetermined capacity (step S37). ). As a result of the determination, when the free storage capacity of the content cache area of the storage unit 22 is not less than the predetermined capacity (step S37: No), the process proceeds to step S39, and when it is less than the predetermined capacity (step S37: Yes). The control unit 21 refers to the used content list in the storage unit 22. Then, the control unit 21 deletes the content not listed in the use content list from the content cache area (step S38).

  And the control part 21 acquires from the P2P network PW the content determined that the acquisition date came in step S36, and memorize | stores it in a content cache area (step S38). Then, the control unit 21 determines whether or not all the contents determined to have acquired the acquisition date and time in step S36 are acquired (step S40), and when all the contents are acquired (step S40: Yes), the process proceeds to step S41. On the other hand, when all the contents have not been acquired (step S40: No), the process proceeds to step S37, and the processes of steps S37 to S40 are repeatedly executed until all the contents are acquired.

  In step S41, the control unit 21 determines whether or not the power of the edge server SEm itself is turned off (step S41). If the power is turned off (step S41: Yes), the processing is performed. finish. On the other hand, when the power is not turned off (step S41: No), the process proceeds to step S30, and the processes of steps S30 to S41 are repeatedly executed until the power is turned off.

  As described above, according to the present embodiment, the edge server SEm acquires a plurality of contents scheduled to be played back at each user terminal Tm-n according to the acquisition list from the P2P network PW and stores them in the content cache area. it can. Further, the edge server SEm transmits the content that has reached the transmission date and time to the corresponding user terminal Tm-n based on the transmission list. As a result, the edge server SEm can accurately transmit the content to the user terminal Tm-n. Further, when receiving the content from the edge server SEm, the user terminal Tm-n stores the received content in the content cache area of the storage unit 42 of the user terminal Tm-n. Then, when the scheduled viewing date and time arrives, the corresponding content is reproduced. Thereby, each user terminal Tm-n can efficiently acquire the content scheduled to be viewed before viewing the content.

  The edge server SEm transmits the usage content list to the user terminal Tm-n, and the user terminal Tm-n is configured to use the content deletion in the content cache area of the storage unit 42 of the user terminal Tm-n. May be.

  In this case, first, the edge server SEm acquires usage registration information (FIG. 7) from the management server SM. Then, the edge server SEm creates a usage content list based on the usage registration information. Specifically, the edge server SEm lists contents that are scheduled to be used within a predetermined period at each user terminal Tm-n based on the use registration information, and displays a use content list for each user terminal Tm-n. create. Then, the edge server SEm transmits to each user terminal Tm-n. Alternatively, the node ID of the user terminal Tm-n scheduled to be used is associated with the content ID in the usage content list transmitted from the management server SM to the edge server SEm. Then, the edge server SEm may be configured to create the usage content list of each user terminal Tm-n based on the node ID of the user terminal Tm-n of the usage content list received from the management server SM.

  Next, the edge server SEm transmits the created usage content list to each user terminal Tm-n. When receiving the usage content list from the edge server SEm, the user terminal Tm-n stores it in the storage unit 42 of the user terminal Tm-n. When new content is transmitted from the edge server SEm, it is determined whether or not the free storage capacity of the content cache area of the storage unit 42 is less than a predetermined capacity. When it is determined that the user terminal Tm-n is less than the predetermined capacity, the content not listed in the used content list is deleted from the content cache area with reference to the used content list in the storage unit 42. As a result of the determination, if the free storage capacity of the content cache area of the storage unit 42 is not less than the predetermined capacity, the new content transmitted from the edge server SEm is stored in the content cache area of the storage unit 42.

  Further, in the above embodiment, each list is created based on the usage registration information and the lesson schedule. For example, the content reproduction history at each site is statistically calculated, and each list is calculated for each site based on the totaled content reproduction total result. It may be configured to create a list. In this case, for example, if there is a lot of reproduction of content related to mathematics at a certain base, a list including the content related to mathematics may be created.

  Furthermore, in the above-described embodiment, the acquisition list and the transmission list are separate lists. However, the edge server SEm may automatically create the transmission list based on the acquisition list. For example, the acquired content may be transmitted in order to the corresponding user terminal Tm-n, or the content transmission order may be registered in the acquisition list in association with each user terminal Tm-n. Alternatively, the edge server SEm may be configured to transmit content according to the transmission order.

  Furthermore, in the acquisition list in the above embodiment, the acquisition date and time is determined for each content, but a fixed time is determined as the content acquisition time by the edge server SEm, and the edge server SEm sets all the contents in the acquisition list to the same content acquisition time. You may comprise so that it may acquire. Furthermore, the content acquisition order may be determined in the acquisition list, and the content may be acquired in accordance with the acquisition order.

  Furthermore, although the edge server SEm in the above embodiment acquires the transmission list from the management server SM, the edge server SEm may be configured to create the transmission list. In this case, the control unit 21 functions as a transmission list creation unit in the present invention by the CPU reading and executing the program stored in the storage unit 22 or the like. Specifically, the edge server SEm acquires a lesson schedule (FIG. 4) or usage registration information (FIG. 7) from the management server SM, and transmits a content ID and content for each user terminal Tm-n in the same base. The date and time, the node ID of the user terminal Tm-n registered for use, and the user information are created in association with each other. Further, the edge server SEm may be configured to create an acquisition list based on the lesson schedule or usage registration information.

  Further, although the content ID is registered in the acquisition list in the above embodiment, only the content name may be registered. In this case, the edge server SEm refers to the content catalog information, acquires the content ID corresponding to the content name, and generates a query.

  Furthermore, in the above-described embodiment, the edge server SEm transmits content to each user terminal Tm-n according to the transmission list. However, each user terminal Tm-n uses the edge server based on the acquisition list for user terminals. You may comprise so that content transmission may be requested | required with respect to SEm.

  In this case, the control unit 41 of the user terminal Tm-n reads and executes a program stored in the storage unit 42 or the like by the CPU, thereby obtaining an acquisition time determination unit, a content request information transmission unit, and a content reception unit in the present invention. Function as. Specifically, first, at the edge server SEm or the management server SM, a user terminal acquisition list is created for each user terminal Tm-n based on the usage registration information or the lesson schedule. The acquisition list for user terminals is a list in which the content ID of the content is associated with the acquisition date and time of the content. The user terminal Tm-n acquires a user terminal acquisition list from the edge server SEm or the management server SM. Then, the user terminal Tm-n acquires the content with the corresponding content ID when the content acquisition date comes based on the acquisition list for user terminal. Specifically, the user terminal Tm-n requests content transmission from the edge server SEm connected to the same base m by specifying the content ID. The requested edge server SEm acquires the requested content from the content cache area of the edge server SEm and transmits it to the requesting user terminal Tm-n. Note that the acquisition date and time of each content in the acquisition list for the user terminal must be earlier than the acquisition date and time of each content in the acquisition list stored in the edge server SEm. When the user terminal Tm-n requests the edge server SEm to transmit a certain content based on the acquisition date and time of the acquisition list for the user terminal, the edge server SEm has already stored the content in the content cache area of the storage unit 22. This is because it is necessary to remember.

  Furthermore, although the base network NLm in the above embodiment has been described by taking a LAN or the like as an example, it may be a logical overlay network constructed on the base network NLm. In this case, each user terminal Tm-n corresponds to a node in the overlay network.

  In the above embodiment, a peer-to-peer network using DHT is applied, but the present invention is not limited to this. For example, other peer-to-peer systems may be applied.

  In the above-described embodiment, when the edge server SEm participates in the P2P network PW, the participation request message is transmitted to the contact node participating in the peer-to-peer network. However, for example, when a peer-to-peer network that does not use DHT is applied to the P2P network PW, the transmission destination of the participation request message may not be a node participating in the peer-to-peer network. For example, the transmission destination of the participation request message may be a server device that manages node information of nodes participating in the peer-to-peer network. Further, the server device that manages node information and the like in the P2P network PW may be, for example, the input server ST. An example of a peer-to-peer system that does not use DHT is a hybrid peer-to-peer system.

11 Control unit 12 Storage unit 13 Communication unit 14 Bus 21, 41 Control unit 22, 42 Storage unit 23, 43 Buffer memory 24, 44 Decoder unit 25, 45 Video processing unit 26, 46 Display unit 27, 47 Audio processing unit 28, 48 Speaker 29, 49 Communication unit 30, 50 Input unit 31, 51 Bus ST Input server SEm Edge server Tm-n User terminal SM Management server SP Portal server MT Management terminal FW Firewall BR Broadband router Lm, LS Communication line NLm Base network NW network NS distribution center network PW P2P network S content distribution system

Claims (5)

An information communication system in which a plurality of contents are transmitted and received between a plurality of node devices,
The information communication system includes a plurality of node devices connected to an external network, the plurality of node devices connected to the same internal network, and a support device connected to the internal network and supporting acquisition of content by the node devices For each internal network,
The support device includes:
Shows a plurality of content information to which the support device itself the respectively identifying a plurality of the content to be reproduced in each said node device connected to the internal network and the same internal network connecting, the time to acquire each of said content Acquisition list acquisition means for acquiring an acquisition list in which acquisition time information is associated with each other;
Node device information for identifying each node device connected to the same internal network, a plurality of the content information, and transmission time information indicating a transmission time for transmitting content to each node device are associated with each other. Transmission information, user information for identifying a plurality of users who use each of the node devices connected to the same internal network, the node device information of each of the node devices, and the use of each user Transmission list acquisition means for acquiring a transmission list created based on usage registration information in which content information for specifying scheduled content and reproduction time information indicating a time for reproducing the content are associated with each other; ,
Use list acquisition means for acquiring content information whose reproduction time is within a predetermined period from the current time as a use list at a predetermined timing;
An acquisition time determination unit that determines whether or not the time for acquiring the content has been reached based on the acquisition time information included in the acquisition list acquired by the acquisition list acquisition unit;
Free capacity determining means for determining whether or not the free storage capacity of the storage means for storing the content is less than a predetermined amount when it is determined by the acquisition time determining means that the time for acquiring the content has been reached; ,
When the free capacity determination means determines that the free storage capacity of the storage means is less than a predetermined amount, the free capacity is stored in the storage means based on the usage list acquired by the usage list acquisition means. A deletion unit that deletes, from the storage unit, a content whose playback time is not within a predetermined period from the current time;
The acquisition included in the acquisition list acquired by the acquisition list acquisition unit when the free storage capacity determination unit determines that the free storage capacity of the storage unit is not less than a predetermined amount, or after deletion by the deletion unit Content acquisition means for acquiring content indicated by the content information corresponding to time information from the other support device;
A storage control means for the stored content acquired by the content acquisition unit in said storage means,
Based on the transmission time information of the transmission list acquired by the transmission list acquisition means, a transmission time determination means for determining whether the time for transmitting the content has been reached;
When the transmission time determination unit determines that the time for transmitting the content has been reached, the identification indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition unit Content transmitting means for acquiring the content to be reproduced next by the node device from the storage means and transmitting the content to the specific node device;
An information communication system comprising: The node device is
The content is acquired based on the acquisition time information in an acquisition list in which content information for specifying content to be reproduced by the node device itself and acquisition time information indicating a time at which the content is acquired are associated with each other. Acquisition time determination means for determining whether the time has been reached;
If the acquisition time determination means determines that the time to acquire the content has been reached, the content that has reached the acquisition time for the support device connected to the internal network to which the node device itself is connected Content request information transmitting means for transmitting content request information including at least content information for identifying
Content receiving means for receiving content corresponding to the content information from a support device connected to the internal network to which the node device itself is connected;
The support device includes:
When the content request information including the content information is received from any of the node devices connected to the internal network to which the support device itself is connected, the content transmission unit corresponds to the content information included in the content request information The information communication system according to claim 1, wherein the content is acquired from the storage unit and transmitted to a node device that is a transmission source of the content request information. A support device provided in an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices,
In the information communication system, a plurality of internal networks are connected to an external network, the plurality of node devices connected to the same internal network, and the support connected to the internal network and supporting acquisition of content by the node devices A device for each internal network,
The support device includes:
A plurality of pieces of content information respectively specifying a plurality of contents scheduled to be reproduced in each node device connected to the same internal network as the internal network to which the support device itself is connected, and a time at which each content is acquired Acquisition list acquisition means for acquiring an acquisition list in which acquisition time information is associated with each other;
Node device information for identifying each node device connected to the same internal network, a plurality of the content information, and transmission time information indicating a transmission time for transmitting content to each node device are associated with each other. Transmission information, user information for identifying a plurality of users who use each of the node devices connected to the same internal network, the node device information of each of the node devices, and the use of each user Transmission list acquisition means for acquiring a transmission list created based on usage registration information in which content information for specifying scheduled content and reproduction time information indicating a time for reproducing the content are associated with each other; ,
Use list acquisition means for acquiring content information whose reproduction time is within a predetermined period from the current time as a use list at a predetermined timing;
An acquisition time determination unit that determines whether or not the time for acquiring the content has been reached based on the acquisition time information included in the acquisition list acquired by the acquisition list acquisition unit;
Free capacity determining means for determining whether or not the free storage capacity of the storage means for storing the content is less than a predetermined amount when it is determined by the acquisition time determining means that the time for acquiring the content has been reached; ,
When the free capacity determination means determines that the free storage capacity of the storage means is less than a predetermined amount, the free capacity is stored in the storage means based on the usage list acquired by the usage list acquisition means. A deletion unit that deletes, from the storage unit, a content whose playback time is not within a predetermined period from the current time;
The acquisition included in the acquisition list acquired by the acquisition list acquisition unit when the free storage capacity determination unit determines that the free storage capacity of the storage unit is not less than a predetermined amount, or after deletion by the deletion unit Content acquisition means for acquiring content indicated by the content information corresponding to time information from the other support device;
Storage control means for storing the content acquired by the content acquisition means in the storage means;
Based on the transmission time information of the transmission list acquired by the transmission list acquisition means, a transmission time determination means for determining whether the time for transmitting the content has been reached;
When the transmission time determination unit determines that the time for transmitting the content has been reached, the identification indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition unit Content transmitting means for acquiring the content to be reproduced next by the node device from the storage means and transmitting the content to the specific node device;
A support device comprising: An information communication system in which a plurality of contents are transmitted and received between a plurality of node devices, wherein a plurality of internal networks are connected to an external network, the plurality of node devices connected to the same internal network, and the internal network A computer included in the support device in the information communication system provided for each internal network with the support device connected and supporting the acquisition of content by the node device,
A plurality of pieces of content information respectively specifying a plurality of contents scheduled to be reproduced in each node device connected to the same internal network as the internal network to which the support device itself is connected, and a time at which each content is acquired An acquisition list acquisition step for acquiring an acquisition list associated with each of acquisition time information,
Node device information for identifying each node device connected to the same internal network, a plurality of the content information, and transmission time information indicating a transmission time for transmitting content to each node device are associated with each other. Transmission information, user information for identifying a plurality of users who use each of the node devices connected to the same internal network, the node device information of each of the node devices, and the use of each user A transmission list acquisition step of acquiring a transmission list created based on usage registration information in which content information for specifying scheduled content and reproduction time information indicating a time for reproducing the content are associated with each other; ,
A usage list acquisition step of acquiring content information whose playback time is within a predetermined period from the current time as a usage list at a predetermined timing;
An acquisition time determination step for determining at a predetermined timing whether or not the time for acquiring the content has been reached based on the acquisition time information included in the acquisition list acquired by the acquisition list acquisition step;
A free capacity determination step for determining whether or not the free storage capacity of the storage means for storing the content is less than a predetermined amount when it is determined in the acquisition time determination step that the time for acquiring the content has been reached; ,
If it is determined in the free capacity determination step that the free storage capacity of the storage means is less than a predetermined amount, the storage means is stored in the storage means based on the usage list acquired in the usage list acquisition step. A deletion step of deleting, from the storage means, the content whose playback time is not within a predetermined period from the current time;
The acquisition included in the acquisition list acquired by the acquisition list acquisition step when it is determined by the free capacity determination step that the free storage capacity of the storage means is not less than a predetermined amount, or after deletion by the deletion step A content acquisition step of acquiring content indicated by the content information corresponding to time information from the other support device;
A storage control step of storing the content acquired by the content acquisition step in the storage means;
A transmission time determination step for determining whether or not the time for transmitting the content has been reached based on the transmission time information of the transmission list acquired by the transmission list acquisition step;
When it is determined by the transmission time determination step that the time for transmitting the content has been reached, the identification indicated by the node device information corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition step A content transmission step of acquiring the content to be reproduced next by the node device from the storage means and transmitting the content to the specific node device;
The program of the support device that executes A content acquisition method in an information communication system in which a plurality of contents are transmitted and received between a plurality of node devices,
The information communication system includes a plurality of node devices connected to an external network, the plurality of node devices connected to the same internal network, and a support device connected to the internal network and supporting acquisition of content by the node devices For each of the internal networks,
The support device includes a plurality of pieces of content information respectively specifying a plurality of contents to be reproduced in each of the node devices connected to the same internal network as the internal network to which the support device itself is connected, and each of the contents. An acquisition list acquisition step for acquiring an acquisition list associated with each of acquisition time information indicating a time to acquire;
Node device information for identifying each of the node devices connected to the same internal network by the support device, a plurality of the content information, and transmission time information indicating a transmission time for transmitting the content to each of the node devices. Each of the transmission lists associated with each other, user information for identifying each of a plurality of users who use each of the node devices connected to the same internal network, the node device information of each of the node devices, Transmission that acquires a transmission list created based on usage registration information in which content information that identifies content that the user plans to use and playback time information that indicates the time at which the content is played back are associated with each other A list acquisition step;
A usage list acquisition step in which the support device acquires, as a usage list, information on content whose playback time is within a predetermined period from the current time, at a predetermined timing;
An acquisition time determination step of determining at a predetermined timing whether or not the support device has reached the time to acquire the content based on the acquisition time information included in the acquisition list acquired by the acquisition list acquisition step; ,
When it is determined by the acquisition time determination step that the time for acquiring the content has arrived, the support device determines whether or not the free storage capacity of the storage means for storing the content is less than a predetermined amount. A free space determination step;
When the support device determines that the free storage capacity of the storage unit is less than a predetermined amount in the free space determination step, the storage device stores the storage based on the use list acquired in the use list acquisition step. A deletion step of deleting, from the storage means, contents whose reproduction time is not within a predetermined period from the current time among the contents stored in the means;
The acquisition acquired by the acquisition list acquisition step when the support device determines that the free storage capacity of the storage means is not less than a predetermined amount by the free capacity determination step, or after deletion by the deletion step A content acquisition step of acquiring the content indicated by the content information corresponding to the acquisition time information included in the list from the other support device;
A storage control step in which the support device stores the content acquired in the content acquisition step in the storage unit;
A transmission time determination step for determining whether the support device has reached a time for transmitting the content based on the transmission time information of the transmission list acquired by the transmission list acquisition step;
The node corresponding to the transmission time information of the transmission list acquired by the transmission list acquisition step when the support device determines that the time for transmitting the content has been reached by the transmission time determination step A content transmission step of acquiring the content to be reproduced next by the specific node device indicated by the device information from the storage unit and transmitting the content to the specific node device;
The content acquisition method characterized by having.

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