JP2006101175A - Network control device, network control method, and network control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network control device capable of surely distributing content, even when a relay function of one of the nodes contained in a network stops, without affecting the processings in nodes below the node, while improving the reliability of the network system itself. <P>SOLUTION: When controlling a node N contained in a network system NS including a server S and a plurality of nodes N constituting a plurality of hierarchies and connected to one another, wherein a content is distributed from the server S to the respective nodes N, it is checked whether a content relay function in a node located at the uplink with respect to any node N in the content distribution has stopped; and when the stop of the relay function is detected, control is performed so that the consumption speed of the content accumulated in the lower node N in the process executed in the node N is smaller than the consumption speed, before the relay function has stopped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to the technical field of a network control device, a network control method, and a network control program, and more specifically, distribution information distributed from a distribution source is connected to a lower layer while forming a plurality of hierarchies. The present invention belongs to the technical field of a network control device and a network control method for controlling a distribution mode in a network system that performs distribution while relaying in stages in a relay device, and a network control program used for controlling the distribution mode.

  In recent years, with the increase in the speed of home Internet lines, a network is constructed by connecting a plurality of personal computers, etc. in each home in the form of a tree, with one distribution device serving as a distribution source at the top. Accordingly, network systems that distribute so-called content such as music and movies as distribution information from the distribution apparatus are becoming common. In addition, what looked at the said network from the viewpoint of the connection mode is called "topology." In such a network, each of the distribution device and each personal computer constituting the network is generally referred to as a “node”.

As a document disclosing the conventional technique regarding the above-described network system, for example, there is Patent Document 1 shown below.
JP2003-169089

  In each node included in the conventional network system represented by the above-mentioned Patent Document 1, content transmitted from a higher-level node is temporarily stored in a buffer memory, and then reproduction processing in each node is performed. It is set as the structure used for. This is to absorb the influence of fluctuations in transmission speed on the Internet line constituting the distribution path in the network system. As the buffer memory, for example, a FIFO (First In First Out) such as a so-called ring buffer memory is used. A form of memory is used.

  On the other hand, in the network system described above, since each node constituting the network system is a personal computer or the like in the home as described above, it is on the distribution route regardless of whether or not the content is being distributed. The power switch may be turned off at any node. In this case, the content relay function is stopped for the lower nodes connected to the node whose power switch is turned off.

  Here, in the above network system, when the relay function at any node on the distribution path is stopped during the distribution of content, the topology including other nodes other than the node at which the relay function is stopped Reconstruction (that is, reconstruction of a distribution route from the distribution apparatus and resumption of distribution for a lower-level node directly connected to the node whose relay function is stopped) is executed.

  However, in the above-described topology reconstruction in the conventional network system, processing such as searching for the shortest path from the distribution apparatus and connection switching using the search result is necessary. Is temporarily interrupted. When the distribution is interrupted, the reproduction processing of the content stored in the buffer memory (in other words, consumption of data as the content stored in the buffer memory) is continued in the lower nodes. However, since the new content is not replenished in the buffer memory, the storage amount in the buffer memory gradually decreases, and in some cases, the content playback process in the lower node is interrupted. There was a problem that it was.

  The interruption of the reproduction process results in a decrease in the reliability of the network system itself when the relay function is stopped in any node included in the network system.

  Therefore, the present invention has been made in view of the above-described problems, and its purpose is to perform processing at a node below it even when the relay function is stopped at any node included in the network system. Network control apparatus and network control method for controlling the distribution mode in the network system so that the content can be reliably distributed while improving the reliability of the network system itself, and the network control apparatus An object of the present invention is to provide a network control program used for controlling distribution modes.

  In order to solve the above problem, the invention according to claim 1 is a distribution device that is a distribution information distribution source, and a plurality of relay devices that are connected to the distribution device while forming a plurality of hierarchies. A network control device that controls any one of the relay devices included in a network system in which the distribution information is distributed from the distribution device to each of the relay devices. Detection means such as a CPU for detecting whether the relay function of the distribution information in any of the relay apparatuses upstream in the distribution information distribution to the relay apparatus is stopped, and the relay function is stopped Unit time when the distribution information accumulated in the target relay device is consumed by being used for processing executed in the target relay device The unit time consumption is consumption per, and a consumption amount control means such as a CPU for controlling so that the relay function is less than the unit time consumption amount before stopping.

  Therefore, when the relay function in the relay device on the upstream side in the network system is stopped, control is performed so that the consumption per unit time of the distribution information stored in the downstream relay device is less than that before the stop. Therefore, while the distribution of the distribution information is interrupted, the network system itself is burdened with processing interruption or extreme processing delay in the downstream relay device due to the distribution information being consumed at the same speed as before the interruption. It can prevent without applying.

  In order to solve the above-mentioned problem, the invention according to claim 2 is the network control device according to claim 1, wherein the distribution information is image information, and the consumption control means is provided in the target relay device. In the buffer means for temporarily storing the image information, the rate at which the amount of image information is reduced by using the image information for the processing is higher than the rate at which the relay function is reduced before the relay function is stopped. The unit time consumption is reduced by slowing down.

  Therefore, in addition to the operation of the invention described in claim 1, the distribution information is image information, and the rate at which the amount of image information stored in the buffer means is reduced is slower than the rate before the relay function is stopped. Therefore, the unit time consumption can be reduced, so that the unit time consumption can be reduced with a simple configuration without performing complicated speed control processing.

  In order to solve the above-mentioned problem, according to a third aspect of the present invention, in the network control device according to the second aspect, the image information is moving image information composed of a plurality of still images, and the consumption control means Is configured to slow down the rate at which the accumulated amount is reduced by repeatedly outputting the same still image from the buffer means a plurality of times.

  Therefore, in addition to the operation of the invention described in claim 2, for the still images constituting the moving image information, the same still image is repeatedly output a plurality of times, thereby reducing the speed of reduction of the accumulated amount. The unit time consumption can be surely reduced by simple processing.

  In order to solve the above problem, the invention according to claim 4 is the network control device according to claim 1, wherein the distribution information is encoded image information, and the consumption control means The unit time consumption is reduced by making the decoding speed of the image information in the processing in the target relay apparatus slower than the decoding speed before the relay function is stopped.

  Therefore, in addition to the operation of the invention described in claim 1, the unit time consumption is reduced by making the decoding speed of the image information in the processing in the target relay apparatus slower than the decoding speed before stopping the relay function. Therefore, the unit time consumption can be surely reduced by simple processing.

  In order to solve the above-mentioned problem, according to a fifth aspect of the present invention, in the network control device according to the first aspect, the distribution information is moving image information composed of a plurality of still images, and the consumption control means Is configured to reduce the unit time consumption by making the display time of the still image longer than the display time before the relay function is stopped.

  Therefore, in addition to the operation of the invention described in claim 1, for still images constituting the moving image information, the display time of the still images is set longer than the display time before the relay function is stopped. Since the consumption amount is reduced, the unit time consumption amount can be surely reduced by simple processing.

  In order to solve the above-described problem, the invention according to claim 6 is the network control device according to any one of claims 1 to 5, wherein the distribution information includes a plurality of continuous unit distribution information, In addition, the unit delivery information at a preset position in the delivery information is empty unit delivery information in which the amount of delivery information provided for the processing is zero, and further, the unit relay information for the target relay device A return means such as a CPU for returning the unit time consumption in the target relay device to the same unit time consumption before the relay function is stopped after distribution is resumed; After the unit time consumption of the target relay device is restored, before the relay function is stopped before the relay function is stopped before the relay function is stopped. Only for every other of the relay devices except the relay device, further comprising a distribution control means such as a CPU to deliver the empty unit distribution information.

  Therefore, in addition to the operation of the invention according to any one of claims 1 to 5, all other relay devices other than the relay device located downstream of the relay device whose relay function is stopped before the relay function is stopped Only for the above, since the empty unit distribution information is distributed after the relay function is restored, the reproduction time axis in the above relay device gradually catches up with the reproduction time axis in the other relay device, and as a result, Regeneration occurring between the relay device and all the other relay devices due to the reduction in unit time consumption at the relay device downstream of the relay device whose relay function has stopped The deviation of the playback position on the time axis can be eliminated.

  In order to solve the above-described problem, the invention according to claim 7 is a distribution device as a distribution information distribution source, and a plurality of relay devices connected to the distribution device while forming a plurality of hierarchies. In the control method for controlling any one of the relay devices included in the network system in which the distribution information is distributed from the distribution device to each of the relay devices, target relay that is the relay device to be controlled A detection step of detecting whether or not the relay function of the distribution information in any of the relay devices upstream in the distribution information distribution to the device is detected; and it is detected that the relay function is stopped Is the amount of consumption per unit time when the distribution information accumulated in the target relay device is consumed by being used for processing executed in the target relay device. The much time consumption, including a consumption amount control step of controlling so that less than the unit time consumption before the relay function stops, the.

  Therefore, when the relay function in the relay device on the upstream side in the network system is stopped, control is performed so that the consumption per unit time of the distribution information stored in the downstream relay device is less than that before the stop. Therefore, while the distribution of the distribution information is interrupted, the network system itself is burdened with processing interruption or extreme processing delay in the downstream relay device due to the distribution information being consumed at the same speed as before the interruption. It can prevent without applying.

  In order to solve the above problem, the invention according to claim 8 is a distribution device that is a distribution information distribution source, and a plurality of relay devices that are connected to the distribution device while forming a plurality of hierarchies. , And a computer included in a network control device that controls any of the relay devices included in a network system in which the distribution information is distributed from the distribution device to each of the relay devices. Detecting means for detecting whether the relay function of the distribution information in any of the relay apparatuses upstream in distribution of the distribution information to the target relay apparatus as a device is stopped, and the relay function is stopped When it is detected that the distribution information accumulated in the target relay device is used for processing executed in the target relay device, it is consumed. The unit time consumption is consumed per unit time, the consumption control means for controlling such that the relay function is less than the unit time consumption amount before stopping, to function as a.

  Therefore, when the relay function in the relay device on the upstream side in the network system is stopped, the computer is configured so that the consumption amount per unit time of the distribution information stored in the relay device in the downstream is less than that before the stop. Therefore, the distribution of the distribution information is interrupted while the distribution information is consumed at the same speed as before the interruption. Can be prevented without imposing a burden.

  According to the first aspect of the present invention, when the relay function in the relay device on the upstream side in the network system is stopped, the consumption amount per unit time of the distribution information accumulated in the relay device in the downstream is reduced. Since the control is performed so that the distribution information is less than before the stop, the distribution information is interrupted while the distribution information is consumed at the same speed as that before the interruption. Can be prevented without imposing a burden on the network system itself.

  Therefore, even if the relay function is stopped in any of the relay devices included in the network system, the stopped relay function can be restored without greatly affecting the processing in the downstream relay device. Distribution information can be reliably distributed while improving its own reliability.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the distribution information is image information, and the rate at which the amount of image information stored in the buffer means is reduced is reduced before the relay function is stopped. Since the unit time consumption is reduced by making the speed slower than the reduction speed, the unit time consumption can be reduced with a simple configuration without performing complicated speed control processing.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 2, accumulation is performed by repeatedly outputting the same still image a plurality of times for the still images constituting the moving image information. Since the rate at which the amount is reduced is reduced, the unit time consumption can be surely reduced by simple processing.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, the decoding speed of the image information in the processing in the target relay apparatus is slower than the decoding speed before the relay function is stopped. By doing so, the unit time consumption is reduced, so that the unit time consumption can be surely reduced by simple processing.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 1, for the still images constituting the moving image information, the display time of the still images is displayed for the display before the relay function is stopped. Since the unit time consumption is reduced by making it longer than the time, the unit time consumption can be surely reduced by simple processing.

  According to the invention described in claim 6, in addition to the effect of the invention described in any one of claims 1 to 6, the relay that was downstream of the relay device in which the relay function was stopped before the relay function was stopped Since the empty unit distribution information is distributed only to all other relay devices except the device after the relay function is restored, the playback time axis in the above relay device gradually catches up with the playback time axis in the other relay devices. As a result, since the unit time consumption was reduced in the relay device that was downstream of the relay device whose relay function was stopped, the relay device and all the other relay devices described above , The deviation of the reproduction position on the reproduction time axis can be eliminated.

  According to the seventh aspect of the present invention, when the relay function in the relay device on the upstream side in the network system is stopped, the consumption amount per unit time of the distribution information accumulated in the relay device in the downstream is reduced. Since the control is performed so that the distribution information is less than before the stop, the distribution information is interrupted while the distribution information is consumed at the same speed as that before the interruption. Can be prevented without imposing a burden on the network system itself.

  Therefore, even if the relay function is stopped in any of the relay devices included in the network system, the stopped relay function can be restored without greatly affecting the processing in the downstream relay device. Distribution information can be reliably distributed while improving its own reliability.

  According to the invention described in claim 8, when the relay function in the relay device on the upstream side in the network system is stopped, the consumption amount per unit time of the distribution information accumulated in the relay device downstream thereof Since the computer functions to be less than that before the suspension, the distribution information distribution is interrupted while the distribution information is consumed at the same speed as before the interruption. Generation of processing delay can be prevented without imposing a burden on the network system itself.

  Therefore, even if the relay function is stopped in any of the relay devices included in the network system, the stopped relay function can be restored without greatly affecting the processing in the downstream relay device. Distribution information can be reliably distributed while improving its own reliability.

(I) Embodiment Next, the best mode for carrying out the present invention will be described with reference to FIGS. In the embodiment described below, a server as a node serving as a distribution device that is a distribution source of content as distribution information, and a user terminal connected to the server as a tree structure while forming a plurality of hierarchies In this embodiment, the present invention is applied to a network control process for controlling a distribution mode of the content in a network system in which the content is distributed including a plurality of nodes.

  1 is a diagram illustrating a schematic configuration of a network system according to the embodiment, FIG. 2 is a block diagram illustrating a detailed configuration of each node included in the network system, and FIGS. 3 to 6 illustrate each node. FIG. 7 to FIG. 13 are diagrams specifically illustrating the distribution processing.

  When the network system of the embodiment is viewed as a physical connection mode, as shown in FIG. 1A, the network system NS is connected to the server S via a line L that is a wired line or a wireless line. A plurality of nodes N which are user terminals are connected to each other via a network NT such as an Internet line so as to be able to exchange information. When the network system NS shown in FIG. 1A is viewed as a topology having the server S as the apex, as shown in FIG. Nodes N are connected, and two nodes N are connected to each node N. In this way, with the topology in which each node N is connected in a tree shape with the server S as the apex, the necessary content is distributed from the server S to the node N that desires the content, following the hierarchy.

  Next, a specific configuration of each node N included in the network system NS described above will be described with reference to FIG.

  As shown in FIG. 2A, the node N according to the embodiment includes a CPU 1 as a detection unit, a consumption control unit, a return unit, and a distribution control unit, a connection authentication unit 2, and a hard disk or a semiconductor memory. A storage unit 3, an input unit 4 composed of a mouse or a keyboard, an output unit 5 composed of a display for image display, a speaker for audio output, a decoder for image and audio decoding, a message transmission / reception unit 6, and data The transmission / reception unit 7 includes a CPU 1, a connection authentication unit 2, a storage unit 3, an input unit 4, an output unit 5, a message transmission / reception unit 6 and a data transmission / reception unit 7. Connected as possible.

  Next, an outline operation will be described.

  First, the message transmitting / receiving unit 6 is functionally connected to a node N (or server S) in an upper layer via a line L, and exchanges messages with the node N and the like in the upper layer. And a portion that is connected to a node N in a lower hierarchy via a line L and exchanges messages with the node N in the lower hierarchy. Here, the message indicates various control information necessary for distributing the necessary content in the network system NS, and an environment in which the actual content is distributed by forming the message is formed. Will be.

  On the other hand, the data transmission / reception unit 7 is functionally connected to the node N etc. in the higher hierarchy via the line L and connected to the node N etc. in the higher hierarchy, like the message transmission / reception unit 6. Divided into a portion that exchanges data between them, and a portion that is connected to a node N in a lower hierarchy via a line L and exchanges data with the node N in the lower hierarchy. Yes. Here, the data refers to data in a packet format including audio or images constituting the content itself distributed in the network system NS, and each content is transmitted from the server S as the content under the environment formed by the exchange of the message. It is delivered to the node N.

  Here, in a packet of data (for example, content for one movie or content for one piece of music, etc.), a packet of data constituting the data is continuous from the top of the content. Assume that a packet number is assigned. Further, the data transmitted as the packet is divided into packs which are units smaller than the packet, and the pack number which is continuous from the top in one content is also given to the pack. Shall.

  Next, for example, when the network system NS is a network system that distributes paid content, the connection authentication unit 2 determines whether or not the node N is permitted to distribute the content under the control of the CPU 1. The so-called authentication processing such as is executed by exchanging authentication information with the server S when the node N joins the network system NS or when another node N is newly connected.

  Furthermore, the memory | storage part 3 memorize | stores each information mentioned later temporarily or non-volatilely so that rewriting is possible, and outputs it to CPU1 as needed.

  On the other hand, when an operation such as designation of content to be played back is executed by the user at the node N in which the input unit 4 is included, the input unit 4 generates an operation signal corresponding to the executed operation and generates the CPU 1. Output to. Then, when the CPU 1 that has received the operation signal controls the other components constituting the node N, the distribution and reproduction processing of the desired content is executed.

  At this time, the reproduction process is executed using the output unit 5 under the control of the CPU 1.

  Next, the detailed configuration of the storage unit 3 will be specifically described with reference to FIG. Note that FIG. 2B shows the storage unit 3 divided into regions for each type of information stored therein.

  As illustrated in FIG. 2B, the storage unit 3 indicates the node N that is connected immediately above the node N in which the storage unit 3 is included on the topology illustrated in FIG. A first upper node information storage area 10 in which upper node information is stored, and upper node information of upper nodes indicating other nodes N that are further connected to the upper node N on the topology in the immediate upper level are stored. Second upper node information storage area 11 and lower node information respectively indicating one or a plurality of nodes N connected to the nearest lower level with respect to the node N including the storage unit 3 on the topology. The lower node information storage area 12 for storing the number of lower nodes, and transmission data for storing transmission data number information indicating the number of packs including data already transmitted to the lower node. Number information storage area 13, received data number information storage area 14 in which received data number information indicating the number of a pack including data already received in the node N itself in which the storage unit 3 is included, and the received data A reproduction speed information storage area 15 in which reproduction speed information indicating the reproduction speed in the output unit 5 such as an image or sound corresponding to data is stored, and a minimum accumulated data amount set in advance for a ring buffer area to be described later The specified value storage area 16 for storing the specified value and the ring buffer area 17 for temporarily storing data actually distributed as content.

  Here, as node information stored in the first upper node information storage area 10, the second upper node information storage area 11, and the lower node information storage area 12, specifically, IP ( Internet Protocol) Global address etc. are included.

  The ring buffer area 17 is a storage area in a ring buffer memory format for temporarily storing data corresponding to the distributed content in a FIFO format, and sequentially stores the packets (and packs) as the content data described above. In addition, in principle, the data is output in the storage order and used for the reproduction process in the output unit 5.

  Next, after a new node N newly joins the network system NS according to the embodiment, a process of receiving the distribution of data corresponding to the content and reproducing the content, and during the reproduction, the node N In the other connected nodes N, for example, the processing in the case where the relay function of data to the other nodes N is stopped due to, for example, the withdrawal of the node N from the network system NS, Processing will be specifically described with reference to the flowcharts shown in FIGS.

  When a new node N is to be joined at a position immediately below one of the nodes N in the existing network system NS, the new node N (hereinafter referred to as the network system NS according to the flowchart shown in FIG. 3) is newly joined. In order to distinguish the node N that performs the data reception process and the reproduction process from other nodes that have already joined the network system NS), first, the higher order node N A process for connecting the joining node N to (or the highest server S in the network system NS) is performed (steps S1 and S2). When the request for the connection is rejected at the higher-level node N (step S2; NO), the joining node N cannot join the existing network system NS at that time. The process at N ends.

  On the other hand, in the determination in step S1, after the subscription is permitted from the higher node N (or server S) and the necessary connection processing is executed with the higher node N (or server S) (step S2). Next, it is confirmed whether or not an operation to withdraw from the currently subscribed network system NS has been executed in the input unit 4 in the joining node N (step S3).

  When the network system NS being withdrawn is withdrawn (step S3; withdrawal), the withdrawal process for that purpose is executed at the joining node N withdrawing (step S4), and the processing as the joining node N is terminated.

  On the other hand, when the data reception process or the like is continuously executed without performing the withdrawal process from the network system NS (step S3; continuation), the process of receiving necessary data from the upper node N is performed (step S5) and output. The received data is reproduced / output using the unit 5 (step S9). Then, a withdrawal message response process for disconnecting the connection between the other node N connected to the joining node N and the joining node N is executed as necessary with the other connected node N. (Step S8), the process returns to Step S3 again to continue the data reception process and the reproduction process as the joining node N.

  At this time, in the subscribing node N, in parallel with the data reproduction processing (step S9), the processing (step S6) for connecting another node N to the nearest lower hierarchy with respect to the subscribing node N and its connection Data transmission (relay) processing (step S7) to the lower node N is executed.

  Next, among the steps shown in FIG. 3, each of steps S1 and S4 to S9 will be described in detail.

  First, the process of step S1 will be described in detail with reference to the flowchart shown in FIG.

  As shown in FIG. 4 (a), in the process of step S1, the fact that the joining node N is requested to join as the nearest lower node N to the other upper node N first. It transmits via the line L (step S10), waits for a reply from the upper node N in response to the request (step S11), and confirms the contents when the reply is received (step S12).

  Then, when it is recognized that the joining node N joins the network system NS according to the reply content (step S12; Yes), the upper node including the IP address corresponding to the nearest higher node N, etc. The node information is stored in the first higher-level node information storage area 10 in the storage unit 3 of the joining node N, and the IP corresponding to the other node N that is further higher than the higher-level node N The upper node information of the upper node including the address and the like is stored in the second upper node information storage area 11 in the storage unit 3 of the joining node N (step S13), and the process proceeds to step S2 shown in FIG.

  On the other hand, if it is determined in step S12 that the joining node N is not allowed to join the network system NS (step S12; impossible), the function as the joining node N cannot be exhibited. After shifting to step S2 shown in FIG. 3 (step S2; NO), the process in the joining node N is terminated.

  Next, the data reception process in step S5 shown in FIG. 3 will be described in detail with reference to the flowchart shown in FIG.

  As shown in FIG. 4B, in the process of step S5, first, the desired data is requested at the joining node N via the line L to the nearest higher-level node N connected at that time. A message to the effect is transmitted (step S15), and the presence / absence of a transmission permission response from the upper node N is confirmed (step S16).

  When the transmission permission response is received (step S16; present), a packet containing desired data is received at the joining node N in accordance with the content of the response (step S17), and is shown in FIG. The process proceeds to steps S6 and S9. On the other hand, if it is determined in step S16 that no transmission permission response is obtained from the upper node N (step S16; none), there is some failure on the line L between the upper node N and the joining node N. Since there is a possibility that the error has occurred, the process of step S1 described above (see FIG. 4A) is performed again in order to eliminate the failure and enable data exchange, and then the process of step S15 again. Returning to step S15, data is received from the reconnected upper node N (steps S15 to S17).

  Next, the lower-level node connection process in step S6 shown in FIG. 3 will be described in detail using the flowchart shown in FIG.

  As shown in FIG. 4C, in the process of step S6, first, a connection request message from a node N connected to the subordinate node N is transmitted to the subscribing node N. If the connection request message has not been transmitted (step S20; no), the process directly proceeds to step S7 shown in FIG. 3, and the connection request message has been transmitted. When (step S20; present), next, between the subordinate node N that has transmitted the connection request message and the subscribing node N (or between the subordinate node N and the server S via the subscribing node N) Authentication processing for determining whether or not the subordinate node N is a node N qualified to join the network system NS, for example, the subordinate node N Executed by the connection authentication unit 2 included in the fine joining node N, respectively (step S21, S22).

  If it is not permitted to join the lower node N to the network system NS by the authentication process (step S22; No), the fact is transmitted to the lower node N as a connection non-permission message (step S25). ), The process proceeds to step S7 shown in FIG.

  On the other hand, in the determination of step S22, if it is permitted to join the lower node N to the network system NS by the authentication process (step S22; Yes), that fact is transmitted to the lower node N as a connection permission message. (Step S23), and further, the lower node information including the IP address corresponding to the nearest lower node N is stored in the lower node information storage area 12 in the storage unit 3 of the joining node N (step S24). The process proceeds to step S7 shown in FIG.

  Next, the data transmission process in step S7 shown in FIG. 3 will be described in detail with reference to the flowchart shown in FIG.

  As shown in FIG. 5A, in the process of step S7, first, a transmission request for data to be reproduced in the lower node N is sent from the node N connected to the subordinate node N in the immediate lower order. Is transmitted as a message (step S35), and if a message to that effect is not received at the joining node N (step S35; no), the process proceeds to step S8 shown in FIG.

  On the other hand, when a message to that effect has been transmitted in the determination in step S35 (step S35; present), a packet corresponding to the order in which the message should be transmitted from the joining node N corresponding to the message is: It is confirmed whether or not it is an empty packet to be described in detail later (refers to a packet that includes only header information as a packet and does not include substantial image information constituting the content) (step) S36) If it is not an empty packet (step S36; NO), the non-empty packet is transmitted as content data to the lower node N via the line L (step S38), and the process proceeds to step S8 shown in FIG. To do.

  On the other hand, if it is determined in step S36 that the packet corresponding to the order to be transmitted is an empty packet (step S36; YES), the joining node immediately before the process of step S7 shown in FIG. The pack number of the pack received by N and the entity data to be transmitted to the lower node N (that is, entity data such as image data or audio data, and this entity data is not included in the empty packet) Comparing the numbers of the packs to be configured, and when the numbers are not consecutive numbers (that is, when an empty packet is received), link the pack number immediately before the empty packet with the pack number immediately after the empty packet Thus, the pack number immediately after the previous pack number is arranged (step S37), and the pack number having the pack number after the arrangement is configured. That the data as a content, and transmitted to a lower node N (step S38), and proceeds to step S8 shown in FIG.

  Next, the withdrawal message response process in step S8 shown in FIG. 3 will be described in detail using the flowchart shown in FIG.

  As shown in FIG. 4D, in the process of step S8, first, any other node N currently connected to the joining node N (specifically, the upper level connected to the latest higher level). It is confirmed whether or not the joining node N has received a message indicating that the node N is leaving the network system NS from either the node N or the lower node N connected to the nearest lower level (step S26). If the message has not been received (step S26; NO), the process directly returns to step S3 shown in FIG. 3, while if a message requesting withdrawal is received (step S26; YES), the message is It is confirmed whether the message is transmitted from the latest higher-order node N or from the latest lower-order node N. -Up S27).

  When the withdrawal request message has been transmitted from the most recent upper node N (step S27; upper level), the withdrawal request message is stored in the second upper node information storage area 11 in the storage unit 3 of the joining node N. Based on the node information indicating the node immediately above the existing upper node N, the above-described step S1 is performed with the node N connected immediately above the upper node N (that is, the node N that transmitted the withdrawal request message). The upper-level node connection process described above is executed to restore the topology (step S1), and the process returns to step S3 shown in FIG.

  On the other hand, when the withdrawal request message is transmitted from the latest lower node N (step S27; lower level), it is stored in the lower node information storage area 12 in the storage unit 3 of the joining node N. The node information indicating the lower node N is deleted from the lower node information storage area 12 (step S28), and the process returns to step S3 shown in FIG.

  Next, with reference to the flowchart shown in FIG. 4E, the node withdrawal process (withdrawal process of the joining node N itself from the network system NS) in step S4 shown in FIG. 3 will be described in detail.

  As shown in FIG. 4 (e), in the process of the step S4, first, the above-described withdrawal for the upper node N connected to the latest higher rank with respect to the joining node N (see FIG. 4 (d)). A request message is transmitted (step S30), and the above-described withdrawal request message is similarly transmitted to the subordinate node N connected to the subordinate node with respect to the joining node N (step S31). Is withdrawn from its own network system NS.

  Finally, the data reproduction process in step S9 shown in FIG. 3 will be described in detail using the flowchart shown in FIG.

  As shown in FIG. 5B, in the process of step S9, first, a regeneration flag in the joining node N (that is, a regeneration flag indicating whether or not the regeneration process using the output unit 5 is being executed). ) Is confirmed (step S40), and when the reproduction flag is “off” (that is, reproduction processing is not currently being executed in the output unit 5) (step S40; OFF), then the ring It is confirmed whether or not data of a predetermined value t or more which is a predetermined value of the storage amount set in advance has already been stored in the buffer area 17 (step S45).

  Then, when data with an information amount equal to or greater than the prescribed value t is not accumulated in the ring buffer area 17 (step S45; NO), data reproduction processing is executed in that state (that is, in the ring buffer area 17). When the data is consumed), the ring buffer area 17 becomes in a so-called underrun state, and the reproduced image or the reproduced music may be interrupted, so that the data is further accumulated through step S8 shown in FIG. Return to step S3.

  On the other hand, if it is determined in step S45 that data equal to or greater than the specified value t has already been accumulated (step S45; YES), the reproduction flag that has been "off" until now is set to "on" (step S46). In the same manner as in the prior art, the stored data is reproduced (for example, display processing in the case of image information) (step S47), and the process proceeds to step S8 shown in FIG.

  On the other hand, if it is determined in step S40 that the in-reproduction flag is “ON” (that is, the reproduction process is currently being executed in the output unit 5) (step S40; ON), next, step S45 described above is performed. In the same manner as in the above determination, it is confirmed whether or not information amount data equal to or greater than the prescribed value t is currently stored in the ring buffer area 17 (step S41), and information amount data equal to or greater than the prescribed value t has been accumulated. When (step S41; YES), the reproduction mode such as the display speed of the image data is set as a normal mode similar to the conventional technique (step S42), and the reproduction process is performed based on the set content, as in step S47. Is executed (step S44), and the process proceeds to step S8 shown in FIG.

  On the other hand, in the determination in step S41, when data having an information amount equal to or greater than the specified value t is not accumulated (step S41; NO), the data reproduction mode is changed to the content corresponding to the accumulation amount. (Step S43), the reproduction process is executed based on the set content (Step S44), and the process proceeds to Step S8 shown in FIG.

  At this time, in the reproduction mode setting change in step S43, when data having an information amount equal to or greater than the specified value t is not accumulated, the data consumption in the reproduction processing in step S44 (that is, accumulated in the ring buffer area 17). The reproduction mode is set so as to reduce the rate at which the accumulated amount of the ring buffer area 17 is reduced by reducing the amount of data being consumed). More specifically, for example, the reading amount per unit time in reading data from the ring buffer area 17 is set to be reduced to about 4/5 at the maximum. More specifically, for example, a reading amount control method is conceivable in which the same pack is read twice with a cycle such as once every time five packs are read. In this case, when there is no stop of the relay function in the upper node N, the above cycle may be set to zero, and the cycle may be shortened as the accumulation amount in the ring buffer region 17 decreases.

  It should be noted that the degree of reduction of the reading amount per unit time in the data reading from the ring buffer area 17 described above may be a degree of reduction that cannot be visually recognized by the user. The number 5 can be changed within that limit.

  Next, the data display process in step S44 shown in FIG. 5B will be specifically described with reference to the flowchart shown in FIG. The data display process described below is based on the assumption that the setting is changed in the process of step S43 so as to reduce the reading speed from the ring buffer area 17.

  As shown in FIG. 6, in the process of step S44, first, data as image information is read from the ring buffer area 17 by the read amount (read speed) per unit time set in the process of step S43 ( In step S50, the read data is decoded by the output unit 5 (step S51) and displayed on a display (not shown) or the like (step S52). Also, in the case of audio information, data is read from the ring buffer area 17 at a reading speed set in the same manner as in the case of image information (step S50), decoded and emitted from a speaker (not shown) or the like (step S51). , S52).

  Next, a more specific description will be given with reference to FIGS. 7 to 13 including the flow of packets constituting data as contents in the series of network control processes described above.

In FIG. 7 to FIG. 12, two nodes N ₁ and N ₂ are connected to the lower first layer as viewed from the server S as the topology with the server S at the top, and the node N ₁ And N ₂ , two nodes N _{3 to} N ₆ are connected to the closest lower level, and two nodes N _{7 to} N ₁₄ are set to the closest lower level for each of the nodes N _{3 to} N _6. It shall be connected. In the network system NS having the connection mode shown by the topology having this configuration, the image data as the content stored in the server S in advance is packetized, and each packet is sent to each of the lower nodes N _{1 to} N ₁₄ for each packet. A description will be given of a process performed when the node N ₄ of the nodes N _{1 to} N ₁₄ withdraws from the network system NS on the way while being distributed.

Further, each of the server S and each of the nodes N _{1 to} N ₆ has a ring buffer area 17, and the packet P as the data is sequentially stored therein, and other nodes N ( It is assumed that the relay process for each of them also has a ring buffer area 17 (see steps S7 and S9 in FIG. 3). In FIG. 7 to FIG. 13, one packet P is indicated by one square, and the numbers in the square indicate packet numbers.

Furthermore, in FIGS. 7 to 12, the ring buffer area 17 in each of the nodes N _{1 to} N ₁₄ is represented in a horizontal row, but the left end of each ring buffer area 17 is used for packet input / output processing. And the right end is connected to form a ring. Each time one packet is subjected to reproduction processing and delivered to the nearest lower node N, the oldest packet among the packets stored in the ring buffer area 17 at that time is delivered from the nearest higher node N. By replacing the incoming new packet, the above-described FIFO-type buffer memory is realized.

  In addition, the downward hollow arrow displayed in the ring buffer area 17 in the server S in FIGS. 7 to 13 is the timing at which a packet in which the left end of □ is located at the position indicated by the arrow is transmitted from the server S. Is shown. Further, the upward black arrow displayed in the ring buffer area 17 in each node N in FIGS. 8 to 13 indicates the image data stored at the position indicated by the arrow in each packet at that time. It shows that. Further, in the packet display (□) of the ring buffer area 17 in the server S and each node N, the case where the inside of the □ is displayed as “-” indicates the ring buffer area corresponding to the displayed packet. The part 17 indicates that no data is stored.

  Here, in the example shown in FIGS. 7 to 13, the value of the specified value t for each node N (that is, the lower limit value t determined to be insufficient as the accumulation amount in the ring buffer area 17) is three packets. Suppose that

First, before packet distribution, as shown in FIG. 7A, packets to be distributed in the server S are stored in the ring buffer area 17 in the order to be distributed. The packets are distributed to the nodes N _{1 to} N ₁₄ connected in the lower order in the numerical order. That is, as shown in FIG. 7A, when the timing at which the packet P ₀ is to be output from the server S has arrived, the packet P _{0 is} placed on the line L connecting the server S and the nodes N ₁ and N _2. (Packet number is “0”). Thereafter, as shown in FIGS. 7B and 7C, the transmitted packet P ₀ is being relayed by the node N in the lower hierarchy as time elapses, and within each node N. Are stored in the ring buffer area 17.

When the packet P ₀ is distributed to the nodes N _{7 to} N ₁₄ connected to the end in the network system NS, next, the packet P ₀ is distributed next to the packet P ₀ as shown in FIG. For the packet P to be transmitted, transmission from the server S is started.

By repeating the above, for example, when image data for three packets is accumulated in the nodes N _{7 to} N ₁₄ connected to the end of the network system NS as shown in FIG. Image reproduction processing in the nodes N _{1 to} N ₁₄ is started from the image data in the packet P ₀ .

Then, as shown in FIG. 8C, when the reproduction processing for one packet using the packet P ₀ in each of the nodes N _{1 to} N ₁₄ is completed, the reproduction processing using the next packet P ₁ is performed for each node N 1. Starting from _{1 to} N ₁₄ , the fourth packet P ₄ is delivered from the server S.

By repeating the above processing, packets as image data are sequentially distributed, and are reproduced while being stored (and erased) in the ring buffer area 17 in the FIFO format. In each of the nodes N _{1 to} N ₁₄ of the embodiment, as shown in FIG. 9 (a), the packet immediately before the currently reproduced packet is left, and the packets stored before that are sequentially transmitted. It shall be updated to a new packet.

Then, as shown in FIGS. 9B and 9C, after the delivery of all the packets to be delivered by the server S is completed, the ring buffer areas 17 in the nodes N _{1 to} N ₁₄ are sequentially emptied. Thus, all distribution processes in the network system NS are completed.

Next, the processing when the node N ₄ in the network system NS stops its relay function due to, for example, its power being turned off and leaves the network system NS itself will be described with reference to FIG. It demonstrates using thru | or FIG.

As illustrated in FIG. 10A, in each of the nodes N _{1 to} N ₁₄ , for example, the reproduction processing of the image data included in the packet P ₁ is completed, and at the same time, the packet P ₅ is transmitted from the server S. It is assumed that the node N ₄ has left the network system NS for the reason described above (see FIG. 4D). Then, after the withdrawal, the delivery of the packet P _{5 to} the lower nodes N ₉ and N ₁₀ is naturally delayed. In this case, as shown in FIG. 10B, the process of reconnecting the node N ₁₀ to the current upper node N, the node N _1, and reconnecting the node N ₉ to the reconnected node N ₁₀ (See step S1 in FIG. 4 (d)), and the node N ₁ after the reconnection has not been delivered to the nodes N ₉ and N ₁₀ at the previous delivery timing. re-distribution is carried out of the packet P _5. As a result, in the ring buffer region 17 included in each of the nodes N ₉ and N ₁₀ , the rewrite timing is delayed by one packet compared to the other nodes N _{1 to} N _{8 and} N _{11 to} N ₁₄ , As a result, as shown in FIG. 10B, there are only two packets (packet P ₃ and packet P ₄ ) before the reproduction process, and so-called data delay occurs (step S41 in FIG. 5B). See NO). From this point onward, until the distribution of all packets is completed, the packets to be reproduced in the nodes N ₉ and N ₁₀ are one packet compared to the other nodes N _{1 to} N _{8 and} N _{11 to} N _14. The state of being delayed by the minute will continue.

Therefore, in the present embodiment, as indicated by the upward slanted arrows in FIGS. 11A and 11B, for the nodes N ₉ and N ₁₀ where the data delay has occurred, the timing at which the data delay has occurred. Thereafter, the reading speed from the ring buffer region 17 is made slower than the other nodes N _{1 to} N _{8 and} N _{11 to} N ₁₄ (see step S41 in FIG. 5 (b); NO and step S50 in FIG. 6), and finally. the number of regeneration treatment before the packet as shown in FIG. 11 (c) is recovered up to 3 described above prescribed value (packet P ₄ to P ₆ in the case of FIG. 11 _(c)).

By the way, for example, as apparent from comparing the state of the ring buffer region 17 in the node N ₉ and the state of the ring buffer region 17 in the node N ₈ in FIG. 11C or FIG. Although the number of unreproduced packets has returned to three in the buffer area 17, the packet reproduced in each node N is the node N ₉ even though it is the packet P ₅ in the node N ₈ . Is the packet P _4, and the nodes N ₉ and N ₁₀ that are in the lower order of the node N ₄ in the lower order are on the time axis of the series of packets P due to the withdrawal of the latest upper node N ₄ from the network system NS. So that the so-called playback delay (that is, the timing of playback for the same content between the nodes N) ) Has occurred. Therefore, in this case, for example, when the user of the node N _{9 and} the user of the node N ₈ are playing a so-called network game, the normal use state of those nodes N that a reproduction delay occurs in both of them Will be inhibited.

  Therefore, in the network control processing of the embodiment, all the other nodes N belonging to the network system NS except for the node N in which the reproduction delay has occurred due to the withdrawal of the upper node N from the network system NS. The above-described empty packet is distributed from the server S to the content reproduction timings of all the nodes N included in the network system NS.

In other words, in the embodiment, as shown in FIG. 12A, the content before distribution stored in the ring buffer area 17 in the server S has a timing or interval in anticipation of future reproduction delay. The empty packet _P00 is inserted between other packets.

Then, FIGS. 12 (a) and 12 (b), the example node _{N 9} and if the reproduction delay occurs in _{N 10,} all other nodes except the node _{N 9} and _{N 10} and the empty packet The data is distributed to N _{1 to} N ₈ and N _{11 to} N ₁₄ (see FIG. 5A). As a result, as shown in FIG. 12C, the reproduction timings of the packets distributed in all the nodes N _{1 to} N ₁₄ included in the network system NS become the same, and the nodes N _{1 to} N ₁₄ are connected to each other. The above-described reproduction delay is eliminated.

Next, a temporal change in a packet transmission / reception mode between the nodes N ₉ and N ₁₀ connected to the nodes N ₉ and N ₁₀ in the latest higher level and the latest lower level, according to the execution of the series of network control processes described above. Will be specifically described with reference to FIGS. In FIG. 13, the horizontal axis is the time in the distribution with the content distribution start time as the left end, and the vertical axis is the pack number in the packet to be distributed (therefore, the lower end of the vertical axis is the pack in the packet P ₀ . Indicates the state of packet transmission / reception between the node N ₉ or N ₁₀ and the other nodes N connected to the nearest higher level and the latest lower level when the pack is numbered “0”) It is.

First, in the case where the relay function of the node N ₄ connected to the nearest higher level in FIG. 7 to FIG. 12 is operating normally, the node N ₉ or N ₁₀ receives the packet from the latest higher level node N ₄ . While receiving the distribution, the operation of relaying this directly to the nearest lower node is repeated. 7 to 12 described so far, the node N ₉ or N ₁₀ is not connected to the nearest lower node N, but the functions of each node N included in the network system NS are more enhanced. For the sake of general explanation, in FIG. 13, it is assumed that another node N is connected to the node N ₉ or N ₁₀ in the nearest lower order.

In parallel with this relay function, the node N ₉ or N ₁₀ accumulates the packets P distributed from the node N ₄ in the ring buffer area 17 in the distribution order (see FIGS. 8 and 9). Decoding and display of data stored in the packet P by the output unit 5 at the timing when three Ps are accumulated (display processing when the data is image data and when the data is audio data) Including audio output processing (hereinafter the same). In the example shown in FIG. 13A, the first packet P ₀ illustrated in FIGS. 7 to 12 is distributed from the server S via the node N ₄ and accumulated in the ring buffer area 17 of the node N ₉ or N _10. Is the left end of the horizontal axis, and from the time on the left end, the subsequent packets P ₁ and P ₂ are similarly distributed and accumulated in the ring buffer area 17, and then the data stored in the packet P ₀ The time until the start of the decoding and display of is the time T ₀ shown in FIG. At this time, the accumulation amount in the ring buffer region 17 (pack amount for three packets in the case of the embodiment) is the amount indicated by the symbol “M” in FIGS. 13A and 13B.

Further, when processing such as decoding and display of data in each packet P is completed, the subsequent packet P delivered thereafter is overwritten in the portion of the ring buffer area 17 where the packet P was recorded. It will be. In the example shown in FIG. 12A, after the decoding and display processing on the data in the packet P ₀ is started, the packet P ₀ has been stored in the part of the ring buffer area 17 that has been stored. Time T ₁ is required until the data in the packet P ₄ is stored (overwritten).

Next, as described above with reference to FIG. 10, when the node N ₄ that was immediately above the nodes N ₉ and N ₁₀ withdraws from the network system NS and the relay function stops, the stop Thereafter, until the reconstruction of the topology shown in FIG. 10B is completed and the delivery of the packet P is restarted, the delivery of the packet P is not performed to the nodes N ₉ and N ₁₀ . Therefore, in this non-delivery period, although time elapses, there is no delivery of the packet P from the upper node N. Therefore, in the nodes N ₉ and N ₁₀ , as shown in FIG. The graph showing the delivery state of the packet P and the relay state of the packet P to the lower node includes a flat portion only during the non-delivery period. As a result, the accumulation amount in the ring buffer area 17 decreases. Note that the slopes of the graph before and after the non-delivery period (that is, the delivery speed and relay speed of the packet P) are the same.

  Next, when there is a non-delivery period as described above, in the embodiment, the reading speed of data from the ring buffer area 17 is slowed to prevent the occurrence of underflow in the ring buffer area 17 (FIG. 5B). (See steps S43 and S44). Therefore, from the timing when the non-delivery period occurs, the speed of data decoding and display decreases as indicated by the thick solid line in FIG. 13B. When the accumulated amount in the ring buffer area 17 is equal to or more than three packets, the decoding and display speeds are restored to the original speed as shown in FIG. At this time, the accumulation amount in the ring buffer area 17 is “M” at the beginning of distribution as in the case shown in FIG. 13A, and this is temporarily less than “M” due to the occurrence of the non-delivery period. However, since the reading speed of the data from the ring buffer area 17 is slow, the original accumulation amount “M” is restored after the slow time T3 has elapsed.

  In FIG. 13B, during the non-delivery period, the overwriting process in the ring buffer area 17 is also delayed only during that period.

Here, as shown in FIG. 12, after the node N ₄ is dropped, the reproduction delay occurs in the nodes N ₉ and N _{10 with} respect to the other nodes N _{1 to} N _{8 and} N _{11 to} N ₁₄ . ing. Therefore, in the embodiment, as shown in FIG. 12, the packet P ₀₀ is mixed in the content in advance, and this is distributed only to the other nodes N _{1 to} N _{8 and} N _{11 to} N ₁₄ .

Therefore, when viewed from the standpoint of the nodes N ₉ and N ₁₀ , as shown in FIG. 13C, the empty packet P ₀₀ is distributed to the other nodes N _{1 to} N _{8 and} N _{11 to} N ₁₄ . At the timing (shown as “blank data” in FIG. 13C), the content is delivered by skipping the empty packet P ₀₀ as described in step S37 of FIG. continuity of the pack numbers when viewed across the entire content of successive that were stored in the original server S interrupted in N ₉ and N _10, as a result of empty packets P _00, as shown in FIG. 13 (c) (in FIG. 13 (c), the indicated by symbol "PK") the amount of pack number fraction pack number with the delivery timing corresponding to the empty packet P ₀₀ while being only flying delivery increases, It would be relayed to the lower nodes N in the same manner as Les. In response to this, the number of packs used for processing such as decryption and display as data also changes in a state where the pack numbers jump and increase.

  As described above, according to the network control processing according to the embodiment, when the relay function in the node N on the upper side in the network system NS is stopped, the content data accumulated in the node N on the lower side is stopped. Since the consumption speed is controlled to be lower than that before the stoppage, the processing interruption in the lower node N caused by the content data being consumed at the same speed as before the interruption while the distribution of the content data is interrupted or The occurrence of an extreme processing delay can be prevented without imposing a burden on the network system NS itself.

  Therefore, even if the relay function is stopped in any one of the nodes N included in the network system NS, the stopped relay function can be restored without greatly affecting the processing in the lower node N. Content data can be reliably distributed while improving the reliability of the network system NS itself.

  In addition, since the content data is image data, and the rate at which the accumulated amount of image data in the ring buffer area 17 is reduced is slower than the reduction rate before the relay function is stopped, the content data consumption rate is reduced. The consumption speed can be reduced with a simple configuration without performing complicated speed control processing.

  Furthermore, since the same still image is repeatedly output over a plurality of times for the still images constituting the moving image data, the speed at which the amount of accumulation in the ring buffer area 17 is reduced is slowed down. The consumption speed can be reduced.

  Furthermore, when it is detected that the relay function is stopped, the consumption speed is controlled to be a maximum of 4/5 compared to the consumption speed before the relay function is stopped. The consumption speed can be reduced without significantly affecting the processing. Note that the amount of reduction of the consumption speed is not only about 4/5 as described above, but is also a reading speed reduction amount that is not perceptible to general viewers (node N users) in the end. I just need it.

Also, since the empty packet P ₀₀ is delivered only to all other nodes N except for the node N that was subordinate to the node N where the relay function stopped before the relay function stopped, As a result, the playback time axis in the other node N is gradually delayed, and as a result, the unit time consumption is reduced in the node N which is lower than the node N where the relay function is stopped. The deviation of the reproduction position on the reproduction time axis that occurs between the node N and all the other nodes N can be eliminated.

(II) Modified Embodiment Next, a modified embodiment according to the present invention will be described with reference to FIG.

  In the above-described embodiment, the method of reducing the data reading speed from the ring buffer area 17 itself is used as a method of reducing the consumption speed of the data stored in the ring buffer area 17. The following two methods are possible for reducing the consumption speed.

  That is, as a first modification, not the reading speed from the ring buffer area 17 itself but the decoding speed at the output unit 5 of the data read from the ring buffer area 17 itself may be reduced. More specifically, in the process of step S43 in FIG. 5 (b), the data decoding speed in the output unit 5 is set to be reduced to about 4/5 at a maximum from the normal level. That is, for example, for still image data constituting moving image data, the frame rate at the time of decoding is set to 30 frames per second when the relay function in the upper node N is not stopped, and the accumulation amount in the ring buffer area 17 is small. Then, it may be 29 frames per second. Then, the frame rate may be changed lower as the accumulation amount in the ring buffer area 17 decreases.

  Further, when the frame rate is changed as described above in the process of step S43, as the process of step S44 executed subsequently, as shown in FIG. Thus, data as image information is read from the ring buffer area 17 (step S53), and the read data is decoded by the output unit 5 using the frame rate set in step S43 (step S54). It displays on the display etc. which do not (step S52). Even in the case of audio information, data is read from the ring buffer area 17 at the same reading speed as in the case of image information (step S53), is decoded at a set frame rate, and is emitted from a speaker or the like (not shown). (Steps S54 and S52).

  As described above, according to the first modification, the data consumption in the ring buffer area 17 is reduced by making the decoding speed of data in the processing in the node N slower than the decoding speed before the relay function is stopped. Since the speed is reduced, the consumption speed can be surely reduced by simple processing.

  Next, as a second modification, the content data is moving image data, and is not the reading speed from the ring buffer area 17 itself and the decoding speed in the output unit 5, but the decoded data. The display speed in the output unit 5 may be reduced. More specifically, in the process of step S43 in FIG. 5 (b), the display time of each still image data constituting the decoded moving image data in the output unit 5 is set to one still image at maximum than usual. The length is set to about 5/4 per corresponding still image data. That is, for example, with respect to the still image data, when the display function of the still image data corresponding to one still image (that is, the display time per still image) is not stopped at the upper node N, the relay function is not stopped. 1/30 seconds may be used, and 1/29 seconds may be used when the accumulation amount in the ring buffer region 17 decreases. Then, the display time may be changed longer as the accumulation amount in the ring buffer area 17 decreases.

  Further, when the display time is changed as described above in the process of step S43, as the process of step S44 executed subsequently, as shown in FIG. Thus, data as image information is read from the ring buffer area 17 (step S53), and the read data is decoded by the output unit 5 using a normal frame rate (step S55), and then set in step S43. The display time for each still image is displayed on a display (not shown) or the like (step S56).

  As described above, according to the second modification, for the still image data constituting the moving image data, the display time of the corresponding still image is made longer than the display time before the relay function is stopped. Since the consumption speed in the ring buffer area 17 is reduced, the consumption speed can be reliably reduced by simple processing.

  The programs corresponding to the flowcharts of FIGS. 3 to 6 and 14 are recorded on an information recording medium such as a flexible disk or a hard disk, or acquired and recorded via the Internet or the like. It is also possible to cause the computer to function as the CPU 1 according to each embodiment by being read and executed by the computer.

  As described above, the present application can be used in the field of content distribution using a network system having a tree structure. In particular, distribution is interrupted in the middle, such as real-time broadcasting of movies and music. If it is applied to the field of content distribution where it is inconvenient to obtain, a particularly remarkable effect can be obtained.

1 is a block diagram illustrating a schematic configuration of a network system according to an embodiment, where (a) is a block diagram illustrating a physical connection mode, and (b) is a block diagram illustrating a connection mode as a topology; FIG. It is a figure which shows the structure of each node contained in the network system which concerns on embodiment, (a) is the block diagram, (b) is a figure which shows the content of the information memorize | stored in the memory | storage part 3. FIG. It is a flowchart which shows the whole process in the node which concerns on embodiment. 5 is a flowchart (I) showing details of processing in the node according to the embodiment, (a) is a flowchart showing upper-level node connection processing, (b) is a flowchart showing data reception processing, and (c) is shown in FIG. It is a flowchart which shows a lower node connection process, (d) is a flowchart which shows a withdrawal message response process, (e) is a flowchart which shows a node withdrawal process. It is a flowchart (II) which shows the detail of the process in the node which concerns on embodiment, respectively, (a) is a flowchart which shows a data transmission process, (b) is a flowchart which shows a data reproduction process. It is a flowchart which shows the data display process in the node which concerns on embodiment. It is figure (I) which illustrates the state of packet delivery in the network system concerning an embodiment, (a) is a figure (i) which illustrates the details, and (b) is a figure (ii) which illustrates the details. (C) is a diagram (iii) illustrating the details. It is figure (II) which illustrates the state of packet delivery in the network system concerning an embodiment, (a) is a figure (iv) which illustrates the details, and (b) is a figure which illustrates the details (v) (C) is a diagram (vi) illustrating the details. It is figure (III) which illustrates the state of packet delivery in the network system concerning an embodiment, (a) is a figure (vii) which illustrates the details, and (b) is a figure (viii) which illustrates the details (C) is a diagram (ix) illustrating the details. It is a figure which illustrates the state of packet delivery when a node withdrawal occurs in the network system according to the embodiment, (a) is a diagram (i) illustrating the details, and (b) illustrates the details. It is figure (ii) to do. It is a figure which illustrates the state of packet delivery when the reconnection after the node withdrawal is completed in the network system according to the embodiment, (a) is a figure (i) illustrating the details, (b) is the figure It is figure (ii) which illustrates details, and (c) is figure (iii) which illustrates the details. It is a figure which illustrates the state of packet delivery at the time of reproduction | regeneration recovery | restoration after node withdrawal and reconnection in the network system which concerns on embodiment, (a) is a figure (i) which illustrates the detail, (b) Is a diagram (ii) illustrating the details, and (c) is a diagram (iii) illustrating the details. It is a figure which illustrates transfer of the data in one node at the time of reproduction | regeneration delay recovery | restoration after a node withdrawal and reconnection in the network system which concerns on embodiment, (a) is a figure which illustrates the state before a node withdrawal, FIG. 7B is a diagram illustrating a state after leaving the node, and FIG. 8C is a diagram illustrating a state of recovery from reproduction delay. It is a flowchart which shows the data display process in the node which concerns on a deformation | transformation form, (a) is a flowchart which shows the data display process in the node which concerns on a 1st modification, (b) is in the node which concerns on a 2nd modification It is a flowchart which shows a data display process.

Explanation of symbols

N node 1 CPU
2 Connection Authentication Unit 3 Storage Unit 4 Input Unit 5 Output Unit 6 Message Transmission / Reception Unit 7 Data Transmission / Reception Unit 8 Bus 10 First Upper Node Information Storage Area 11 Second Upper Node Information Storage Area 12 Transmission Data Number Information Storage Area 14 Received Data Number Information storage area 15 Playback speed information storage area 16 Specified value storage area 17 Ring buffer area NS Network system S Server N, N ₁ , N ₂ , N ₃ , N ₄ , N ₅ , N ₆ , N ₇ , N ₈ , N ₉ , N ₁₀ , N ₁₁ , N ₁₂ , N ₁₃ , N ₁₄ node L line NT network

Claims (8)

A distribution device that is a distribution source of the distribution information, and a plurality of relay devices that are connected to the distribution device while forming a plurality of hierarchies. The distribution information from the distribution device to each of the relay devices In the network control device that controls any of the relay devices included in the network system to which
Detecting means for detecting whether the relay function of the distribution information in any one of the relay apparatuses upstream in distribution of the distribution information to the target relay apparatus that is the relay apparatus to be controlled is stopped;
Consumption per unit time when it is detected that the distribution information stored in the target relay device is used for processing executed in the target relay device when it is detected that the relay function is stopped Consumption control means for controlling the unit time consumption, which is a quantity, to be less than the unit time consumption before the relay function stops;
A network control apparatus comprising: The network control device according to claim 1,
The distribution information is image information,
The consumption amount control means is configured to reduce a speed at which the storage amount of the image information in the buffer means for temporarily storing the image information in the target relay device is reduced by using the image information for the processing. A network control apparatus characterized in that the unit time consumption is reduced by making the speed slower than the reduction speed before the relay function is stopped. The network control device according to claim 2,
The image information is moving image information composed of a plurality of still images,
The network control apparatus characterized in that the consumption control means slows down the accumulation amount by repeatedly outputting the same still image from the buffer means over a plurality of times. The network control device according to claim 1,
The distribution information is encoded image information;
The consumption control means reduces the unit time consumption by making the decoding speed of the image information in the processing in the target relay device slower than the decoding speed before the relay function is stopped. A network control device characterized. The network control device according to claim 1,
The distribution information is moving image information composed of a plurality of still images,
The network control device, wherein the consumption control means reduces the unit time consumption by making the display time of the still image longer than the display time before the relay function is stopped. In the network control device according to any one of claims 1 to 5,
The distribution information comprises a plurality of continuous unit distribution information,
In addition, the unit distribution information at a preset position in the distribution information is empty unit distribution information in which the information amount of the distribution information provided for the processing is zero,
Further, after the delivery to the target relay device is resumed, the unit time consumption at the target relay device is restored to the same unit time consumption as the unit time consumption before the relay function is stopped. Return means
After return of the unit time consumption in the target relay device, all other than the relay device that is downstream in the distribution before the relay function is stopped with respect to the relay device in which the relay function is stopped Distribution control means for distributing the empty unit distribution information only to the relay device;
A network control device further comprising: A distribution device that is a distribution source of the distribution information, and a plurality of relay devices that are connected to the distribution device while forming a plurality of hierarchies. The distribution information from the distribution device to each of the relay devices In a control method for controlling any of the relay devices included in a network system to which
A detection step of detecting whether the relay function of the distribution information in any one of the relay apparatuses upstream in distribution of the distribution information to the target relay apparatus that is the relay apparatus to be controlled is stopped;
Consumption per unit time when it is detected that the distribution information stored in the target relay device is used for processing executed in the target relay device when it is detected that the relay function is stopped A consumption control step for controlling the unit time consumption, which is a quantity, to be less than the unit time consumption before the relay function stops;
A network control method comprising: A distribution device that is a distribution source of the distribution information, and a plurality of relay devices that are connected to the distribution device while forming a plurality of hierarchies. The distribution information from the distribution device to each of the relay devices A computer included in the network control device that controls any of the relay devices included in the network system to which
Detecting means for detecting whether or not the relay function of the distribution information in any of the relay apparatuses upstream in distribution of the distribution information to the target relay apparatus that is the relay apparatus to be controlled; and
Consumption per unit time when it is detected that the distribution information stored in the target relay device is used for processing executed in the target relay device when it is detected that the relay function is stopped Consumption control means for controlling the unit time consumption, which is a quantity, to be less than the unit time consumption before the relay function stops;
Network control program characterized by functioning as

Images