JP2009246817A - Server system, and distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a server system and a distribution system achieving system stabilization. <P>SOLUTION: The server system 100 includes: an information receiving section 132 for receiving report information of content distribution when a j-th node on a distribution network receives contents from a high-order i-th node and transmits the received contents to a low-order k-th node according to a P2P (Peer-to-Peer) relay system; an evaluation point calculation section 136 which performs processing for giving the j-th node an evaluation point corresponding to a transfer data amount of the contents from the j-th node to the k-th node on the basis of the received report information; and an evaluation point storage section 173 for storing the evaluation point in relation to the j-th node. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a server system and a distribution system.

  In recent years, services that distribute stream data of contents such as video and audio via a distribution network such as the Internet are increasing. In such a content distribution service, it is desired to further increase the bandwidth of the distribution network, but the cost of the distributor managing the server is heavy. For example, high-quality video content compatible with full high-definition is provided to viewers. It was difficult to provide it.

  In order to solve such a problem, as disclosed in Patent Document 1, for example, there is a system that distributes content by a so-called P2P (Peer to Peer) relay system (bucket relay system, cash and toss system). Proposed. In the technique of this patent document 1, in order to perform transmission / reception of stream data between each node of the distribution network, each node exchanges topology information indicating the connection relationship between the upstream node and the downstream node, and from the upstream node to the downstream node The stream data is being relayed to In this method, since topology information is exchanged between the nodes, each node can autonomously store and update the topology information and manage it.

  In this P2P relay system, the system becomes stable when content data is sufficiently accumulated in the content buffer of the client terminal of each node. However, when the amount of accumulated data decreases, the system becomes unstable. become. However, since the node that has finished viewing is excluded from the distribution network, if such node exclusion frequently occurs, the system may become unstable. Therefore, in order to stabilize the system, it is important how to give an incentive to stay as a content distribution source to users who participate in the community.

Also, depending on the structure of the distribution network, the amount of data transmitted as the content distribution source may be larger than the amount of data received as the content distribution destination. Cause
JP 2003-169089 A

  According to some aspects of the present invention, it is possible to provide a server system and a distribution system that can realize system stabilization.

  The present invention is a server system for content distribution using a distribution network, in which the j-th node of the distribution network receives content from a higher-level i-th node, and receives the received content as P2P (Peer to Peer) relay method, and an information receiving unit that receives report information of content distribution from the j-th node to the k-th node when transmitted to the lower-level k-th node, and the received report An evaluation point calculation unit that performs a process of assigning an evaluation point corresponding to a transfer data amount of content from the jth node to the kth node to the jth node based on the information; Further, the present invention relates to a server system including an evaluation point storage unit that stores the evaluation points in association with the j-th node.

  According to the present invention, the j-th node of the distribution network transmits the content received from the i-th node to the k-th node by the P2P relay method. Then, the report information notifying the content delivery from the jth node to the kth node is received by the information receiving unit of the server system. Then, based on the received report information, an evaluation point corresponding to the amount of data transferred from the jth node to the kth node is given to the jth node and stored in the evaluation point storage unit. Will come to be. This makes it possible to properly evaluate the contribution of the j-th node that relays and distributes content to the k-th node, which can lead to stabilization of the P2P distribution system. become.

  In the present invention, the evaluation point calculation unit may receive the report information from the jth node on the condition that the report information has been received from the kth node that has received content from the jth node. You may perform the process which provides the said j-th node with the evaluation point according to the transfer data amount of the content to a node.

  In this way, it is possible to effectively prevent a situation where an unauthorized evaluation point is given to the j-th node.

  Also, in the present invention, the information receiving unit receives, as the report information, information on the received data amount of content received by the k-th node from the j-th node from the k-th node, and the evaluation The point calculation unit may perform a process of assigning an evaluation point calculated based on the reported information on the received data amount to the j-th node.

  In this way, it is possible to realize an appropriate evaluation point calculation process based on the amount of received data that is report information.

  In the present invention, the information receiving unit receives the received data amount information and identification information for specifying the j-th node as the report information, and the evaluation point calculation unit is reported. You may perform the process which provides the evaluation point calculated based on the information of the said received data amount with respect to the said jth node specified by the said identification information.

  In this way, it is possible to appropriately give evaluation points to the j-th node specified by the identification information.

  Also, in the present invention, the evaluation point calculation unit is configured to receive the report information from both the j-th node that has transmitted the content and the k-th node that has received the content. You may perform the process which gives an evaluation point with respect to a node.

  In this way, it is possible to more effectively prevent a situation where an unauthorized evaluation point is given to the j-th node.

  Further, in the present invention, the evaluation point calculation unit may be configured such that the transmission data amount of the content transmitted by the jth node is greater than the reception data amount of the content received by the jth node. You may perform the process which gives an evaluation point with respect to the node of j.

  In this way, it is possible to appropriately evaluate the contribution of the j-th node that has transmitted data having a transmission data amount larger than the reception data amount.

  Further, the present invention includes a billing processing unit that performs billing processing for content distribution, and the evaluation point calculation unit finishes billing settlement for the j-th node from determination of playback content at the j-th node When the content is distributed from the j-th node to the k-th node in the settlement period until the settlement period, the transfer data amount of the content distributed in the settlement period is excluded, and the j-th node You may calculate the evaluation point provided with respect to it.

  In this way, it is possible to prevent a situation where an unauthorized evaluation point is given to the j-th node by repeating the action of canceling the payment after the content is determined.

  In the present invention, the k-th node starts a process of counting the received data amount of the content received from the j-th node after receiving the report of the settlement completion at the j-th node, and The reception unit receives, as the report information, the received data amount after the settlement at the j-th node from the k-th node, and the evaluation point calculation unit receives the reception at the k-th node. You may perform the process which provides the evaluation point according to data amount with respect to the said jth node.

  In this way, it is possible to calculate the evaluation points and give them to the jth node using the received data amount accumulated after the settlement at the jth node.

  In the present invention, the distribution network includes a column of basic nodes connected in series from a content distribution source and a column of branch nodes connected in series to each basic node of the basic node column, and the evaluation point calculation unit The evaluation point may be calculated so that the evaluation point for the basic node is higher than the evaluation point for the branch node.

  In this way, it is possible to give an evaluation point according to the degree of contribution to the basic node where the amount of content transmission data inevitably increases.

  The present invention is also a server system for content distribution using a distribution network, in which the j-th node of the distribution network receives content from a higher-level i-th node, and receives the received content as P2P ( Peer to Peer) When transmitting to the lower k-th node in the relay system, an evaluation point calculation unit that performs a process of assigning an evaluation point to the j-th node, and the given evaluation point An evaluation point storage unit that stores the evaluation points in association with the j-th node, wherein the distribution network includes a series of basic nodes connected in series from a content distribution source and a branch connected in series to each basic node of the basic node series The evaluation point calculation unit has a sequence of nodes when the j-th node is the backbone node, than when the j-th node is the branch node. It related to the server system to increase the evaluation point given to node j.

  Further, the present invention includes a node management unit that performs node management processing of the distribution network, and a management information storage unit that stores node management information for the node management processing, and the node management unit is included in the distribution network. When a new node is added, the node that can be connected to the content distribution destination node is searched for the node with the oldest addition order to the distribution network, and the new node is connected to the searched node. Processing may be performed.

  In this way, it is possible to realize the process of adding a new node with a simple process, so that the processing load can be reduced.

  In the present invention, the node management unit may exclude the branch node when a branch node is excluded from the distribution network and a lower branch node exists as a content distribution destination node of the excluded branch node. A process of connecting a higher-order node to a lower-order branch node of the excluded branch node may be performed.

  In this way, it is possible to connect an upper node and a lower branch node of the excluded branch node so as to fill a gap between the excluded branch nodes.

  According to the present invention, the node management unit excludes the branch node from the distribution network when the trunk node is excluded from the distribution network and a branch node exists as a content distribution destination node of the excluded trunk node. Alternatively, a new basic node may be set in place of the basic node.

  In this way, the branch node can be set as a new basic node instead of the excluded basic node so as to fill the gap between the excluded basic nodes.

  Further, in the present invention, the node management unit includes a basic node that is lower than the new basic node, and the addition order of the lower basic node to the distribution network is higher than the addition order of the new basic node. In the case where it is ahead, the new core node and the branch node string connected thereto may be replaced with the subordinate core node and the branch node string connected thereto.

  If such a replacement process is performed, it becomes possible to maintain the order of adding nodes in the distribution network, and appropriate content distribution can be realized.

  In the present invention, the node management unit may include a branch node as a content distribution destination node of the excluded basic node, and a subordinate basic node as a content distribution destination node of the excluded basic node. Alternatively, a process may be performed in which a higher-order core node of the excluded basic node is connected to the lower-level basic node of the excluded basic node.

  In this way, it is possible to connect the higher-order basic node and the lower-order basic node so as to fill the gap between the excluded basic nodes.

  In the present invention, the node management unit may connect the new node as a content distribution destination node of a core node of the distribution network when a new node is added to the distribution network. You may permit according to the number of nodes.

  In this way, it is possible to prevent a situation where the number of basic nodes increases unnecessarily, and to improve the efficiency of content distribution.

  According to the present invention, the node management unit adds the number of nodes that can be added in the branch node string connected to the lower core node of the distribution network in the branch node string connected to the upper core node. You may perform the process which restrict | limits the number of nodes which can be added in each branch node row | line so that it may become smaller than the number of possible nodes.

  In this way, it is possible to achieve uniform delivery time lag at the end nodes.

  In the present invention, the node management unit has a predetermined number of nodes in a first node set constituted by a first trunk node row and a first branch node row group connected to the first backbone node row. When the number reaches, the second core node column connected in series to the first core node column and the second branch node column group connected to the second core node column Two node sets may be set, and a new node may be added to the second node set.

  In this way, it is possible to efficiently increase the number of nodes while reducing the processing load.

  The present invention also relates to a distribution system including any one of the server systems described above and the distribution network.

  Hereinafter, this embodiment will be described. In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration requirements of the present invention.

1. Distribution System and Server System FIG. 1 shows a configuration example of a content distribution system (node management system) and server system realized by this embodiment.

  The distribution system of FIG. 1 includes a distribution system 10 having a server system 100 and a plurality of nodes N1 to N10 that are clients of the server system 100. The distribution system is not limited to the configuration shown in FIG. 1, and various modifications such as adding other components are possible.

  The distribution network 10 (network, communication line) is, for example, a communication path using the Internet. In addition to a dedicated line (dedicated cable) for direct connection, a LAN using Ethernet (registered trademark), a telephone communication network or a cable network. Or other communication networks. The communication method may be wired / wireless.

  Distribution network 10 includes a plurality of nodes N1 to N10 that are communicatively connected to each other. Each node is configured by a client terminal having a function of connecting to the Internet or the like. This client terminal is realized by, for example, a home game device, a portable game device, a PC (personal computer), a portable information terminal, and the like, for an operation unit, a processing unit, a communication control unit, a storage unit, and an information storage medium (not shown). Interface.

  As shown in FIG. 1, the distribution network 10 includes a core node column KNL that is a column of core nodes N1, N3, N6, and N10 connected in series (connected) from a content distribution source (server system, content distribution unit). . That is, these basic nodes N1, N3, N6, and N10 are connected in series in a line from the server system 100 in the downward direction (first direction).

  Further, the distribution network 10 includes a series of branch nodes BNL1, BNL2, and BNL3 connected in series (connected) to each basic node (starting node) of the basic node string KNL. Specifically, the branch nodes N2, N4, and N7 constituting the branch node row BNL1 are connected in series to the backbone node N1. That is, the branch nodes N2, N4, and N7 are connected in series in a line without branching from the trunk node N1 in the horizontal direction (second direction orthogonal to the first direction). Similarly, the branch nodes N5 and N8 constituting the branch node row BNL2 are connected in series to the backbone node N3, and the branch node N9 constituting the branch node row BNL3 is connected in series to the backbone node N6.

  As described above, in the simple branch type distribution network 10 of FIG. 1, the basic nodes N1, N3, N6, and N10 that are basically connected in series are provided, and the basic nodes N1, N3, N6, and N10 are used as starting points. The rows of branch nodes N2, N4, N7, the rows of N5, N8, and the row of N9 are connected in series. Note that the numbers of the nodes N1 to N10 represent content distribution order numbers (node addition order). Specifically, the starting node N1 (higher node) receives content from a server (server system, content distribution unit) that is the content distribution source. The received content is relayed and transmitted (retransmitted) to the content distribution destination nodes N2 and N3 (lower nodes). Upon receiving the content from the content distribution source node N1, the node N2 (higher node) relays the content and transmits it to the content distribution destination node N4 (lower node). Similarly, when the node N3 (higher node) receives the content from the content distribution source node N1, the node N3 relays the content and transmits it to the content distribution destination nodes N5 and N6 (lower node).

  The distribution network 10 of the present embodiment is not limited to the configuration shown in FIG. 1, and various modifications can be made. For example, FIGS. 2A and 2B show other configuration examples of the distribution network.

  FIG. 2A shows an example of an ordered distribution network. In FIG. 2A, nodes N1, N2, and N3 are connected in series in the distribution order (node addition order) to the server that is the content distribution source. That is, in FIG. 2A, when receiving the content from the server, the node N1 relays the received content and transmits it to the node N2. When receiving the content from the node N1, the node N2 relays the received content and transmits it to the node N3.

  In the sequential distribution network of FIG. 2A, when the client that is the node N2 is excluded from the distribution network due to the end of viewing or line disconnection, N1 and N3 that are the nodes before and after the connection are connected, There is an advantage that the distribution network can be maintained with a minimum processing load (processing cost). However, in the sequential distribution network shown in FIG. 2A, when the number of nodes in the distribution network increases, a long time lag occurs before content distribution to the end node starts. There is also. For example, a certain relay time is required for data buffering, distribution preparation, and the like until the node N2 receives the content from the node N1, relays (relays) the received content, and transmits it to the node N3. For this reason, at the end node, a time lag in which the relay times are accumulated by the number of nodes is generated, which delays the content viewing start time and increases the waiting time of the user.

  FIG. 2B is an example of a binary tree distribution network. In this binary tree distribution network, for example, the nodes N1 and N2 are connected to the server, the nodes N3 and N4 are connected to the node N1, and the nodes N5 and N6 are connected to the node N2. It has a 1-input / 2-branch tree structure. This binary tree type distribution network has an advantage that the time lag of the distribution time at the terminal node can be shortened as compared with the distribution network of FIG. However, when a specific node is excluded from the distribution network due to the end of viewing or line disconnection, there is a problem that the load of the reconstruction process of the topology of the node that does not break the distribution order is very large.

  In this respect, the simple branch type distribution network 10 shown in FIG. 1 is compared with FIG. 2A when the time lag of the distribution start at the end nodes N7, N8, N9, and N10 is compared with the same number of nodes. There is an advantage that it can be made small. For example, when the number of nodes is 10, 9 relay processes are required in FIG. 2A until the content reaches the end node, but in FIG. 1, only 3 relay processes are required, so the time lag is reduced. It can be greatly reduced. Further, the simple branch type distribution network 10 of FIG. 1 has an advantage that the processing load of the topology reconstruction for maintaining the distribution order can be reduced as compared with FIG.

  As described above, the simple branch type distribution network 10 of FIG. 1 has an advantage that it is possible to achieve both reduction of the time lag and reduction of the processing load of the topology reconstruction, but the configuration of the distribution network of the present embodiment is limited to FIG. However, it is possible to adopt distribution networks having various configurations according to the situation.

  In FIG. 1, the server system 100 includes a content distribution unit 110, a node management unit 120, a control processing unit 130, a charging processing unit 140, a database 170, and a communication control unit 190. The server system 100 is not limited to the configuration shown in FIG. 1, and various modifications such as omitting some of these components (for example, the content distribution unit) and adding other components are possible. .

  The database 170 (database server) is a relational database realized by, for example, MySQL, and stores various information necessary for content distribution, server management, node management, and evaluation point calculation. For example, distribution management information, server management information, node management information, user information, evaluation point information, and the like are stored. Specifically, the database 170 includes a content storage unit 172, an evaluation point storage unit 173, and a management information storage unit 174. The content storage unit 172 stores content such as video and audio to be distributed. The evaluation point storage unit 173 stores evaluation points (cooperation points) given to each node (client terminal, viewer, user). Specifically, the evaluation point is stored in association with each node (identification information of each node). The management information storage unit 174 stores node management information (node information, distribution network information, etc.) for node management processing.

  The communication control unit 190 (communication server) performs various communication control processes for information transfer via the distribution network 10. Specifically, various processes necessary for communication according to a protocol such as the Internet are performed.

  The content distribution unit 110 (content server, content distribution source) is a video (movie), audio (music), still image, text, game program, game data, or the like stored in the content storage unit 172 (content database) of the database 170. Content distribution processing (stream distribution). Specifically, the content that is distributed from the content distribution source node of the distribution network 10 to the content distribution destination node by the P2P (Peer to Peer) relay method is used as the basic node starting from the basic node sequence KNL. Send to N1. Then, the core node N1 that has received the content from the content distribution unit 110 distributes (stream transfers) the content as a content distribution source to the content distribution destination nodes N2 and N3 by a relay method. In this case, if necessary, the content distribution unit 110 performs content encryption processing using a common key encryption method such as DES or AES, or a public key encryption method. Each node that is a client performs a decryption process on the encrypted content. Each node performs content decryption processing and playback processing, and also performs relay processing for redistributing content to lower-order nodes at the subsequent stage.

  The node management unit 120 (node management server, mediation server) performs node management processing of the distribution network 10. For example, a process for adding a new node to the distribution network 10, a process for removing a node that has been viewed or disconnected from the distribution network 10, a process for rearranging the connection of node rows, a process for responding to various requests from the node, Processing for issuing various requests to the node is performed.

  Specifically, when a new node is added to the distribution network 10, the node management unit 120 has the oldest addition order (distribution order) to the distribution network 10 among the nodes that can be connected to the content distribution destination node. Search for a node. That is, the node having the smallest number in the addition order (distribution order number) is searched. Then, processing for connecting a new node to the searched node (search, connection request processing, response processing, etc.) is performed. For example, when the branch node is not connected as the content distribution destination node of the searched node (when the branch node can be connected), the new node is connected as a new branch node. On the other hand, when the branch node is connected as the content distribution destination node of the searched node but the backbone node is not connected (when the branch node cannot be connected but the backbone node can be connected). Connects the new node as a new core node.

  Further, the node management unit 120 excludes the branch node from the distribution network 10 due to the end of viewing or disconnection of the line, and when there is a lower (downstream) branch node as the content distribution destination node of the excluded branch node (lower branch) If a node is connected), an upper (upstream) node (branch node or backbone node) of the excluded branch node is connected to the lower branch node.

  On the other hand, the node management unit 120 excludes the core node from the distribution network 10 due to the end of viewing or disconnection of the line, and when the branch node exists as the content distribution destination node of the excluded basic node (when the branch node is connected) ), The branch node is moved up and set as a new basic node. At this time, when there is a lower (downstream) basic node of the new basic node, and the addition order of the lower basic node to the distribution network 10 is earlier than the addition order of the new basic node (number) Is young), the new core node and the branch node string connected thereto are replaced with the lower core node and the branch node string connected thereto. When a plurality of branch node sequences are connected to the excluded core node, among the branch nodes that are the starting points of the plurality of branch node sequences, the branch node having the oldest addition order to the distribution network 10 (the oldest node) A branch node having a smaller number may be set as a basic node instead of the excluded basic node.

  In addition, the node management unit 120 does not have a branch node as the content distribution destination node of the excluded basic node, and has a lower level basic node as the content distribution destination node of the excluded basic node (the branch node is not connected). In the case where the lower core node is connected), the upper core node of the excluded basic node is connected to the lower core node.

  Furthermore, when a new node is added to the distribution network 10, the node management unit 120 connects the new node as a content distribution destination node of the core node of the distribution network 10. The number may be permitted (restricted). For example, when the number of nodes of the distribution network 10 is K, the number of basic nodes is n, and the predetermined number represented by the function f (n) of n is L = f (n), the number of nodes K is a predetermined number. A new node is connected as a content distribution destination node of the core node on condition that it is L or more. Alternatively, the number of nodes that can be added in the branch node sequence connected to the lower level core node of the distribution network 10 is smaller than the number of nodes that can be added in the branch node sequence connected to the higher level core node. Restrict. Specifically, when the function of p is G (p), the number of nodes that can be added to the branch node string connected to the p-th basic node is limited to M = G (p). Alternatively, when the number of nodes of the first node set constituted by the first basic node sequence and the first branch node sequence group connected thereto becomes a predetermined number, the second basic node sequence and You may set the 2nd node set comprised by the 2nd branch node sequence group connected.

  The control processing unit 130 (control processing server) performs various control processes, and includes an information reception unit 132, an information transmission unit 134, and an evaluation point calculation unit 136.

  The information receiving unit 132 performs processing for receiving information from each node or the like. For example, request information and report information from each node are received. Specifically, the j-th node of the distribution network receives the content from the upper i-th node, and the received content is transferred to the lower k-th (for example, i, j) by the P2P (Peer to Peer) relay method. , K is an integer satisfying i <j <k). In this case, the information receiving unit 132 receives the content distribution report information (information indicating that the content distribution has been performed between the j-th node and the k-th node and information about the content), for example, the k-th node. And from at least one of the j-th node.

  More specifically, the information receiving unit 132 receives, as report information, information on the received data amount of content received by the kth node from the jth node from the kth node. Here, the received data amount information may be the received data amount itself, or information indicating the amount of received data amount (for example, the number of receptions). Alternatively, as report information, received data amount information and identification information (ID) for specifying the j-th node (client terminal or user of the j-th node) may be received.

  The information transmission unit 134 performs processing for transmitting information to each node or the like. For example, request information and notification information are transmitted to each node.

  The evaluation point calculation unit 136 performs calculation processing of evaluation points (cooperation points, contribution points). Specifically, based on the received report information, a process of assigning (adding) an evaluation point corresponding to the amount of data transferred from the jth node to the kth node to the jth node I do. For example, an evaluation point that increases as the amount of transfer data increases is given to the j-th node (point addition). This evaluation point is stored in the evaluation point storage unit 173 in association with the jth node. The evaluation point corresponding to the transfer data amount may be calculated based on the transfer data amount (reception data amount, transmission data amount) itself, or based on information corresponding to the transfer data amount (for example, the number of transfers). You may calculate.

  Further, the evaluation point calculation unit 136 sets the transfer data amount of the content from the jth node to the kth node on condition that the report information is received from the kth node that has received the content from the jth node. A corresponding evaluation point may be given to the j-th node. That is, the evaluation point of the j-th node is calculated based on the report information from the k-th node that is the receiving side, not the report information from the j-th node that is the transmitting side (beneficiary side). For example, the information receiving unit 132 receives information on the received data amount of content received from the jth node as report information from the kth node. In this case, the evaluation point calculation unit 136 gives an evaluation point calculated based on the reported information on the received data amount to the jth node. Alternatively, when the information reception unit 132 receives identification information for specifying the j-th node in addition to the reception data amount information, the evaluation point calculation unit 136 reports the received reception data amount information. The evaluation point calculated based on is given to the j-th node specified by the received identification information.

  The evaluation point calculation unit 136 assigns evaluation points to the j-th node on condition that report information has been received from both the j-th node that has transmitted the content and the k-th node that has received the content. (Addition) may be performed.

  Also, the evaluation point calculation unit 136 evaluates the j-th node when the amount of transmission data of the content transmitted by the j-th node is larger than the amount of received data of the content received by the j-th node. Give (add) points. For example, the evaluation point is increased as the transmission data amount is larger than the reception data amount.

  In addition, the content from the j-th node to the k-th node in the settlement period from the determination of the playback content at the j-th node (determination of playback content by the user) to the end of the billing settlement for the j-th node Is delivered. In this case, the evaluation point calculation unit 136 may calculate the evaluation points for the j-th node by excluding the transfer data amount of the content distributed during this settlement period. That is, the points generated during this settlement period are not added to the evaluation points of the jth node.

  It is assumed that the k-th node (client terminal) starts a process of counting the received data amount of the content received from the j-th node after receiving the report of the settlement completion at the j-th node. In this case, the information receiving unit 132 receives, as report information, information on the amount of received data after completion of settlement at the jth node from the kth node. Then, the evaluation point calculation unit 136 gives an evaluation point corresponding to the received data amount at the kth node to the jth node.

  For example, when the distribution network 10 having the configuration shown in FIG. 1 is adopted, the evaluation point calculation unit 136 is configured so that the evaluation point for the core node is higher than the evaluation point for the branch node. Evaluation point calculation processing may be performed. For example, the point addition value is made larger (for example, doubled) for the user of the basic node than the user of the branch node. In this way, it is possible to eliminate the inequality that is felt by the users arranged in the core node.

  The evaluation points in the present embodiment are, for example, evaluations (contributions) to viewers (nodes) according to the transfer data amount (including information corresponding to the transfer data amount such as the number of transfers) in content distribution, Parameter). As the usage form of this evaluation point, for example, as a usage form such as a point added to a point card in a home appliance mass production store, or a numerical value from which data is converted into other forms such as privilege data or virtual money data Can be assumed. For example, when the evaluation point reaches a certain value, the evaluation point is returned to the viewer in the billing process, and the content distribution amount (download amount) is discounted, or one or more times of content viewing are made free. Alternatively, the numerical value (parameter) of evaluation points stored as internal data is converted into privilege data such as character data, item data, or wallpaper data, or converted into virtual money data that is a monetary value on the network. And given to the node (viewer, user, player) (corresponding to the node in the storage unit). Or you may rank a viewer as a member based on an evaluation point. For example, when the numerical value of the evaluation points reaches a certain value, the viewer is promoted to a higher rank member called a gold member or a premium member. Specifically, the viewer's member rank designation flag is changed based on the numerical value of the evaluation points. Thus, various usage forms can be considered as evaluation points.

2. Client Terminal FIG. 3 shows a configuration example of a client terminal (information processing device, game device, etc.) provided in each node of the distribution network 10. The client terminal includes a processing unit 200, an operation unit 260, a storage unit 270, an interface (I / F) unit 282 for the information storage medium 280, a display unit 290, a sound output unit 292, and a communication control unit 296. Note that the client terminal according to the present embodiment is not limited to the configuration shown in FIG. 3, and various modifications such as omitting some of the components or adding other components are possible.

  The processing unit 200 performs various processes. Specifically, the decryption process of the encrypted content, the reproduction process of video and audio, and the like are performed. Also, a process of buffering (caching) content data received from a content distribution source node in the storage unit 270 and retransmitting the buffered content data to a content distribution destination node by a relay method (bucket relay method) Etc. The function of the processing unit 200 can be realized by a processor such as a CPU, a program that operates on the processor, or the like.

  The operation unit 260 is used for the viewer to perform various inputs necessary for viewing the content, and can be realized by, for example, a keyboard, a mouse, a game controller, or the like.

  The storage unit 270 functions as a work area for the processing unit 200 and the communication control unit 296, and the function can be realized by a RAM, an HDD, or the like. The storage unit 270 includes a content buffer 272, a management information storage unit 274, a settlement end flag storage unit 276, and a received data amount storage unit 278.

  The content buffer 272 functions as a cache memory for content data received from the content distribution source node. The management information storage unit 274 stores management information such as information on its own node and information on other nodes.

  The settlement end flag storage unit 276 stores a settlement end flag that is turned on at the end of settlement of content distribution. The reception data amount storage unit 278 stores the data amount (total result) of the content received from the content distribution destination.

  The I / F unit 282 performs interface processing such as access processing to the information storage medium 280 in which programs and data are stored.

  An information storage medium 280 (a computer-readable medium) stores programs, data, and the like, and functions thereof by an optical disk (CD, DVD), HDD (hard disk drive), memory (ROM, etc.), and the like. realizable. The processing unit 200 performs various processes of the present embodiment based on a program (data) stored in the information storage medium 280. That is, in the information storage medium 280, a program for causing a computer (an apparatus including an operation unit, a processing unit, a storage unit, and an output unit) to function as each unit of the present embodiment (a program for causing the computer to execute processing of each unit). Is memorized.

  The display unit 290 displays content video and the like, and its function can be realized by a CRT, LCD, touch panel display, HMD (head mounted display), or the like. The sound output unit 292 outputs a sound of content and the like, and the function can be realized by a speaker, a headphone, or the like.

  The communication control unit 296 performs various communication control processes for data transmission / reception with other nodes and servers. Specifically, various processes necessary for communication according to a protocol such as the Internet are performed. The function of the communication control unit 296 can be realized by a communication ASIC or firmware.

  The processing unit 200 includes a connection establishment unit 202, a content reception unit 204, a decryption unit 206, a reproduction unit 208, a content transmission unit 210, a display control unit 212, an information reception unit 214, an information transmission unit 216, and a received data amount totaling unit 218. including. Various modifications such as omission of some of these components and addition of other components are possible.

  The connection establishment unit 202 performs processing for establishing a connection (session) between nodes. Here, establishing a connection is a process of securing a virtual communication path between nodes. Specifically, prior to actual communication of data such as content data, a virtual communication path is secured between the transmission source node and the transmission destination node, and data can be transferred between the nodes. It is a process to make. Taking TCP (Transmission Control Protocol) as an example, the establishment of a connection is realized by a three-way handshake.

  The content receiving unit 204 performs content (content data) reception processing. Specifically, the content is received from the j-th node, which is the upper node in content distribution. When the j-th node is excluded from the distribution network 10 due to viewing stoppage or line disconnection, a spare connection established in advance between the k-th node and the i-th node is used. The content from the i-th node is received. As a result, the reconnection process when the j-th node is excluded can be shortened.

  The decryption unit 206 performs a process of decrypting the content received from the upper node. The playback unit 208 performs processing for playing back the decrypted content. For example, content video or audio is reproduced. Then, the content transmission unit 210 performs processing for transmitting the content received from the upper node to the lower node. Specifically, the content received from the upper node is accumulated in the content buffer 272, and the content transmission unit 210 relays the content accumulated in the content buffer 272 and transmits it to the lower node. As a result, it is possible to distribute content in the P2P relay system (bucket relay system, cache and toss system).

  The display control unit 212 performs display control of the display unit 290. For example, display control of a content selection screen, a payment settlement screen, a content playback screen, and the like is performed.

  The information receiving unit 214 performs processing for receiving various types of information from the server system 100 and other nodes. For example, various request information and report information are received from the server system 100 and other nodes. The information transmission unit 216 performs processing for transmitting various types of information to the server system 100 and other nodes. For example, various request information and report information are transmitted to the server system 100 and other nodes.

  The received data amount totaling unit 218 performs a totaling process for the data amount of the content received from the upper node. The total received data amount that is the total result is stored in the received data amount storage unit 278. Specifically, when the user selects a desired content on the content selection screen displayed on the display unit 290, the total received data amount up to the previous time is cleared. When the content data is received from the upper node, the total received data amount increases according to the received data amount. In this case, for example, the totaling process of the received data amount may be started on the condition that the settlement end flag from the upper node is turned on.

3. In the P2P relay system, in order to maintain the stable state of the system, each node that is a content distribution source in the distribution network is connected to each node that is a content distribution destination. It is necessary to supply content stably. For example, the larger the amount of data stored in the content buffer of the client terminal of each node, the more stable the entire system becomes. Specifically, if one content (one movie) is accumulated in the content buffer of each node, an absolute stable state is obtained.

  However, when the user of each node finishes viewing or when there is a failure such as a line disconnection, the node is excluded from the distribution network. If such node exclusion frequently occurs, the system becomes unstable. Therefore, in order to stabilize the system, it is important to give an incentive to stay as a content distribution source to users who participate in the community.

  For example, in the distribution network 10 configured as shown in FIG. 1, the core nodes N1, N3, and N6 distribute content to two distribution destination nodes. On the other hand, the branch nodes N2, N4, and N5 distribute content only to one distribution destination node, and the branch nodes N7, N8, and N9 do not distribute content to any node. Therefore, although the nodes belong to the community of the same distribution network 10, the amount of transmission data differs depending on the position in the distribution network where the node is located. For example, some Internet providers may limit the amount of transmission data, and such a difference in the amount of transmission data may create an unfair feeling among users. In particular, the position of the own node in the distribution network is determined by the system side, and the user has no selection right. Therefore, such unfairness can be a big problem.

  Therefore, in this embodiment, a method is adopted in which an evaluation point corresponding to the transfer data amount of the node is given to the node. For example, when the amount of transmission data is larger than the amount of received data of content, the evaluation point for that node is increased. Then, according to the evaluation point, for example, the fee for the distribution service can be discounted at the next content distribution, or the evaluation point can be converted into virtual money or various services. In this way, evaluation points become incentives, and the user stays in the distribution network, leading to system stabilization. Further, imparting many points to a node that has transmitted a large amount of content data can eliminate unfairness and inequality.

  For example, in FIG. 4A, the i-th node Ni is an upper node of the j-th node Nj, and the j-th node Nj is an upper node of the k-th node Nk. Here, “higher” indicates that the content distribution order (connection addition order) is higher, and specifically indicates that the distribution order number (additional order number) is young. In FIG. 4A and the like, a case where the nodes Ni, Nj, and Nk are adjacent to each other is shown for the sake of simplicity, but the present embodiment is not limited to this.

  In FIG. 4A, the node Nj receives the content from the upper node Ni, and transmits (relays) the received content to the lower node Nk by the P2P relay method. In this case, information indicating that the content has been distributed between the nodes Nj and Nk and information for reporting the content are transmitted to the server system 100, and the information receiving unit 132 receives the report information. Here, the report information is preferably transmitted by the node Nk on the receiving side (receiver side), but may be transmitted by the node Nj.

  Based on the received report information, the evaluation point calculation unit 136 gives an evaluation point corresponding to the amount of data transferred from the node Nj to Nk to the node Nj. For example, a higher evaluation point is given as the amount of data transferred from the node Nj to Nk increases. As shown in FIG. 4A, this evaluation point is stored in the evaluation point storage unit 173 in association with the node Nj. Therefore, for example, the billing processing unit 140 of FIG. 1 can execute discount processing of content viewing fees with reference to the evaluation points of the evaluation point storage unit 173.

  As shown in FIG. 4B, when the point of the node Nj is evaluated, the evaluation point may be given to the node Nj based on the report information from the node Nk that receives the content from the node Nj. desirable. For example, if points are added based on the report information from the node Nj on the beneficiary side to which the points are added, there is a possibility that an illegal act by misrepresentation will be performed.

  In this regard, as shown in FIG. 4B, the occurrence of such a situation can be prevented by calculating the evaluation points based on the report information of the node Nk on the receiving side. In the present embodiment, the evaluation point calculation process is not performed locally at each node, but is performed by the evaluation point calculation unit 136 on the server system 100 side, and the evaluation point information is converted to the evaluation point on the server system 100 side. It is stored in the storage unit 173. Thereby, generation | occurrence | production of a user's fraud etc. can be prevented still more effectively.

  In FIG. 4B, the report information from the node Nk includes information on the received data amount RDAk of the content received by the node Nk from the node Nj, and identification information IDj for specifying the node Nj. When the information reception unit 132 receives the received data amount RDAk and the identification information IDj, the evaluation point calculation unit 136 reads the previous evaluation points PTj of the node Nj from the evaluation point storage unit 173 based on IDj. Then, an addition point obtained based on the information of the received data amount RDAk is added to the read evaluation point PTj. In this way, the evaluation point of the node Nj can be calculated.

  For example, assume that N1 in FIG. 1 is a node Ni, N3 is a node Nj, and N5 is a node Nk. Then, the node N3 (Nj) transmits the content received from the node N1 (Ni) to the node N5 (Nk) and also to the node N6. Therefore, in this case, the point of the node N3 (Nj) is added based on the report information (reception data amount) from the node N5, and also based on the report information (reception data amount) from the node N6. , The point of the node N3 (Nj) is added. If the report information includes the information of the identification information IDj and the received data amount RDAk, it is possible to add points based on the report information from a plurality of receiving nodes.

  Note that, as shown in FIG. 5A, the calculation processing of the evaluation point of the node Nj may be performed based on both the report information from the node Nj and the report information from the node Nk. For example, when the report information from the node Nj matches the report information from the node Nk (when the transmission data amount and the reception data amount match), the evaluation point of the node Nj is added. In this way, user fraud can be prevented more effectively, and appropriate point evaluation can be realized.

  Further, as shown in FIG. 5B, when the transmission data amount TDAj of the content transmitted by the node Nj is larger than the reception data amount RDAj of the content received by the node Nj, the evaluation point for the node Nj May be added (added). Specifically, for example, a point corresponding to TADj−RDAj that is a difference between the transmission data amount TADj and the reception data amount RDAj is added to the evaluation point PTj of the node Nj. In this way, more evaluation points are given to a node that has transmitted more data, and the unfairness felt by the user can be further reduced.

  Further, for example, the distribution network 10 in FIG. 6 has a column of basic nodes connected in series from the server system 100 that is a content distribution source, and a column of branch nodes connected in series to each basic node of the basic node column. In the distribution network 10 having such a configuration, for example, the basic nodes N1, N3, N6, N10, and N15 necessarily have a larger transmission data amount than the branch nodes N2, N4, N5, and the like. Accordingly, in this case, the evaluation point calculation process may be performed so that the evaluation point for the core node is higher than the evaluation point for the branch node. Specifically, for example, a certain evaluation point is assigned by default to the basic node, and an evaluation point is not provided to the branch node, or less than the evaluation points assigned to the basic node. Points are given to branch nodes. Alternatively, the point conversion coefficient KP described later with reference to FIG. 8 may be set so that the basic node has a larger value than the branch node. In this way, it is possible to eliminate the user's unfairness that has been set as a core node regardless of his / her own intention by preferentially using evaluation points.

  For example, as shown in FIG. 7, when a user views a content such as a movie, a title selection screen is displayed on the display unit of the user's client terminal, and a desired title is selected from the displayed titles. And decide. Thereafter, the payment processing by the charging processing unit 140 is performed, and when the payment is completed, the reproduction of the content on the client terminal is started.

  However, as shown in FIG. 7, for example, a certain settlement period TD is required from when the user of the node Nj determines the playback content until the settlement of the billing for the user of the node Nj is completed. In order to stabilize the entire system, it is desirable that the node Nj also performs a content transfer process as a relay point of the P2P relay method even during the settlement period TD.

  However, if an evaluation point is given to the user of the node Nj even for the amount of transfer data generated in the settlement period TD, the user of the node Nj may acquire an illegal evaluation point by misrepresentation. is there. That is, by repeating the act of canceling at the settlement stage after the title is determined, an unauthorized evaluation point is given to the user of the node Nj.

  Therefore, in FIG. 7, in such a case, the evaluation point for the node Nj is calculated by excluding the transfer data amount of the content distributed (relayed) in the settlement period TD. Specifically, in the settlement period TD, the aggregation process is started after the settlement period TD is completed without performing the aggregation process of the transfer data amount. Specifically, the node Nk, which is lower than the node Nj, receives the content received from the node Nj after receiving the report of the settlement end at the node Nj (after the settlement end flag is turned on at the node Nj). Start the data amount aggregation process. Then, the evaluation point calculation unit 136 gives an evaluation point corresponding to the total amount of received data to the node Nj. In this way, it is possible to effectively prevent a situation in which an unauthorized evaluation point is given to the user of the node Nj due to the unauthorized action as described above.

4). Detailed Processing of the Method of the Present Embodiment Next, a detailed processing example of the method of the present embodiment will be described using the flowcharts of FIGS.

  FIG. 8 is a flowchart of the evaluation point calculation process. First, as described with reference to FIG. 4B, the received data amount RDAk from the node Nj and the identification information IDj of the node Nj are received as report information from the node Nk (step S71). Here, the received data amount RDAk is the total amount of data received by the node Nk from the node Nj after the previous report. The identification information IDj is an ID for specifying the client of the node Nj, and the addition points for the same ID are added together.

  Next, the addition point APj is calculated based on the point conversion coefficient KP and the received data amount RDAk (step S72). Specifically, for example, arithmetic processing of APj = KP × RDAk is performed. Here, the point conversion coefficient KP is a coefficient for converting the actual received data amount into an evaluation point (cooperation point).

  Next, the addition point APj obtained in step S72 is added to the evaluation point PTj of the node Nj specified by the identification information IDj (step S73). Specifically, an addition process of PTj = PTj + APj is performed. That is, as described with reference to FIG. 4B, the evaluation point storage unit 173 adds the addition point APj to the evaluation point PTj stored in association with the node Nj. Thereby, an evaluation point corresponding to the received data amount RDAk can be given to the node Nj.

  FIG. 9 is a flowchart (data flow) schematically showing processing after the client terminal of the node Nj starts receiving content until the client terminal of the node Nk starts receiving the same content. In FIG. 9, three tasks “procedure”, “content reception”, and “content transmission” are simultaneously operating in the client terminal of the node Nj. Then, as described with reference to FIG. 7, after the settlement end flag (step S89) that is turned on by the node Nj is monitored by the node Nk that is the content receiver (step S109) and the settlement end flag is turned on, The system is configured to start a process of counting received data from the node Nj (step S110).

  Specifically, in the node Nj (procedure task), after the settlement end flag is turned off (step S81), the content is determined (step S82). That is, the user of the node Nj selects and decides content on the content selection screen. Then, a settlement screen is displayed (step S83), and when the settlement is accepted (step S84), a settlement is requested to the billing processing unit 140 (billing server) (step S85).

  Then, the billing processing unit 140 performs a settlement procedure process (step S86), and transmits a notification notifying the end of the settlement (step S87). As a result, the node Nj turns on the settlement end flag (step S88), and informs the node Nk that is the content receiver that the settlement end flag is turned on (step S89). Thereafter, the process proceeds to content reproduction processing.

  The node Nj (content reception task) clears the total received data amount after the content determination in step S82 (step S90). Then, an introduction request for the determined content distribution source is made to the node management unit 120 (mediation server) (step S91), and the node management unit 120 introduces the distribution source to the node Nj (step S92). Thereby, the node Nj requests the node Ni that is the introduced distribution source to transmit the content (step S93). Then, a part of the content is transmitted from the node Ni (step S94).

  After receiving a part of the transmitted content (step S95), the node Nj determines that the settlement end flag of the node Ni is turned on by contact from the node Ni (step S99) (step S96). Data amount aggregation processing is started (step S97). When reception of all contents is completed (step S98), the task of reception processing ends.

  In the node Nk, after the settlement end flag is turned off (step S101), the content is determined (step S102). Then, the total received data amount is cleared (step S103), a request for introducing the determined content distribution source is made to the node management unit 120 (step S104), and the node management unit 120 introduces the distribution source (step S104). Step S105). Thereby, the node Nk requests the node Nj that is the introduced distribution source to transmit the content (step S106). Then, a part of the content is transmitted from the node Nj (step S107).

  After receiving a part of the transmitted content (step S108), the node Nk determines that the settlement end flag of the node Nj is turned on by contact from the node Nj (step S89) (step S109). Data amount aggregation processing is started (step S110). When reception of all contents is completed (step S111), the task of reception processing ends.

5. Node Connection Management Method Details of this embodiment when the distribution network 10 having the structure shown in FIG. 1 is adopted will be specifically described below.

  In the P2P distribution system of this embodiment, the distribution order is set so that a plurality of clients (nodes) requesting content distribution can be quickly and smoothly connected to each other between servers and clients or between two clients. Optimize and arrange connections. In other words, a server system that implements a distribution system (simply referred to simply as a server as appropriate) has limited bandwidth performance and a small number of clients that can be distributed simultaneously. Therefore, the system of this embodiment allows efficient node connection management (mediation). ). Hereinafter, a node connection management method in the case of distributing a moving image such as a movie will be described in detail with reference to FIGS.

  In the present embodiment, content data is sequentially transferred between clients (nodes) connected in series by a P2P relay method (bucket relay method, cache and toss method). When a client is removed from the distribution network due to the end of viewing or line disconnection, the distribution network is maintained at the minimum processing cost by connecting the upper and lower clients before and after the client. At this time, in order to quickly change the connection of the distribution network, a preliminary session (connection) is established in advance between clients of connection change candidates, and the load (cost) of the connection switching process is reduced. In addition, the distribution network is optimized by a small change process, for example, by changing the order of two clients that are directly P2P connected.

Specifically, in this embodiment, as shown in FIG. 1, in addition to the sequential distribution network which is the basis of FIG. 2A, branch nodes are further connected in series starting from each basic node. Then, the following rule is adopted as the order of P2P connection.
(1) For the core nodes (nodes N1, N3, N6, and N10 in FIG. 1), up to two connections (I in a broad sense) are permitted as distribution destination nodes. On the other hand, for the branch nodes (nodes N2, N4, N5, N7, N8, and N9), only one connection (J in a broad sense) is permitted as a distribution destination node.

In other words, if the number of content distribution destination nodes connectable to the core node is I and the number of content distribution destination nodes connectable to the branch node is J, I> J To do. In FIG. 1, I = 2 and J = 1, so that two content distribution destination nodes can be connected to the basic node, and one content distribution destination node can be connected to the branch node. Note that two or more branch node strings may be connected to each basic node, and in this case, I ≧ 3. Therefore, in this embodiment, the relationship of I ≧ 2 and J = 1 is established.
(2) When a new node is added to the distribution network, the new node is connected to the node with the oldest addition order (connection order) to the distribution network among the nodes that can be connected to the content distribution destination node. .

  For example, in FIG. 10A, the backbone nodes N1 and N3 are connected in series to the server, and the branch node N2 is connected to the backbone node N1. Here, according to the rule (1), the connectable number of delivery destination nodes to the basic nodes N1 and N3 is I = 2, and the connectable number of delivery destination nodes to the branch node N2 is J = 1. Therefore, in FIG. 10A, the new node added cannot be connected to the basic node N1, two new nodes can be connected to the basic node N3, and one new node is connected to the branch node N2. Can connect.

  When new nodes N4, N5, and N6 (newly started clients) are added to the distribution network having the connection configuration shown in FIG. 10A, the final connection configuration is shown in FIG. 10 (D).

  That is, in FIG. 10A, N2 and N3 are connected to the node N1 as content distribution destination nodes (nodes that transmit content themselves), and the number of connectable core nodes N1 is I = 2. Therefore, a new content distribution destination node cannot be connected. On the other hand, the content distribution destination node is not connected to the nodes N2 and N3, and a new content distribution destination node can be connected. Therefore, according to the rule (2), the node having the oldest addition order to the distribution network is searched from the nodes N2 and N3 that can be connected to the content distribution destination node. Then, since node N2 is older in order of addition than N3 (because of the smaller number), new node N4 is connected to node N2 as shown in FIG. 10B according to rule (2).

  In FIG. 10B, a new content distribution destination node cannot be connected to the nodes N1 and N2. This is because, from the above rule (1), the connectable number of the trunk node N1 is I = 2, and the connectable number of the branch node N2 is J = 1. On the other hand, a new content distribution destination node can be connected to the nodes N3 and N4. Node N3 has an older order of addition to the distribution network (number is younger) than N4. Therefore, the new node N5 is connected to the node N3 according to the rule (2) as shown in FIG.

  In FIG. 10C, the nodes N3, N4, and N5 can be connected to a new content distribution destination node. Node N3 is older in the order of addition to the distribution network than N4 and N5. Therefore, according to the rule (2), the new node N6 is connected to the node N3 as shown in FIG.

  Here, focusing on the node N2 in FIG. 10A, since the branch node is not connected as the content distribution destination node of the node N2, as shown in FIG. 10B, the new node N4 is a new branch node. Connected as When attention is paid to the node N3 in FIG. 10C, the branch node N5 is connected as the content distribution destination node of the node N3, but the backbone node is not connected. Therefore, as shown in FIG. The new node N6 is connected as a new basic node.

  Next, node (client) exclusion (leaving) processing and distribution network recombination processing will be described with reference to FIGS.

  For example, in FIG. 11A, the core node N1 is excluded due to the end of viewing. Further, a branch node N2 exists as a content distribution destination node of the excluded basic node N1. In this case, this branch node N2 is set as a new basic node that replaces the excluded basic node N1. That is, when a node (client) is excluded from the distribution network due to the end of viewing or line disconnection, the remaining nodes in each branch node sequence are filled to the left to fill the gap.

  In FIG. 11B, the basic node N1 is excluded, but no branch node is connected to the basic node N1. Therefore, in this case, the nodes N3, N5, and N6 in the lower row are sequentially raised.

  In FIG. 11A, it is assumed that the branch node N2 is excluded from the distribution network. In this case, there is a lower branch node N4 as the content distribution destination node of the excluded branch node N2. Therefore, in this case, the upper node N1 (branch node or backbone node) of the excluded branch node is connected to the lower branch node N4. In other words, the node N4 remaining due to the exclusion of the node N2 is narrowed to the left to fill the gap.

  When the basic node N1 is excluded, there is a case where the distribution network needs to be reconfigured. For example, in FIG. 12, the basic node N2 is excluded, and the node N4 is set as a new basic node. Then, there is a subordinate basic node N3 of the new basic node N4, and the addition order of the subordinate basic node N3 to the distribution network is ahead of the addition order of the new basic node N4. Accordingly, in this case, a replacement process is performed for the new basic node N4 and the branch node string connected thereto, and the lower-level basic node N3 and the branch node string connected thereto. In other words, when the main node is replaced with a new main node due to rearrangement, it is checked whether the order of addition (distribution order) is reversed between the upper and lower core nodes. Replace.

6). Node Management Information Next, details of the node management information stored in the management information storage unit 174 of FIG. 1 will be described with reference to FIGS.

  The node management information of this embodiment can include node information, node distribution order information, and distribution network information. Here, the node information is information such as the distribution order of each node, the position in the distribution network, and its connection node. FIG. 13A shows an example of the data structure of the node information. This node information includes connection node information, node distribution order number, and distribution network position information.

  The connection node information is information indicating whether or not another node is connected to the node, and which node is connected when it is connected. Specifically, the connection node information includes an upper core node of the node, an upper branch node, a lower branch node, a lower core node number, and the like.

  The node distribution order number is a numerical value representing the order in which nodes are added to the distribution network. The distribution network position information is information for knowing the position where the node is arranged in the distribution network and whether the node is a basic node or a branch node. Specifically, the distribution network position information includes a node string number and a node connection order number (order in the node string).

  As shown in FIG. 13B, the node distribution order information is information in which the node information of each node is listed in the order added to the distribution network. When searching for the addition position of the new node, the node information is checked in the order of the list of the node distribution order information.

  FIG. 13B shows an example of node information of the node N3 in the case of the node configuration as shown in FIG. In this node information, as shown in FIG. 10 (D), it is shown that the upper trunk node, lower branch node, and lower trunk node of node N3 are nodes N1, N5, and N6, respectively, and there is no upper branch node. Has been. In addition, the distribution order number of the node N3 is “3”, and the distribution network position is [1, 0].

  The distribution network information is information for managing the information of the entire distribution network, and includes the total number of nodes, the number of basic nodes (number of node columns), and the number of connected nodes in the node sequence as shown in FIG. For example, FIG. 14 corresponds to the node configuration of FIG. 10D, the total number of nodes is 9, the number of basic nodes is 3, and the number of node sequence nodes is [3, 2, 1]. Yes. Further, in FIG. 14, the node connection order number (horizontal axis) and the node column number (vertical axis) of FIG. 13A are shown, and the node information of the nodes N1 to N6 is schematically shown. .

7). Detailed Processing Next, a detailed processing example of this embodiment when a new node is added will be described with reference to the flowcharts of FIGS.

  15 and 16 are flowcharts relating to the new node addition processing. When a new node is added, first, as shown in FIG. 15, it is determined whether there is a node connected to the distribution network (step S1). If no other node exists, the added new node is connected to the server as a starting core node (step S2). On the other hand, if it exists, a process for connecting the new node to the distribution network is executed (step S3).

  FIG. 16 is a flowchart showing details of the process in step S3 of FIG. First, a node having the oldest addition order to the distribution network is searched (step S11). This search process can be realized by using the node distribution order information shown in FIG.

  Next, it is determined whether or not a branch node is connected as a content distribution destination node (lower node) of the searched node (step S12). This determination process can be realized using the node information shown in FIG. If no branch node is connected to the retrieved node, the new node is connected as a new branch node (step S13).

  On the other hand, if a branch node is connected to the retrieved node, it is determined whether or not a core node is connected as a content distribution destination node (lower node) (step S14). If not connected, the new node is connected as a new basic node (step S15). On the other hand, when the core node is connected, since the new node cannot be connected to the searched node, the searched node is excluded from the candidates (step S16). Then, it is determined whether or not another candidate node exists (step S17), and if it exists, the process returns to step S11.

  If the new node addition process is performed as described above, it is possible to connect the new node to the distribution network with an efficient process with a low load while maintaining a time lag with a small start of distribution to the end node.

  FIG. 17 is a flowchart related to the recombination processing of the distribution network at the time of node exclusion. Here, in order to simplify the explanation, it is assumed that the nodes are connected as shown in FIG. 19A or 19B. That is, in FIG. 19A, the node A is a branch node excluded due to the end of viewing and the like, the node B is an upper node (branch node, backbone node) connected to the node A, and the node C Are subordinate branch nodes connected to node A. In FIG. 19B, node A is an excluded basic node, node D is an upper node of node A, and node E is a lower node of node A.

  As shown in FIG. 17, first, it is determined whether or not the excluded node A is a core node (step S21). Then, as shown in FIG. 19A, when the node A is not a basic node but a branch node, it is determined whether or not a lower branch node C exists (step S22). Node B and node C are connected to each other (step S23). In this way, when the node A is excluded, the node C can be connected to the node B with the node C being left-justified.

  On the other hand, as shown in FIG. 19B, when it is determined that the excluded node A is a core node in step S21, it is determined whether or not a lower branch node C exists (step S21). S24). If node C exists, node C is set as a new basic node (step S25). That is, the node C is left-justified and set as a basic node instead of the node A. And the process which rearranges the connection order of a node row | line | column is performed (step S27).

  On the other hand, when it is determined in step S24 that the lower branch node C does not exist, it is determined whether or not the lower trunk node E exists (step S28). If there is a lower-ranking core node E, the core node D and the core node E are connected to each other (step S29). In this way, when the node A is excluded, the node E can be connected to the node D with the node E placed upward.

  FIG. 18 is a flowchart showing details of the process in step S27 of FIG. That is, FIG. 19B is a flowchart relating to recombination processing when node C is set as a new basic node.

  First, it is determined whether or not a lower core node is connected to the node C (step S31). If it is connected, it is determined whether or not the order of addition of the subordinate basic node E to the distribution network is ahead of the node C (step S32). If it is earlier, the node C and its branch node string are replaced with the node E and its branch node string (step S33). That is, the replacement process described in FIG. 12 is performed. Then, the connection with the upper and lower nodes of the replaced node is updated (step S34).

  By performing the rearrangement process as described above, even when the node A is excluded, the distribution order in the P2P relay system can be maintained with a small processing load.

8). Limitation of the Number of Basic Nodes Now, when node connection or the like is managed by the above-described method of the present embodiment, the number of branch nodes does not increase so much, and the number of basic nodes may increase significantly. If the number of basic nodes increases in this way, the time lag of distribution to the end node increases, and there is a possibility that efficient distribution cannot be realized.

  That is, in the present embodiment, the new node connection processing and the like are performed according to the above-described rules (1) and (2). However, with these rules (1) and (2) only, when the number of basic nodes gradually increases when nodes are regularly added, the number of basic nodes is decreased. All nodes need to be excluded from the distribution network before nodes are added to the column. Therefore, the number of basic nodes does not decrease easily only by natural node exclusion by the end of viewing. As a result, the number of basic nodes (number of node columns) increases as the number of nodes in the distribution network is increased as nodes are repeatedly added and removed. If the number of basic nodes increases and the distribution network becomes longer vertically, the number of relay nodes until reaching the end node increases, resulting in a deterioration in distribution efficiency.

In order to solve such a problem, for example, it is desirable to set a condition for addition of a basic node to prevent an increase in the number of unidirectional basic nodes. Therefore, in addition to the above rule (1), the following rule (3) is added.
(3) In rule (1), for example, the connection of a node to be a new core node out of two connection destinations of the core node, when the number of nodes currently connected to the distribution network is sufficiently large Only allow connection. That is, when a new node is added to the distribution network, connection of the new node as a content distribution destination node of the core node is permitted according to the number of nodes of the distribution network.

  Specifically, it is assumed that the number of nodes of the distribution network is K, the number of core nodes of the distribution network is n, and a predetermined number represented by a monotonically increasing function f (n) of n is L = f (n). . In this case, on the condition that the number of nodes K is equal to or greater than a predetermined number L, it is permitted to connect the new node as the content distribution destination node of the core node.

  For example, it is assumed that L = f (n) = {(n + 1) × (n + 2) / 2} −1. In FIG. 20A, the number of nodes in the distribution network is K = 9, and the number of core nodes is n = 3. Therefore, L = {(3 + 1) × (3 + 2) / 2} −1 = 9, and K ≧ L = 9. Therefore, in this case, it is permitted to connect the new node N10 as a basic node lower than the basic node N3.

  On the other hand, in FIG. 20B, the number of nodes in the distribution network is K = 6, and the number of core nodes is n = 3. Therefore, since L = {(3 + 1) × (3 + 2) / 2} −1 = 9, K <L = 9. Therefore, in this case, it is prohibited to connect the new node N8 as a basic node lower than the basic node N3.

  In this way, it is possible to prevent the distribution network from being unnecessarily expanded in the vertical direction, and to improve the efficiency of content distribution.

  21 and 22 show flowcharts of processing for realizing the above-described method of the present embodiment. FIG. 21 is a flowchart corresponding to FIG. 15. FIG. 21 is different from FIG. 15 in that steps S53 and S54 are added in FIG. 21, and the other steps are the same. is there.

  That is, in step S53, it is determined whether the number of nodes (total number of nodes) in the distribution network is sufficiently larger than the number of basic nodes. Specifically, as described above, when K is the number of nodes in the distribution network and n is the number of basic nodes, it is determined whether K ≧ L = f (n). If the number of nodes K in the distribution network is sufficiently larger than the number of basic nodes n, a process of connecting the new node in step S55 to the distribution network is performed. That is, the normal connection process described in FIG. 16 is performed.

  On the other hand, if the number of nodes in the distribution network is not sufficiently large with respect to the number of core nodes, as shown in step S54, processing for connecting the new node to the distribution network by limiting to the branch node is performed. Specifically, the processing shown in the flowchart of FIG. 22 is performed.

  Here, FIG. 22 differs from FIG. 16 in that the processing of steps S14 and S15 is performed in FIG. 16, whereas the processing corresponding to steps S14 and S15 is not performed in FIG. That is, if it is determined in step S62 in FIG. 22 that the branch node is connected as the content distribution destination node of the searched node, the core node is connected as the content distribution destination node of the searched node. The search node is unconditionally excluded from the candidates (step S66) without determining whether or not it exists (without determining step S14 in FIG. 16). Accordingly, the process shown in step S15 in FIG. 16 (process for connecting a new node as a basic node) is not performed, and an increase in the basic nodes can be prevented.

9. Next, various methods for restricting the addition of a basic node will be described. The following methods (I), (II), and (III) can be considered as a method for restricting addition of the core node.
(I) Rectangular system This system is a technique that can be realized only by applying the above-described basic node addition restriction rule (3). The shape of the distribution network is a triangle from the start of distribution network formation until node exclusion occurs, but gradually changes to a rectangle as shown in FIG. This method is advantageous in that it can prevent the shape of the distribution network from extending unnecessarily in the vertical direction, the restriction method is simple, and the processing load of distribution network management is light.
(II) Triangular method This method is a method of managing while maintaining a triangular shape without changing the shape of the distribution network. In this method, as shown in FIG. 23B, the number of relay nodes up to each of the end nodes N15, N14, N13, N12, and N11 can be made almost constant, and the time lag of distribution at the terminal node can be reduced. There is an advantage that equalization can be achieved and the delay until data is transmitted can be easily predicted. In this method, the number of connected nodes is managed for each node string, and the addition is limited by the number of nodes in the node string to which the investigation target node belongs at the time of additional node search.

  Specifically, the number of nodes that can be added in the branch node string connected to the lower-level core node of the distribution network is smaller than the number of nodes that can be added in the branch node string connected to the upper-level core node. To be limited. More specifically, when the monotonically decreasing function of p is G (p), the number of nodes that can be added to the branch node sequence connected to the p-th basic node of the basic node sequence is M = G (p). Restrict.

  For example, in FIG. 23B, the number of nodes that can be added in the branch node string BNL4 connected to the lower trunk node N10 is greater than the number of nodes that can be added in the branch node string BNL1 connected to the upper trunk node N1. Is smaller than By doing so, the shape of the distribution network is maintained in a triangle.

  For example, the number of basic nodes is n, and G (p) = n−p. Then, in FIG. 23B, since the number of basic nodes is n = 5, the number of nodes that can be added to the branch node string BNL1 connected to the first (p = 1) basic node N1 is M = G ( p) = 5-1 = 4. Similarly, the number of nodes that can be added to the branch node string BNL2 connected to the second (p = 2) basic node N3 is limited to M = G (p) = 5-2 = 3, and the third (p = The number of nodes that can be added to the branch node string BNL3 connected to the basic node N6 in 3) is limited to M = G (p) = 5-3 = 2 and is connected to the fourth (p = 4) basic node N10. The number of nodes that can be added to the branch node string BNL4 to be added is limited to M = G (p) = 5-4 = 1. Therefore, as a result, the shape of the distribution network is maintained as a triangle.

In FIG. 23C, addition of the new node N16 to the branch node string BNL3 is impossible, and addition of the new nodes N17 and N18 to the branch node string BNL4 is also impossible.
(III) Additional partition management method This method stops adding a certain number of nodes to the first node set, which is a set of nodes in the distribution network that currently exists, and uses the nodes added thereafter. In this method, a new second node set is connected to the end of the basic node of the first node set. According to this method, when adding a node, it is not necessary to check the first node set for which the addition of the node is stopped, and it is possible to limit the nodes to be the additional position search target. Can be suppressed.

  Specifically, in FIG. 24, it is assumed that the number of nodes in the first node set NAG1 configured by the first branch node sequence group connected to the first basic node sequence KNL1 and KNL1 has reached a predetermined number. In this case, a second node set NAG2 configured by the second basic node sequence KNL2 connected in series to the first basic node sequence KNL1 and the second branch node sequence group connected to KNL2 is set. . Thereafter, the added new nodes N21, N22, and N23 are connected to the nodes of the second node set NAG2 instead of the first node set NAG1. This makes it possible to efficiently increase the number of nodes while reducing the processing load.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. In addition, the evaluation point calculation method, the information reporting method, the content distribution method, the node connection management method, the node row connection recombination method, and the like are not limited to those described in this embodiment, and are equivalent to these methods. Are also included within the scope of the present invention.

The structural example of the delivery system and server system to which this embodiment is applied. FIG. 2A and FIG. 2B are examples of a sequential distribution network and a binary tree distribution network. 2 is a configuration example of a client terminal according to the present embodiment. FIG. 4A and FIG. 4B are explanatory diagrams of the method of this embodiment. FIG. 5A and FIG. 5B are explanatory diagrams of the method of this embodiment. Explanatory drawing of the method of this embodiment. Explanatory drawing of the method of this embodiment. The flowchart for demonstrating the process of this embodiment. The flowchart for demonstrating the process of this embodiment. FIG. 10A to FIG. 10D are explanatory diagrams of the node connection management method of this embodiment. FIG. 11A and FIG. 11B are explanatory diagrams of the node connection management method of this embodiment. Explanatory drawing of the node connection management method of this embodiment. 13A and 13B are explanatory diagrams of node management information. Explanatory drawing of node management information. The flowchart for demonstrating the process of this embodiment. The flowchart for demonstrating the process of this embodiment. The flowchart for demonstrating the process of this embodiment. The flowchart for demonstrating the process of this embodiment. FIG. 19A and FIG. 19B are diagrams for explaining the processing of this embodiment. 20A and 20B are explanatory diagrams of a method for limiting an increase in the number of basic nodes. FIG. 21 is a flowchart for explaining processing of the method of FIG. 20 (A) and FIG. 20 (B). FIG. 21 is a flowchart for explaining processing of the method of FIG. 20 (A) and FIG. 20 (B). FIG. 23A, FIG. 23B, and FIG. 23C are explanatory diagrams of a quadrilateral method and a triangular method. Explanatory drawing of the method of an additional partition management system.

Explanation of symbols

Ni i th node, N j j th node, N k k th node,
KNL core node string, BNL1, BNL2, BNL3 branch node string,
10 distribution network, 100 server system, 110 content distribution unit,
120 node management unit, 130 control processing unit, 132, information receiving unit,
134 information transmission unit, 136 evaluation point calculation unit, 140 billing processing unit,
170 database, 172 content storage unit, 173 evaluation point storage unit,
174 management information storage unit, 190 communication control unit,
200 processing unit, 202 connection establishing unit, 204 content receiving unit,
206 decryption unit, 208 playback unit, 210 content transmission unit, 212 display control unit,
214 Information receiving unit, 216 Information transmitting unit, 218 Received data amount totaling unit,
260 operation unit, 270 storage unit, 272 content buffer,
274 management information storage unit, 280 information storage medium, 282 I / F unit,
290 display unit, 292 sound output unit, 296 communication control unit

Claims (19)

A server system for content distribution using a distribution network,
When the j-th node of the distribution network receives content from the upper i-th node and transmits the received content to the lower k-th node in a P2P (Peer to Peer) relay scheme, An information receiving unit for receiving report information of content distribution from the jth node to the kth node;
Based on the received report information, an evaluation point calculation for performing a process of assigning an evaluation point corresponding to the amount of data transferred from the jth node to the kth node to the jth node And
An evaluation point storage unit for storing the assigned evaluation points in association with the j-th node;
A server system comprising: In claim 1,
The evaluation point calculator is
Evaluation according to the amount of data transferred from the jth node to the kth node on the condition that the report information has been received from the kth node that has received the content from the jth node A server system that performs a process of assigning points to the j-th node. In claim 2,
The information receiving unit
As the report information, the k-th node receives, from the k-th node, information on the received data amount of the content received from the j-th node,
The evaluation point calculator is
The server system characterized by performing the process which assign | provides with respect to the said jth node the evaluation point calculated based on the information of the reported said received data amount. In claim 3,
The information receiving unit
As the report information, the received data amount information and the identification information for specifying the j-th node are received,
The evaluation point calculator is
The server system characterized by performing the process which provides with respect to the said jth node specified by the said identification information the evaluation point calculated based on the information of the reported said received data amount. In any one of Claims 1 thru | or 4,
The evaluation point calculator is
A process of assigning evaluation points to the j-th node is performed on the condition that the report information is received from both the j-th node that has transmitted the content and the k-th node that has received the content. A server system characterized by that. In any one of Claims 1 thru | or 5,
The evaluation point calculator is
Processing for assigning evaluation points to the j-th node when the amount of transmission data of content transmitted by the j-th node is larger than the amount of received data of content received by the j-th node A server system characterized by In any one of Claims 1 thru | or 6.
Including a billing processing unit that performs billing processing for content distribution;
The evaluation point calculator is
When content is distributed from the j-th node to the k-th node in the settlement period from the determination of the playback content at the j-th node to the end of the billing settlement for the j-th node. A server system that calculates an evaluation point to be given to the j-th node, excluding a transfer data amount of content distributed in the settlement period. In claim 7,
The k-th node, after receiving a report of the end of settlement at the j-th node, starts a process of counting received data amount of content received from the j-th node,
The information receiving unit
As the report information, the received data amount after settlement at the j-th node is received from the k-th node,
The evaluation point calculator is
The server system which performs the process which provides the evaluation point according to the said received data amount in the said kth node with respect to the said jth node. In any one of Claims 1 thru | or 8.
The distribution network has a series of core nodes connected in series from a content distribution source, and a series of branch nodes connected in series to each basic node of the basic node series,
The evaluation point calculator is
An evaluation point calculation process is performed so that an evaluation point for the basic node is higher than an evaluation point for the branch node. A server system for content distribution using a distribution network,
When the j-th node of the distribution network receives content from the upper i-th node and transmits the received content to the lower k-th node in a P2P (Peer to Peer) relay scheme, An evaluation point calculation unit that performs a process of assigning an evaluation point to the j-th node;
An evaluation point storage unit for storing the given evaluation point in association with the j-th node,
The distribution network has a series of core nodes connected in series from a content distribution source, and a series of branch nodes connected in series to each basic node of the basic node series,
The evaluation point calculator is
When the j-th node is the backbone node, a higher evaluation point is given to the j-th node than when the j-th node is the branch node. system. In claim 9 or 10,
A node management unit for performing node management processing of the distribution network;
A management information storage unit for storing node management information for the node management processing,
The node management unit
When a new node is added to the distribution network, the node that can be connected to the content distribution destination node is searched for the node with the oldest addition order to the distribution network, and the new node is searched for the searched node. A server system characterized by performing processing for connecting nodes. In any of claims 9 to 11,
The node management unit
When a branch node is excluded from the distribution network and a lower branch node exists as a content distribution destination node of the excluded branch node, a higher node of the excluded branch node is selected as the excluded branch. A server system that performs processing for connecting to a branch node below a node. In any of claims 9 to 12,
The node management unit
When a basic node is excluded from the distribution network and a branch node exists as a content distribution destination node of the excluded basic node, the branch node is replaced with a new basic node that replaces the excluded basic node. Server system characterized by being set to In claim 13,
The node management unit
When there is a basic node that is lower than the new basic node and the order of addition of the lower basic node to the distribution network is earlier than the addition order of the new basic node, the new basic node A server system that performs a replacement process of a node and a branch node string connected thereto, and the lower-level core node and a branch node string connected thereto. In claim 13 or 14,
The node management unit
When there is no branch node as the content distribution destination node of the excluded basic node and there is a lower level basic node as the content distribution destination node of the excluded basic node, the higher level of the excluded basic node The server system is characterized in that a process of connecting the basic node to the subordinate basic node of the excluded basic node is performed. In any of claims 9 to 15,
The node management unit
When a new node is added to the distribution network, the new node is permitted to be connected as a content distribution destination node of a core node of the distribution network according to the number of nodes of the distribution network. Server system. In any of claims 9 to 16,
The node management unit
Each of the addable nodes in the branch node string connected to the lower trunk node of the distribution network is smaller than the addable nodes in the branch node string connected to the upper trunk node. A server system that performs a process of limiting the number of nodes that can be added in a branch node sequence. In any of claims 9 to 17,
The node management unit
When the number of nodes of the first node set constituted by the first basic node sequence and the first branch node sequence group connected to the first basic node sequence reaches a predetermined number, the first A second node set composed of a second backbone node row connected in series to the backbone node row and a second branch node row group connected to the second backbone node row, and A server system characterized in that a new node is added to the node set. A server system according to any one of claims 1 to 18,
The distribution network;
A distribution system comprising:

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