JP4692278B2 - Content distribution system, terminal device, information processing method thereof, and program thereof - Google Patents

Description

  The present invention belongs to the technical field of a content distribution system, a terminal device, an information processing method thereof, and a program thereof. More specifically, the present invention includes a plurality of terminal devices distributed and arranged on a network. The present invention belongs to the technical field of a content distribution system that transmits and receives data, a terminal device, an information processing method thereof, and a program thereof.

  In recent years, so-called content distribution systems that distribute content data (hereinafter also referred to as “content”) such as music, movies, and talk programs via a network such as the Internet have been actively studied.

  As a basic configuration of the conventional content distribution system, there is a server-client type distribution system. This server-client type distribution system is configured to access a server that accumulates content from a terminal device that is a client and receive the distribution of the content.

  However, in this type of distribution system, access from the terminal device is concentrated on a server device having specific popular content, and the desired content is made high-quality without stress in the terminal devices of a plurality of users who want to distribute the content. There is a disadvantage that it is difficult to obtain and view.

  In view of this, a technique has been proposed in which a distributed overlay table (DHT (Distributed Hash Table)) is used to logically construct an overlay network to efficiently distribute and distribute information to achieve load distribution.

  In this system, each terminal device (hereinafter also referred to as “node device”) does not recognize link information (for example, IP address) to all terminal devices participating in the overlay network. In addition, only link information to some terminal devices obtained at the time of participation is held, and data inquiries and the like are performed based on the link information.

In this overlay network, even when the participation and withdrawal (leaving) of terminal devices are frequently performed, it is necessary to appropriately perform load balancing. Non-Patent Document 1 describes joining and leaving (leaving) in an overlay network. ), A technique for appropriately distributing the load even when it is frequently performed is disclosed.
"Examination of lightweight load balancing method for distributed hash table" The Institute of Electronics, Information and Communication Engineers IEICE technical report

  In a peer-to-peer type content distribution system that uses the technology of Non-Patent Document 1 for a content distribution system, each terminal device becomes a content distribution server that holds content data, and each terminal device also serves as a content distribution request client. Become.

  Also, in such a content distribution system, it is known that not only the terminal device that is a content distribution server holds content data but also other terminal devices on the network hold a copy of the content data. ing. Hereinafter, a terminal device that holds a copy of content data is also referred to as a content holding node. The terminal device which is a content distribution request client can also obtain the requested content from such a content holding node. Accordingly, when a distribution request for a certain content increases, the content can be distributed not only from the node device that is the content distribution server but also from the content holding node that holds a copy thereof. The concentration of access can be avoided.

  As described above, in a peer-to-peer type content distribution system, in addition to a node device having a specific popular content, a content holding node holding a copy of the content is arranged, so that the content distribution server as described above Concentration of access to the node device is avoided.

  However, if participation and withdrawal of the terminal devices constituting the overlay network are frequently performed, the stability of the content distribution system is lowered. For example, if participation and withdrawal of content holding nodes are frequently performed, a state in which the arrangement of the content holding nodes becomes insufficient occurs, and the same inconvenience as in the conventional server-client type content distribution system is assumed. That is, in the node devices of a plurality of users who desire content distribution, it takes a long time until content distribution or an error occurs, so that the content quality is likely to deteriorate. Therefore, it becomes difficult for the user to obtain and view the content with high quality without stress.

  The present invention has been made in view of the above inconveniences, and in a P2P type content distribution system having a plurality of terminal devices distributed and arranged on a network, by suppressing participation and withdrawal of terminal devices, It is an object of the present invention to provide a content distribution system and method with improved performance.

In order to solve the above-mentioned problem, the invention according to claim 1 is composed of a plurality of terminal devices distributed on a network, and the terminal device in a content distribution system that transmits and receives content data between the terminal devices. A communication control unit that performs control related to communication, and an output control unit that is provided independently of the communication control unit and performs control to output content data, and the communication control unit includes: A routing table for storing distribution content receiving means for receiving content data distributed from other terminal devices, and a routing table associating identification information and position information of some terminal devices among the plurality of terminal devices Storage means, destination identification information of a message received via the network, and the routing table Based on the bets, and message destination determination means for determining whether the received message is addressed to its own terminal apparatus, said message the destination determination means by the message received via the network is not addressed to its own terminal apparatus If it is determined, based on the destination identification information of the received message, message transfer means for taking out the location information of the transfer destination terminal device from the routing table and transferring the received message to the terminal device of this location information; A setting state determination unit that determines a state set by the state setting unit included in the output control unit; a power source for communication control unit that supplies power to the communication control unit; a content data storage unit that stores the content data; When the content data is stored in the content data storage means, the network is stored. A predetermined terminal device arranged on the workpiece, the positional information of the own apparatus is the first state that may require content data to a state where it is determined by the setup state determining means the communication control means Distribution source information notifying means for notifying content data distribution source information including information indicating whether the content data is in a second state in which no content data is requested, and information relating to the content data, and the output control means the state of the output control means, and before Symbol first state, the said state setting means for setting to one of the second state, in the first state, the content data supplied by the communication control means The supplied content data receiving means for receiving the received content data and the control for outputting the content data received by the supplied content data receiving means. Content output control means and an output control means power supply that is independent of the power supply for the communication control means and in which the power supply state to the output control means is turned on or off, and the communication control The setting state determining means of the means determines that the power supply for the output control means is in the first state, and determines that the power supply for the output control means is in the second state when the power supply for the output control means is in the off state. It is characterized by that.

The invention according to claim 2 is the invention according to claim 1 , wherein the communication control means is arranged on the network from the other terminal device that holds content data. First content data distribution source information for receiving content data distribution source information including information, information indicating whether the terminal device is in the first state or the second state, and information regarding the content data Content data from a receiving means, content data distribution source information storage means for storing content data distribution source information received by the first content data distribution source information reception means, and other terminal devices arranged on the network Upon receiving a transmission request for distribution source information, the content data distribution source is stored from the content data distribution source information storage means. Remove the distribution, characterized by having a content data distribution source information returning means for returning to the content data delivery the terminal device that requested the original information.

Further, an invention according to claim 3, in the invention described in claim 2, wherein the communication control means, from a predetermined terminal device located on the network, other of the terminal apparatus holding the content data A second content data distribution source information including position information, information indicating whether the other terminal device is in the first state or the second state, and the content data information is received. When it is determined that the content data distribution source information received by the content data distribution source information receiving means and the content data distribution source information received by the second content data distribution source information receiving means includes two or more terminal devices holding the same content data, Content distribution terminal device selection means for preferentially selecting the terminal device in the state, and the terminal device selected by the content distribution terminal device selection means And having a content distribution request means for requesting the distribution of content data for.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the communication control means is arranged on the network from the other terminal device that holds content data. First content data distribution source information for receiving content data distribution source information including information, information indicating whether the terminal device is in the first state or the second state, and information regarding the content data Content data from a receiving means, content data distribution source information storage means for storing content data distribution source information received by the first content data distribution source information reception means, and other terminal devices arranged on the network When receiving a transmission request for distribution source information, the content data distribution source information storage means stores the content in the second state. Content data distribution information that is preferentially selected for the terminal device in the second state and is sent back to the terminal device that requested the selected content data distribution source information And original information return means.

The invention according to claim 5 is the first content according to any one of claims 1 to 4 , wherein the output control means outputs the content data received by the communication control means. Mode setting means for setting the mode to either a data output mode or a second content data output mode for outputting content data other than the content data received by the communication control means; The setting state determination unit determines that the first content data output mode is set when the first content data output mode is set as the mode set by the mode setting unit, and the second content data output mode. It is determined that the state is the second state when is set.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the output control means includes an operation detection means for detecting an operation by a user, and an operation related to the first content data output mode is the operation. When detected by the detecting means, a first operation information transmitting means for transmitting first operation information corresponding to the operation to the communication control means, and an operation relating to the second content data output mode is the operation detecting means. The second operation information transmitting unit that transmits the second operation information corresponding to the operation to the communication control unit, and the operation detecting unit detects an operation related to the second content data output mode. And an operation processing unit that performs a process corresponding to the operation, and the communication control unit is operated by the first operation information transmitting unit. A first operation control unit configured to perform predetermined communication with the other terminal device according to the received first operation information, and the setting state determination unit includes a second operation information transmitted by the second operation information transmission unit. The second state is determined according to operation information.

Further, in the invention described in claim 7 , in the invention described in claim 6, when the operation detecting unit detects an operation of selecting content data received by the distribution content receiving unit, the first The operation information transmitting unit transmits content data selection information to the communication control unit, and the first operation control unit of the communication control unit includes the identification information of the content data selected according to the content data selection information and the routing Content data inquiry for determining the terminal device that is a predetermined condition from the identification information of the terminal device stored in the table, and requesting the distribution of the selected content data to the determined terminal device It is characterized by transmitting information.

The invention according to claim 8 is the invention according to any one of claims 1 to 7 , wherein the communication control means is connected to the output control means wirelessly.

The invention according to claim 9 is the invention according to any one of claims 1 to 8 , wherein the communication control means and the output control means are accommodated in a separate housing. And

The invention according to claim 10 includes the communication control circuit as the communication control means and the output control circuit as the output control means in the invention according to any one of claims 1 to 9. It is characterized by that.

The invention described in Claim 11, computer, characterized in that it is a program for causing to function as each means in the terminal device according to any one of claims 1-9.

The invention according to claim 12 is a program for causing a computer to function as each means of the communication control circuit and the output control circuit in the terminal device according to claim 10 .

The invention according to claim 13 is a content distribution system that includes a plurality of terminal devices distributed on a network and transmits / receives content data between the terminal devices. A communication control means for performing control relating to the output, and an output control means for controlling the output of content data, which is provided independently of the communication control means, and the communication control means includes the other terminal. Distribution content receiving means for receiving content data distributed from a device, routing table storage means for storing a routing table in which identification information and position information of some terminal devices among the plurality of terminal devices are associated, and Based on the destination identification information of the message received via the network and the routing table, the reception is performed. A message is the message destination determination means for determining whether or not addressed to its own terminal device, when the message destination determination means by the message received via the network is determined not to be addressed to its own terminal apparatus, received Based on the message destination identification information, the position information of the transfer destination terminal device is extracted from the routing table, the message transfer means for transferring the received message to the terminal device of this position information, and the output control means A setting state determination unit that determines a state set by the setting unit; a power source for communication control unit that supplies power to the communication control unit; a content data storage unit that stores the content data; and When content data is accumulated, it is placed on the network The constant of the terminal device, never requested the position information of the own device, whether the content data is the first state in which there is a possibility that a state where it is determined by the setup state determining means requests content data to the communication control means information indicating whether the second state in which no, anda distribution source information notifying means for notifying the content data distribution source information including, the information on the content data, the output control means, said output control means the state, before Symbol first state, said state setting means for setting any of the second state, in the first state, the supply content data receives the content data supplied by the communication control means Content output control means for performing control to output content data received by the receiving means and the supplied content data receiving means And a power supply for the output control means that is independent of the power supply for the communication control means and in which the power supply state to the output control means is turned on or off, and the setting of the communication control means The state determining means determines that the power supply for the output control means is in the first state, and determines that the power supply for the output control means is in the second state when the power supply for the output control means is in the off state. To do.

The invention according to claim 14 is an information processing method for the terminal device in a content distribution system which is composed of a plurality of terminal devices distributed on a network and which transmits and receives content data between the terminal devices. The terminal device is provided independently of communication control means for controlling communication, power supply for communication control means for supplying power to the communication control means, and the communication control means. An output control unit that performs control to output, and a power source for the output control unit that is independent of the power source for the communication control unit and in which the power supply state to the output control unit is an on state or an off state, wherein the communication control means, and the distribution contents receiving step of receiving a content data distributed from the other of the terminal devices, the plurality of terminal devices A routing table storing step for storing a routing table in which identification information and location information of some terminal devices are associated with each other, and destination reception information of the message received via the network and the routing table Message destination determination step for determining whether the received message is addressed to the own terminal device, and if the message received via the network is determined not to be addressed to the own terminal device, the message destination determination step Based on the destination identification information of the message, the location information of the destination terminal device is extracted from the routing table, the message transfer step for transferring the received message to the terminal device of this location information, and the output control means execute It was set by the state setting step A setup state determining step of determining status, and content data storage step of storing the content data, the content data when Oite the content data in the storage step are stored, predetermined terminal device located on the network In addition, the position information of the device itself and the state determined in the setting state determination step are the first state in which there is a possibility of requesting the content data from the communication control means, or the second state in which the content data is never requested and information indicating whether it is, the information on the content data, and the distribution source information notification step of notifying the content data distribution source information including, the execution, by the output control means, the state of the output control means, the state setting step of setting before Symbol a first state, in any one of the second state And, in the first state, a supplied content data receiving step for receiving the content data supplied by the communication control means, and a content output control step for controlling the output of the content data received by the supplied content data receiving step If, then the execution, by the setup state determining step, said output control means for power supply is determined to be the first state when the oN state, power supply wherein the output control means in the second state when the oFF state It is judged that there exists.

According to the invention described in claim 1, 10-14, the terminal device includes a communication control unit, and an output control means independent of its communication control means. The communication control means determines whether or not the received message is addressed to the own terminal device based on the destination identification information and the routing table of the message received via the network, and the received message is addressed to the own terminal device. If not, based on the destination identification information of the received message, the location information of the terminal device of the transfer destination is extracted from the routing table, and the received message is transferred to the terminal device of this location information. The output control means sets either the first state that may request content data from the communication control means or the second state that never requests content data. In the first state, the communication control means The content data supplied by is received, and control is performed to output the content data. Therefore, the stability of the content distribution system can be improved by continuing the operation of the communication control means even when the output control means is not operating. That is, since the communication control means continues to operate regardless of the operation of the output control means, it is possible to continue to participate in the content distribution system.
Further, since the communication control unit determines the state (first state or second state) set by the output control unit, the communication control unit can also perform control according to the state set by the output control unit. .
The communication control means has a power supply for communication control means for supplying power to the communication control means. The output control means is independent of the power supply for communication control means, and the power supply state to the output control means is on. A power supply for the output control means that is in a state or an off state is provided. Compared to a terminal device in which the communication control means and the output control means do not operate independently, even if the power supply for the communication control means in the communication control means is on, the power for the output control means in the output control means can be turned off. Therefore, it is possible to continue to participate in the content distribution system and to stabilize the content distribution system. Moreover, since the power supply for the output control means can be turned off when the output control means is not used, the content distribution system can be stabilized and the power consumption can be reduced. . Further, it is possible to arrange the communication control means and the output control means at a location some distance away.
The communication control means determines that the output control means power supply is in the first state, and determines that the output control means power supply is in the second state when the output control means power supply is in the off state. Therefore, when the power supply for the output control means is in the on state, the content data supplied by the communication control means can be received and the content data can be output.
The communication control means determines that the output control means power supply is in the first state, and determines that the output control means power supply is in the second state when the output control means power supply is in the off state. Therefore, when the power supply for the output control means is in the on state, the content data supplied by the communication control means can be received and the content data can be output.
In addition, when the content data is accumulated, the communication control unit stores the position information of the own device and information indicating whether the device is in the first state or the second state in a predetermined terminal device arranged on the network. And content data distribution source information including content data information. Therefore, the communication processing means can notify the state where the internal processing load is low when the content data is not received from the network and the content data is not output to the output control means. It is possible to select a content holding node with a low processing load. In addition, since the content is not output by the output control means in the second state, the content data is not received by the communication control means. Therefore, when the terminal device which is a content holding node is connected to the network by a modulation system line such as RADSL (Rate adaptive Asymmetric Digital Subscriber Line), the downlink line is not used. The content data can be distributed quickly.

According to the second aspect of the present invention, the communication control means receives the position information of the terminal device and whether the terminal device is in the first state or the second state from another terminal device that holds the content data. Content data distribution source information including information indicating whether or not the content data is received and stored. When a transmission request for the content data distribution source information is received, the content data distribution source information is returned. Therefore, the communication processing unit can notify the content holding node in a state of low internal processing load in which the content data is not received from the network and the content data is not output to the output control unit. In this way, it is possible to select a content holding node with a low internal processing load. In addition, when a terminal device that is a content holding node is connected to a network by a modulation system line such as RADSL, since the downlink line is not used, the uplink speed is increased. It is possible to notify a content holding node that can quickly distribute content data.

According to the third aspect of the present invention, the communication control means determines whether the position information of the other terminal device holding the content data and the state of the other terminal device are the first state or the second state. Content data distribution source information including information indicating whether or not there is content data information is received. When it is determined that there are two or more terminal devices that hold the same content data in the content data distribution source information, the terminal device in the second state is preferentially selected, and the content data is transmitted to this terminal device. Request delivery. Therefore, it is possible to receive content data by selecting a content holding node with a low internal processing load in which the communication processing means does not receive the content data from the network and output the content data to the output control means. become. In addition, when a terminal device that is a content holding node is connected to a network by a modulation system line such as RADSL, since the downlink line is not used, the uplink speed is increased. By selecting content data in this way, it is possible to receive content data quickly.

According to a fourth aspect of the present invention, the communication control means transmits the position information of the terminal device and whether the terminal device is in the first state from the other terminal device holding the content data. When content data distribution source information including information indicating whether or not there are two states and information regarding content data is received and stored, and content data distribution source information in the second state exists in the content data distribution source information storage unit Upon receiving the content data distribution source information transmission request, the terminal device in the second state is preferentially selected and returned. Therefore, it is possible to select and notify the request node of a content holding node having a low internal processing load in which the communication processing means does not receive content data from the network and output content data to the output control means. In addition, when a terminal device that is a content holding node is connected to a network by a modulation system line such as RADSL, since the downlink line is not used, the uplink speed is increased. By selecting and notifying content data in this way, it is possible to cause the request node to receive content data early.

According to the invention described in claim 5 , the output control means includes a first content data output mode for outputting the content data received by the communication control means, and content data other than the content data received by the communication control means. The mode is set to one of the second content data output modes for outputting content data. The communication control means determines that it is in the first state when the first content data output mode is set, and determines that it is in the second state when the second content data output mode is set. . Therefore, not only when the power supply for the output control means is in the off state, but also when the communication processing means does not receive the content data from the network and does not output the content data to the output control means, the second state where the internal processing load is low. It can be in the state of.

According to the sixth aspect of the present invention, the output control means receives the first operation information when an operation relating to the first content data output mode is performed, and performs an operation relating to the second content data output mode. The second operation information is transmitted to the communication control means. On the other hand, the communication control means performs predetermined communication with the other terminal device according to the first operation information, and determines that it is in the second state according to the second operation information. Therefore, the communication control unit can detect the second state based on the information from the output control unit.

According to the invention of claim 7 , the output control means transmits the content data selection information to the communication control means, and the communication control means includes the identification information of the content data selected according to the content data selection information and Content data inquiry for determining the terminal device satisfying a predetermined condition from the identification information of the terminal device stored in the routing table, and requesting the distribution of the selected content data to the determined terminal device Send information. Therefore, the user of the terminal device can select and reproduce the content data by controlling the output control means independent of the communication control means.

According to the invention described in claim 8 , the communication control means is connected to the output control means wirelessly. Therefore, the communication control means and the output control means can be arranged at some distance, and the wiring work is not complicated.

According to the ninth aspect of the present invention, the communication control means and the output control means are accommodated in a separate housing. Therefore, the communication control means and the output control means are separated to some extent. It becomes possible to arrange in the place.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. The embodiment described below is an embodiment when the information to be distributed is content data such as music data and video data, and the present invention is applied to a content distribution system.

[1. Content distribution system configuration]
First, a schematic configuration and the like of a content distribution system as an information distribution system will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a connection mode of each node device that is a terminal device in the content distribution system according to the present embodiment. This content distribution system is composed of a plurality of node devices distributed on a network, and transmits and receives content data between the node devices.

As shown in the lower frame 101 of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4, DSL (Digital Subscriber Line) line operator (device) 5, FTTH (Fiber To The Home) line A network (real-world network) 8 such as the Internet is constructed by a business operator (device) 6 and a communication line (for example, a telephone line or an optical cable) 7. Note that the DSL network equipment has RADSL (Rate
Adaptive Asymmetric Digital Subscriber Line) devices are also included.

  As shown in the upper frame 100 of FIG. 1, the content distribution system S includes a plurality of node devices 1a, 1b, 1c... 1x, 1y as terminal devices of the present invention connected to each other via a network 8. , 1z... And a peer-to-peer (P2P) network system. Each node device 1a, 1b, 1c... 1x, 1y, 1z,... Is assigned a unique manufacturing number and IP (Internet Protocol) address (position information in the present invention) as information indicating the node device. Yes. The production number and the IP address are not duplicated among the plurality of node devices 1. In the following description, when any one of the node devices 1a, 1b, 1c... 1x, 1y, 1z.

[1.1. Outline of DHT]
The algorithm using the distributed hash table (hereinafter referred to as “DHT” (Distributed Hash Table)) according to the present embodiment will be described below.

  In the content distribution system S described above, when the node devices 1 exchange information with each other, they must know the IP address as the node information of each other.

  For example, in a system for sharing content with each other, it is a simple technique for each node device 1 participating in the network 8 to know the IP addresses of all the node devices 1 participating in the network 8. However, when the number of terminals becomes as large as tens of thousands and hundreds of thousands, it is not realistic to remember the IP addresses of all the node devices 1. When the power of any node device is turned on or off, the IP address of the arbitrary node device stored in each node device 1 is frequently updated, which makes operation difficult.

  Therefore, in one node device 1, only the minimum necessary IP address of the node device 1 among all the node devices 1 participating in the network 8 is remembered (stored), and the IP address is set. For node devices 1 that are not known (not stored), a system has been devised in which information is transferred between the node devices 1 and sent to each other.

  As an example of such a system, an overlay network 9 as shown in the upper frame 100 of FIG. 1 is constructed by an algorithm using DHT. That is, the overlay network 9 means a network that forms a virtual link formed by using the existing network 8.

  In this embodiment, it is assumed that the overlay network 9 is constructed by an algorithm using DHT, and the node device 1 arranged on the overlay network 9 participates in the content distribution system S (in other words, the overlay network 9). The node device 1 participating in the network. Participation in the content distribution system S is performed when a node device that has not yet participated sends a participation request to an arbitrary node device 1 that has already participated.

  The node ID (identification information) of each node device 1 participating in the content distribution system S is assigned a unique (unique) number for each node device 1. This number must have a number of bits sufficient to accommodate the maximum number of node devices. For example, if a 128-bit number is used, 2 ^ 128 = 340 × 10 ^ 36 node devices can be operated.

  More specifically, the node ID of each node device 1 is obtained by hashing a unique value for each node device 1 such as the IP address or manufacturing number of each node device 1 with a common hash function (hash algorithm). The obtained hash value is distributed and arranged in one ID space without deviation. Thus, the node ID obtained (hashed) by the common hash function has a very low probability of having the same value if the IP address or the manufacturing number is different. Since the hash function is publicly known, detailed description thereof is omitted. In the present embodiment, a node ID is a value obtained by hashing an IP address (global IP address) with a common hash function.

  In addition, content (for example, movies, music, etc.) data as shared information distributed from one node device 1 to another node device 1 is distributed to a plurality of node devices 1 participating in the content distribution system S. However, a unique (unique) number (hereinafter referred to as “content ID”) is assigned to each piece of content data.

  Then, the content ID has the same length as the node ID (for example, 128 bits). For example, when a keyword such as a content name (content title) or content outline information (summary) obtains the node ID. And the node ID that is hashed by a common hash function (that is, placed in the same ID space as the hash value of the IP address of the node device 1) and closest to the hash value (for example, the higher-order digits match more). The node device 1 that has the content holds link information (IP address of the content holding node) to the node device 1 that holds the content data (hereinafter referred to as “content holding node”). The content holding nodes are distributed and arranged by an input server (not shown). As a result, the content data can be distributed on the content distribution system S without any bias. Note that even if the content data is different, it is assumed that the same keyword (for example, the name of the content) is used. In this case, the hash value is the same to avoid the same hash value. The keyword may be, for example, a combination of content name and copyright information (for example, performer name, director name, original author name, singer name, composer name, or songwriter name).

  Thus, since the node ID and the content ID assigned to each node device 1 and each content data are generated by a common hash function, as shown in FIG. 2, there is no significant bias on the same ring-shaped ID space. Can be thought of as being scattered and present. This figure shows a node ID and content ID assigned in 32 bits. In the figure, a black dot indicates a node ID, a black diamond indicates a content ID, and the ID increases counterclockwise.

  Next, which node device 1 holds which content data is determined under a certain rule. In the present embodiment, the rule is that “a node device 1 that manages content data having a certain content ID is a node device 1 having a node ID close to that content ID”. Here, the definition of “close” does not exceed the content ID, and the difference between the content ID and the node ID is the smallest. In practice, each content data is managed by each node device 1. It is only necessary to be consistent when allocating. In the example shown in FIG. 2, based on this definition, the content IDa is managed by the node device 1 having a node ID close to the content IDa (hereinafter referred to as “node IDa”), and the content IDb is the content IDb. Managed by the node device 1 having a node ID close to IDb (hereinafter referred to as “node IDb”), and the content IDc has a node ID close to the content IDc (hereinafter referred to as “node IDc”). Managed by the device 1.

  Here, “management” does not mean that content data is held, but means “knows which node device 1 holds content data”. That is, in FIG. 2, the node device 1 having the node IDa knows which node device 1 holds the content data having the content IDa, and the node device 1 having the node IDb and the node having the node IDc. Similarly, the device 1 knows which node device 1 holds the content data having the content IDb and the content data having the content IDc. In this way, the node device 1 that knows which node device 1 holds certain content data is called the root node of the content data. That is, the node device 1 having the node IDa is the root node of the content data having the content IDa, and the node device 1 having the node IDb is the root node of the content data having the content IDb and has the node IDc. The node device 1 is a root node of content data having a content IDc. The node device 1 that holds content data is called a content holding node.

[1.2. Create routing table]
Here, an example of a method for creating a routing table used in DHT will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of how a routing table is created by DHT.

  First, as shown in FIG. 3A, the ID space is divided into several areas. Actually, about 16 divisions are often used, but in order to simplify the explanation, here, it is assumed that 4 divisions are used, and the ID is represented by a quaternary number having a bit length of 16 bits. An example in which the node ID of the node device 1N is “10230210” and the routing table of the node device 1N is created will be described.

(Level 1 routing)
First, if the ID space is divided into four areas, each area is represented by four numbers with different maximum digits "0XXXXXXX", "1XXXXXXX", "2XXXXXXX", "3XXXXXXX" (X is a natural number from 0 to 3, The same). Since the node ID of the node device 1N itself is “10230210”, the node device 1N exists in the area “1XXXXXXX” in the lower left in the figure. Then, the node device 1N appropriately selects the node device 1 that exists in an area other than the area where the node device 1 exists (that is, the area of “1XXXXXXX”), and the position information of the node ID, that is, the IP of the node ID Store the address in the level 1 table. FIG. 4A shows an example of a level 1 table. Since the second column indicates the node device 1N itself, it is not necessary to store the IP address.

(Level 2 routing)
Next, as shown in FIG. 3B, among the areas divided into four by the above routing, the area where the user exists is further divided into four, and further four areas “10XXXXXX”, “11XXXXXX”, “12XXXXXX”, “13XXXXXX” ". Then, similarly to the above, the node device 1 existing in an area other than the area in which it is present is appropriately selected, and the IP address which is the position information of the node ID is stored in the level 2 table. FIG. 4B is an example of a level 2 table. Since the first column indicates the node device 1N itself, it is not necessary to store the IP address.

(Level 3 routing)
Further, as shown in FIG. 3C, among the areas divided into four by the above routing, the area where the user exists is further divided into four, and further four areas “100XXXXX”, “101XXXXX”, “102XXXXX”, “103XXXXX” And divide. Then, similarly to the above, the node device 1 existing in an area other than the area in which it is present is appropriately selected, and the IP address which is the position information of the node ID is stored in the level 1 table. FIG. 4C is an example of a level 3 table. Since the third column shows the node device 1N itself, it is not necessary to store the IP address, and the second column and the fourth column are blank because there is no node device in the area.

  In this way, all the 16-bit IDs can be covered by creating the routing table as shown in FIG. As the level goes up, white space becomes more noticeable in the table.

  All the node devices 1 each create and own the routing table created according to the method described above.

[1.3. Content data search method]
Next, an example of a search method for the node device 1 that holds content data will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a state in which the node device 1 holding content data is searched by DHT.

  Here, a node device 1-1 having a node ID “12003030” (hereinafter, a node device that searches for content data and requests reception of content data is referred to as a “request node”) has a content ID “31330012”. A procedure for searching for content data having “” will be described.

  The request node 1-1 refers to the level 1 table of the routing table held by the request node 1-1 and inquires the node device having the node ID in the same area as the content ID “31330012” about the location of the content. Request information as inquiry information (hereinafter referred to as “inquiry message”) is transmitted. That is, since the content ID “31330012” is the area of “3XXXXXXX”, the node device 1 belonging to the area of “3XXXXXXX” knows the IP address (that is, the IP address is stored in the routing table held by itself). An inquiry message is transmitted to the node device 1-2 in which the address is stored. Thus, the inquiry message includes a content ID that is unique identification information corresponding to the content, and this content ID is used as destination identification information in the inquiry message.

  According to the example shown in FIG. 5, since the IP address of the node device 1-2 whose node ID is “30100000” is stored in the routing table of the request node 1-1, the request node 1-1 has the node ID An inquiry message is transmitted to the node device 1-2 with “30100000”.

  Next, the node device 1-2 that has received the inquiry message determines whether or not the inquiry message is a message addressed to the own node device 1-2. Whether the message is addressed to the own node apparatus 1-2 is determined based on the destination identification information. Specifically, it is determined whether the destination identification information is close to the identification information of the own node device 1-2. That is, with respect to the destination identification information, the identification information of the closest node device from the identification information of the node device stored in the routing table held by the node device 1-2 itself is itself or other It is determined whether it is a node device. Since the identification information of the other node device is closer to the destination identification information than the identification information of the own node device 1-2, the node device 1-2 itself holds the node device 1-2. Referring to the level 2 table of the routing table, among the node devices 1 belonging to the “31XXXXXX” area, the inquiry message is transferred to the node device 1-3 (node ID “31012001”) that knows the IP address. To do.

  As described above, when the transfer of the inquiry message proceeds in the manner of adapting the digit of the content ID in order from the top and finally reaches the node device 1-5 that manages the content data, that is, the root node, the route The node searches the content ID “31330012” included in the inquiry message from index information described later managed by itself, and obtains the IP address and the like of the node device 1 that owns the content data as the request node 1. Reply to -1.

  In this way, the request node 1-1 receives and knows the location information of the content data with the content ID “31330012” from the root node 1-5, that is, the IP address of the held node device 1, and holds the hold. The content data is downloaded and acquired from the node device 1 that has been processed.

[1.4. How to register content data]
In the content distribution system S having such a configuration, for example, a method when a certain node device 1 publishes new content data so that it can be seen by other node devices on the content distribution system S will be described. This node device 1 serves as a content holding node as an information storage node device that stores and holds content data.

  The content holding node obtains a content ID from the content title or the like, and sends a registration message toward the node device having the same node ID as the content ID (whether or not this node device actually exists at this time). Send. Then, this registration message is also transferred one after another according to the routing table in the same manner as the inquiry message, and when the node is transferred to the node device 1 having the node ID closest to the content ID included in the registration message, the node When the device 1 determines that there is no other destination node device, the device 1 determines that the node device 1 itself should be the root node of the content, and the content ID and auxiliary information (title) included in the inquiry message. , Attribute information such as genre, copyright information such as director name) and the IP address of the content holding node are stored as index information.

  Furthermore, in the present embodiment, even in a node device in the middle of a route along which the registration message is transferred to the root node, the index information such as the content ID, auxiliary information, and content holding node IP address included in the inquiry message is cached. Such a node device is called a cache node. Thus, before the root node receives the inquiry message, the cache node returns the IP address of the content holding node to the request node that inquired about the location of the content when the inquiry message is transferred to the cache node earlier. It becomes possible.

  When transferring the registration message, the cache node normally holds only the index information based on the inquiry message as described above.

  Therefore, in FIG. 6, when the content holding node transmits a registration message including index information, the node device 1 that has received this functions as a cache node (1) by holding the index information. The cache node (1) transfers the registration message. The node device 1 that has received the registration message functions as a cache node (2) by holding the index information. The cache node (2) transfers the registration message. The node device 1 that has received the registration message functions as a root node by holding the index information. In FIG. 6, the two node devices between the content holding node and the root node function as cache nodes. However, the present invention is not limited to this, and the number of cache nodes and all transferred node devices are not limited thereto. Whether or not to be a cache node can be freely determined in the content distribution system S.

[1.5. Content Data Search Method and Registration Method According to Node Device Status]
Here, the content data search method and registration method according to the state of the node device 1 will be specifically described with reference to FIG. FIG. 7 is a diagram for explaining a content data search method and registration method according to the state of the node device 1 of the content distribution system S in the present embodiment.

  The node device 1 determines whether the node device 1 is in the first state or the second state, as will be described later. The node device 1 is provided with a communication control unit that performs control related to communication and an output control unit that performs control for outputting content data, and the first state is the output control unit in the node device 1. There is a possibility that content data may be requested from the communication control means in the node device 1, and the second state is a state in which content data is never requested. When the node device 1 is in the second state, the communication control means is in a state in which no content data is exchanged with the output control means, so the processing load on the communication control means is reduced. In particular, when the node apparatus 1 is connected to the network by a modulation system line such as RADSL, the downlink line is not used, so that the uplink speed is increased and other node apparatuses are connected. The transmission of content data to 1 becomes faster.

  Therefore, in the content distribution system S according to the present embodiment, a content data search method and registration method corresponding to the state of the node device 1 are performed.

  In FIG. 7, it is assumed that the node devices 1 with node IDi, IDj, and ID1 are content holding nodes having content data with content IDa, and the node device 1 with node IDa is a root node.

  In such a state, when the node device 1 with the node ID m holds content data with the content IDa, a registration message is transmitted to the root node as a content holding node that holds the content IDa. As shown in FIG. 7, the registration message includes a message identifier P indicating that it is a registration message, and a content ID a of retained content data that is information about the retained content data (here, the content ID is “102938576789 ”, The IP address that is the location information of the node device 1 (here,“ 24.56.1.1 ”), and the state of the node device 1 (here, the node device of the node ID m) 1 is assumed to be in the second state).

  As described above, the registration message transmitted from the node device 1 having the node IDm is notified to the root node, which is the node device 1 having the content IDa, via the node device 1 having the node IDk, the node IDh, and the node IDc. The root node registers the information included in the registration message notified in this way as index information as shown in FIG.

  Thereafter, when a content request message related to the content IDa is notified from the node device 1 of the node IDe, the root node of the content IDa, as shown in FIG. The distribution source information that is position information and status) is notified to the node device 1 of the node IDe.

  The node device 1 of the node IDe that has received the distribution source information searches the content holding node in the second state from the distribution source information. If there is a content holding node in the second state (in this case, the content holding node with node ID m corresponds), a content request is made to this content holding node, and distribution of content data with content IDa is received.

  As described above, according to the content distribution system S in the present embodiment, since the content distribution can be received from the content holding node having a small processing load on the communication control unit, the content holding node in the state receiving the content distribution can receive the content distribution. By receiving the content distribution, an overload on the content holding node can be avoided as much as possible. In addition, when the content holding node is connected to the network by a modulation system line such as RADSL, the downstream line is not used in the second state, so that the uplink speed is increased. , The transmission of content data to the request node becomes faster.

  In the above configuration, the root node notifies all the content holding nodes of the content ID related to the content request. However, if there is at least one content holding node in the second state, the content in the second state Only the IP address of the holding node may be notified.

[2. Explanation of Configuration of Node Device 1]
Next, the configuration and operation of the node device 1 will be described with reference to the drawings. FIG. 8 is a diagram showing a schematic configuration of the node device 1 in the content distribution system S according to the present embodiment.

  As shown in FIG. 8, the node device 1 includes a LAN side device 10 having a communication control circuit as communication control means and an AV side device 20 having an output control circuit as output control means. The LAN side device 10 and the AV side device 20 are provided separately from each other, and will be described later in detail.

  The LAN side device 10 mainly performs control related to communication with other node devices 1 participating in the content distribution system S. Communication with the other node devices 1 is performed via a router 2 connected by a LAN cable in a wired manner. Further, the LAN side device 10 transmits and receives data such as content data and other control data by performing wireless communication with the AV side device 20.

  The AV side device 20 mainly performs control related to output (reproduction) of content data. The content data is output by performing wireless communication with the LAN side device 10 to receive the content data from the LAN side device 10 and converting the content data into a video signal or an audio signal, and then the display 159 and the speaker 162. This is done by outputting from That is, a display 159 and a speaker 162 are connected to the AV-side device 20 by wire, and the AV-side device 20 controls the display 159 to display the content video, and the content sound from the speaker 162. Control to output. Furthermore, the AV side device 20 is configured to be able to perform infrared communication with a remote control 155 that can be operated by the user, and the user operates the remote control 155 to output content data and the like. Can be done.

  As described above, in the node device 1 according to the present embodiment, the communication control unit and the output control unit are provided independently, so that the communication control unit continues to operate even when the output control unit is not operating. Thus, the stability of the content distribution system S can be improved.

  That is, since the communication control means continues to operate regardless of the operation of the output control means, it becomes possible to participate in the content distribution system S continuously. Therefore, when the node device 1 functions as a content holding node, communication is not interrupted by stopping the operation of the communication control means during the distribution of the content. Further, when the node device 1 functions as a root node, it is not necessary to move the root node function to another node device 1 in the content distribution system S by stopping the operation of the communication control means. Furthermore, there is no need to re-edit the routing table in the node device 1.

  By the way, in a conventional content distribution system, when a node device is installed in a home, a terminal device such as a router is connected to a telephone line or an optical fiber cable disposed in a home entrance or kitchen, and the terminal device is connected to the terminal device. Node devices were connected by cables (for example, LAN cables).

  However, when the distance between the position of the terminal device connected to the telephone line or the optical fiber cable is far from the position of the node device, a long cable must be used, and the wiring work is complicated. Moreover, in order to wire the cable inconspicuously, a dedicated member is required, and the wiring work is further complicated.

  Therefore, it is conceivable to eliminate the complexity of the wiring work as described above by wirelessly connecting the terminal device and the node device. For example, when a terminal device and a node device are connected by a wireless LAN, a cable between the terminal device and the node device is not required by using a wireless LAN router as the terminal device and attaching a wireless LAN card to the node device. To do.

  However, when the terminal device and the node device are connected wirelessly in this way, a large amount of content data is transmitted and received wirelessly, resulting in a decrease in throughput with other node devices. There is a fear. That is, the amount of data per unit time that can be transmitted and received by wireless communication is small compared to the amount of data that can be transmitted and received by wired communication, and communication between node devices depends on the transmission and reception capabilities in the wireless communication part. become. In particular, when the node device 1 functions as a content holding node, when content data is transmitted to a plurality of request nodes at the same time, the throughput in the wireless part is greatly reduced.

  Therefore, the node device 1 in the present embodiment is configured such that the communication control unit and the output control unit are provided separately, and the communication control unit and the output control unit communicate wirelessly. A content holding node function, a cache node function, and the like are provided not on the output control means side but on the communication control means side. Therefore, it is possible to dispose the communication control unit and the output control unit at some distance while suppressing a reduction in throughput in the wireless portion.

[2.1. Description of the configuration of the LAN side device 10]
Next, the configuration and operation of the LAN side device 10 will be described with reference to FIG.

  The LAN-side device 10 can be a general personal computer in addition to a dedicated computer. As shown in FIG. 9, the CPU 101 and a rewritable main memory that stores (stores) various programs as a communication control circuit. Communication between the first storage unit 102 as a storage device, the second storage unit 103 configured by an HDD (Hard Disk Drive) or the like for storing various data, and the other node devices 1 via the Internet 4 And a wireless communication interface 105 that communicates with the AV device 20 via a wireless line. These various components are connected to each other via a system bus 106. Has been. In the present embodiment, the CPU 101 and the first storage unit 102 constitute a control means 107. The network interface 104 is connected to the Internet 4 via the router 2.

  The LAN side device 10 is electrically operated by a power source supplied from a power source unit 108 separate from a power source unit 165 (see FIG. 10) in the AV side device 20 described later. As described above, the LAN side device 10 as the communication control unit has the communication control unit power source that operates independently of the output control unit power source. Therefore, for example, as compared with a node device in which the communication control means and the output control means do not operate independently, if the power supply for the communication control means in the communication control means is on, the power supply for the output control means in the output control means is Even in the off state, the user can continue to participate in the content distribution system S, and the content distribution system S can be stabilized. In addition, it is possible to dispose the communication control unit and the output control unit at some distance from each other while suppressing a reduction in throughput in the wireless portion.

(About the first storage unit 102)
The first storage unit 102 includes an OS program 110 for providing basic functions as a computer of the node device 1, a request node control program 111 for executing a function as a request node, and a root node. A root node control program 112 for executing a function, a content holding node control program 113 for executing a function as a content holding node, a cache node control program 114 for executing a function as a cache node, and wireless A wireless communication program 115 or the like for transmitting / receiving data to / from the AV device 20 via the communication interface 105 is stored. These are read by the CPU 101, and functions according to these programs are executed by the CPU 101. .

  Here, the OS program 110 is read and executed by the CPU 101, thereby performing basic functions of the computer that is the LAN side device 10 such as memory management such as the first storage unit 102 and the second storage unit 103. It makes it executable. Then, with the OS program 110 being executed by the CPU 101, the request node control program 111, the root node control program 112, the content holding node control program 113, the cache node control program 114, the wireless communication program 115, etc. It is read from the first storage unit 102 and executed.

  Note that the OS program 110, the request node control program 111, the root node control program 112, the content holding node control program 113, the cache node control program 114, the wireless communication program 115, and the like can be obtained from, for example, a server connected to the Internet 4. It may be downloaded to the first storage unit 102, or after being recorded on a storage medium such as a CD-ROM, it may be read into the first storage unit 102 via the drive of the storage medium.

  Further, the first storage unit 102 stores the above-described routing table in which identification information and position information of some of the node devices 1 among the plurality of node devices 1 constituting the content distribution system S are associated, It functions as a routing table storage means. Further, the first storage unit 102 functions as a content data distribution source information storage unit that stores content data distribution source information received by a first content data distribution source information reception unit described later.

(About the second storage unit 103)
The second storage unit 103 serves as content storage means for storing content data input from an input server (not shown) that inputs content data to the content distribution system S and a copy of content data received from a content holding node. Content storage area.

(Regarding the control means 107)
The control means 107 is composed of the CPU 101 and the first storage unit 102 as described above, and the CPU 101 reads out and executes the various programs 110 to 115 stored in the first storage unit 102, so that the entire node device 1 is controlled. Centralized control and inquiry message transmission means, second content data distribution source information reception means, content distribution terminal device selection means, content distribution request means, distribution content reception means, message destination determination means, message transfer means, 1 content data distribution source information reception means, content data distribution source information return means, distribution source information notification means, content distribution means, wireless communication means, information reception means, setting state determination means, content data output supply means, content data output regulation It functions as a control means.

  When the CPU 101 executes the request node control program 111, an inquiry message transmission unit, a second content data distribution source information reception unit, a content distribution terminal device selection unit, a content distribution request unit, a distribution content reception unit, a message destination determination As a first content data distribution source information receiving unit, a content data distribution source information return unit, a message destination determination unit, a message transfer unit, etc. Further, when the CPU 101 executes the content holding node control program 113, the CPU 101 controls the cache node as a distribution source information notification unit, a content distribution unit, a message destination determination unit, a message transfer unit, and the like. By executing the program 114, it functions as a content distribution unit, a message destination determination unit, a message transfer unit, etc., and when the CPU 101 executes the wireless communication program 115, it functions as a wireless communication unit, a setting state determination unit, etc. It has become.

(Inquiry message sending means)
Based on the content data selection information transmitted from the AV side device 20, the inquiry message transmission means transmits an inquiry message to the root node that manages the information of the content holding node that holds the content data.

(Distributed content receiving means)
The distributed content receiving means has a function of receiving content data distributed from other content holding nodes. Distribution of the content data from the content holding node is stored and distributed in the content body transmission message as fragment data in which the content data is divided by a predetermined size (cut size). As shown in FIG. 20 (c), the content body transmission message stores an identifier CD indicating the content body transmission message, a fragment data size (frag_size), and a fragment data serial number (fragment number). At the same time, content fragment data is stored in the main body. The distribution content receiving means detects the identifier of the message transmitted from the content holding node via the Internet 4 to determine that the message is the content main body transmission message, and the content fragment included in the content main body transmission message. Data is stored in the second storage unit 103.

(About message destination determination means)
The message destination determination unit determines whether or not the received message is addressed to the own node device 1 based on the destination identification information of the message received via the network and the routing table. The message determined by the message destination determination means includes a participation request message for the node device to participate in the content distribution system S, a registration message for the content holding node to register index information in the root node, and a content holding node in the root node Inquiry messages for inquiring the location information of

  To determine whether or not the received message is addressed to the own node device 1, the destination node ID included in the message (hereinafter also referred to as “destination identification information”) is extracted and stored in the first storage unit 102. Based on the routing table, the control means 107 described later makes a determination. That is, when a participation request message, a registration message, or the like is received via the network interface 104, the message destination determination unit compares the destination identification information included in the received message with the node ID stored in the routing table, and determines the message. If it is determined that the node ID on the routing table closest to the included destination identification information is the node ID of the own node device 1, it is determined that the message is addressed to the own node device 1.

(About message transfer means)
When the message transfer means determines that the message received via the network is not addressed to the own node apparatus 1, the message transfer means determines the position of the transfer destination node apparatus 1 based on the destination identification information of the received message. Information is taken out from the routing table, and the received message is transferred to the node device 1 of this position information. Specifically, the destination identification information included in the received message is compared with the node ID stored in the routing table, and the next level (for example, upper four levels) that matches the destination identification information included in the message. If the digits are the same, the IP address corresponding to the node ID of the upper fifth digit) is taken out, and the received message is transferred to the IP address.

(About setting information judgment means)
The setting information determination unit determines a state set by a state setting unit described later in the output control unit. For example, it is determined that the power supply for the output control means is in the first state, and is determined to be in the second state when the power supply for the output control means is in the off state. Further, it is determined that the state is the second state according to the second operation information transmitted by the second operation information transmitting unit described later in the output control unit. Further, the determining means determines that the first content data output mode is set as the mode set by the mode setting means (to be described later) in the output control means, and determines that the state is the first state, and outputs the second content data. When the mode is set, it is determined that the state is the second state.

(Distributor information notification means)
When the content data is accumulated in the content data accumulation area of the second storage unit 103, the distribution source information notifying means sends the IP information that is the location information of the own node device 1 to the predetermined node device 1 arranged on the Internet 4. Content data including an address, information indicating whether a state determined by a determination unit (to be described later) in the output control unit is the first state or the second state, and information (content ID, auxiliary information, etc.) regarding the content data The distribution source information is notified (transmitted) to the root node as a registration message.

  Here, for the notification to the root node, the distribution source information notifying unit calculates the content ID from the title of the content data stored in the second storage unit 103, and has the node ID closest to the content ID from the routing table. A registration message is transmitted to the node device 1. Thereafter, the registration message is transferred to the root node.

(First content data distribution source information receiving means)
The first content data distribution source information receiving means is arranged on the Internet 4 and from the content holding node holding the content data, the position information of the content holding node and whether the content holding node is in the first state or not Content data distribution source information including information indicating whether the status is present and information related to the content data is received.

  Then, the first content data distribution source information receiving unit stores the received content data distribution source information as index information in the content data distribution source information storage unit of the first storage unit 102.

(About content data distribution source information return means)
When the content data distribution source information return means receives an inquiry message, that is, a transmission request for content data distribution source information, from a request node arranged on the Internet 4, the content data distribution source information return means It is determined whether or not index information for the inquired content data is stored. If the index information is stored, the index information is extracted and transmitted to the request node as content data distribution source information.

(Second content data distribution source information receiving means)
In the second content data distribution source information receiving means, the position information of the content holding node that holds the content data from the root node or the cache node arranged on the Internet 4 and the state of the content holding node are the first state. Or content data distribution source information including information indicating whether the state is the second state and content data information is received.

(About content distribution node device selection means)
When the content distribution node device selection unit determines that the content data distribution source information received by the second content data distribution source information reception unit includes two or more node devices 1 that hold the same content data, The node device 1 is configured to be selected with priority.

(About content distribution request means)
The content distribution request unit requests the node device 1 selected by the content distribution node device selection unit to distribute the content data. The inquiry message transmission unit and the content distribution request unit constitute a first operation control unit.

(About content data distribution source information storage means)
The content data distribution source information storage unit stores the content data distribution source information received by the first content data distribution source information reception unit in the content data distribution source information storage unit of the first storage unit 102.

(About content data distribution source information return means)
When the content data distribution source information return means receives a transmission request for the content data distribution source information from the request node arranged on the Internet 4, the content data distribution source information in the second state is stored in the content data distribution source information storage means. If it is stored, the content holding node in the second state is preferentially selected, and the selected content data distribution source information is returned to the requesting node that requested it.

(About the first operation control means)
The first operation control means performs predetermined communication with another node device 1 in accordance with first operation information transmitted by a first operation information transmission means (to be described later) in the output control means. For example, a node device that satisfies a predetermined condition is determined from the identification information of the content data selected according to the content data selection information transmitted from the output control means and the identification information of the node device stored in the routing table, and determined. An inquiry message for requesting delivery of the selected content data is transmitted to the selected node device.

(About catalog receiving means)
The catalog receiving means accesses an input server (not shown), requests and acquires a list of contents that can be distributed in the content distribution system S (hereinafter referred to as “catalog”).

(About system participation request means)
The system participation requesting means stores position information of a predetermined node device (hereinafter referred to as “contact node”) stored in the first storage unit 102 in order to cause the node device 1 to participate in the content distribution system S. It has a function of taking out and transmitting a participation request message to this contact node.

(Wireless communication means)
The wireless communication means is used to perform wireless communication with the AV side device 20. The wireless communication means includes information receiving means for receiving various information from the AV side device 20, content data output supplying means for supplying the received content data to the AV side device 20, and content data by the content data output supplying means. It functions as content data output restriction control means for restricting supply of content.

  This information receiving means receives power supply state information relating to the power supply state in the AV side device 20, content data selection information relating to content selection in the AV side device 20, and the like.

  Further, the content data output supply means, when it is determined by the setting state determination means described above that the AV side device 20 is in the ON state to output the content data, the content data received by the distribution content data reception means, It has a function of supplying to the AV side device 20. Note that, as described above, since the LAN side device 10 and the AV side device 20 are connected wirelessly, this content data output supply means is also connected to the AV side device 20 wirelessly. be able to.

  Further, when it is determined that the content data output restriction control unit is in the off state, the content data output regulation unit causes the content data output supply unit to supply the content data output supply unit to the AV side device 20. It has a function to perform control to regulate. Therefore, when the output control unit is set to the second state, the communication control unit regulates the supply of content data, so that the processing load on the communication control unit and the output control unit can be reduced.

(About the setting status determination means)
The setting state determination unit has a function of determining a state set in the AV side device 20 based on the received power state information regarding the power state in the AV side device 20. In particular, in the present embodiment, when the power supply unit 165 in the AV side device 20 is in the on state, the setting state determination means is the first state in which the state set by the AV side device 20 outputs the content data. When the power supply unit 165 in the AV side device 20 is in the off state, it is determined that the state set by the AV side device 20 is the second state in which no content data is output. It becomes. Further, the setting state determination means, as will be described later, when reproduction from a disk drive (not shown) in the AV side device 20 is not selected, the state set by the AV side device 20 displays the content data. If the playback from the disk drive in the AV side device 20 is selected, the state set by the AV side device 20 is the second state in which content data is not output. It is determined that it is in a state. A disk drive such as a CD may be in the LAN side device 10. In this case, for example, when the reproduction from the disk drive in the LAN side device 10 is not selected, the setting state determination unit determines that the state is the first state in which the content data is output. When playback from a disk drive is selected, it is determined that the content data is not output in the second state.

[2.2. Description of configuration of AV side device 20]
Next, the configuration and operation of the AV device 20 will be described with reference to FIG.

  The AV device 20 can be a general personal computer in addition to a dedicated computer. As shown in FIG. 10, the CPU 151 and a rewritable main memory that stores (stores) various programs as output control means. A first storage unit 152 as a storage device, a second storage unit 153 composed of an HDD or the like for storing various data, a wireless communication interface 154 for performing wireless communication with the LAN side device 10 described above, A remote controller 155 that transmits and receives a predetermined infrared signal to remotely operate the AV device 20 by the user, an infrared port 156 for communicating with the remote controller 155 by infrared, and the AV device 20 can be operated by the user Operation switch 157, infrared port 156 and peripheral device control chip 158 for controlling operation switch 157, and image data from CPU 151 A video chip 160 for writing to an internal video memory (not shown) and displaying the data written to the video memory on a display 159, which will be described later, and a sound source such as an FM sound source or a Wave Table sound source, and an audio signal to a speaker And a sound source chip 161 that outputs sound waves from the speaker 162 by outputting to 162, and these various components are connected to each other via a system bus 163. In the present embodiment, the CPU 151 and the first storage unit 152 constitute a control unit 164.

  Further, the AV side device 20 is electrically operated by a power source supplied from a power source unit 165 separate from the power source unit 108 in the LAN side device 10 described above. As described above, the AV side device 20 as the communication control means has the power supply for the output control means that operates independently of the power supply for the communication control means. Therefore, for example, as compared with a node device in which the communication control means and the output control means do not operate independently, if the power supply for the communication control means in the communication control means is on, the power supply for the output control means in the output control means is Even in the off state, the function as the root node, the function as the content holding node, or the function as the cache node can be executed, and the content distribution system S can be stabilized. In addition, it is possible to dispose the communication control unit and the output control unit at some distance from each other while suppressing a reduction in throughput in the wireless portion.

(About the first storage unit 152)
The first storage unit 152 also has an OS program 170 for providing basic functions as a computer of the AV side device 20, a screen control program 171 for controlling the display 159, etc., and distributed content data A player program 172 for performing playback, a state management program 173 for managing various states such as power supply state and mode setting, a wireless communication program 174 for performing wireless communication with the LAN side device 10, and the like These are stored and read out by the CPU 151, and the function according to these programs is executed by the CPU 151.

  Here, the OS program 170 is read out and executed by the CPU 151, thereby performing functions related to input / output of the remote controller 155 and the operation switch 157, memory management of the first storage unit 152, the second storage unit 153, and the like. The basic function of the computer which is the AV side device 20 can be executed. Then, in a state where the OS program 170 is executed by the CPU 151, the screen control program 171, the player program 172, the state management program 173, the wireless communication program 174 and the like described above are read from the first storage unit 152 and executed. .

  Note that the OS program 170, the screen control program 171, the player program 172, the state management program 173, the wireless communication program 174, and the like are, for example, from the server connected to the Internet 4 via the LAN side device 10 or the like. It may be downloaded to the storage unit 152, or after being recorded on a storage medium such as a CD-ROM, it may be read into the first storage unit 152 via the drive of the storage medium.

(Regarding the control means 164)
As described above, the control means 164 includes the CPU 151 and the first storage unit 152. The CPU 151 reads out and executes the various programs 170 to 174 stored in the first storage unit 152, whereby the entire AV side device 20 is read. And a content output control unit, a first operation information transmission unit, a second operation information transmission unit, an operation processing unit, a mode setting unit, an operation detection unit, a state setting unit, a wireless communication unit, and a decoding unit, which will be described later. It functions as a display control means or the like.

  It should be noted that the CPU 151 executes the OS program 170 as operation detection means, operation processing means, etc., the CPU 151 executes the screen control program 171 as display control means, etc., and the CPU 151 executes the player program 172. As a decoding unit and content output control unit, the CPU 151 executes the state management program 173, as a state setting unit, and the CPU 151 executes the wireless communication program 174 as a wireless communication unit. , Each is supposed to work.

(About operation detection means)
The operation detection unit has a function related to input / output of the remote controller 155 and the operation switch 157 that can be operated by the user, such as an operation of selecting content data received by the LAN side device 10. That is, the operation detecting means detects an operation by the user.

(About state setting means)
The state setting means has a function of performing control related to the state of the AV side device 20, such as detecting whether the power supply unit 165 is in an on state or an off state. In other words, the state setting means sets either the on state in which the content data received from the LAN side device 10 is output or the off state in which the content data received from the LAN side device 10 is not output. . In the present embodiment, the case where the power is on is an example of the first state, and the case where the power is off is an example of the second state.

(About wireless communication means)
The wireless communication unit has a function of controlling the wireless communication interface 154 to transmit / receive data to / from the LAN side device 10. The wireless communication interface 154 in the present embodiment is a wireless communication interface that employs a wireless LAN (IEEE802.11a / b / g, etc.), but is not limited thereto.

  This wireless communication means has a function as supplied content data receiving means for receiving content data supplied from the LAN side device 10 when the LAN side device 10 is in the second state.

  Further, this wireless communication means indicates the power state of the AV-side device 20 when the power supply unit 165 changes from the off state to the on state, or when the power supply unit 165 changes from the on state to the off state. It also functions as power state information transmitting means for transmitting power state information to the LAN side device 10.

  Further, this wireless communication means, when an operation related to the first content data output mode or an operation related to the second content data output mode is performed by input / output of the remote controller 155 or the operation switch 157, this operation information Functions as first operation information transmission means and second operation information transmission means for transmitting the message to the LAN side device 10.

  The first operation information transmission unit transmits the first operation information corresponding to the operation to the communication control unit when an operation relating to the first content data output mode is detected by the operation detection unit. For example, the first operation information transmitting unit transmits the content data selection information to the communication control unit of the LAN side device 10 when the operation detecting unit detects an operation for selecting the content data received by the distribution content receiving unit. .

  When the operation relating to the second content data output mode is detected by the operation detection unit, the second operation information transmission unit transmits the second operation information corresponding to the operation to the communication control unit.

(Decoding means)
The decoding means decodes the content data encoded in the data format for streaming distribution for output (reproduction) to the speaker 162, the display 159, or the like.

(About content output control means)
The content output control means has a function of performing control to sequentially reproduce the content data received from the LAN side device 10, that is, the content packets received by the supplied content data receiving means. This content output control means realizes this function by operating the video chip 160 and the sound source chip 161, and converts the data converted into a predetermined content data format (for example, Wave format) by the decoding means to the sound source chip 161. After being converted into an audio signal or a video signal by the video chip 160, the audio signal is output to the speaker 162, or the video signal is output to the display 159 to reproduce the content data. Note that the content output control means including the decoding means described above can also be used. That is, the content output control means performs control to output the content data received by the above-described supply content data receiving means to the output means such as the display 159 and the speaker 162.

(Display control means)
The display control means has a function of controlling the video chip 160 and the display 159 to display content data and various information. In other words, the display control means can control how the content video and various types of information are displayed on the display 159.

  When image data is not distributed from the LAN side device 10, the display control means displays the image data stored in the first storage unit 152 or the second storage unit 153 in advance on the display 159. Also good.

(About operation processing means)
When an operation relating to the second content data output mode is detected by the operation detection unit, the operation processing unit performs processing corresponding to the operation. For example, as the second content data, the content data stored in the second storage unit 153, the content data read from a medium inserted in a disk drive (not shown) such as a DVD drive, etc. are the remote controller 155, etc. When the operation is selected by the user, this operation is detected, and reproduction control of these content data (output of video from the display 159 and output of sound such as sound from the speaker 162) is performed.

[3. Explanation of various processes]
Hereinafter, detailed operations of the node device 1, that is, the LAN side device 10 and the AV side device 20, will be described more specifically with reference to the flowcharts of FIGS.

  First, the operation of the LAN side device 10 in the node device 1 will be described. 11 is a flowchart showing a LAN side apparatus main process in the LAN side apparatus 10, FIG. 12 is a flowchart showing a retained content registration process in the LAN side apparatus 10, FIG. 13 is a flowchart showing a content request process in the LAN side apparatus 10, and FIG. Is a flowchart showing message processing in the LAN side device 10, FIG. 15 is a flowchart showing content body transmission message reception processing in the LAN side device 10, FIG. 16 is a flowchart showing participation request message reception processing in the LAN side device 10, and FIG. 18 is a flowchart showing a participation response message reception process in the LAN side device 10, FIG. 18 is a flowchart showing a routing table update process in the LAN side device 10, and FIG. 19 is a flowchart showing a LAN side device main process in the AV side device 20. Over DOO, FIG. 20 is a diagram showing a structure of each message.

(Main processing of LAN side device)
As shown in FIG. 11, when the power supply unit 108 of the LAN side device 10 is turned on, the control means 107 performs initial setting in the LAN side device 10 by executing the programs 110 to 115 (step S100). .

  Thereafter, the control means 107 takes out the IP address which is the position information of the contact node stored in the first storage unit 102, transmits a participation request message to the contact node (step S101), and starts a timer (for example, 10 seconds timer is started) (step S102).

  Next, the control unit 107 determines whether the state set by the setting state determination unit of the AV-side device 20 is a trigger for transition to the first state or a trigger for transition to the second state (steps S103 and S104). ).

  Here, the control is performed when the power supply for the output control means is changed from the off state to the on state, or when the setting is changed from the second content data output mode to the first content data output mode by the control means 164. It is determined that the means 107 is an opportunity to shift to the first state. In addition, when the power source for the output control unit is changed from the on state to the off state, when the second operation information is transmitted by the control unit 164, or from the first content data output mode to the second content data by the control unit 164. When the setting is changed to the output mode, the control means 107 determines that it is an opportunity to shift to the second state.

  Then, when the control means 107 determines that it is an opportunity to shift to the second state (step S103: Yes), the control means 107 determines that the AV-side device 20 has been changed to the second state, and the first storage unit The state is set in a predetermined area 102 (step S106). In this second state, the control means 107 does not transmit / receive data to / from the AV side device 20. For example, when the power supply for the output control means is in an off state, a saving mode for saving power consumption in the AV side device 20 is set.

  Further, when the control means 107 determines that it is an opportunity to shift to the first state (step S104: Yes), the control means 107 determines that the AV side device 20 has been changed to the first state and determines the first storage unit. The state is set in a predetermined area 102 (step S105). In this first state, the control means 107 transmits / receives data to / from the AV side device 20. That is, the normal operation mode is set.

  If it is determined that it is neither the trigger for transition to the second state (step S103: No) nor the trigger for transition to the first state (No at step S104), the control means 107 has expired the timer set in step S102. It is determined whether or not (step S107).

  When it is determined in step S107 that the timer has expired (step S107: Yes), or when the state has shifted to the first state (step S105), or has shifted to the second state (step S106), the control means 107 Performs a “retention content registration process” to be described later in order to register content data stored in the second storage unit 103 (hereinafter referred to as “retention content”) in the root node (step S108). When this registered content registration process is completed, the control means 107 activates a timer in the same manner as in step S102 (step S109).

  When it is determined in step S107 that the timer has not expired (step S107: No), or when the timer is activated in step S109, the control means 107 determines whether or not a content request operation has been performed (step S110). ). The detection of the content request operation is performed based on content data selection information transmitted from the AV side device 20 when an operation for selecting content data is performed in the AV side device 20.

  If it is determined that there has been a content request operation (step S110: Yes), the control means 107 requests the content holding node that distributes the content data according to the content data selection information to send the content data, which will be described later. "Request processing" is performed (step S111).

  When it is determined in step S110 that there is no content requesting operation (step S110: No), or when the content requesting process in step S111 is completed, the control means 107 is connected from another node device 1 via the network interface 104. It is determined whether or not the message is received (step S112).

  If it is determined in step S112 that a message from another node device 1 has been received (step S112: Yes), the control means 107 performs “processing for each message” on the received message (step S113).

  When the control means 107 determines in step S112 that a message from another node apparatus 1 has not been received (step S112: No), or when the received message processing in step S113 is completed, the control means 107 It is determined whether or not the content reception completion flag is 1 (step S114).

  When determining that the content completion flag is 1 (step S114: Yes), the control means 107 sets the content data reception completion flag to 0 (step S115), and reception from the other node device 1 is completed. The content data is delivered to the output control means of the AV side device 20 (step S116).

  On the other hand, when it is determined that the content completion flag is not 1 (step S114: No), or when the process of step S116 is completed, the control unit 107 proceeds to the process of step S103.

(About retained content registration process)
Next, with reference to FIG. 12, the “retained content registration process” (the process in step S108 described above) in the LAN side device 10 will be described.

  The control means 107 detects the number N of retained content stored in the second storage unit 103 and stores the detected retained content number N in the retained content number storage area of the first storage unit 102 (step S200). The counter is initialized (counter value i = 1) (step S201).

  Thereafter, the control means 107 transmits a registration message for registering the i-th content data to the root node, reflecting the current mode state to the root node (step S202). This registration message has a structure as shown in FIG. That is, the message identifier P indicating the registration message, the content ID of the content to be registered, the IP address of the own node device 1, and the state of the device (1: first state, 2: second state) are included in the registration message.

  When the process in step S202 is completed, the control unit 107 determines whether or not the counter value i is the same value as the content number N, that is, whether or not the process in step S202 has been repeated N times. (Step S204). When the counter value i is not equal to the content number N (step S204: No), the control means 107 increments the counter value i by 1 (step S203) and repeats the process of step S202. On the other hand, when the counter value i is the same value as the number of contents N, the control means 107 ends this retained content registration process.

(About content request processing)
Next, the details of the “content request process” (the process in step S111 described above) in the LAN side device 10 will be described with reference to FIG.

  The control means 164 of the AV side device 20 displays the catalog information received from the input server on the display 159, and then the desired content data is selected from the catalog information by the operation of the operation switch 157 by the user of the node device 1. Then, the content data selection information as the first operation information is transmitted to the control means 107 of the LAN side device 10. When the control means 107 receives the content data selection information from the AV side device 20 (step S110 in FIG. 11: Yes), the control means 107 calculates a content ID using a hash function from information regarding the content data corresponding to the content data selection information. Then, an inquiry message with the content ID as destination identification information is transmitted from the network interface 104 (step S300). As shown in FIG. 7, the inquiry message has an inquiry message identifier Q, a content ID as destination identification information, and an IP address as source location information (not shown).

  After transmitting the inquiry message, the control means 107 waits for the inquiry response message to be transmitted from the root node or the cache node (step S301). Upon receiving the inquiry response message, the control means 107 determines whether there are two or more content holding nodes in the content holding node list (index information) included in the inquiry response message, and whether there is a content holding node in the second state. Whether or not is checked (step S302). As shown in FIG. 20A, the inquiry response message includes an identifier QR indicating an inquiry response message, an IP address for each content holding node, and its state (whether the first state or the second state). (Not shown) and an IP address as location information of the transmission source.

  As a result of the investigation in step S302, if there is a content holding node in the second state in the holding node list (step S303: Yes), the control means 107 sends a content request message to the content holding node in the second state. Transmit (step S305). On the other hand, when there are no two or more content holding nodes in the holding node list or there is no content holding node in the second state (step S303: No), the control unit 107 determines that the content holding node in the holding node list A content request message for requesting the distribution of the content data is transmitted (step S304). As shown in FIG. 20B, the content request message has an identifier CR indicating that it is a content request message, a content ID, and an IP address as transmission source location information (not shown). .

  After transmitting the content request message, the control means 107 sets the content data reception completion flag in the content data reception completion flag area of the first storage unit 102 to 0 (step S306), and ends the content request processing.

(Processing for each message)
Next, with reference to FIG. 14, the details of the “process for each message” (the process in step S113 described above) in the LAN side device 10 will be described.

  The control means 107 determines whether or not the received message (hereinafter referred to as “received message”) is a content body transmission message (step S400). This determination is performed by determining whether or not the message identifier included in the received message is a CD.

  If it is determined that the received message is a content body transmission message (step S400: Yes), the control means 107 performs “processing upon reception of a content body transmission message” described later (step S403). On the other hand, if it is determined that the received message is not a content body transmission message (step S400: No), the control means 107 determines whether or not the received message is a content request message (step S401).

  If it is determined that the received message is a content request message (step S401: Yes), the control means 107 retrieves the requested content data from the second storage unit 103, and retrieves the requested content data to the request node that has transmitted the content request message. The content data is transmitted via the network interface 104 (step S404). On the other hand, if it is determined that the received message is not a content request message (step S401: No), the control means 107 determines whether or not the received message is a participation response message (step S402).

  If it is determined that the received message is a participation response message (step S402: Yes), the control means 107 performs “processing upon reception of a participation response message” described later (step S405). On the other hand, if it is determined that the received message is not a participation response message (step S402: No), the control unit 107 acquires the node device 1 that is the message transfer destination from the routing table stored in the first storage unit 102. Is performed (step S406). The acquisition processing of the transfer destination node device 1 is performed by comparing the destination identification information included in the received message with the node ID stored in the routing table.

  The control unit 107 determines whether or not the node device 1 that is the transfer destination of the message acquired in step S406 is addressed to the own node device 1 (step S407). Specifically, as a result of comparing the destination identification information included in the received message with the node ID stored in the routing table, the node ID on the routing table closest to the destination identification information included in the message is that of the own node device 1. If the node ID is determined, it is determined that the message is addressed to the own node device 1.

  If it is determined that the received message is addressed to the own node device 1 (step S407: Yes), the control means 107 determines whether or not the received message is a registration message (step S411). If it is determined that the received message is a registration message (step S411: Yes), the control unit 107 holds the content ID and the set of the IP address of the transmission source (publishing content holding node) contained in the received message. The node state (whether the state is the first state or the second state) is stored as index information in the index information storage area of the first storage unit 102 (step S412).

  If the control means 107 determines that the received message is not a registration message (step S411: No), the control means 107 determines whether the received message is an inquiry message (step S413). If it is determined that the received message is an inquiry message (step S413: Yes), the control means 107 searches the index information for the inquiry content ID included in the inquiry message. Then, the distribution node list including the IP address of the content holding node having the content data of the searched content ID is returned to the node device 1 that is the inquiry message transmission source (step S414). In addition to the IP address of the content holding node having the content data of the content ID, this distribution node list has the state of this content holding node (whether it is the first state or the second state).

  In step S414, the distribution node list including the IP address of the content holding node and its state (whether it is the first state or the second state) is returned to the node device 1 that sent the inquiry message. Among the content holding nodes having the content data of the inquiry content ID included in the inquiry message, when the content holding node in the second state is included, the content holding node is preferentially notified to the request node. It may be. This configuration is particularly effective when it is not possible to include a large number of content holding node information in the response message to the inquiry message.

  If the control means 107 determines in step S413 that the received message is not an inquiry message (step S413: No), it performs processing corresponding to the received message (step S415).

  On the other hand, if it is determined in step S407 that the received message is not addressed to the own node device 1 (step S407: No), the control means 107 determines whether or not the received message is a participation request message (step S408). If it is determined that the received message is a participation request message (step S408: Yes), the control means 107 performs “processing upon reception of a participation request message” (step S410), which will be described later, and the received message is not a participation request message. If determined (step S408: No), the received message is transferred to the transfer destination node device 1 via the network interface 104 (step S409). The transfer of the received message is performed by the control means 107 extracting the position information of the transfer destination node device from the routing table based on the destination identification information of the received message. Specifically, the destination identification information included in the received message is compared with the node ID stored in the routing table, and the node ID corresponding to the next level of the upper digit number level matching the destination identification information included in the message is supported. The IP address to be retrieved is taken out from the routing table, and the received message is transferred to the IP address.

  When the processes of steps S403 to S405, S409, S410, S412, S414, and S415 are completed, the control unit 107 performs a “routing table information update process” (step S416) described later.

(About content body transmission message reception processing)
Next, with reference to FIG. 15, the details of the content body transmission message reception process (the process of step S403 described above) in the LAN side device 10 will be described.

  When the received message is a content body transmission message, the control means 107 stores the content data fragment included in the message at a predetermined position in a predetermined area of the second storage unit 103 (step S500).

  Then, the control means 107 determines whether or not all pieces of content data have arrived (step S501). This determination is performed by comparing the serial number included in the content body transmission message with the overall size information included in the catalog information. That is, the serial number is added to the fragment size of the content data that can be transmitted by the content body transmission message, and when it is the same as the entire size information, it is determined that all the content data fragments have arrived.

  If it is determined that all pieces of content data have arrived (step S501: Yes), the content data reception completion flag in the content data reception completion flag area of the first storage unit 102 is set to 1 (step S502), and the content body transmission message The process at the time of reception ends. On the other hand, when it is determined that all pieces of content data have not arrived (step S501: No), the processing at the time of receiving the content body transmission message is similarly terminated.

(About participation request message reception processing)
Next, with reference to FIG. 16, the details of the participation request message reception process (the process in step S405 described above) to the LAN side device 10 will be described.

  When the received message is a participation request message, the control means 107 obtains the level of the table to be returned from the routing table stored in the first storage unit 102 based on the transfer count counter included in the participation request message. (Step S600). For example, when the value of the transfer counter is 4, level 4 in the routing table is the level of the table to be returned. Note that the participation request message is configured as shown in FIG. That is, it has an identifier JO which is a participation request message, a transfer counter (Relay counter), and an IP address as location information of a transmission source (not shown).

  Then, the control means 107 takes out a row of node IDs and IP addresses corresponding to the level of the routing table obtained in step S600 from the routing table, and takes them out in the participation response message to the transmission source node device 1 of the participation request message. The node ID and IP address for one column are inserted, and this participation response message is returned (step S601).

  Next, the control means 107 generates a participation request message obtained by incrementing the transfer number counter in the participation request message received in step S112 by one (step S602), and sends this participation request message to the transfer destination node device 1. Transfer (step S603). The transfer process to the transfer destination node apparatus 1 is a process of transmitting a participation request message to the IP address of the transfer destination node apparatus 1 obtained in S406.

(About participation response message reception processing)
Next, with reference to FIG. 17, the details of the participation response message reception process (the process in step S410 described above) to the LAN side device 10 will be described.

  When the received message is a participation response message, the control means 107 acquires the level number of the routing table from the value of the transfer number counter included in the participation response message (step S700). For example, when the value of the transfer counter is 4, level 4 in the routing table is the level of the table to be returned. As shown in FIG. 20 (f), the participation response message includes an identifier JR indicating that it is a participation response message, a transfer counter (Relay counter), a node ID for one column of the routing table, and these nodes. And an IP address in the node device 1 of the ID.

  Thereafter, the control means 107 writes the data for one column of the routing table included in the participation response message into the routing table of the own node device 1 as the same level data and stores it (step S701). For example, when the value of the transfer count counter is 4, data is written at the level 4 location in the routing table. When the process of step S701 ends, the control unit 107 ends the participation response message reception process.

(About routing table update processing)
Next, details of the routing table update process (the process of step S416 described above) in the LAN side device 10 will be described with reference to FIG.

  The control means 107 performs a random calculation so that the probability is 1/2 and becomes Yes, and determines whether or not the result of the calculation is Yes (step S800). If the calculation result is Yes (step S800: Yes), since all the messages include the node ID and IP address of the source or relay source node device 1, the control means 107 determines whether the source or relay source is the source. It is determined in which level of the routing table the IP address of the node device 1 should be entered (step S801). That is, the control means 107 compares the node ID of the source or relay source node device 1 with the node ID of its own node device 1 and determines to which upper digit it matches. Then, the level which is the upper digit number which does not match is obtained, and the row of the routing table corresponding to the level is obtained.

  The control unit 107 enters (registers) the node ID and the IP address of the source or relay source node device 1 in the row of the routing table obtained in step S801 (step S802). This entry deletes one node ID registered in the row of the routing table obtained in step S801 and the corresponding IP address, and the node ID of the transmission source or relay source node device 1 is added to the deleted location. This is done by registering an IP address. When the process of step S802 is completed, the control unit 107 ends the routing table update process.

(Main processing of AV side device)
Next, with reference to FIG. 19, the details of the main process in the AV side apparatus 20 will be described.

  As shown in FIG. 19, when the power supply unit 165 of the AV side device 20 is turned on, the control means 164 performs initial setting in the AV side device 20 by executing the programs 170 to 174 (step S900). . At this time, the control unit 164 transmits power-on information to the effect that the power supply unit 165 is turned on to the control unit 107 of the LAN side device 10 via the wireless communication interface 154.

  When the initial setting of the AV side device 20 is completed, the control means 164 makes a catalog information transmission request to the control means 107 of the LAN side device 10 via the wireless communication interface 154. The control means 107 that has received the catalog information transmission request makes a request for catalog information to the input server via the network interface 104. Thereafter, the control means 107 displays the catalog information received from the input server on the display 159 (step S901).

  It waits for the user of the AV side device 20 to select content by operating the operation switch 157 or the remote controller 155 (step S902). When the user of the AV side device 20 selects content from the catalog, the control unit 164 transmits the content selection as content data selection information to the control unit 107 of the LAN side device 10 via the wireless communication interface 154 ( Step S903). Note that the operation of the operation switch 157 for the user of the AV side device 20 to select content from the catalog corresponds to the operation related to the first content data output mode. The content data selection information corresponds to the first operation information.

  The control unit 164 waits for the content data requested in step S903 to be transmitted from the LAN side device 10 (step S904). When the content data is transmitted from the LAN side device 10, the control means 164 outputs the content data to the display 159, the speaker 162, etc., and reproduces it (step S905). Thereafter, the control means 164 repeats the processing from step S901 to step S905.

  Further, in step 901 or step S902, the user of the AV side device 20 operates the operation switch 157 or the remote controller 155, so that the content is not selected from the catalog, but a DVD drive provided in the AV side device 20 or the like. When it is selected that content is reproduced from a medium inserted in a disk drive (not shown), the control means 164 performs control to reproduce the content from the medium by controlling the disk drive. Further, the control means 164 transmits information indicating that the content is reproduced from the disk drive to the control means 107 of the LAN side device 10 through the wireless communication interface 154 as second operation information.

  Here, although not shown in the flowchart, when the power supply of the power supply unit 165 is on, the power-on information is transmitted to the LAN side device 10 at a predetermined cycle and the power supply of the power supply unit 165 is turned off. In addition, power-on information is not transmitted. When detecting that the power-on information has not arrived for a certain period, the LAN-side device 10 knows that the AV-side device 20 has been turned off. The power-on information indicating that the power supply unit 165 is turned on is transmitted by the control means 164 to the control means 107 of the LAN side device 10 via the wireless communication interface 154.

  In this embodiment, after the operation switch is operated so that the power supply of the power supply unit 165 is turned on, power-on information is transmitted at a predetermined cycle, and the power supply of the power supply unit 165 is turned off. In this case, the power-on information is not transmitted. However, the present invention is not limited to this. For example, a power-on message indicating that the power supply unit 165 is turned on is transmitted, and the power supply unit 165 is turned off. It may be configured to transmit the power-off information to the effect. In other words, the power-off switch is not a hardware switch, but a soft switch (a configuration in which the on / off of the switch can be detected by software and the power-off can be commanded by software), and the power is turned off by the LAN. The power supply unit 165 may be turned off after notifying the side device 10. Thereby, also in the LAN side device 10, the state set in the AV side device 20 can be determined.

  In the present embodiment, information for determining whether the AV side device 20 is in the power-on state or the power-off state is transmitted to the LAN side device 10. An inquiry may be made to the apparatus 20, and if the inquiry is answered, it is determined that the power supply unit 165 is in a power-on state, and if there is no response to the inquiry, it may be determined that the power supply unit 165 is in a power-off state.

  As described above, the content distribution system S in the present embodiment can continue the operation of the LAN side device 10 even when the AV side device 20 is in a power OFF state or the like. Therefore, in a content distribution system having a plurality of node devices 1 distributed on the network, stability can be improved by suppressing participation and withdrawal of terminal devices.

  Further, the LAN device 10 and the AV device 20 are each provided with a CPU, a main storage device, and a power supply unit. However, the LAN device 10 and the AV device 20 are integrated, and the CPU, the main storage device, and the power supply unit are integrated. May be provided one by one and function as each means of the LAN side device 10 and each means of the AV side device 20 by a program.

It is a figure which shows an example of the connection aspect of each node apparatus in the content delivery system which concerns on this embodiment. It is explanatory drawing of ID space. It is a figure which shows an example of a mode that a routing table is produced by DHT. (A) An example of a level 1 table. (B) An example of a level 2 table. (C) An example of a level 3 table. (D) An example of a completed routing table. It is a figure which shows an example of a mode that the node apparatus 1 which is the holding | maintenance source of content data is searched by DHT. It is the figure which represented a mode that the registration message of a content holding node was transferred in the spanning tree shape. It is a figure for demonstrating the search method and registration method of content data according to the state of the node apparatus of the content delivery system in embodiment. It is a figure which shows the example of a schematic structure of a node apparatus. It is a figure which shows the example of schematic structure of the LAN side apparatus in this embodiment. It is a figure which shows the example of schematic structure of the AV side apparatus in this embodiment. The flowchart which shows the LAN side apparatus main process in a LAN side apparatus. The flowchart which shows the holding | maintenance content registration process in a LAN side apparatus. The flowchart which shows the content request process in a LAN side apparatus. The flowchart which shows the process for every message in a LAN side apparatus. The flowchart which shows the process at the time of the content main body transmission message reception in a LAN side apparatus. The flowchart which shows the participation request message reception process in a LAN side apparatus. The flowchart which shows the participation response message reception process in a LAN side apparatus. The flowchart which shows the routing table update process in a LAN side apparatus. It is a flowchart which shows the AV side apparatus main process in AV side apparatus. It is a figure which shows the structure of each message.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Node apparatus 4 Internet 10 Router 10 LAN side apparatus 20 AV side apparatus 107 Control means of LAN side apparatus 164 Control means of AV side apparatus S Content distribution system

Claims (14)

The terminal device in a content distribution system, which is composed of a plurality of terminal devices distributed on a network and transmits / receives content data between the terminal devices,
Communication control means for controlling communication,
Output control means that is provided independently of the communication control means and performs control to output content data;
The communication control means includes
Distribution content receiving means for receiving content data distributed from another terminal device;
Routing table storage means for storing a routing table that associates identification information and position information of some of the plurality of terminal devices;
Message destination determination means for determining whether or not the received message is addressed to its own terminal device based on destination identification information of the message received via the network and the routing table;
When the message destination determination means determines that the message received via the network is not addressed to the terminal device itself, the location information of the transfer destination terminal device is obtained based on the destination identification information of the received message. A message transfer means for transferring the received message to the terminal device of this location information,
A setting state determination unit that determines a state set by the state setting unit included in the output control unit ;
A power supply for communication control means for supplying power to the communication control means;
Content data storage means for storing the content data;
When the content data is stored in the content data storage means, the position information of the own device and the state determined by the setting state determination means are stored in the communication control means in a predetermined terminal device arranged on the network. notification information indicating which never second state that does not require either the content data is first state that may require content data, the content data distribution source information including, the information on the content data for Distribution source information notification means for
The output control means includes
The state of the output control means, and before Symbol first state, said state setting means for setting any of said second state,
Supply content data receiving means for receiving the content data supplied by the communication control means in the first state;
Content output control means for performing control to output the content data received by the supplied content data receiving means;
Power supply for output control means independent of the power supply for communication control means, the power supply state to the output control means is turned on or off, and
Have
The setting state determination unit of the communication control unit determines that the first state is in the on state when the power source for the output control unit is on, and the second state when the power source for the output control unit is in the off state. A terminal device that determines that The communication control means includes
Position information of the terminal device, information indicating whether the terminal device is in the first state or the second state, from other terminal devices that are arranged on the network and hold content data; First content data distribution source information receiving means for receiving content data distribution source information including information about the content data;
Content data distribution source information storage means for storing the content data distribution source information received by the first content data distribution source information reception means;
When the content data distribution source information transmission request is received from the other terminal device arranged on the network, the other one that holds at least the content of the content data distribution source information from the content data distribution source information storage unit 2. The terminal device according to claim 1, further comprising: content data distribution source information return means that extracts location information and status of the terminal device and returns the content data distribution source information to the terminal device that requested the content data distribution source information. . The communication control means includes
Whether the position information of the other terminal device holding the content data from the predetermined terminal device arranged on the network and the state of the other terminal device are the first state or the second state A second content data distribution source information receiving means for receiving content data distribution source information including:
When it is determined that there are two or more terminal devices holding the same content data in the content data distribution source information received by the second content data distribution source information receiving means, the terminal device in the second state is given priority. Content distribution terminal device selection means to select; content distribution request means to request distribution of content data to the terminal device selected by the content distribution terminal device selection means;
The terminal device according to claim 2, comprising: The communication control means includes
Position information of the terminal device, information indicating whether the terminal device is in the first state or the second state, from other terminal devices that are arranged on the network and hold content data; First content data distribution source information receiving means for receiving content data distribution source information including information about the content data;
Content data distribution source information storage means for storing the content data distribution source information received by the first content data distribution source information reception means;
When a content data distribution source information transmission request is received from another terminal device arranged on the network, the content data distribution source information in the second state is stored in the content data distribution source information storage means. In the case, the content data distribution source information return means that preferentially selects the terminal device in the second state and returns the selected content data distribution source information to the terminal device that has requested the selected content data distribution source information. The terminal device according to claim 1. The output control means includes
One of a first content data output mode for outputting content data received by the communication control means and a second content data output mode for outputting content data other than the content data received by the communication control means Mode setting means for setting the mode to
The setting state determining means of the communication control means is
When the first content data output mode is set as the mode set by the mode setting means, the first state is determined, and the second content data output mode is set. The terminal device according to claim 1, wherein the terminal device is determined to be in the second state. The output control means includes
An operation detection means for detecting an operation by a user;
A first operation information transmission unit that transmits first operation information corresponding to the operation to the communication control unit when an operation related to the first content data output mode is detected by the operation detection unit;
A second operation information transmission unit configured to transmit second operation information corresponding to the operation to the communication control unit when an operation related to the second content data output mode is detected by the operation detection unit;
An operation processing unit that performs a process corresponding to the operation when the operation relating to the second content data output mode is detected by the operation detection unit;
The communication control means includes
Having first operation control means for performing predetermined communication with the other terminal device according to the first operation information transmitted by the first operation information transmitting means;
The terminal apparatus according to claim 5, wherein the setting state determination unit determines that the state is the second state according to the second operation information transmitted by the second operation information transmission unit. When the operation detecting unit detects an operation of selecting content data received by the distribution content receiving unit, the first operation information transmitting unit transmits content data selection information to the communication control unit,
The first operation control unit of the communication control unit includes the terminal having a predetermined condition based on the identification information of the content data selected according to the content data selection information and the identification information of the terminal device stored in the routing table 7. The terminal device according to claim 6, wherein a device is determined, and content data inquiry information for requesting delivery of the selected content data is transmitted to the determined terminal device.   The terminal device according to claim 1, wherein the communication control unit is wirelessly connected to the output control unit.   The terminal device according to claim 1, wherein the communication control unit and the output control unit are housed in a separate housing.   The terminal device according to claim 1, comprising a communication control circuit as the communication control unit and an output control circuit as the output control unit.   The program for functioning a computer as each means in the terminal device of any one of Claims 1-9.   The program for functioning a computer as each means of the said communication control circuit in the terminal device of Claim 10, and the said output control circuit. A content distribution system comprising a plurality of terminal devices distributed on a network and transmitting / receiving content data between the terminal devices,
The terminal device
Communication control means for controlling communication,
Output control means that is provided independently of the communication control means and performs control to output content data;
The communication control means includes
Distribution content receiving means for receiving content data distributed from another terminal device;
Routing table storage means for storing a routing table that associates identification information and position information of some of the plurality of terminal devices;
Message destination determination means for determining whether or not the received message is addressed to its own terminal device based on destination identification information of the message received via the network and the routing table;
When the message destination determination means determines that the message received via the network is not addressed to the terminal device itself, the location information of the transfer destination terminal device is obtained based on the destination identification information of the received message. A message transfer means for transferring the received message to the terminal device of this location information,
A setting state determination unit that determines a state set by the state setting unit included in the output control unit ;
A power supply for communication control means for supplying power to the communication control means;
Content data storage means for storing the content data;
When the content data is stored in the content data storage means, the position information of the own device and the state determined by the setting state determination means are stored in the communication control means in a predetermined terminal device arranged on the network. notification information indicating which never second state that does not require either the content data is first state that may require content data, the content data distribution source information including, the information on the content data for Distribution source information notification means for
The output control means includes
The state of the output control means, and before Symbol first state, said state setting means for setting any of said second state,
Supply content data receiving means for receiving the content data supplied by the communication control means in the first state;
Content output control means for performing control to output the content data received by the supplied content data receiving means;
Power supply for output control means independent of the power supply for communication control means, the power supply state to the output control means is turned on or off, and
Have
The setting state determination unit of the communication control unit determines that the first state is in the on state when the power source for the output control unit is on, and the second state when the power source for the output control unit is in the off state. Content distribution system that determines that. An information processing method for the terminal device in a content distribution system that includes a plurality of terminal devices distributed on a network and transmits / receives content data between the terminal devices,
The terminal device
Communication control means for controlling communication,
A power supply for communication control means for supplying power to the communication control means;
An output control means that is provided independently of the communication control means and performs control to output content data;
A power supply for the output control means that is independent of the power supply for the communication control means and in which the power supply state to the output control means is turned on or off,
By the communication control means,
A delivery content receiving step of receiving content data delivered from another terminal device;
A routing table storage step for storing a routing table that associates identification information and position information of some of the plurality of terminal devices;
A message destination determination step for determining whether or not the received message is addressed to its own terminal device based on destination identification information of the message received via the network and the routing table;
If it is determined in the message destination determination step that the message received via the network is not addressed to the terminal device itself, based on the destination identification information of the received message, the location information of the transfer destination terminal device is stored in the routing table. A message transfer step of transferring the received message to the terminal device of this location information,
A setting state determination step for determining a state set by the state setting step executed by the output control means ;
A content data storage step for storing the content data;
When the content data storage step Oite the content data is stored, said the predetermined terminal devices located on a network, the positional information of the own device, the setup state determining state is the communication controlled by the decision step information indicating which never requested not second state in the first state is whether the content data that may require content data to means, the content data distribution source information including, the information on the content data run the, and the distribution source information notification step of notifying the,
By the output control means,
The state of the output control means, and before Symbol first state, said state setting step of setting any of said second state,
A supply content data receiving step of receiving content data supplied by the communication control means in the first state;
A content output control step for performing control to output the content data received by the supply content data receiving step;
Run
A terminal device that, by the setting state determination step , determines that the output control means power supply is in the first state when it is on, and determines that the output control means power supply is in the second state when the output control means power supply is off. Information processing method.

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