JP2003169089A - Stream data decentralized distribution method and its system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stream data decentralized distribution technique which can actualize autonomous or personal stream data distribution in network environment such as the Internet, specially, between user terminals. <P>SOLUTION: The stream data decentralized distribution system is actualized which allows nodes 10 to mutually send and receive stream data in the network environment such as the Internet. Each node 10 exchanges topology information showing connection relation between upstream and downstream nodes and relays stream data from the upstream node to the downstream node. Each node 10 is optionally disconnected from the network and connected to the upstream node under a predetermined condition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a method for distributing and distributing stream data in a network environment, and more particularly to a technique for realizing a distributed distribution function of stream data among user terminals on the Internet.

[0002]

2. Description of the Related Art In recent years, in information communication network environments typified by the Internet, the promotion of broadband has facilitated easy transmission of mainly moving image (video) and audio content information (hereinafter sometimes referred to as stream data). It is becoming possible. As a broadband network environment, for example, ADSL (as
ymmetric digital subscriber line) Transmission method and CAT
In addition to a wired communication system using a V (cable television) network, a network environment using a wireless communication system (mobile communication system) such as a mobile phone is also included.

By the way, as a user terminal connected to the Internet, a personal computer, various digital information devices (for example, a digital television receiver, etc.), a mobile phone (including PHS), or portable information having a wireless communication function is used. Terminal (PDA: personal digital
(also called assistant)) etc. are included.

By using these user terminals in a broadband network environment, it is possible to receive stream data and reproduce moving image and audio content information without causing the user discomfort. Becomes Conventionally, in information services via the Internet and in information exchange between individuals, text information and still images have been the main subjects, and communication of stream data such as moving images and audio has been limited. Therefore, in the future, along with the spread of broadband network environments, not only in business fields such as stream data distribution service business,
Even in the private field where personal information is exchanged between users, the demand for stream data distribution is expected to increase.

[0005]

By promoting the use of broadband in a network environment, it is possible to increase the bandwidth and reduce the communication cost of the backbone system of the Internet and the branch line system connected to the user terminal of each home. It's starting.

On the other hand, however, along with the increase in demand for stream data distribution, there is a demand for an increase in load capacity (distribution capacity) of a system for transmitting stream data. This leads to an increase in cost required for system construction, which requires a large amount of capital investment especially for servers.

[0007] Generally, a stream data delivery system is realized by a server managed by a service provider (Internet service provider: ISP, etc.). Therefore, if the service provider cannot increase the load capacity of the server in terms of cost, it will not be able to cope with the increasing demand for stream data distribution, and it will not be possible to fully utilize the Internet bandwidth increased by the broadbandization. .

In order to solve such problems, various techniques for distributed distribution (delivery) of stream data have been developed. These prior arts can reduce the load on the server that transmits (delivers) stream data. However, any of the prior arts is basically a system in which a distributed distribution system is centrally controlled by a server managed by a company. Therefore, although the load on the server for transmitting the stream data can be reduced, on the other hand, the load on the server for controlling the topology (connection relationship between the nodes) for configuring the distributed distribution system increases. .

Further, the method of centrally controlling the distributed distribution system is an approach for a business operator that distributes stream data by a server managed by a service business operator. In other words, in the private field where personal information is exchanged between users, a technology related to a distributed distribution system that realizes so-called autonomous or personal stream data distribution without the need for a server managed by a service provider has been developed. It has not been.

Therefore, an object of the present invention is to provide a stream data decentralized distribution technique capable of realizing autonomous or personal stream data distribution, especially between user terminals, in a network environment such as the Internet.

[0011]

SUMMARY OF THE INVENTION An aspect of the present invention is to provide a method for dynamically constructing a stream data distributed distribution system for transmitting and receiving stream data between user terminals (nodes) in a network environment such as the Internet. Regarding The feature of this method is that each node (user terminal) manages the topology information for recognizing the network connection relationship of each user terminal in a distributed manner. In other words, each node autonomously stores topology information,
It has a function to manage such as updating and providing.

A stream data distributed distribution method according to an aspect of the present invention is a method for realizing a stream data distributed distribution function by executing transmission / reception of stream data between nodes in a network constructed by interconnecting nodes. Each node has means for managing topology information for recognizing the connection relationship between upstream nodes and downstream nodes, means for exchanging the topology information between nodes, and means for transmitting / receiving the stream data. , Performing a connection with an upstream node or a downstream node, exchanging topology information with the connected upstream node or a downstream node, and being recognized based on the topology information when operating as an upstream node And transmitting the stream data to a downstream node.

The stream data distributed delivery method according to the aspect of the present invention does not require a stream data delivery server managed by a service provider, a distributed delivery system control server, or the like, for example, between user terminals connected to the Internet. With, stream data can be transmitted, received, or relayed.

Each node can connect to the upstream node recognized by the topology information and can receive the stream data transmitted from the upstream node. Also, the stream data can be transmitted to the downstream node recognized by the topology information. In this case, the own node that functions as an upstream node can connect to a plurality of downstream nodes and transmit stream data simultaneously in parallel. A downstream node that receives stream data from an upstream node functions as an upstream node in response to a connection request from another downstream node, and transmits (in short, relays) the received stream data to the downstream node. You can Therefore, the distributed distribution of the stream data can be realized among the user terminals connected to the Internet without requiring a high-performance stream data distribution server operated by the service provider. However, in general, each user terminal will be connected to the Internet via an ISP or a communication carrier.

If the stream data distributed distribution method of the present invention is used, it can be said that the general user distributes the personally photographed video to only the persons concerned using a personal computer connected to the Internet. Service becomes possible. Further, the user or the business operator can realize so-called Internet broadcasting in which relay broadcasting such as live performances and concerts is broadcast to many viewers. In this case, the Internet broadcaster can reduce the load on the distribution server in the commercial Internet stream data distribution service. That is, from the server managed by the Internet broadcaster,
Stream data can be distributed to a small number of user terminals, and the stream data can be distributed from each user terminal to each other user terminal. As a result, the load on the server managed by the Internet broadcaster can be reduced according to the number of user terminals to which the stream data is directly distributed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Basic Configuration of System) FIG. 1 is a diagram showing the concept of a stream data distributed distribution system according to this embodiment.

The present system is particularly designed for a constantly connected high-speed network environment such as the broadband Internet, and has a configuration in which stream data is distributed and distributed by a plurality of nodes 10 connected to the network. Here, the stream data means continuous digital data such as a moving image (video) and audio. The node 10 is generally a user terminal connected to the network, but may be a network device such as a server or a router. As the user terminal, specifically, a personal computer, a portable information terminal having a wireless communication function (meaning a PDA, a notebook personal computer, or the like), or a digital information device such as a mobile phone (including PHS) ( Device).
Further, the user terminal may mean not only the above-mentioned device alone but also a system configured by connecting a plurality of devices by LAN or wireless LAN.

In this system, the node 10 that receives the stream data transmitted from a certain node 10 (A)
(B) decodes and reproduces (views) the stream data and relays it to another node 10. In this case, the node 10 (B) relays the stream data to the plurality of nodes 10 within the allowable range of the data processing capacity and the network connection band.

In short, this system relays stream data from an upstream node to a downstream node, so that stream data can be delivered to a large number of user terminals without requiring a high-performance delivery server. A distributed distribution function is realized. Here, the upstream node is an upstream node with respect to its own node and is a source node or a relay node of stream data. The downstream node is a node to which stream data is transmitted with respect to the own node. The downstream node is a receiving node that receives the stream data, or a relay node that further transmits the stream data to the downstream node.

FIG. 2 is a block diagram showing an example of a concrete configuration of this system.

As a concrete assumption of this system, stream data is sent to each user terminal participating in the stream data distributed distribution system in a network constructed by connecting a large number of user terminals, that is, nodes 10 to the Internet 20. It is a configuration to be delivered. Each node 10
Assumes an environment in which an ADSL transmission system or a CATV network is used to connect to the Internet by a constant connection type high-speed line.

A certain node 10 is a user terminal having, for example, a personal computer (PC) 11 and a broadband network connection interface (BBNID) 12. BBNID (Broad-Band Network I
The interface device 12 is a network device in which an ADSL modem, a cable modem (CATV Internet modem) or the like is integrated with a router function. These nodes 10 reproduce the stream data received via the Internet 20, for example, on the display of the PC 11 and relay it to another downstream node 10.

A certain node 10 is, for example, a PC 11
And a digital video camera (DVC) 13.
These nodes 10 are upstream nodes, which are user terminals that transmit stream data composed of video (including audio) captured by the DVC 13 by software (main constituent element of the embodiment) set in the PC 11.

(Node Configuration) Next, referring to FIG.
The configuration of the node 10 which is the user terminal of the embodiment will be described.

The node 10 of the embodiment comprises, for example, a personal computer, software set in the computer, and various devices. Figure 3
[Fig. 3] is a block diagram showing a software configuration which is a main component of the embodiment and operates in the PC 11.

All the nodes 10 constituting the stream data distributed distribution system have the same software configuration and realize the functions of transmitting, receiving, relaying and reproducing stream data. Hereinafter, each element of the software configuration will be specifically described. The software configuration of the embodiment is designed to be independent of a specific OS (operating system).

This software configuration has a topology engine 30, a stream engine 31, a stream switch section 32, and a GUI (grap) that controls the operating environment of the entire node.
hical user interface) 33 and stream playback unit 34
Consists of.

The topology engine 30 roughly exchanges messages (control information) so that each node 1
A function of forming a network connection relationship (topology) between 0s is realized. Specifically, the topology engine 30 performs TCP / IP (transmissi
on control protocol / internet protocol) to connect and receive various messages. Further, the topology engine 30 recognizes the existence of directly or indirectly connected nearby nodes through the exchange of messages. The topology engine 30 obtains an alternative topology from the existence information of the neighboring node and the reception state of the stream data, and each node 1 once configured according to the topology.
Change the connection relationship between 0s.

The stream engine 31 is software that realizes the functions of transmitting, receiving, and relaying stream data between the nodes 10. Stream engine 31
Based on the topology information (topology information table described later) received from the topology engine 30 transmits the stream data to the downstream node (single or plural) that is the adjacent node. Also, the stream data is received from the upstream node (single or plural) that is the adjacent node.

Here, the adjacent node means an upstream or downstream node directly connected to the own node. In addition, the neighboring node means an upstream or downstream node that is indirectly connected to the own node. The topology information (topology information table) specifies information indicating the logical connection relationship between each node (information identifying upstream / downstream and adjacent / neighborhood), and the adjacent or nearby node in which the connection relationship is formed. Information (network address etc.) to be included (see FIG. 15).

The stream engine 31 establishes a TCP / IP connection for transmitting / receiving stream data and executes transmission / reception of stream data between each node. The stream engine 31 has a general-purpose delivery function that does not depend on the data format (encoding method) of stream data, and, for example, MP
This is a configuration applicable to various data formats such as the EG standard.

The stream switch section 32 is software for realizing the function of linking the stream engine 31 with other functions, devices, and files. The stream switch unit 32 has a main function as a stream reproducing unit 34.
Is started, and the stream data extracted from the stream engine 31 is passed. The stream reproduction unit 34 is software for decoding output video and audio from stream data and reproducing the decoded video and audio. Further, the stream switch unit 32 is a local device such as a digital video camera (DVC) 13 or a local file device 36.
The function of transmitting the stream data to another node by extracting the stream data from the stream data and passing it to the stream engine 31 is realized.

The GUI 33 includes a topology engine 30, a stream engine 31, and a stream data switch section 3.
It provides an interface between each of the two and the user. Specifically, the GUI 33 visually displays the topology (connection relationship) between adjacent or neighboring nodes or the communication data amount of the stream engine 31 visually on the screen of the display. Further, the GUI 33 makes an explicit connection request to another node or sets a connection key of its own node in response to a command input from the user. The connection key is key data used in the authentication function regarding the connection between the nodes included in the topology engine 30.

Here, the connection key (CK) and public key (PK)
The authentication function using and will be specifically described. When a node serves as a distribution source (role of distribution server), the public key acquisition unit 336 of the GUI 33 acquires the public key (PK) from the connection key issuing server 71 and connects it to the topology engine 30 as described later. The authentication unit 307 receives and stores the data (see FIGS. 4 and 7). The connection authentication unit 307 uses the public key (PK) in response to the authentication request (including the connection key CK) from the connection request reception unit 306, and then the connection key (CK).
To decrypt and authenticate.

On the other hand, the node that participates in viewing and listening is G
The connection key acquisition unit 334 of the UI 33 makes the connection key issuing server 71
The connection key (CK) is obtained from the connection authentication unit 307, and the connection authentication unit 307 of the topology engine 30 receives and stores it. In addition, when the connection request to the upstream node is made, the topology engine 30
The connection request unit 305 receives the connection key (CK) from the connection authentication unit 307 and makes a connection request to the upstream node.

Further, referring to FIGS. 4 to 7, the node 1
Each software configuration of 0 will be specifically described.

(Topology Engine) Topology Engine 3
As shown in FIG. 4, 0 indicates the topology management unit 300, the topology table 301, the load state monitoring unit 302, the control data communication units 303 and 304, the connection requesting unit 305, the connection request receiving unit 306, and the connection authentication unit 307. It has each functional element part.

The topology management unit 300 recognizes the existence of the adjacent node group or the neighboring node group and the connection relationship (topology) between these nodes based on the topology information (TI) received from the directly connected upstream node. To do. The topology management unit 300 also stores a topology information table in the form of a table of the topology information (TI) in the topology table 301 (hereinafter, TI may be referred to as an information table). The topology management unit 300 updates the information table (TI) stored in the topology table 301 according to the change in the topology between the nodes.

The topology management unit 300 passes to the stream engine 31 the node identifiers (network addresses) of the directly connected adjacent nodes, that is, the upstream node (normally one) and the downstream node (single or plural). The stream engine 31 establishes a TCP / IP connection for transmitting / receiving stream data with the adjacent node. In addition, the topology management unit 300 uses the topology table 301.
The information table (TI) stored in the GUI is passed to the GUI 33. The GUI 33 visualizes the topology between the nodes based on the information table (TI) and displays it on the screen (see FIG. 7).

Here, the topology information table (TI) will be specifically described with reference to FIGS. 14 and 15.

FIG. 14 is a diagram showing an example of a connection relationship (topology) in which each node 10 is connected on the network. Each node 10 is specified by an identifier (node0 to node5) corresponding to a network address, for example. Each node 10 basically receives topology information (TI) from its upstream node with respect to its own node,
Register as the topology table 301. Then, each node 10 responds to the connection request from the downstream node, and the topology information (T
I) is provided to the downstream node.

Here, it is assumed that the upstream node 1 of node0
0 provides the downstream node (node1, 4) with the topology information (TI-0) recording the connection relationship with the downstream node (node1, 4). This topology information (T
I-0) is, as shown in FIG. 15A, a node identifier (node0, 1, 4) having a connection relationship and an identifier (only node0) of an upstream node which is an adjacent node (a node directly connected). ) Is associated with the information table. In addition, each identifier of the downstream node (node1, 4)
May be added with flag information indicating that the node is a downstream node. That is, the own node (node0) can recognize the identifier (node1, 4) registered in the topology information (TI-0) as a downstream node that is an adjacent node, based on the flag information.

As shown in FIG. 14, the downstream node (node1) has its own node serving as the upstream node and the downstream node (node1).
It is assumed that a connection relationship with odes 2 and 3) has been established. In this case, the downstream node (node1) has the topology information (TI-) provided by the upstream node (node0).
0), the topology information (TI-
1) is generated and provided to the downstream nodes (node2, 3) (see FIG. 15B). This topology information (TI
Similarly, in -1), each identifier (n
Flag information indicating that the node is a downstream node may be added to nodes 2 and 3).

Here, the downstream node (node2) can recognize the connection relationships (1) to (3) from the provided topology information (TI-1). That is, as the connection relationship (1), in addition to the own node, the upstream node (node
e1) as an adjacent node to the downstream node (node
The existence of e3) can be recognized. As the connection relationship (2), it is possible to recognize the existence of the node (node0) that is further upstream with respect to the upstream node (node1) of the own node. As the connection relation (3), the existence of the downstream node (node4) of the upstream node (node0) can be recognized. These indirectly connected nodes node0, node3, and node
Reference numeral 4 is a neighbor node for the own node (node2).

Similarly, the downstream node (node3) can recognize the connection relationships (1) to (3) from the provided topology information (TI-1). That is, as the connection relationship (1), in addition to the own node, the upstream node (node
e1) as an adjacent node to the downstream node (node
The existence of e2) can be recognized. As the connection relationship (2), it is possible to recognize the existence of the node (node0) that is further upstream with respect to the upstream node (node1) of the own node. As the connection relation (3), the existence of the downstream node (node4) of the upstream node (node0) can be recognized.

On the other hand, the downstream node (node4) is shown in FIG.
As shown in FIG. 4, it is assumed that the own node has established a connection relationship with the downstream node (node5) as an upstream node. In this case, the downstream node (node4) generates topology information (TI-4) in which the connection relationship is added to the provided topology information (TI-0) and provides it to the downstream node (node5) (Fig. 15 (C)). Also in this topology information (TI-4), similarly, flag information indicating that the node is a downstream node may be added to the identifier (node5) of the downstream node.

In summary, each node basically manages (registers, updates, provides, etc.) the topology information (TI) provided from upstream to downstream as the topology table 301, so that the existence of adjacent nodes and neighboring nodes Can be recognized. As described above, the adjacent node is an upstream node or a downstream node that is directly connected to the own node. The neighboring node is a node indirectly connected to the own node (not necessarily a relationship upstream or downstream of the own node).

The amount of topology information (TI) increases as it goes downstream. Therefore, if the upper limit value of the information amount is set in advance and the upper limit value is exceeded,
The topology management unit 300 preferably has a configuration that deletes the information (identifier, etc.) of the node that is in the farthest relationship with its own node.

As shown in FIG. 4, the load state monitoring unit 302 stores the storage state (SB) of the stream data buffer (FIFO type buffer) of the stream engine 31 described later.
Is monitored, and the load state of the stream engine 31 is determined by this. When the load status of the stream engine 31 exceeds the allowable range, the load status monitoring unit 302 instructs the topology management unit 300 to disconnect the downstream node. As will be described later, the storage state (SB) of the stream data buffer of the stream engine 31 is GU.
I33 is also notified.

The control data communication unit 303 has a connection request unit 3
According to the instruction from 05, the control data communication channel with the upstream node 10A is established. The upstream node 10A corresponds to the source node of the stream data from the own node 10. The control data communication unit 303 uses the topology information (T
I) is received from the upstream node 10A. Further, the control data communication unit 303 disconnects the control data communication channel when switching the upstream node 10A to another node.

The control data communication section 304 establishes a control data communication channel with the downstream node 10B in response to an instruction from the connection request receiving section 306. Downstream node 10B
Corresponds to the destination node of the stream data transmitted from its own node. The control data communication unit 304 transmits the topology information (TI) to the downstream node 10B. The control data communication unit 304 disconnects the control data communication channel when the downstream node 10B switches the upstream node from its own node to another node.

The connection request unit 305 issues a connection request to the upstream node 10A in accordance with the designation (CR) of the upstream node from the GUI 33. Furthermore, the connection request unit 305
Instructs the control data communication unit 303 to connect in response to the connection acceptance notification from the upstream node 10A that transmitted the connection request. At this time, with respect to the topology management unit 300, the upstream node 1 with which the control data communication channel is established
Instruct to register the 0A network address. The connection request unit 305 exchanges the connection key data (CK) and the public key data (PK) necessary for the connection authentication process with the upstream node 10A to be connected in response to the connection request.

The connection request acceptance unit 306 determines that the downstream node 10
When the connection authentication unit 307 authenticates the connection request from B, the connection is accepted. Connection request acceptance unit 30
Reference numeral 6 indicates a connection to the control data communication unit 304 in response to acceptance of the connection, and the downstream node 1 which has established a control data communication channel to the topology management unit 300.
Instruct to register the 0B network address. The connection request receiving unit 306 exchanges the connection key data (CK) and the public key data (PK) necessary for the connection authentication process with the downstream node 10B to be connected with the connection reception.
The connection authentication processing procedure will be described later.

The connection authentication unit 307 executes the connection authentication processing required by the connection request unit 305 and the connection acceptance unit 306 to connect to other nodes (upstream node and downstream node).
The connection authentication unit 307 executes the authentication process using the public key cryptosystem, and the connection key data (C
K) and public key data (PK) are received from the GUI 33. Further, the connection authentication unit 307 exchanges the connection key data (CK) and the public key data (PK) with the connection request unit 305 and the connection request reception unit 306, respectively.

Here, as described above, when a node serves as a distribution source (role of distribution server), the public key acquisition unit 336 of the GUI 33 acquires public key data (PK) from the connection key issuing server 71, The connection authentication unit 307 of the topology engine 30 receives this and stores it. Connection authentication unit 30
Reference numeral 7 denotes the public key data (PK) in response to the authentication request (including the connection key data CK) from the connection request receiving unit 306.
To decrypt and authenticate the connection key data (CK).
In the nodes participating in the viewing, the connection key acquisition unit 334 of the GUI 33 causes the connection key issuing server 71 to access the connection key data (C
K) is acquired, and the connection authentication unit 307 of the topology engine 30 receives and stores this. When requesting a connection to an upstream node, the connection request unit 3 of the topology engine 30
05 receives the connection key data (CK) from the connection authentication unit 307 and executes a connection request to the upstream node.

(Stream Engine) As shown in FIG. 5, the stream engine 31 includes a stream data transmission unit 311, a stream data reception unit 312, a stream data buffer 313, a stream data buffer state monitoring unit 314, and a stream data communication connection management. Part 31
It has 5 functional element parts.

The stream data transmitter 311 transmits (relays) the stream data stored in the stream data buffer 313 to the downstream node. At this time, the stream data transmission unit 311 transmits the stream data to the downstream node to which the connection permission instruction has been given from the stream data communication connection management unit 315.

The stream data buffer 313 receives the stream data from the upstream node received by the stream data receiving unit 312 or the stream switch unit 3
2 is a FIFO type buffer for temporarily storing the stream data received from 2. The stream data buffer status monitoring unit 314 uses the stream data buffer 313.
The storage state (SB) of the topology engine 3 is constantly monitored.
0 and the GUI 33 are notified. Here, the storage state (S
B) means the amount of data in which the stream data is stored with respect to the size of the buffer 313.

The stream data reception unit 312 establishes a stream data communication channel with the upstream node designated by the stream data communication connection management unit 315. Then, the stream data transmitted from the upstream node is received and written in the stream data buffer 313. The stream data communication connection management unit 315
The topology engine 30 receives a list of adjacent nodes that should establish a connection relationship by the stream data communication channel.

(Stream Switch Unit) As shown in FIG. 6, the stream data switch unit 32 switches input / output of stream data according to a designation (SW) from the GUI 33. That is, the stream switch unit 32 transfers the stream data received from the stream engine 31 to the stream data reproducing unit 34 or the local file device 60 of the node. The stream switch unit 32 also reads stream data from a digital video camera (DVC) 35, which is a local device, or an encoder device 36, or stream data stored in a local file device 60, and transfers the stream data to the stream engine 31. .

(GUI) The GUI 33 is, as shown in FIG. 7, a stream data relay control unit 331, a relay state (quality) display unit 332, a topology display unit 333, a connection key acquisition unit 334, an upstream node determination unit 335, and It has each functional element part of the public key acquisition part 336. The GUI 33 inputs a command corresponding to an operation on an icon on the display screen of the display device 70 and displays various display information on the display screen.

The stream data relay control unit 331 gives an instruction (SC) to the stream engine 31 to stop or restart the stream data relay in response to a command input from the user. Relay status (quality) display unit 332
Executes the process of reading the storage state (SB) of the stream data buffer 313 from the stream engine 31 and displaying it on the display screen.

The topology display unit 333 receives the topology information (TI) from the topology engine 30 and executes the processing of displaying the connection relation of the adjacent node or the neighboring node on the display screen. The connection key acquisition unit 334 receives the connection key data (CK) input by the user or the connection key data (CK) issued by the connection key issuing server 71 described later.
Is passed to the topology engine 30. When making a connection request to an upstream node, the connection request unit 305 of the topology engine 30
Receives the connection key data (CK) from the connection authentication unit 307 and makes a connection request to the upstream node.

The public key acquisition unit 336 of the GUI 33 acquires public key data (PK) from the connection key issuing server 71 when a node serves as a distribution source (role of distribution server).
It is passed to the connection authentication unit 307 of the topology engine 30. The connection authentication unit 307 uses the public key data (PK) to decrypt and authenticate the connection key data (CK) in response to the authentication request (including the connection key data CK) from the connection request reception unit 306. .

The upstream node determination unit 335 passes to the topology engine 30 the network address of the upstream node designated by the user or the upstream node mediated by the node mediated server 72 described later.

(Connection Establishing Procedure) With reference to FIG. 8, the procedure of the connection processing between the nodes of the embodiment will be described below.

The connection processing between the nodes includes the connection processing with the downstream node as seen from the own node shown in FIG. 8A and the connection processing with the upstream node as seen from the own node shown in FIG. 8B. Be divided. In short, the own node executes the connection process with the upstream node or the downstream node as a relative relationship.

First, in the connection processing with the upstream node, the topology engine 30 of its own node transmits a connection request message to the upstream node (step S1). Specifically, the connection request unit 305 illustrated in FIG. 4 transmits a connection request message including connection key data and ID data. I
The D data includes, for example, a group ID for the purpose of constructing a specific network for delivering stream data, a content ID set for each content of stream data, or the like. The ID data also includes ID data for identifying the hardware of each node (for example, the MAC address of the network interface or the serial number embedded in the microprocessor).

The self node is in a standby state until it receives a reply to the connection request (result of the connection authentication process) from the upstream node (step S2). When the connection permission message is received from the upstream node, the topology engine 3
0 establishes a control communication channel with the upstream node,
The upstream node is registered in the topology table 301 (step S4). The topology engine 30 also stores the public key data included in the connection permission message received from the upstream node. Furthermore, the topology engine 30
Causes the connected upstream node to be registered in the stream engine 31 (step S5). As a result, the stream engine 31 connects the upstream node and the stream data communication channel, and enters a state in which stream data can be received.

On the other hand, when the self-node receives the connection refusal message from the upstream node, it can shift to the process of trying a connection with another upstream node (NO in step S3, S
6). Here, another upstream node is an upstream node required to receive distribution of stream data desired by the own node, and is a node belonging to the same group that constitutes the stream data distributed distribution network (described later). .

Next, the connection processing with the downstream node, that is, the connection processing when the own node is a relatively upstream node will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG.

Upon receiving the connection request message including the connection key data from the downstream node, the self node executes the connection authentication process (steps S11 and S12). The connection authentication unit 307 of the topology engine 30 executes the connection authentication process by decrypting the connection key using the public key data acquired in advance, and when the authentication cannot be performed, returns the connection refusal message to the downstream node ( NO in step S13, S
17).

On the other hand, when the authentication is successful, the topology engine 30 determines whether or not the quality of stream data relay to the existing downstream node is equal to or higher than a specified value, and if the determination result is equal to or lower than the specified value. Returns a connection refusal message to the downstream node (NO in step S114, S17). That is, when the relay quality becomes equal to or lower than the specified value as a result of connecting a new downstream node, the own node rejects the connection in order to prevent the number of downstream nodes from increasing.

When finally permitting the connection, the topology engine 30 returns a connection permission message including the public key data to the downstream node (YE in step S14).
S, S15). Further, the topology engine 30 registers the downstream node, which is permitted to be connected, in the topology table 301 and also registers the downstream node in the stream engine 31 (step S16). As a result, the stream engine 31 connects the downstream node and the stream data communication channel, and enters a state in which stream data can be transmitted.

By the connection processing as described above, the connection between the upstream node and the downstream node is established, and
As shown in, a network of stream data distributed distribution system can be configured.

(Upstream node acquisition procedure) Referring to FIG. 9 below, in order for the own node to receive stream data distribution,
That is, a procedure for newly acquiring an upstream node in order to participate in the distributed stream data distribution system will be described. Here, steps S21 to S26 shown in FIGS. 7A and 7C show the processing procedure on the side of each node. Also,
Step S31 to step S37 shown in FIG.
Indicates a processing procedure on the node mediation server side.

Here, assuming the existence of a node mediation server (server 72 in FIG. 7), a configuration for receiving an introduction of an upstream node from this node mediation server will be described.

The node mediation server registers in the node database 720 a plurality of nodes corresponding to the group ID, that is, belonging to one stream data distributed distribution system. Of course, the node database 720 can register the nodes belonging to each of a plurality of group IDs (stream data distributed distribution system).

First, the self node transmits an upstream node introduction request message (including a group ID) to the node mediation server (step S21). The node mediation server is
When the message is received, the node database 72
A node belonging to the stream data distributed distribution system is searched from 0 (steps S31 and S32). Then, the node mediation server returns a response message including the network address of the searched node (step S33).

The self node acquires the network address of the upstream node introduced from the response message and shifts to the connection processing with the upstream node (steps S22, S).
23). Step S23 is a processing step started from step S1 of FIG. In this connection process, as described above, the introduced upstream node executes the connection authentication process, and finally executes the connection permission or connection refusal determination. When the connection with the upstream node is not completed, the own node transmits the introduction request message to the node mediation server again (NO in step S24, S21).

When the connection with the upstream node is completed, a connection completion message is sent to the node mediation server (YES in step S24, S25). Upon receiving the message, the node mediation server registers the own node in the node database 720 (steps S34 and S35).
On the other hand, when the node intermediation server receives a node leave message indicating the departure from the stream data distributed delivery system network from its own node, the node database 72
The registration of the own node is deleted from 0 (step SS2).
6, S36, S37).

By the above processing, a user who wants to participate in the stream data distributed distribution network can connect to an upstream node that relays stream data. If the network address of the upstream node can be obtained by another method without interposing the node mediation server, connection to the upstream node is possible.

(Topology changing procedure) With reference to FIG. 10, a procedure for changing the topology, which is the connection relationship of the stream data distributed distribution network constituted by connecting the respective nodes, will be described below.

Here, as shown in FIG. 10A, a topology in which a relatively downstream node (1), a node (2), and an upstream node (3) are connected is assumed. . As shown in FIG. 2B, the node (2) executes the upstream node changing process for the node (1) as the topology changing process. That is, the node (2) transmits the upstream node change message including the designation of the alternative upstream node (3) to the downstream node (1) (step S41).

When the downstream node (1) receives the upstream node change message from the upstream node (2), the downstream node (1) executes a connection process to the designated alternative upstream node (3) ( Steps S45, S46). In the connection process, the downstream node (1) sends a connection request message to the alternative upstream node (3). The alternative upstream node (3) executes a connection process with the downstream node (1) based on the received connection request message, as shown in FIG. Then, the alternative upstream node (3) returns a connection permission message or a connection refusal message to the downstream node (1). Note that steps S46 and S50 are steps S1 and S11 of FIG.
Corresponding to the processing steps starting from.

When the downstream node (1) receives the connection permission message from the alternative upstream node (3), it sends a notification of upstream change completion to the upstream node (2) (step S47). The downstream node (1) disconnects the communication channel (control data communication channel and stream data communication channel) with the upstream node (2), and the topology table 30
Delete the registration of the upstream node (2) from 1 (step S
48, S49).

On the other hand, when the upstream node (2) receives the notification of the completion of the upstream change, it disconnects the communication channel (control data communication channel and stream data communication channel) with the downstream node (1), and the downstream from the topology table 301. The registration of the node (2) is deleted (steps S42 and S4).
3, S44).

By the above-mentioned upstream change processing, the connection relation between the upstream node and the downstream node is changed, and as a result, the topology which is the connection relation between the respective nodes can be changed.
This topology changing function is effective, for example, when the node (2) leaves the network or when a new node (3) joins. That is, the downstream node (1)
Since the upstream node can be dynamically and autonomously changed according to the situation of each node, stream data can be received without stopping.

(Connection disconnection procedure) Referring to FIG. 11 below,
The procedure of the connection disconnection process between the nodes of the embodiment will be described. Here, the procedure for disconnecting the connection from the downstream node to the upstream node will be described. In the opposite case, the procedure is basically the same.

First, the downstream node transmits a disconnection message to the connected upstream node, as shown in FIG. 9A (step S61). When the upstream node receives the disconnection message, as shown in FIG. 7B, the upstream node transmits a disconnection acceptance notification to the downstream node (steps S66 and S67).

Upon receiving the disconnection acceptance notification from the upstream node, the downstream node disconnects the communication channel (control data communication channel and stream data communication channel) with the upstream node (steps S62 and S63). Further, the downstream node deletes the registration of the upstream node from the topology table 301 (step S64).

On the other hand, the upstream node disconnects the communication channel (control data communication channel and stream data communication channel) with the downstream node (step S68). Further, the upstream node deletes the registration of the downstream node from the topology table 301 (step S69).

By the connection disconnection processing as described above, each node can disconnect the connection with the node having the connection relationship at an arbitrary timing. This disconnection process changes the topology between the nodes.

(Processing Procedure of Downstream Node) FIG. 12 is a flow chart for organizing and explaining the processing procedure on the downstream node side.

First, when the user participates in the stream data distributed distribution network, the user terminal executes the initialization process as a downstream node (step S70). Specifically, as described above, the introduction of the upstream node is received from the node mediation server (step S8).
0). The downstream node executes a connection request to the introduced upstream node (step S81). When the connection permission notification is received from the upstream node, the connection with the upstream node is completed (YES in step S82). This allows the downstream node to receive the stream data from the introduced upstream node.

Next, when the upstream change message is received from the connected upstream node (step S71), the downstream node makes a connection request to the alternative upstream node included in the message (step S81). In response to this connection request, when the connection permission notification is received from the alternative upstream node, the connection with the upstream node is completed (YES in step S82). Here, the downstream node receives the introduction of the new upstream node from the node mediation server when the connection refusal notification is received from the introduced upstream node or the alternative upstream node or when no response is obtained (step S82). NO (A), S80).

On the other hand, when the downstream node detects communication interruption (including disconnection of the communication channel) with the connected upstream node (step S72), the topology table 3
Select another upstream node from 01 (step S8)
3). The downstream node executes the connection request to the selected upstream node (step S81). When the connection permission notification is received from the upstream node, the connection with the upstream node is completed (YES in step S82).

When the connection refusal notification is received from the selected upstream node, the downstream node determines the topology table 30.
From 1 to all upstream node candidates, selection and connection requests are executed (NO (B), S84 in step S82).
NO). When the connection refusal notifications are received from all the upstream node candidates, the downstream node receives the introduction of a new upstream node from the node mediation server again (YES in step S84, S80).

Further, when the downstream node detects the deterioration of the quality of the stream data relay from the connected upstream node (step S73), it disconnects from the upstream node, and another topology table 301 is called. The process moves to the process of selecting the upstream node (steps S85, S8).
3). Subsequent processing is the same as in the case of the communication interruption with the upstream node.

(Topology Information Exchange Procedure) FIG. 13 is a flow chart for organizing and explaining the topology information exchange procedure between the nodes.

As described above, each node includes the topology management unit 300, the topology table 301, and the control data communication units 303 and 304 in the topology engine 30.
Exchange the topology information table (TI).

Here, it is assumed that the topology information table (TI) is transmitted from the upstream node to the downstream node. The upstream node transmits, to the connected downstream node, the topology information table indicating the connection relationship between the own node and the adjacent node or the neighboring node (step S).
90). Upon receiving the topology information table from the upstream node, the downstream node merges (adds) it to the topology table 301 and stores it (steps S91, S9).
2).

As described above, according to the embodiment, particularly in a network environment such as the broadband Internet, the function of the topology engine 30 provided in each node connects the nodes to each other, and the upstream node and the downstream node are connected. It is possible to form a stream data distributed distribution network composed of Specifically, FIG.
As shown in, the stream data transmitted from the most upstream node 10 (A) is transferred to the downstream node 10 in the vicinity.
Deliver to (B). The downstream node 10 (B) decodes and reproduces the received stream data, and at the same time, as the upstream node, relays the stream data to the downstream node. Similarly, each downstream node decodes and reproduces the received stream data and, at the same time, relays it to the downstream node as an upstream node. However, in general, each node uses an ISP (Internet connection service provider) or a communication carrier to
You will be connecting to the Internet.

Therefore, even if there is no server for stream data distribution, it is possible to realize a stream data distribution network composed only of clients (user terminals). By using such a distributed network forming function, it is possible to reduce the load required for the distribution process of the server even in the case of the network in which the stream data distribution server distributes the stream data. That is, for example, the server operated by the broadcaster can deliver the stream data to each user terminal, and also deliver the stream data from each user terminal to each other user terminal. As a result, the load on the server operated by the broadcaster can be kept low without depending on the number of user terminals to which stream data is delivered.

Further, not a so-called commercial stream data distribution system network, but a private network for the user to distribute a personal photographed video or the like to each node of only the persons connected to the Internet. You can By using such a private network, it is possible to provide a service that can be called a personal broadcast.

In the embodiment, the case where the node mediation server is assumed to exist is mentioned. This node mediation server is completely different from the server for stream data distribution, that is, the central control server of the distributed distribution system, and is a server that has only a limited function of introducing candidates as upstream servers. is there. Therefore, the server does not need a database that correctly recognizes all the nodes configuring the network, and an unknown node may exist among the nodes participating in the network. Further, when the user knows the upstream node by a method other than the introduction from the node mediation server, the node mediation server is, of course, unnecessary. In short, in the embodiment, the existence of the node mediation server is not an essential requirement, but is desirable from the viewpoint of practical service efficiency.

(Business Model or Application Example Applicable to the Embodiment) By applying the stream data distributed delivery network of the embodiment, the following business model or application example can be realized.

(1) It is possible to realize a system which can be called a personal broadcast or a community broadcast in which a video personally photographed by a user at a wedding reception or the like is distributed as stream data to each user (only relevant persons).
In this case, each node constructing the network is composed only of user terminals specified by the connection authentication function by the public key method, for example.

(2) As an extension system of the above (1), a plurality of users who have prepared video cameras gather and send and receive at the same time among the users, so that the video chat service can be realized.

(3) A node equipped with a video camera is installed at a specific outdoor place such as a street, a building, a concert hall, etc., and an image taken by the video camera when an incident or event occurs ( It is possible to realize a business model in which voice (with voice) can be called a location service in which a node is contracted in advance and relayed to each node to which a connection key is distributed. In this case, each node contracts with the service business company to connect to the network operated by the company and receive the relay service. Specifically, so-called internet concert live broadcasting can be easily realized.

(4) Commercial distribution of contents In a service-related network, when a server operated by a business distributes paid contents to each user, the user provides a relay node so that the server side The distribution load can be reduced. In this case, the system of the embodiment can be effectively used by giving the user who has provided the relay node an incentive to provide points for exchanging the viewing ticket of the content.

(5) Peer-to-peer between nodes including information communication from a downstream node to an upstream node by using a control data communication channel between nodes
By connecting by communication, various communication services can be realized simultaneously with stream distribution. For example, by gathering information from the downstream side to the upstream side, it becomes possible to provide a popular voting service for distributed contents and a real-time service for quizzes and questionnaires.
In this case as well, it is an advantage that a large-scale server that processes simultaneous access is unnecessary. In addition, communication such as chat can be realized between downstream nodes simultaneously with stream distribution. It is possible to provide a service where viewers can chat while watching a concert broadcast.

[0114]

As described above in detail, according to the present invention, in a network environment such as the Internet, it is possible to provide a stream data decentralized distribution technique capable of realizing autonomous or personal stream data distribution, especially between user terminals. . Specifically, for example, it is possible to realize distributed distribution of moving image / audio stream data among clients (terminal nodes) by using a broadband network environment without preparing a special stream data distribution server.

[Brief description of drawings]

FIG. 1 is a diagram showing a concept of a stream data distributed distribution system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a specific configuration of a system according to the same embodiment.

FIG. 3 is a block diagram showing a configuration of a node (user terminal) according to the same embodiment.

FIG. 4 is a block diagram showing a configuration of a topology engine of the same node.

FIG. 5 is a block diagram showing the configuration of a stream engine of the same node.

FIG. 6 is a block diagram showing a configuration of a stream data switch unit of the same node.

FIG. 7 is a block diagram showing the configuration of a GUI of the same node.

FIG. 8 is an exemplary flowchart for explaining a procedure of connection establishment processing between nodes according to the first embodiment.

FIG. 9 is a flowchart for explaining an upstream node acquisition procedure according to the same embodiment.

FIG. 10 is an exemplary flowchart for explaining a topology changing procedure according to the first embodiment.

FIG. 11 is an exemplary flowchart for explaining a procedure of connection disconnection processing between nodes according to the first embodiment.

FIG. 12 is a flowchart for explaining a processing procedure on the downstream node side according to the embodiment.

FIG. 13 is an exemplary flowchart for explaining a procedure of exchanging topology information between nodes according to the first embodiment.

FIG. 14 is an exemplary view for explaining contents of topology information according to the embodiment.

FIG. 15 is a diagram showing an example of the same topology information.

[Explanation of symbols]

10 ... Node 11 ... Personal computer (PC) 12 ... Router 13 ... Digital video camera (DVC) 20 ... Internet 30 ... Topology engine 31 ... Stream engine 32 ... Stream switch section 33 ... GUI 34 ... Stream data reproducing unit 300 ... Topology management unit 301 ... Node table 302 ... Load condition monitoring unit 303 ... Control data communication unit 304 ... Control data communication unit 305 ... Connection request unit 306 ... Connection request acceptance unit 307 ... Connection authentication unit 311 ... Stream data transmission unit 312 ... Stream data receiving unit 313 ... Stream data buffer 314 ... Stream data buffer status monitoring unit 315 ... Stream data communication connection management unit

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Claims (22)

[Claims] 1. A method for realizing a stream data distributed distribution function for transmitting and receiving stream data between nodes in a network constructed by interconnecting the nodes, wherein each node is an upstream node. Topology management means for managing topology information for recognizing a connection relationship with a downstream node, means for exchanging the topology information between nodes, and transmission / reception means for the stream data, and connection with an upstream node or a downstream node And a step of exchanging the topology information with a connected upstream node or a downstream node, and a stream for a downstream node recognized based on the topology information when operating as an upstream node. A distributed distribution method of stream data, which comprises the step of transmitting data. 2. The topology managing means registers a function of registering the topology information including identification information of an upstream node or a downstream node for recognizing a connection relationship with its own node; The stream data distributed delivery method according to claim 1, wherein the stream data distributed delivery method is configured to realize a function of updating topology information and a function of providing the topology information to a downstream node. 3. The method according to claim 1, further comprising the step of receiving stream data transmitted from an upstream node recognized based on the topology information when operating as a downstream node. The stream data distributed delivery method according to any one of items. 4. Receiving stream data transmitted from an upstream node recognized based on the topology information,
The method further comprises a step of implementing a relay function of transmitting the stream data to a downstream node recognized based on the topology information.
4. The stream data distributed delivery method according to claim 3. 5. The topology management means further comprises a step of updating the topology information in response to establishment of a connection with a new upstream node or a downstream node or disconnection of an existing upstream node or a downstream node. The stream data decentralized distribution method according to any one of claims 1 to 4. 6. Disconnecting the connection with the existing upstream node,
A step of establishing a connection with a new upstream node, and a step of receiving stream data transmitted from an upstream node recognized by the topology information updated by the updating step in response to connection establishment by the connection establishing step And a step of transmitting the stream data received by the receiving step to the downstream node when there is a downstream node recognized by the topology information. The stream data distributed delivery method according to any one of items. 7. A step of receiving a stream data transmitted from the upstream node, wherein a server for distributing the stream data is an upstream node, and the stream data received by the receiving step is
7. The method according to claim 1, further comprising a step of relaying to a downstream node recognized based on the topology information. 8. An upstream node that is connectable from the server as a downstream node, wherein a server that registers a plurality of upstream nodes connected to the network and introduces to each node is provided on the Internet. And a step of executing a connection request to the upstream node introduced from the server, and a step of connecting to an upstream node permitted to connect in response to the connection request. Claim 1
8. The stream data distributed delivery method according to claim 7. 9. The distributed stream data distribution method according to claim 8, further comprising the step of registering the own node in the server after the step of connecting to the upstream node. 10. A step of executing connection authentication processing in response to a connection request from a downstream node, and a step of communicating with the downstream node if the processing result of the connection authentication processing step is connection permission. The stream data distributed delivery method according to any one of claims 1 to 9, further comprising: 11. The distributed stream data distribution method according to any one of claims 1 to 10, further comprising a step of reproducing the received stream data. 12. A program for executing stream data transmission / reception between nodes to realize a stream data distributed distribution function in a network constructed by interconnecting nodes, wherein each node comprises: A management function including a function of registering, updating, and providing topology information for recognizing a connection relationship between an upstream node and a downstream node, and a connection with the upstream node or the downstream node And a function for exchanging the topology information with the connected upstream node or downstream node, and a stream for the downstream node recognized based on the topology information when operating as an upstream node. A program for causing the computer to realize a function of transmitting or relaying data. 13. When the computer operates as a downstream node, the computer has a function of receiving stream data transmitted from an upstream node recognized based on the topology information and a function of reproducing the received stream data. 13. Realizing this is achieved.
The program described in. 14. The computer is made to realize the function of updating the topology information in response to the establishment of a connection with a new upstream node or a downstream node or the disconnection of an existing upstream node or a downstream node. The program according to any one of claims 12 and 13. 15. A function of executing connection authentication processing in response to a connection request from a downstream node, and a function of communicating with the downstream node when the result of the connection authentication processing is connection permission. 15. The computer-implemented computer system according to claims 12 to 14.
The program according to any one of 1. 16. The program according to claim 12, wherein the program realizes the function of reproducing the received stream data in the computer. 17. A system for realizing a stream data distributed distribution function for transmitting and receiving stream data between nodes in a network constructed by interconnecting nodes, wherein each node is an upstream node or Between the means for establishing or disconnecting the connection with the downstream node, the topology management means for managing the topology information for recognizing the connection relationship between the upstream node and the downstream node, and the connected upstream node or downstream node. Stream data distribution comprising: means for exchanging the topology information; and means for transmitting the stream data to a downstream node recognized based on the topology information when operating as an upstream node. Delivery system. 18. The topology management means comprises: means for registering the topology information including identification information of an upstream node or a downstream node for recognizing a connection relationship with the own node; and a new upstream node or a downstream node. It is characterized by including means for updating the topology information in response to a change in the connection relationship due to connection establishment or disconnection with an existing upstream node or downstream node, and means for providing the topology information to a downstream node. The stream data distributed delivery system according to claim 17. 19. When operating as a downstream node, there is a means for receiving stream data transmitted from an upstream node recognized based on the topology information, and a downstream node recognized based on the topology information. The stream data distribution system according to claim 17 or 18, further comprising a relay unit that transmits the stream data received by the receiving unit to the downstream node. 20. Each of the nodes executes a connection authentication process in response to a connection request from a downstream node, a means for connecting to the downstream node when the connection is permitted, and a connection when the connection is rejected. 20. A stream data distributed distribution system according to any one of claims 17 to 19, further comprising means for transmitting a message indicating rejection to the downstream node. 21. The receiving means disconnects a connection with an existing upstream node, and in accordance with establishment of a connection with a new upstream node, the upstream recognized by the topology information updated by the topology management means. The stream data transmitted from the node is received, and the relay unit transmits the stream data received by the receiving unit to the downstream node when a downstream node recognized by the topology information exists. 20. The stream data distributed delivery system according to claim 19. 22. The stream data distributed distribution system according to claim 17, wherein each of the nodes further includes a unit that reproduces the received stream data.