JP2016072670A - Communication system and information processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction in time necessary for a terminal device to download content when the terminal device is connected with a second network connected with a first network where an overlay network is constructed.SOLUTION: An information processing device comprises: first storage means that stores terminal location information indicating the location of a terminal device connected with a second network, and node location information indicating the location of a node device connecting with the second network connected with the terminal device; first transmission means that associates content identification information with the terminal location information and transmits them to the node device of which the location indicated by the node location information stored in the first storage means at a prescribed time before distribution schedule time of content distributed to the terminal device connected with the second network; and second transmission means that transmits the content identification information transmitted by the first transmission means and the node location information on the node device to which the content identification information was transmitted to the terminal device to which contents indicated by the content identification information is distributed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a technical field of a distribution system using an overlay network.

  In recent years, a system for distributing content to a plurality of node devices using an overlay network as disclosed in Patent Document 1 is known. In such a system, the node device acquires content from another node device that stores the content via the overlay network.

JP 2006-197400 A

  By the way, there are cases where there are bases in various places such as a company, a school, a hotel, a karaoke store, and one or a plurality of terminal devices exist 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 WAN (Wide Area Network).

  When distributing content to a terminal device, it is conceivable to arrange a node device in each private network and construct an overlay network on the public network. In this case, the terminal device requests content from a node device connected to the same private network as the terminal device, for example. If the node device has already stored the requested content, the terminal device can download the content directly from the node device.

  However, when the node device connected to the same private network as the terminal device does not store the content, the node device, for example, must acquire the content from another node device via the overlay network. In this case, since the content passes through the public network, the time required for downloading the content by the terminal device becomes long.

  The present invention has been made in view of the above points, and when a terminal device is connected to a second network connected to the first network in which the overlay network is constructed, the content is downloaded by the terminal device. It is an object of the present invention to provide a communication system and an information processing apparatus that can reduce the time required for the process.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a communication system in which a plurality of contents are transmitted and received between a plurality of node devices, wherein the communication system includes the plurality of node devices and a plurality of node devices. An overlay network that includes a terminal device and an information processing device that controls distribution of content and that can transmit and receive content stored in a distributed manner among the plurality of node devices is constructed on the first network. A plurality of second networks are connected to the first network, and each of the second networks includes any one of the plurality of node devices and one or more terminal devices of the plurality of terminal devices. The information processing device is connected to the terminal location information indicating the location of the terminal device connected to the second network; First storage means for storing node location information indicating the location of the node device connected to the second network, and a predetermined time of scheduled delivery time of content distributed to the terminal device connected to the second network Before, the content identification information that can identify the content is transmitted to the node device in which the node location information stored in the first storage means is associated with the terminal location information indicating the location of the terminal device. A first transmission unit configured to transmit the content identification information transmitted by the first transmission unit after the scheduled delivery time, and the node location information indicating the location of the node device to which the content identification information is transmitted. And second transmission means for transmitting to the terminal device to which the content indicated by the content identification information is distributed, and the node device First receiving means for receiving the content identification information transmitted from the information processing apparatus; and first acquisition means for acquiring the content indicated by the content identification information received by the first receiving means from the overlay network; And a second storage means for storing the content acquired by the first acquisition means, wherein the terminal device receives the content identification information and the node location information transmitted from the information processing apparatus. Receiving means; and second acquisition means for acquiring the content indicated by the content identification information received by the second receiving means from the node device indicated by the node location information received by the second receiving means; It is characterized by providing.

  According to a second aspect of the present invention, the second transmission unit is a terminal that indicates a location of the terminal device to which the content identification information transmitted by the first transmission unit and the content indicated by the content identification information are distributed. The node location information stored in the first storage means in association with location information is transmitted to the terminal device.

  According to a third aspect of the present invention, the first storage means is content identification information capable of identifying the terminal location information, the node location information, and the content distributed to the terminal device indicating the location of the terminal location information. In association with the terminal location information indicating the location of any of the terminal devices to which the content indicated by the content identification information transmitted by the first transmission unit is distributed, and the first storage unit If the node location information is not stored in the first storage unit, the second transmission unit further includes third acquisition unit that acquires the node location information stored in the first storage unit in association with the content identification information. , The content identification information transmitted by the first transmission means to any one of the terminal devices, and the node location information acquired by the third acquisition means, And transmitting.

  The invention according to claim 4 is a communication system in which a plurality of contents are transmitted and received between a plurality of node devices, wherein the communication system includes the plurality of node devices and a plurality of terminal devices, An overlay network capable of transmitting and receiving content distributed and stored in a plurality of node devices is constructed on the first network, a plurality of second networks are connected to the first network, and each of the second networks Connected to the second network in an information processing apparatus included in a communication system in which any one of the plurality of node devices and one or more terminal devices of the plurality of terminal devices are connected to a network Terminal location information indicating the location of the terminal device and the node device connected to the second network to which the terminal device is connected A first storage means for storing node location information indicating the location of the content, and content capable of identifying the content before a predetermined delivery time of the content delivered to the terminal device connected to the second network First transmission means for transmitting identification information to the node device indicating the location of the node location information stored in the first storage means in association with the terminal location information indicating the location of the terminal device; and the distribution schedule After the time, the content indicated by the content identification information distributes the content identification information transmitted by the first transmission means and the node location information indicating the location of the node device to which the content identification information is transmitted. Second transmission means for transmitting to the terminal device.

  According to a fifth aspect of the present invention, the second transmission means is a terminal indicating the location of the terminal device to which the content identification information transmitted by the first transmission means and the content indicated by the content identification information are distributed. The node location information stored in the first storage means in association with location information is transmitted to the terminal device.

  According to a sixth aspect of the present invention, the first storage means can identify the terminal location information, the node location information, and the content distributed to the terminal device indicating the location of the terminal location information. In association with the terminal location information indicating the location of any of the terminal devices to which the content indicated by the content identification information transmitted by the first transmission unit is distributed, and the first storage unit If the node location information is not stored in the first storage unit, the second transmission unit further includes third acquisition unit that acquires the node location information stored in the first storage unit in association with the content identification information. , The content identification information transmitted by the first transmission means to any one of the terminal devices, and the node location information acquired by the third acquisition means, And transmitting.

  According to the first or fourth aspect of the present invention, the node device that has received the content identification information from the information processing device a predetermined time before the content distribution scheduled time is a terminal connected to the same second network as the node device. Content distributed to the device is acquired from the overlay network and stored. After the content distribution scheduled time, the terminal device that has received the content identification information and the node location information from the information processing device acquires the content from the node device that stores the content to be distributed to the terminal device. Therefore, the terminal device connected to the second network can download the content from the node device that is connected to the same second network as the terminal device and stores the content. It can be shortened.

  According to the invention described in claim 2 or 5, the terminal device connected to the second network downloads the content from the node device connected to the same second network as the terminal device and storing the content. The time required for downloading can be shortened.

  According to the invention described in claim 3 or 6, since the node device from which the content is downloaded is not determined in advance because the terminal device is not connected to the second network, Content can be downloaded from any node device. Therefore, it is possible to prevent the content distribution load for the terminal devices not connected to the second network from being concentrated on a specific device.

It is a figure showing an example of outline composition of communications system S of one embodiment. (A) is a block diagram showing a schematic configuration example of the center server SS. (B) is a block diagram showing a schematic configuration example of the router Nn. (C) is a figure which shows the example of a schematic structure of the user terminal Tn. (A) is a figure showing an example of composition of a terminal list. (B) is a figure which shows the structural example of a router list | wrist. (C) is a figure which shows the structural example of a content list. 6 is a sequence diagram illustrating an example of content distribution operation in the communication system S. FIG. (A) is a flowchart which shows an example of the server prior delivery control process of the control part 1 of center server SS. (B) is a flowchart showing an example of a router pre-download process of the control unit 11 of the router Nn. (A) is a flowchart which shows an example of the server regular delivery control process of the control part 1 of center server SS. (B) is a flowchart which shows an example of the acquisition source information generation process of the control part 1 of center server SS. (A) is a flowchart which shows an example of the terminal regular download process of the control part 21 of the user terminal Ti. (B) is a flowchart showing an example of router upload processing of the control unit 11 of the router Nn.

  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 communication system.

[1. Overview of communication system configuration and operation]
First, the configuration and operation outline of the communication system of the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration example of a communication system S of the present embodiment. As shown in FIG. 1, the communication system S of this embodiment includes a center server SS, a router Nn (n = 1, 2, 3... K), a user terminal Ti (i = 1, 2, 3... p) and the like. The center server SS and the router Nn are connected to the network NW. The network NW includes a public network such as the Internet or a WAN (Wide Area Network). The center server SS is an example of an information processing apparatus in the present invention.

  The center server SS inputs content into the overlay network ON. The input of content means that the content is stored in any router Nn, and the stored content can be acquired by each router Nn from the overlay network ON. Further, the center server SS controls distribution of content to the router Nn and the user terminal Ti.

  As shown in FIG. 1, in the communication system S, a base network NLn is constructed for each of a plurality of bases Pn. Examples of the base include a karaoke store, a school, a company, a house, and other facilities. The base network NLn is a private network such as a LAN (Local Area Network), for example. Each network NLn is connected to the network NW.

  Further, a router Nn and one or a plurality of user terminals Ti are connected to each base network NLn. The router Nn is, for example, a relay device lent to the base Pn from a business operator that operates the communication system S. Specifically, the router Nn relays an IP (Internet Protocol) packet between the network NW and the base network NLn. For example, the router Nn may be a broadband router Nn or the like.

  Further, the router Nn has a function as an edge server that provides content to the user terminal Ti connected to the same base network NLn. A router Nn connected to the same base network NLn as a certain user terminal Ti is referred to as a router immediately above the user terminal Ti. The user terminal Ti may have a function of reproducing content downloaded from the router Nn, for example. For example, when the base Pn is a karaoke store, the user terminal Ti is a commander that reproduces content for karaoke. For example, when the base Pn is a school, it is a viewing terminal that reproduces content for teaching materials. For example, when the base Pn is a company, it is a viewing terminal that reproduces content for training. For example, when the base Pn is a house, it is a set-top box that reproduces content for a broadcast program.

  One or a plurality of user terminals Ti not connected to the base network NLn may exist among the plurality of user terminals. This user terminal Ti is connected to the network NW. The user terminal Ti downloads content from any router Nn.

  As shown in FIG. 1, in the communication system S, an overlay network ON is configured by participation of a plurality of routers Nn that can communicate with each other via a network NW. The router Nn connected to the overlay network ON is referred to as a “node”. Note that the center server SS may or may not be able to participate in the overlay network ON. The overlay network ON is a logical network that forms a virtual link. The overlay network ON is realized by a specific algorithm, for example, an algorithm using a distributed hash table. The distributed hash table is hereinafter referred to as “DHT (Distributed Hash Table)”. Here, participating in the overlay network ON means operating in a state in which various messages can be transmitted to and received from other nodes via the overlay network ON based on a routing table using DHT. Note that a routing table using DHT is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  In the communication system S, various contents are distributed and stored in a plurality of nodes. Each content is given a content ID. The content ID is unique identification information for identifying the content from the content stored in the overlay network ON. The content ID is an example of content identification information of the present invention.

  Here, the node storing the content is hereinafter referred to as a “content holder”. The location of the content holder is stored as index information in a node that manages the location of the content. A node that manages the location of content is hereinafter referred to as a “root node”. The index information includes a set of node information of the content holder storing the content and the content ID of the content. The node information includes, for example, the router ID, IP address, and port number of the content holder. The router ID is unique identification information that can identify the router Nn. For example, the root node is determined to be a node to which a router ID closest to the content ID is assigned. The router ID closest to the content ID is, for example, a router ID with the highest number of upper digits that match.

  A certain node may acquire content from the content holder via the overlay network ON. Here, the node that acquires the content is hereinafter referred to as a “user node”. The user node searches the overlay network ON for the location of the content holder that stores the content. Specifically, the user node transmits a search message. The search message is a message for inquiring about the location of the content to be acquired to the root node of the content. The search message includes the content ID of the content to be acquired. The search message is transferred to the root node by routing using DHT. The root node acquires index information corresponding to the content ID included in the received search message from the index information cache. The root node returns the acquired index information to the user node that is the source of the search message. As a result, the user node receives the IP address of the content holder from the root node. Note that the process of inquiring the location of the content to the root node is well known in, for example, Japanese Patent Application Laid-Open No. 2007-053662, and detailed description thereof is omitted. Then, the user node transmits a content request message to the content holder. The content request message is a message indicating a content request. The content request message includes the content ID of the content to be acquired. The content holder uploads the content corresponding to the content ID included in the content request message (hereinafter referred to as “content request”) to the user node. As a result, the user node acquires content.

  When the user node acquires the content from the content holder, the user node publishes the content. The disclosure of content means that the content acquired by the user node can be acquired from the overlay network ON. Specifically, the user node stores the acquired content. Then, the user node transmits a publish message to the root node. The publish message is a message for notifying the root node that the content has been saved. The publish message includes the content ID of the saved content and the node information of the user node that saved the content. The root node stores index information including a set of content ID and node information included in the received publish message in the index information cache. In this way, the user node becomes a new content holder for storing the content.

[2. Configuration of center server]
Next, the configuration of the center server SS will be described with reference to FIG. FIG. 2A is a block diagram illustrating a schematic configuration example of the center server SS. As illustrated in FIG. 4A, the center server SS includes a control unit 1, a storage unit 2, a communication unit 3, and the like. The control unit 1, the storage unit 2, and the communication unit 3 are connected to each other via a bus 4.

  The storage unit 2 is composed of, for example, a hard disk drive. The storage unit 2 stores an operating system, a distribution control program, and the like. The distribution control program is a program for controlling content distribution. The distribution control program or the like may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the distribution control program or the like may be recorded on a recording medium such as a DVD and read via a drive. The storage unit 2 stores the original of each content. The storage unit 2 stores a terminal list, a router list, a content list, and the like.

  FIG. 3A is a diagram illustrating a configuration example of a terminal list. The terminal list is a list of information related to the user terminal Ti. In the terminal list, for each user terminal Ti, a terminal ID, an IP address of the user terminal Ti, a router ID of an immediately above router, a terminal distribution list, and the like are stored in association with each other. The terminal ID is identification information that can identify the user terminal Ti. The IP address of the user terminal Ti is an example of terminal location information of the present invention. When there is no router directly above, that is, when the user terminal Ti is not connected to the base network NLn, the router ID of the router directly above is not stored. The terminal distribution list is a list of content IDs of contents distributed to the user terminal Ti. The terminal ID, IP address, and router ID are stored in advance when the user terminal Ti is installed, for example. The terminal distribution list is updated before content distribution.

  FIG. 3B is a diagram illustrating a configuration example of a router list. The router list is a list of information related to the router Nn. The router list stores a router ID, an IP address of the router Nn, a line type, a router distribution list, and the like for each router Nn. The IP address of the router Nn is an example of node location information according to the present invention. The IP address of the user terminal Ti stored in the terminal list and the IP address of the router Nn stored in the router list are associated by the router ID. The router distribution list is a list of content IDs of contents distributed to the router Nn. The line type indicates the speed of the line to which the router Nn and the network NW are connected. Examples of the line type include low speed and high speed. The router ID, IP address, and line type are stored in advance when the router Nn is installed, for example. The router distribution list is updated by the center server SS.

  FIG. 3C is a diagram illustrating a configuration example of a content list. The content list is a list of information regarding the content to be distributed. In the content list, a content ID, a distribution date and time, a distribution router list, and the like are stored in association with each content. The distribution date and time indicates the date and time when the content is distributed to the user terminal Ti. The distribution router list is a list of router IDs of routers to which contents are distributed. The content ID and the distribution date and time are stored, for example, when the content is generated. The distribution router list is updated by the center server SS.

The communication unit 3 performs communication control with the router Nn and the like through the network NW. The control unit 1 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 1 functions as a first transmission unit, a second transmission unit, a third transmission unit, and a third acquisition unit in the present invention when the CPU reads and executes a program stored in the storage unit 2 or the like.
[3. Configuration of router Nn]
Next, the configuration and function of the router Nn will be described with reference to FIG. FIG. 2B is a block diagram illustrating a schematic configuration example of the router Nn. As illustrated in FIG. 2B, the router Nn includes a control unit 11, a storage unit 12, a communication unit 13a, a communication unit 13b, and the like. The control unit 11, the storage unit 12, the communication unit 13 a, and the communication unit 13 b are connected to each other via the bus 14.

  The storage unit 12 is composed of, for example, a hard disk drive. The storage unit 12 stores an operating system, a P2P program, and the like. The P2P program is a program for communicating with other routers Nn using a routing table. The P2P program or the like may be downloaded from a predetermined server connected to the network NW, for example. Alternatively, the P2P program or the like may be recorded on a recording medium such as a DVD and read via a drive. The storage unit 12 stores a routing table and the like. Further, the storage unit 12 stores the content in association with the content ID. The storage unit 12 stores the IP address and port number of the center server SS.

  The communication unit 13a performs communication control with other routers Nn, the center server SS, and the like through the network NW. The communication unit 13b performs communication control with the user terminal Ti through the base network NLn.

  The control unit 11 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 11 has a clock function and a timer function. And the control part 11 functions as a 1st receiving means and a 1st acquisition means in this invention, when CPU reads and runs the program memorize | stored in the memory | storage part 12 grade | etc.,.

[4. Configuration and functions of user terminal]
Next, the configuration and function of the user terminal Tn will be described with reference to FIG. FIG. 2C is a diagram illustrating a schematic configuration example of the user terminal Tn. As shown in FIG. 2C, the user terminal Tn includes a control unit 21, a storage unit 22, a buffer memory 23, a decoder unit 24, a video processing unit 25, a display unit 26, an audio processing unit 27, a speaker unit 28, a communication unit. The unit 29 and the input unit 30 are configured. 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.

  The storage unit 22 is composed of, for example, a hard disk drive. The storage unit 22 stores an operating system, a download program, and the like. The download program is a program for downloading content from the router Nn. Further, the storage unit 22 stores the content in association with the content ID. The storage unit 22 stores the IP address and port number of the router directly above.

  The buffer memory 23 temporarily stores downloaded contents and the like. The decoder unit 24 decodes encoded video data and audio data included in the content. The video processing unit 25 performs a predetermined drawing process on the decoded video data or the like and outputs it as a video signal. The display unit 26 displays video based on the video signal output from the video processing unit 25. The audio processing unit 27 D / A converts the decoded audio data into an analog audio signal, and then amplifies this with an amplifier and outputs it. The speaker 28 outputs the audio signal output from the sound processing unit 27 as a sound wave. The communication unit 29 performs communication control with the router Nn, the center server SS, and the like through the network NLn. The input unit 30 includes, for example, a keyboard, a mouse, a remote controller, an operation panel, or the like. The input unit 30 receives an instruction from the user and outputs an instruction signal corresponding to the instruction to the control unit 21.

  The control unit 21 includes a CPU having a calculation function, a working RAM, a ROM, and the like. The control unit 21 has a clock function and a timer function. And the control part 21 functions as a 2nd receiving means and a 2nd acquisition means in this invention, when CPU reads and runs the program memorize | stored in the memory | storage part 22 grade | etc.,.

[5. Content distribution]
Next, content distribution will be described with reference to FIG. FIG. 4 is a sequence diagram illustrating an operation example of content distribution in the communication system S.

  In the communication system S, content is distributed to the user terminal Ti. There is regular distribution as content distribution. Regular distribution refers to distributing one or more contents to one or more user terminals Ti at a predetermined distribution date and time. For example, when the distribution date has passed, the center server SS transmits a message instructing downloading of content to the user terminal Ti. The user terminal Ti downloads content from the directly above router. At this time, the router directly above may not store the content. In this case, the directly above router needs to download the content from the overlay network ON in order to upload the content to the user terminal Ti. In this case, since the content passes through the network NW, it takes time to download the content by the user terminal Ti as compared to the case where the router immediately above stores the content. Therefore, the center server SS performs control for storing the content to be distributed to the user terminal Ti in a router immediately above the user terminal Ti before a predetermined time before the distribution date and time of regular distribution. Distributing regularly distributed content to a router directly above in advance is called prior distribution.

  Specifically, when content that is regularly distributed is input to the overlay network ON, the content ID and the distribution date and time of the content are added to the content list. In the terminal list, the content ID of the content that is regularly distributed is added to the terminal distribution list corresponding to the terminal ID of the user terminal Ti that is the distribution destination. Since the content ID of the content to be distributed is added to the terminal distribution list, the terminal distribution list may include the content ID of the content that has already been regularly distributed to the user terminal Ti.

  When a predetermined time before the distribution date and time of the pre-distribution has elapsed, the center server SS transmits a download request to the directly above router Nn as shown in FIG. 4 (step S1). The timing for transmitting the download request may be, for example, one day before the distribution date and time of regular distribution, or may be before another predetermined time. The timing of transmitting the download request is the timing of advance distribution. The center server SS acquires a router ID corresponding to the content ID of the content distributed in advance from the terminal list. The center server SS adds the content ID of the content to be distributed in advance to the router distribution list corresponding to the acquired router ID. Next, the center server SS acquires an IP address corresponding to the acquired router ID from the router list. That is, the center server SS acquires the IP address of the router Nn associated with the IP address of the user terminal Ti to which content is distributed. Then, the center server SS transmits a download request to the router immediately above using the acquired IP address.

  The router Nn that has received the download request acquires the router distribution list corresponding to the router Nn from the center server SS (step S2). Then, the router Nn downloads the content indicated by the content ID included in the router distribution list from the overlay network ON (step S3).

  Thereafter, when the distribution date and time of regular distribution has elapsed, the center server SS transmits a download request to the distribution destination user terminal Ti (step S4). The user terminal Ti that has received the download request acquires a terminal distribution list corresponding to the user terminal Ti from the center server SS (step S5). Next, the user terminal Ti acquires the IP address of the router Nn from which the content is acquired for each content ID included in the terminal distribution list (step S6). Specifically, this IP address is the IP address of the immediately above router that acquired the distribution list in step S2. Then, the user terminal Ti transmits a content request to the directly above router using the acquired IP address (step S7). Then, the user terminal Ti downloads the content transmitted from the immediately above router in response to the content request (step S8). At this time, since the router immediately above has only to upload the content that has already been saved in advance distribution, the content does not pass through the network NW during regular distribution. Therefore, it is possible to reduce the time required for downloading content by the user terminal Ti.

  Incidentally, there may be a user terminal Ti that is not connected to the base network NLn. There is no router directly above this user terminal Ti. That is, the router ID of the immediately above router is not stored in the terminal list in association with the terminal ID of the user terminal Ti. In this case, for example, it is assumed that the user terminal Ti has downloaded content from the center server SS. Then, the processing load of the center server SS increases. Therefore, when the center server SS transmits the IP address to the user terminal Ti in step S6, the center server SS transmits the IP address of the router Nn that has downloaded the content to be distributed in advance distribution. Specifically, the center server SS acquires from the router list the IP address corresponding to the content ID of the content distributed to the user terminal Ti that does not have an immediately above router. The center server SS transmits one of the acquired IP addresses to the user terminal Ti. Thereby, the user terminal Ti not connected to the base network NLn can download the content from the router Nn that stores the content. As a result, the content distribution load is distributed to the plurality of routers Nn.

  At this time, the center server SS may transmit only the IP address of the router Nn whose line type is high-speed in the router list to the user terminal Ti. Thereby, the time required for downloading content by the user terminal Ti can be shortened. The user terminal Ti that does not have an immediately above router downloads content from the router Nn connected to any of the base networks NLn via the network NW. Therefore, the content passes through the base network NLn to which the download source router Nn is connected and the connection line between the network NW. The faster the line speed of this connection line, the shorter the time required for downloading.

[6. Operation of communication system]
Next, operations of the communication system S of the present embodiment will be described with reference to FIGS. FIG. 5A is a flowchart illustrating an example of server pre-delivery control processing of the control unit 1 of the center server SS. The control unit 1 executes server pre-delivery control processing, for example, every predetermined time. As shown in FIG. 5A, the control unit 1 has passed a predetermined time before the delivery date and time after the previous server advance delivery control process was executed based on the delivery date and time stored in the content list. The content ID of the content is acquired from the content list (step S12). Next, for each acquired content ID, the control unit 1 searches the terminal distribution list including the content ID from the terminal list. And the control part 1 acquires router ID corresponding to the searched terminal list from a terminal list (step S13). Next, for each acquired router ID, the control unit 1 adds the content ID acquired from the content list to the router distribution list corresponding to the router ID in the router list (step S14). Since the content ID of the content to be distributed is added to the router distribution list, the router distribution list may include the content ID of the content that has already been pre-distributed to the router Nn.

  Next, the control unit 1 selects the first router ID among the router IDs acquired from the terminal list (step S15). Next, the control unit 1 acquires an IP address corresponding to the selected router ID from the router list. And the control part 1 transmits a download request to the router Nn corresponding to the acquired IP address (step S16). Thereafter, the control unit 1 receives a distribution list request transmitted from the router Nn that has received the download request (step S17). Next, the control unit 1 acquires a router distribution list corresponding to the selected router ID from the router list. Then, the control unit 1 transmits the acquired router distribution list to the router Nn (step S18).

  Next, the control unit 1 determines whether or not all the router IDs acquired from the terminal list have been selected (step S19). At this time, if the control unit 1 determines that there is a router ID that has not been selected (step S19: NO), the control unit 1 proceeds to step S20. In step S20, the control unit 1 selects the router ID in the next order from the router IDs acquired from the terminal list. Next, the control unit 1 proceeds to step S16. On the other hand, when it determines with having selected all acquired router ID (step S19: YES), the control part 1 complete | finishes a server prior delivery control process.

  FIG. 5B is a flowchart illustrating an example of the router pre-download process of the control unit 11 of the router Nn. For example, when the power of the router Nn is turned on, the control unit 11 executes router pre-download processing. As shown in FIG. 5B, the control unit 11 determines whether or not the router Nn is requested to be turned off (step S21). At this time, if the control unit 11 determines that the power OFF is not requested (step S21: NO), the control unit 11 proceeds to step S22. In step S22, the control unit 11 determines whether a download request has been received from the center server SS. At this time, when it is determined that the download request has not been received (step S22: NO), the control unit 11 proceeds to step S21. On the other hand, if it is determined that the download request has been received (step S22: YES), the control unit 11 proceeds to step S23. In step S23, the control unit 11 transmits a distribution list request to the center server SS. Thereafter, the control unit 11 receives the router distribution list transmitted from the center server SS (step S24).

  Next, the control unit 11 acquires the first content ID from the received router distribution list (step S25). Next, the control unit 11 determines whether or not content corresponding to the acquired content ID is stored in the storage unit 12 (step S26). At this time, if the control unit 11 determines that the content is stored in the storage unit 12 (step S26: YES), the control unit 11 proceeds to step S28. On the other hand, when the control unit 11 determines that the content is not stored in the storage unit 12 (step S26: NO), the control unit 11 proceeds to step S27. In step S27, the control unit 11 downloads the content indicated by the content ID acquired from the router distribution list from the overlay network ON. Then, the control unit 11 stores the downloaded content in the storage unit 12 in association with the content ID acquired from the router distribution list. Next, the control unit 11 proceeds to step S28.

  In step S28, the control unit 11 determines whether all content IDs have been acquired from the router distribution list. At this time, when it is determined that there is a content ID that has not been acquired (step S28: NO), the control unit 11 proceeds to step S29. In step S29, the control unit 11 acquires the content ID in the next order from the router distribution list. Next, the control unit 11 proceeds to step S26. On the other hand, if the control unit 11 determines that all content IDs have been acquired (step S28: YES), the control unit 11 proceeds to step S21. In step S21, when the control unit 11 determines that power-off is requested (step S21: YES), the control unit 11 ends the router pre-download process.

  FIG. 6A is a flowchart illustrating an example of server steady delivery control processing of the control unit 1 of the center server SS. The control unit 1 executes server steady delivery control processing, for example, every predetermined time. For example, the center server SS may continuously execute the server advance delivery control process and the server steady delivery control process. As shown in FIG. 6A, the control unit 1 determines the content ID of the content whose distribution date and time has passed since the previous server regular distribution control process was executed based on the distribution date and time stored in the content list. Obtained from the content list (step S31). Next, for each acquired content ID, the control unit 1 searches the terminal distribution list including the content ID from the terminal list. And the control part 1 acquires terminal ID corresponding to the searched distribution list for terminals from a terminal list (step S32).

  Next, the control unit 1 selects the first terminal ID among the terminal IDs acquired from the terminal list (step S33). Next, the control unit 1 acquires an IP address corresponding to the selected terminal ID from the terminal list. Then, the control unit 1 transmits a download request to the user terminal Ti corresponding to the acquired IP address (step S34). Thereafter, the control unit 1 receives a distribution list request transmitted from the user terminal Ti that has received the download request (step S35). Next, the control unit 1 acquires a terminal distribution list corresponding to the selected terminal ID from the terminal list. Then, the control unit 1 transmits the acquired terminal distribution list to the user terminal Ti (step S36).

  Thereafter, the control unit 1 receives an acquisition source introduction request transmitted from the user terminal Ti that has received the terminal distribution list (step S37). The acquisition source introduction request includes one of content IDs included in the terminal distribution list. The control unit 1 acquires the content ID from the acquisition source introduction request. Next, the control unit 1 determines whether or not the router ID of the immediately above router corresponding to the selected terminal ID is stored in the terminal list (step S38). At this time, if the control unit 1 determines that the router ID of the immediately above router is stored (step S38: YES), the control unit 1 proceeds to step S40. In step S40, the control unit 1 acquires the router ID of the immediately above router from the terminal list. Next, the process proceeds to step S42. On the other hand, when it is determined that the router ID of the immediately above router is not stored (step S38: NO), the control unit 1 executes acquisition source information generation processing (step S41).

  FIG. 6B is a flowchart illustrating an example of the acquisition source information generation process of the control unit 1 of the center server SS. As shown in FIG. 6B, the control unit 1 searches the router distribution list including the content ID acquired from the acquisition source introduction request from the router list. And the control part 1 acquires router ID corresponding to the searched distribution list for routers from a router list (step S51). Next, the control unit 1 specifies a distribution router list corresponding to the content ID acquired from the acquisition source introduction request from the content list, and stores the router ID acquired from the router list in this content list (step S52).

  Next, the control unit 1 acquires an array of router IDs from the identified content list (step S53). Next, the control unit 1 acquires the line type corresponding to each router ID stored in the array from the router list. Then, the control unit 1 determines whether or not one or more router IDs with a high-speed line type exist in the router IDs stored in the array (step S54). At this time, if the control unit 1 determines that there is no router ID having a high-speed line type (step S54: NO), the control unit 1 proceeds to step S56. On the other hand, if the control unit 11 determines that there is one or more router IDs with a high-speed line type (step S54: YES), the control unit 11 proceeds to step S55. In step S55, the control unit 1 deletes the router ID whose line type is low speed from the router ID array. Next, the control unit 1 proceeds to step S56.

  In step S56, the control unit 1 acquires one router ID from the array of router IDs. For example, the control unit 1 may acquire a router ID at random. Next, the control unit 1 acquires an IP address corresponding to the acquired router ID from the router list (step S57). When step S57 is completed, the control unit 11 ends the acquisition source information generation process, and proceeds to step S42 as shown in FIG.

  In step S42, the control unit 1 transmits the IP address acquired in step S40 or S41 to the user terminal Ti. Next, the control unit 1 determines whether all of the terminal IDs acquired from the terminal list have been selected (step S43). At this time, if the control unit 1 determines that there is a terminal ID that has not been selected (step S43: NO), the control unit 1 proceeds to step S44. In step S44, the control unit 1 selects a terminal ID in the next order among the terminal IDs acquired from the terminal list. Next, the control unit 1 proceeds to step S34. On the other hand, when it determines with having selected all acquired terminal ID (step S43: YES), the control part 1 complete | finishes a server regular delivery control process.

  FIG. 7A is a flowchart illustrating an example of the terminal steady download process of the control unit 21 of the user terminal Ti. For example, when the power of the user terminal Ti is turned on, the control unit 21 executes a terminal steady download process. As shown in FIG. 7A, the control unit 21 determines whether or not the user terminal Ti is requested to be turned off (step S61). At this time, when the control unit 21 determines that the power OFF is not requested (step S61: NO), the control unit 21 proceeds to step S62. In step S62, the control unit 21 determines whether a download request has been received from the center server SS. At this time, when it is determined that the download request has not been received (step S62: NO), the control unit 21 proceeds to step S61. On the other hand, when it is determined that the download request has been received (step S62: YES), the control unit 21 proceeds to step S63. In step S63, the control unit 21 transmits a distribution list request to the center server SS. Thereafter, the control unit 21 receives the terminal distribution list transmitted from the center server SS (step S64).

  Next, the control unit 21 acquires the first content ID from the received terminal distribution list (step S65). Next, the control unit 21 determines whether or not content corresponding to the acquired content ID is stored in the storage unit 12 (step S66). At this time, if the control unit 21 determines that the content is stored in the storage unit 12 (step S66: YES), the control unit 21 proceeds to step S71. On the other hand, when the control unit 21 determines that the content is not stored in the storage unit 12 (step S66: NO), the control unit 21 proceeds to step S67. In step S67, the control unit 21 transmits an acquisition source information request including the content ID acquired from the terminal distribution list to the center server SS. Thereafter, the control unit 21 receives the IP address transmitted from the center server SS (step S68). Next, based on the received IP address, the control unit 21 transmits a content request to the router Nn corresponding to the IP address (step S69). The content request includes the content ID acquired from the terminal distribution list. Thereafter, the control unit 21 downloads the content transmitted from the router Nn (step S70). Then, the control unit 21 stores the downloaded content in the storage unit 22 in association with the content ID. Next, the control unit 21 proceeds to step S71.

  In step S71, the control unit 21 determines whether all content IDs have been acquired from the terminal distribution list. At this time, when it is determined that there is a content ID that has not been acquired (step S71: NO), the control unit 21 proceeds to step S72. In step S72, the control unit 21 acquires the content ID in the next order from the terminal distribution list. Next, the control unit 21 proceeds to step S66. On the other hand, if it is determined that all the content IDs have been acquired (step S71: YES), the control unit 21 proceeds to step S61. In step S61, when it is determined that the power-off is requested (step S61: YES), the control unit 21 ends the terminal steady download process.

  FIG. 7B is a flowchart showing an example of router upload processing of the control unit 11 of the router Nn. For example, when the power of the router Nn is turned on, the control unit 11 executes router upload processing. As shown in FIG. 7B, the control unit 11 determines whether or not the router Nn is requested to be turned off (step S81). At this time, if the control unit 11 determines that the power OFF is not requested (step S81: NO), the control unit 11 proceeds to step S82. In step S82, the control unit 11 determines whether a content request has been received from the user terminal Ti. At this time, when it is determined that the content request has not been received (step S82: NO), the control unit 11 proceeds to step S81. On the other hand, if it is determined that the content request has been received (step S82: YES), the control unit 11 proceeds to step S83. In step S83, the control unit 11 acquires a content ID from the content request. Then, the control unit 11 determines whether or not content corresponding to the acquired content ID is stored in the storage unit 12. At this time, if the control unit 11 determines that the content corresponding to the acquired content ID is stored in the storage unit 12 (step S83: YES), the control unit 11 proceeds to step S85. On the other hand, when it is determined that the content corresponding to the acquired content ID is not stored in the storage unit 12 (step S83: NO), the control unit 11 proceeds to step S84. In step S <b> 84, the control unit 11 downloads the content indicated by the content ID acquired from the content request from the overlay network ON and stores the content in the storage unit 12. Next, the control unit 11 proceeds to step S85. In step S85, the control unit 11 uploads the content stored in the storage unit 12 in association with the content ID acquired from the content request to the user terminal Ti. Next, the control unit 11 proceeds to step S81. In step S81, when it is determined that the power-off is requested (step S81: YES), the control unit 11 ends the router upload process.

  As described above, according to the present embodiment, the center server SS sets the content ID of the content to a predetermined time before the scheduled distribution time of the content distributed to the user terminal Ti connected to the base network NLn. The IP address of the immediately above router stored in the storage unit 11 in association with the IP address of the user terminal Ti is transmitted to the router Nn indicating the location. The center server SS sends the content ID transmitted to the router Nn after the scheduled distribution time and the IP address of the router Nn to which the content ID is transmitted to the user terminal Ti to which the content indicated by the content ID is distributed. Send. Therefore, the time required for downloading by the user terminal Ti connected to the base network NLn can be shortened.

  In the above embodiment, the peer-to-peer network using DHT is applied to the overlay network, but the present invention is not limited to this. For example, another peer-to-peer system or a system using an overlay network may be applied. As an overlay network that does not use DHT, for example, there is a hybrid peer-to-peer network system. In the case of a hybrid peer-to-peer network system, for example, the center server SS stores index information of all contents.

1,11,21 control unit 2,12,22 storage unit 3,13a, 13b, 29 communication unit SS center server Nn router Ti user terminal NW network NLn base network ON overlay network S communication system

Claims (6)

A communication system in which a plurality of contents are transmitted and received between a plurality of node devices,
The communication system is:
The plurality of node devices;
A plurality of terminal devices;
An information processing device for controlling distribution of content;
With
An overlay network capable of transmitting and receiving content stored distributed among the plurality of node devices between the node devices is constructed on the first network,
A plurality of second networks connected to the first network;
Any one of the plurality of node devices and any one or more terminal devices of the plurality of terminal devices are connected to each of the second networks,
The information processing apparatus includes:
First storage for storing terminal location information indicating the location of the terminal device connected to the second network and node location information indicating the location of the node device connected to the second network to which the terminal device is connected Means,
Corresponding to the terminal location information indicating the location of the terminal device, content identification information capable of identifying the content before a predetermined time of delivery of content distributed to the terminal device connected to the second network A first transmission means for transmitting the node location information stored in the first storage means to a node device indicating the location;
The content identification information indicates the content identification information transmitted by the first transmission unit and the node location information indicating the location of the node device to which the content identification information is transmitted after the scheduled delivery time. Second transmitting means for transmitting to the terminal device to which the content is distributed;
With
The node device is
First receiving means for receiving the content identification information transmitted from the information processing apparatus;
First acquisition means for acquiring content indicated by the content identification information received by the first reception means from the overlay network;
Second storage means for storing the content acquired by the first acquisition means;
With
The terminal device
Second receiving means for receiving the content identification information and the node location information transmitted from the information processing apparatus;
Second acquisition means for acquiring the content indicated by the content identification information received by the second reception means from the node device indicated by the node location information received by the second reception means;
A communication system comprising: The second transmission means includes
The content identification information transmitted by the first transmission means and the terminal location information indicating the location of the terminal device to which the content indicated by the content identification information is distributed are stored in the first storage means in association with each other 2. The communication system according to claim 1, wherein node location information is transmitted to the terminal device. The first storage means stores the terminal location information, the node location information, and content identification information capable of identifying content distributed to the terminal device indicating the location, in association with each other,
The node location information is stored in the first storage unit in association with the terminal location information indicating the location of any of the terminal devices to which the content indicated by the content identification information transmitted by the first transmission unit is distributed. If not, further comprising third acquisition means for acquiring the node location information stored in the first storage means in association with the content identification information;
The second transmission unit transmits the content identification information transmitted by the first transmission unit and the node location information acquired by the third acquisition unit to any one of the terminal devices. The communication system according to claim 1 or 2. A communication system in which a plurality of contents are transmitted and received between a plurality of node devices,
The communication system is:
The plurality of node devices;
A plurality of terminal devices;
With
An overlay network capable of transmitting and receiving content stored distributed among the plurality of node devices between the node devices is constructed on the first network,
A plurality of second networks connected to the first network;
In an information processing apparatus included in a communication system in which each node device of the plurality of node devices and any one or more terminal devices of the plurality of terminal devices are connected to each of the second networks,
First storage for storing terminal location information indicating the location of the terminal device connected to the second network and node location information indicating the location of the node device connected to the second network to which the terminal device is connected Means,
Corresponding to the terminal location information indicating the location of the terminal device, content identification information capable of identifying the content before a predetermined time of delivery of content distributed to the terminal device connected to the second network A first transmission means for transmitting the node location information stored in the first storage means to a node device indicating the location;
The content identification information indicates the content identification information transmitted by the first transmission unit and the node location information indicating the location of the node device to which the content identification information is transmitted after the scheduled delivery time. Second transmitting means for transmitting to the terminal device to which the content is distributed;
An information processing apparatus comprising: The second transmission means includes
The content identification information transmitted by the first transmission means and the terminal location information indicating the location of the terminal device to which the content indicated by the content identification information is distributed are stored in the first storage means in association with each other The information processing apparatus according to claim 4, wherein node location information is transmitted to the terminal apparatus. The first storage means stores the terminal location information, the node location information, and content identification information capable of identifying content distributed to the terminal device indicating the location, in association with each other,
The node location information is stored in the first storage unit in association with the terminal location information indicating the location of any of the terminal devices to which the content indicated by the content identification information transmitted by the first transmission unit is distributed. If not, further comprising third acquisition means for acquiring the node location information stored in the first storage means in association with the content identification information;
The second transmission unit transmits the content identification information transmitted by the first transmission unit and the node location information acquired by the third acquisition unit to any one of the terminal devices. The information processing apparatus according to claim 4 or 5.

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