JP6310264B2 - Content distribution system and address information notification server - Google Patents

Description

  The present invention constructs a distribution tree (a P2P network having a tree structure) in which a plurality of P2P terminals are hierarchically connected with a content distribution server (hereinafter referred to as “distribution server”) as a content distribution source serving as a vertex. In particular, the present invention relates to an address information notification server and a P2P terminal constituting the content distribution system, and an address information notification method.

  In recent years, as Internet users have become more broadband in their network connection environment, while watching broadcasts from broadcast stations, etc., on broadcast receivers, they can acquire content on the network from distribution servers, etc. using terminals such as PCs connected to the network. The number of users is increasing. For this reason, a phenomenon in which many users access the content from the terminal at the moment when the URL information indicating the location of the Internet content is disclosed by broadcasting is often observed.

  In recent years, research and development for broadcasting / communication cooperation services has been conducted. For example, Hybridcast (registered trademark) described in Non-Patent Document 1 receives broadcast content, and simultaneously obtains related information through an IP (Internet Protocol) network and plays it in synchronization with the broadcast. Expanded content services that extend content functions and services are being studied. In addition, a service that presents address information such as a URL to a recommended content on a screen by various means and promotes viewing of new content from the address information is being studied.

  For example, when a recommended content such as a replay video of a scene of interest or a digest video of another venue was prepared during a sports program broadcast, the address information of the content was pushed to the terminal and the content was prepared A service that encourages viewing by displaying a pop-up icon to be displayed on the terminal screen is conceivable. However, as described above, at the moment when the address information for the recommended content is notified, access to the content is concentrated, and the load on the distribution server may increase.

  As a distribution method for reducing the load on the distribution server with respect to access concentration, a distributed content distribution technique using a P2P (peer-to-peer) technique has been developed. In this technology, a logical tree is formed between P2P terminals that request content, and application software operating on the P2P terminal performs data transfer with each other, thereby enabling content distribution with reduced load on the distribution server.

  For example, in the stream data distributed delivery method described in Patent Document 1, each node transmits and receives stream data between network nodes in a network environment such as the Internet. Therefore, each node has a topology indicating a connection relationship between an upstream node and a downstream node. The stream data is relayed from the upstream node to the downstream node by exchanging information. In this stream data distributed delivery method, each node has a function of performing management such as storing, updating, and providing topology information autonomously in order to exchange topology information between the nodes. In constructing a distribution tree for such a content distribution system, a P2P terminal capable of relaying a stream to many terminals can be connected to a distribution server closer to the distribution server, thereby providing stable content distribution to more terminals.

  In addition, for example, in the P2P Internet live broadcast service system described in Patent Document 2, a streaming server for streaming content on the Internet and a large number of peers (P2P terminals) that receive or relay the streaming by a tree-structured P2P method The peer divides the transmission rate to its lower peers by the amount of streaming content per hour to determine the number of sessions, and the peer with the higher number of sessions becomes the upper peer of the peer with the lower number of sessions. Form a structure.

JP 2003-169089 A JP 2010-109976 A

Japan Broadcasting Corporation, “Overview and Technology of Hybridcast ™”, NHK R & D, no. 124, p. 10-17, November 2010, Japan Broadcasting Publishing Association

  However, in such a content distribution system, since the individual P2P terminals are connected to the P2P network in the order in which they accessed the content and start receiving the content, when access to the content is instantaneously concentrated as described above. The P2P terminal that can relay the stream to many terminals cannot always be connected near the distribution server.

  Further, in Patent Document 2, after constructing a P2P network, the number of sessions between the own peer (P2P terminal) and its own peer is periodically compared. Rejoin the upper peers of the other as their upper peers, compare the number of sessions between their lower peers, and instruct the lower peers with fewer sessions to join the lower peers with more sessions as the upper peers. Thus, a method for reconstructing a distribution tree and rearranging a P2P terminal capable of relaying a stream to many terminals at a higher level of the distribution tree is disclosed. When such processing is performed throughout the distribution tree, There is a possibility that the traffic of the control message related to the processing increases or the P2P network becomes unstable.

  An object of the present invention made in view of such circumstances is to provide a content distribution system, an address information notification server, a P2P terminal, and an address notification method capable of constructing a stable P2P network while suppressing the number of layers. is there.

In order to solve the above problems, a content distribution system according to the present invention includes a plurality of P2P terminals, an address information notification server that transmits content address information, which is information related to a content acquisition destination, to the P2P terminal, and a content distribution source A content distribution system that distributes content by constructing a P2P network having a tree structure in which a plurality of P2P terminals are hierarchically connected with the distribution server at the top, wherein the P2P terminal A relay capability measuring unit that measures the relay capability of relaying to other P2P terminals on the downstream side, and an address information requesting unit that transmits the relay capability to the address information notification server and requests the content address information, The address information notification server obtains the relay capability from the P2P terminal. And ® emission control unit, the order to notify the content address information to the P2P terminal, a notification order determination unit which determines the descending order of the relay capability, the relay capability of P2P terminal that has notified the content address information immediately before, Next, the relay capability of the P2P terminal that notifies the content address information is compared, and if there is a difference greater than or equal to a predetermined value, a delay insertion unit that notifies the P2P terminal of the content address information after a predetermined delay time has elapsed Is provided.

In order to solve the above problems, the address information notification server according to the present invention constructs a P2P network having a tree structure in which a plurality of P2P terminals are hierarchically connected with a distribution server as a content distribution source as a vertex. In a content distribution system for distributing content, an address information notification server for notifying a P2P terminal of content address information, which is information related to a content acquisition destination, from the P2P terminal to the P2P terminal A session control unit that acquires a relay capability to relay to the P2P terminal, a notification rank determination unit that determines the order in which the content address information is notified to the P2P terminal in descending order of the relay capability, and the content address information immediately before And the relay capability of the P2P terminal that notified the Comparing the relay capability of P2P terminals communicating information, if there is a difference of more than a predetermined, after a predetermined delay time, and a delay insertion unit for notifying the content address information to the P2P terminals.

  According to the present invention, the address information notification server preferentially notifies the content address information, which is the information related to the content acquisition destination, to the P2P terminal having a larger relayable number, so that the P2P terminal having the larger relayable number is notified. Since the P2P network can be connected earlier in time, it is possible to construct a stable P2P network with a reduced number of hierarchies because these P2P terminals are positioned higher in the distribution tree.

It is the schematic which shows the structural example of the content delivery system which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of the P2P terminal which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of the address information notification server which concerns on one Embodiment of this invention. It is a flowchart which shows the content delivery method of the content delivery system which concerns on one Embodiment of this invention. 3 is a flowchart illustrating a content address information notification method according to an embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating a configuration example of a content distribution system according to an embodiment of the present invention. The content distribution system includes a plurality of P2P terminals 1, an address information notification server 2, a distribution server 3, and a terminal management server 4, which are connected via the Internet. The content distribution system constructs a distribution tree (a P2P network having a tree structure) in which a plurality of P2P terminals 1 are hierarchically connected with the distribution server 3 as a vertex, and distributes content by the P2P method. In the following description, when distinguishing between its own P2P terminal (own terminal) and another P2P terminal, the code of the other P2P terminal is denoted as 1 '.

  The distribution server 3 is a server that provides a content distribution service as a content distribution source, and sequentially distributes content data packets (hereinafter referred to as “content data”) to the P2P terminals 1 participating in the P2P network. .

  The address information notification server 2 transmits content address information, which is information related to a content acquisition destination, to the P2P terminal 1. Details of the address information notification server 2 will be described later.

  The P2P terminal 1 receives the content address information from the address information notification server 2, and connects to the distribution server 3 or other P2P terminal 1 'belonging to the P2P network that distributes the content. Then, the content data is received from the distribution server 3 or other P2P terminal 1 'connected to the upstream side of the distribution tree (the number of hops indicating the number of relay stages from the distribution server is equal to or less than the number of hops of the own terminal 1) and reproduced. At the same time, the content data is relayed (distributed or transferred) to another P2P terminal 1 ′ connected to the downstream side of the distribution tree (the hop count is larger than the hop count of the own terminal 1). Details of the P2P terminal 1 will be described later.

  The terminal management server 4 holds terminal information that is information related to content distribution of the distribution server 3 and each P2P terminal 1 participating in the content distribution system. The terminal information includes information necessary for data transfer such as an IP address and a port number in association with the terminal ID of the distribution server 3 or the P2P terminal 1 participating in the content distribution system.

  In addition, the terminal management server 4 receives a connection destination introduction request for desired content from the P2P terminal 1, and returns a connection destination candidate list. The connection destination candidate list is a list including one or more terminal information of the distribution server 3 or the P2P terminal 1 ′ that is a connection destination candidate of the P2P terminal 1.

[P2P terminal]
Next, the P2P terminal 1 will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration example of the P2P terminal 1 according to the present invention.

  The P2P terminal 1 includes a communication I / F 11, a relay capability measuring unit 12, an address information requesting unit 13, an application activation control I / F 14, a connection destination introduction requesting unit 15, a connection control unit 16, and a content data relay. Unit 17, content reproduction unit 18, and storage unit 19. The storage unit 19 includes a relay capability storage unit 191, an address information storage unit 192, a terminal information storage unit 193, and a content buffer 194.

  The communication I / F 11 connects to the Internet and transmits / receives data via the Internet.

  The relay capability measuring unit 12 measures the transmission capability related to transmission / reception of content data in the own terminal 1, determines the relay capability of content data, and stores it in the relay capability storage unit 191. The relay capability can be the number of terminals (number of relayable) that can relay content data to another P2P terminal 1 ′, for example. The relay capability is determined by the following method, for example.

  As a first method, the transmission / reception history of past content data is referred to, and the ratio of the data amount of the transmitted content data to the data amount of the past received content data is set as the relay capability. As a second method, the throughput (Mbit / sec), which is the data transfer amount per unit time, is measured from the past communication history, or the throughput is measured in advance, and the measured throughput with respect to the bit rate of the content data ( The ratio of (transmission capability) is the relay capability. Further, as a third method, a predetermined value set in advance according to the information of the contracted line type to which the terminal 1 is connected (for example, FTTH = 8, ADSL when the contracted line type is FTTH, ADSL, or a mobile line) = 4, mobile line = 1) is the relay capability.

  The address information requesting unit 13 requests the address information notification server 2 for content address information, which is information related to the content acquisition destination, and sends a content address information request including a relay capability via the communication I / F 11 to the address information notification server 2. 2 to send. Then, the content address information is received from the address information notification server 2 via the communication I / F 11, and the received content address information is stored in the address information storage unit 192 and is output to the application activation control I / F 14.

  The application activation control I / F 14 is an interface that performs acquisition start control of content specified by content address information input from the address information request unit 13. For example, when the content address information is input, the connection destination introduction request unit 15 may cause the content to join the P2P network, or a pop-up icon indicating that the content can be acquired is displayed on the screen. In addition, a configuration may be adopted in which the participation process to the P2P network related to the content is started by a user operation.

  The connection destination introduction request unit 15 specifies a connection introduction request including a terminal ID and a connection standby address (information necessary for data transfer such as an IP address and a port number) by content address information via the communication I / F 11. To the terminal management server 4 to be transmitted. Then, the connection destination candidate list is received from the terminal management server 4 via the communication I / F 11 and stored in the terminal information storage unit 193.

  The connection control unit 16 selects and connects another P2P terminal 1 ′ or distribution server 3 as a connection partner based on the connection destination candidate list stored in the terminal information storage unit 193, or another P2P terminal Accepts connection from 1 'and joins P2P network.

  The content data relay unit 17 sequentially receives content data from the P2P terminal 1 ′ connected to the upstream side of the distribution tree via the communication I / F 11, and the P2P terminal 1 that connects the received content data to the downstream side of the distribution tree. And the received content data is stored in the content buffer 194.

  The content reproduction unit 18 takes out the content data from the content buffer 194, sequentially decodes and reproduces it.

[Address information notification server]
Next, the address information notification server 2 will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration example of the address information notification server 2 according to the present invention.

  The address information notification server 2 includes a communication I / F 21, a session control unit 22, a storage unit 23, an address information generation unit 24, a notification order determination unit 25, a delay insertion unit 26, and an address information notification unit 27. Is provided. The storage unit 23 includes a session information management table 231. The address information notification server 2 continues to maintain the session after receiving the content address information request from the P2P terminal 1, generates content address information and determines the notification order, and then notifies the P2P terminal 1 of push notification.

  The communication I / F 21 connects to the Internet and transmits / receives data via the Internet.

  The session control unit 22 receives a content address information request from the P2P terminal 1 via the communication I / F 21. Then, the relay capability is extracted from the content address information request, and stored in the session information management table 231 in association with the session ID that is an identifier for specifying the connection with the P2P terminal 1. The session ID may be the terminal ID of the P2P terminal 1.

  The session information management table 231 is a table in which a session ID or terminal ID (hereinafter referred to as a session ID) is associated with a relay capability. An example of the session information management table 231 is shown in Table 1. Here, the relay capability is the number that can be relayed.

  The address information generation unit 24 generates content address information that is information related to the content acquisition destination, and outputs the content address information to the notification order determination unit 25. Here, the content address information includes a content ID that is an identifier for uniquely identifying the content when the distribution server 3 is ready to distribute the content, and address information (URL or IP) of the terminal management server 4 to be accessed. Address).

  The notification order determination unit 25 determines the order of notification of the content address information to the P2P terminal 1 and notifies the delay insertion unit 26 of the order. For this notification order, the session information management table 231 is referred to, and the relay capability in the order of the relay capability associated with the session ID included in the content address information input from the address information generation unit 24 is in descending order (in descending order of relayable number). To decide.

  The delay insertion unit 26 relays the P2P terminal 1 that notified the content address information immediately before and the relay capability of the P2P terminal 1 that next notifies the content address information based on the notification order determined by the notification order determination unit 25. And compare. If the difference in relay capability is greater than or equal to a predetermined value, a predetermined delay time (for example, 1 second) is inserted, and the session ID and content address information are output to the address information notification unit 27 after the delay time has elapsed. When the difference in capability is smaller than a predetermined value, the session ID and the content address information are output to the address information notification unit 27 without inserting a delay time.

  The address information notification unit 27 notifies the content address information to the P2P terminal 1 corresponding to the session ID input from the delay insertion unit 26 via the communication I / F 21.

[Content delivery method]
Next, a content distribution method in the content distribution system will be described with reference to FIG. FIG. 4 is a flowchart showing a content distribution method in the content distribution system according to the embodiment of the present invention.

  When the P2P terminal 1 is activated, the relay capability measuring unit 12 measures the relay capability of relaying the content to another P2P terminal 1 ′ on the downstream side of the distribution tree (step S101). Subsequently, the address information requesting unit 13 A content address information request including the relay capability is transmitted to the address information notification server 2 to request content address information (step S102). In step S101, the relay capability may be newly measured, or the relay capability measured at the previous content distribution may be read from the relay capability storage unit 191.

  The address information notification server 2 acquires the relay capability from the content address information request by the session control unit 22, determines the order in which the content address information is notified to the P2P terminal 1 by the notification order determination unit 25, in descending order of relay capability, and delays A delay is inserted as necessary by the insertion unit 26 (step S103). Then, the address information notification server 2 transmits the content address information to the P2P terminal 1 by the address information notification unit 27 (step S104).

  Upon receiving the content address information, the P2P terminal 1 transmits a connection introduction request to the terminal management server 4 by the connection destination introduction request unit 15 (step S105). Upon receiving the connection introduction request from the P2P terminal 1, the terminal management server 4 transmits a connection destination candidate list to the P2P terminal 1 (step S106).

  The P2P terminal 1 participates in the P2P network based on the connection destination candidate list by the connection control unit 16 (step S107). Then, the P2P terminal 1 receives and relays the content data by the content data relay unit 17, and reproduces the content data by the content reproduction unit 18 (step S108).

[Address information notification method]
Next, an address information notification method in the address information notification server 2 will be described with reference to FIG. explain. FIG. 5 is a flowchart illustrating an address information notification method according to an embodiment of the present invention. Here, the relay capability is the number that can be relayed.

  First, the address information notification server 2 confirms whether or not content distribution preparation is complete (step S201). If the content distribution preparation is not complete (step S201-NO), a new content address is received from the P2P terminal 1. The reception of the information request is confirmed (step S202). When a content address information request is received (step S202—YES), a session is established with the P2P terminal 1 and a session ID is assigned to the session (step S203). Next, the relayable number is extracted from the content address information request and stored in the session information management table 231 in association with the session ID (step S204). In step S202, if a new content address information request is not received from the P2P terminal 1 (step S202—NO), the process returns to step S201.

  Returning to step S201, when content distribution preparation is complete (step S201-YES), content address information is generated (step S205), session information during the establishment of the current session is extracted from the session information management table 231, and session information is obtained. Are sorted in descending order of the number of relayable items (the number of extractions is N) (step S206).

  Next, the loop counter i is set to 0 (step S207), and loop processing is performed. If i <N (step S208-YES), the i-th session information is extracted (step S209), the i-th session information relayable number (relayable number (i)) and the i-1th session. The number of relayable information (number of relayable (i-1)) is compared, and whether or not “number of relayable (i−1) −number of relayable (i)> = S” (for example, S = 2) is satisfied. To check. If not established or i = 0 (step S210—NO), the process proceeds to step S212. If established (step S210-YES), after inserting a preset delay time (for example, 1 second) (step S211), the content address information is transmitted to the i-th session (step S212), and the session is disconnected. (Step S213).

  Next, the loop counter i is incremented (step S214), and the process returns to step S208. If i <N is not satisfied in step S208 (step S208-NO), the session information management table 231 is cleared to indicate that the content address information has been transmitted to all sessions (step S215), and the process Exit.

  As described above, in the content distribution system according to the present invention, the P2P terminal 1 measures the relay capability of relaying the content to another P2P terminal 1 ′ on the downstream side of the distribution tree and transmits it to the address information notification server 2. The address information notification server 2 determines the order of notifying the content address information to the P2P terminal 1 in descending order of relay capability. For this reason, P2P terminals 1 with higher relay capabilities can be connected to the P2P network earlier in time, and these P2P terminals 1 are positioned higher in the distribution tree so that a stable distribution tree can be constructed with a reduced number of layers. It becomes possible to do.

  Further, the address information notification server 2 inserts a certain delay time according to the relay capability when notifying the content address information. For this reason, it is possible to alleviate the concentration of the P2P network participation process (connection destination introduction request from the P2P terminal 1 to the terminal management server 4). As a result, the load on the terminal management server 4 can be reduced, the concentration of connection processing to the P2P network between the P2P terminals 1 can be eased, and the processing load on the P2P terminal 1 can be reduced, so that stable content distribution can be performed. become able to.

  Further, the P2P terminal 1 can relay the content data to an average of how many P2P terminals at the same time by setting the relay capacity as the ratio of the data amount of the transmitted content data to the data amount of the previously received content data. You can predict if there is. Further, by setting the relay capability as the ratio of the throughput, which is the data transfer amount per unit time, to the bit rate of the content, the transmission capability can be predicted based on the throughput of the line to which the P2P terminal is connected.

  Although the above embodiment has been described as a representative example, it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications and changes can be made without departing from the scope of the claims. For example, a plurality of constituent blocks described in the embodiments can be combined into one, or one constituent block can be divided.

1 P2P terminal 2 Address information notification server 3 Distribution server 4 Terminal management server 11 Communication I / F
12 Relay capability measurement unit 13 Address information request unit 14 Application activation control I / F
DESCRIPTION OF SYMBOLS 15 Connection destination introduction request part 16 Connection control part 17 Content data relay part 18 Content reproduction part 19 Memory | storage part 21 Communication I / F
22 Session Control Unit 23 Storage Unit 24 Address Information Generation Unit 25 Notification Order Determination Unit 26 Delay Insertion Unit 27 Address Information Notification Unit 191 Relay Capability Storage Unit 192 Address Information Storage Unit 193 Terminal Information Storage Unit 194 Content Buffer 231 Session Information Management Table

Claims (2)

A plurality of P2P terminals, an address information notification server that transmits content address information that is information relating to a content acquisition destination to the P2P terminal, and a distribution server that is a content distribution source. A content distribution system for distributing content by constructing a tree-structured P2P network in which terminals are hierarchically connected,
The P2P terminal is
A relay capability measuring unit that measures the relay capability of relaying content to other P2P terminals on the downstream side;
An address information requesting unit that transmits the relay capability to the address information notification server and requests the content address information;
The address information notification server
A session control unit for acquiring the relay capability from the P2P terminal;
A notification order determining unit that determines the order of notifying the P2P terminal of the content address information in descending order of the relay capability ;
The relay capability of the P2P terminal that has notified the content address information immediately before is compared with the relay capability of the P2P terminal that is notified of the content address information. If there is a difference greater than or equal to a predetermined value, a predetermined delay time has elapsed. A delay insertion unit for notifying the P2P terminal of the content address information .
Content distribution system. Content that is information related to a content acquisition destination in a content distribution system that builds a tree-structured P2P network in which a plurality of P2P terminals are hierarchically connected with a distribution server that is a content distribution source as a vertex. An address information notification server for notifying address information to a P2P terminal,
A session control unit for acquiring a relay capability from the P2P terminal to relay the content to another P2P terminal on the downstream side;
A notification order determining unit that determines the order of notifying the P2P terminal of the content address information in descending order of the relay capability;
The relay capability of the P2P terminal that has notified the content address information immediately before is compared with the relay capability of the P2P terminal that is notified of the content address information. If there is a difference greater than or equal to a predetermined value, a predetermined delay time has elapsed. A delay insertion unit for notifying the P2P terminal of the content address information;
An address information notification server.

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