JP2006033514A - Connection mode control apparatus, connection mode control method, and connection mode control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection mode control apparatus or the like in a network capable of continuing reproduction processing or the like in a node being a subordinate node of a node whose function is stopped without interruption even when the function of the node belonging to a higher-order layer in the tree-structure network is stopped. <P>SOLUTION: Even when the function of the node 2-1 in the higher-order layer is stopped, the connection mode control apparatus searches another node 1-1 to which contents can be distributed and connects with the node 1-1, and increases the distribution speed after the connection faster than that before the function stop. Further, two lines, that is, a main line and a sub line are connected to one node, and data obtained from the main line are ordinarily reproduced. On the occurrence of a fault on the main line, the main line is switched immediately to the sub line and another line is used for a new sub line. On the occurrence of a fault on the sub line, the main line is used as it is and another new sub line is formed again. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present application belongs to the technical field of a connection mode control device, a connection mode control method, and a connection mode control program, and more specifically, a distribution device as a distribution information distribution source and a so-called tree structure having the distribution device as a vertex. A connection mode control device, a connection mode control method, and a connection sun for controlling a connection state of each device in a network system configured by a plurality of relay devices connected as a tree structure including a plurality of hierarchies It belongs to the technical field of the connection mode control program used for the control.

  In recent years, with the increase in the speed of home Internet lines, a network is formed by connecting a plurality of personal computers or the like in each home, etc. in a tree shape with one distribution device as a distribution source at the top. A network system that configures what is called “topology” from the viewpoint of the connection mode and distributes so-called content such as music and movies from the distribution device via the network is becoming common.

  In such a network, each of the distribution device and each personal computer constituting the network is generally referred to as a “node”.

Here, as a conventional technique regarding a broadband router having a function as the node, for example, there is one disclosed in the following patent document.
JP 2003-169089 A

  However, in the case of the configuration of the invention described in Patent Document 1, in a node that belongs to a higher hierarchy in the tree structure and relays distribution information, for example, the relay in that node due to the power being turned off, etc. When the function is stopped, a new network (topology) including other relay devices other than the relay device for which the relay function is stopped will be automatically reconstructed as a vertex with the distribution device. There is a problem that a relay device that is in a lower level than the relay device in which the relay function is stopped interrupts the information reproduction process using the distribution information distributed until then for a certain period of time.

  Therefore, the present application has been made in view of the above-described problems, and the purpose thereof is lower than the stopped relay device even when the function of the relay device belonging to the upper layer in the tree structure network stops. An object of the present invention is to provide a connection mode control device and a connection mode control method for a network that can continue a reproduction process or the like in a relay device without interruption, and a connection mode control program used for controlling the connection mode.

  In order to solve the above-described problem, the invention described in claim 1 is connected to a distribution device such as a node as a distribution information distribution source and a tree structure while forming a plurality of hierarchies for the distribution device. In a connection mode control device for controlling a connection mode between the distribution device and the relay device in a network system in which the distribution information is distributed including a plurality of relay devices such as nodes, etc., in any of the relay devices When the relay function is stopped, a search unit such as a CPU for searching for another relay apparatus other than the relay apparatus for which the relay function is stopped and capable of relaying the distribution information; and Connection means such as a CPU for connecting the relay device that is to receive distribution of the distribution information to the other relay device that has been searched, and the other relay device that is connected Distribution means for continuing distribution of communication information, such as a CPU that continues the distribution by making the distribution information distribution speed via the other relay device faster than before the suspension of the relay function Continuation means.

  Therefore, when the relay function of any relay device stops, when searching for another relay device capable of relaying distribution information and continuing distribution of distribution information via the searched other relay device Since the distribution speed of the distribution information is made higher than before the relay function is stopped and the distribution is continued, the distribution information processing in the relay apparatus belonging to the lower hierarchy is continued with respect to the relay apparatus in which the relay function is stopped. Can be made.

  In order to solve the above problem, the invention according to claim 2 is the connection mode control device according to claim 1, wherein the distribution continuation means is configured to distribute the distribution information via the other connected relay device. The distribution speed is continuously increased to a speed up to the maximum value of the distribution speed defined in the network connecting the distribution apparatus and each relay apparatus, and the distribution is continued.

  Therefore, since the distribution is continued while increasing the distribution speed of the distribution information via the other connected relay apparatuses up to the maximum with the maximum value of the distribution speed, the relay apparatus belonging to the lower hierarchy is more rapid. It is possible to obtain necessary distribution information.

  In order to solve the above-mentioned problem, the invention according to claim 3 is the connection form control device according to claim 1 or 2, wherein the distribution continuation means is the distribution destination of the distributed distribution information. The distribution is continued at a higher speed than before the relay function is stopped until the storage amount in the relay device reaches a predetermined amount set in advance.

  Therefore, the distribution function is continued faster than before the stop of the relay function until the storage amount of the distributed information reaches the predetermined amount set in advance in the relay device as the distribution destination. It is possible to reliably continue the distribution information processing in the relay device belonging to the lower hierarchy with respect to the stopped relay device.

  In order to solve the above problems, the invention according to claim 4 is connected to a distribution device such as a node as a distribution information distribution source and a tree structure while forming a plurality of hierarchies for the distribution device. In a connection mode control device for controlling a connection mode between the distribution device and the plurality of relay devices in a network system in which the distribution information is distributed including a plurality of relay devices such as nodes, etc., the one relay device By connecting a plurality of other relay devices to the one relay device to form a plurality of routes through which the distribution information is distributed to the one relay device, and one main route. The distribution information distributed to the one relay device via a route is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device and to the one relay device The distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is supplied to the one relay device. Distribution control means such as a CPU that distributes to another relay device belonging to the lower hierarchy.

  Therefore, a main route and a sub route are formed so that a plurality of relay devices are connected to one relay device, and distribution information distributed via the main route is an external output process and lower order in the one relay device. Used for distribution to other relay devices belonging to the same hierarchy, and distribution information distributed via the main route or the sub route which is one route to other relay devices belonging to the lower hierarchy Therefore, by multiplexing the routes in each relay device, redundancy can be increased in preparation for the stop of the relay function in any relay device, and the relay device belonging to the lower hierarchy Stopping external output processing can be prevented.

  In order to solve the above-described problem, the invention according to claim 5 is the connection mode control device according to claim 4, wherein the one relay device belongs to the higher hierarchy on the main route. A CPU that switches the distribution information distributed to the one relay device via the sub route to be used for the external output processing in the one relay device when the relay function in the relay device is stopped The switching means is further provided.

  Therefore, when the relay function in a relay device belonging to a higher hierarchy on the main route is stopped for one relay device, the distribution information distributed via the sub route is used for external output processing. Since the switching is performed, the external output process in the one relay device is not interrupted.

  In order to solve the above problem, the invention according to claim 6 is the connection mode control device according to claim 5, wherein the distribution information distributed to the one relay device via the sub route is The new relay that belongs to the higher hierarchy with respect to the distribution device or the one relay device when switched by the switching means to be used for the external output processing in the one relay device Search means for searching for any one of the devices is further provided, and the connection means is configured to connect the one searched by the search means to the one relay device to form a new route.

  Therefore, when the distribution information distributed via the sub route is switched to be used for external output processing, a new relay device belonging to a higher hierarchy with respect to the distribution device or the one relay device Any one of these is searched, and the searched distribution device or relay device is connected to one relay device to form a new route, so that redundancy can be secured and maintained.

  In order to solve the above-described problem, the invention according to claim 7 is the connection mode control apparatus according to claim 4, wherein the one relay apparatus belongs to the higher hierarchy on the sub route with respect to the one relay apparatus. When the relay function in the relay device is stopped, the relay device further includes search means for searching for either the distribution device or the new relay device belonging to the higher hierarchy with respect to the one relay device, The connection means is configured to connect the one searched by the search means to the one relay device to form a new sub route.

  Therefore, when a relay function in a relay device belonging to a higher hierarchy on the sub route with respect to one relay device is stopped, a new one belonging to a higher hierarchy with respect to the distribution device or the one relay device Since one of the relay devices is searched and the searched distribution device or relay device is connected to one relay device to form a new sub route, the relay in the relay device that was on the previous sub route Even if the function stops, a new sub-path can be formed to ensure and maintain redundancy.

  In order to solve the above problem, the invention according to claim 8 is the connection mode control device according to any one of claims 6 and 7, wherein the search means includes the one relay device. The other relay device in the existing hierarchy is configured to search for the one so as to be included in the new main route.

  Therefore, since another relay device in the hierarchy to which the one relay device belongs searches for the distribution device or the relay device so that it is included in the new main route, the relay device via the relay device in the same hierarchy is used. Delivery information can be supplied.

  In order to solve the above-described problem, the invention according to claim 9 is the connection mode control device according to any one of claims 1 to 8, wherein the connection means is in the hierarchy different from each other. A plurality of routes are formed by connecting each relay device to the one relay device.

  Therefore, by connecting relay devices in different layers to one relay device to form a plurality of routes to the one relay device, there is a possibility of occurrence of a failure such as a relay function stop for each layer. Even when they are different, it is possible to ensure sufficient redundancy.

  In order to solve the above-described problem, the invention according to claim 10 is connected to a distribution device such as a node as a distribution information distribution source and a tree structure while forming a plurality of hierarchies for the distribution device. In a connection mode control method for controlling a connection mode between the distribution device and the relay device in a network system in which the distribution information is distributed including a plurality of relay devices such as nodes, etc., in any of the relay devices When the relay function is stopped, a search step for searching for another relay device other than the relay device for which the relay function is stopped and capable of relaying the distribution information; and A connection step of connecting the relay device that is to receive distribution of the distribution information to another relay device, and distribution of the distribution information via the other connected relay device A delivery connection process to continue, including delivery speed of the distribution information via the another relay device, and a distribution continuing step for continuing the delivery faster than the previous stop of the relay function.

  Therefore, when the relay function of any relay device stops, when searching for another relay device capable of relaying distribution information and continuing distribution of distribution information via the searched other relay device Since the distribution speed of the distribution information is made higher than before the relay function is stopped and the distribution is continued, the distribution information processing in the relay apparatus belonging to the lower hierarchy is continued with respect to the relay apparatus in which the relay function is stopped. Can be made.

  In order to solve the above-described problem, the invention according to claim 11 is connected to a distribution device such as a node as a distribution information distribution source, in a tree structure while forming a plurality of hierarchies for the distribution device. In a connection mode control method for controlling a connection mode between the distribution device and the plurality of relay devices in a network system in which the distribution information is distributed including a plurality of relay devices such as nodes, the one relay device A plurality of other relay devices are connected to each other to form a plurality of routes through which the distribution information is distributed to the one relay device, and a main route which is the one route. The distribution information distributed to the one relay device is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device, and the distribution information in the one relay device is The distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is supplied to the one relay device. And a delivery control step of delivering to another relay device belonging to the lower hierarchy.

  Therefore, a main route and a sub route are formed so that a plurality of relay devices are connected to one relay device, and distribution information distributed via the main route is an external output process and lower order in the one relay device. Used for distribution to other relay devices belonging to the same hierarchy, and distribution information distributed via the main route or the sub route which is one route to other relay devices belonging to the lower hierarchy Therefore, by multiplexing the routes in each relay device, redundancy can be increased in preparation for the stop of the relay function in any relay device, and the relay device belonging to the lower hierarchy Stopping external output processing can be prevented.

  In order to solve the above-described problem, the invention according to claim 12 is connected to a distribution device such as a node as a distribution information distribution source, in a tree structure while forming a plurality of hierarchies for the distribution device. A relay device such as a plurality of nodes, and a computer included in a connection mode control device that controls a connection mode between the distribution device and the relay device in a network system in which the distribution information is distributed, Search means for searching for another relay device other than the relay device in which the relay function is stopped and capable of relaying the distribution information when the relay function in the relay device is stopped; Via the connecting means for connecting the relay device that is to receive distribution of the distribution information to the other relay device that has been searched, and via the other connected relay device A distribution continuation means for continuing the distribution of the distribution information, the distribution continuation means for continuing the distribution by making a distribution speed of the distribution information via the other relay device faster than before the suspension of the relay function. To function as.

  Therefore, when the relay function of any relay device stops, when searching for another relay device capable of relaying distribution information and continuing distribution of distribution information via the searched other relay device Since the computer functions so that the distribution speed of the distribution information is made higher than before the stop of the relay function and the distribution is continued, the relay apparatus belonging to a lower hierarchy with respect to the relay apparatus in which the relay function is stopped Processing of distribution information can be continued.

  In order to solve the above-described problem, the invention according to claim 13 is connected to a distribution device such as a node as a distribution information distribution source and a tree structure while forming a plurality of hierarchies for the distribution device. A computer included in a connection mode control device for controlling a connection mode between the distribution device and the plurality of relay devices in a network system in which the distribution information is distributed including a plurality of relay devices such as nodes. A plurality of other relay devices connected to the relay device, thereby forming a plurality of routes through which the distribution information is distributed to the one relay device, and a single route. The distribution information distributed to the one relay device via a certain main route is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device and the one relay device The distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is subjected to external output processing in the relay device, and the one relay device To the distribution control means for distributing to another relay device belonging to the lower hierarchy.

  Therefore, a main route and a sub route are formed so that a plurality of relay devices are connected to one relay device, and distribution information distributed via the main route is an external output process and lower order in the one relay device. Used for distribution to other relay devices belonging to the same layer, and distribution information distributed via the main route or sub route as one route is distributed to other relay devices belonging to the lower layer Since the computer functions as used in the above, by multiplexing the routes in each relay device, it is possible to increase redundancy in preparation for the stop of the relay function in any of the relay devices, and belong to a lower hierarchy It is possible to prevent the external output process from stopping in the relay device.

  According to the first aspect of the present invention, when the relay function in any of the relay devices is stopped, another relay device capable of relaying the distribution information is searched, and the other relay device searched for is searched for. When continuing to distribute the distribution information, the distribution information is distributed at a higher speed than before the relay function is stopped, so that the distribution is continued. Therefore, the relay function belongs to a lower hierarchy with respect to the relay device in which the relay function has stopped. Processing of distribution information in the relay device can be continued.

  Therefore, even if another relay device is connected to a lower level of the relay device whose relay function is stopped, it is possible to continue the process such as reproduction using the distribution information without the influence of the function stop.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the distribution speed of distribution information via another connected relay device is set with the maximum value of the distribution speed as an upper limit. Since the distribution is continued while the speed is successively increased, the necessary distribution information can be acquired more quickly in the relay apparatus belonging to the lower hierarchy.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, a predetermined amount in which the storage amount of the distributed distribution information in the relay device as the distribution destination is set in advance. Until the relay function stops, the distribution is continued faster than before the stop of the relay function, so that the processing of the distribution information in the relay apparatus belonging to the lower hierarchy is surely continued for the relay apparatus in which the relay function is stopped. be able to. According to the fourth aspect of the present invention, the main route and the sub route are formed so that a plurality of relay devices are connected to one relay device, and the distribution information distributed via the main route is Used for external output processing in other relay devices and distribution to other relay devices belonging to a lower layer, and distribution information distributed via a main route or sub route as one route is in a lower layer Since it is used for distribution to other relay devices to which it belongs, by multiplexing the routes in each relay device, it is possible to increase redundancy in preparation for stopping the relay function in any of the relay devices. It is possible to prevent the external output process from stopping in the relay apparatus belonging to the hierarchy.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, the relay function in the relay apparatus belonging to the higher hierarchy on the main route with respect to one relay apparatus is stopped. At this time, since the distribution information distributed via the sub route is switched to be used for the external output process, the external output process in the one relay device is not interrupted.

  According to the invention described in claim 6, in addition to the effect of the invention described in claim 5, when the distribution information distributed via the sub route is switched to be subjected to the external output process, Search for either one of the distribution device or a new relay device belonging to a higher hierarchy with respect to the one relay device, and connect the searched distribution device or relay device to the one relay device to create a new route Therefore, redundancy can be secured and maintained.

  According to the invention described in claim 7, in addition to the effect of the invention described in claim 4, the relay function in the relay apparatus belonging to the higher hierarchy on the sub route with respect to one relay apparatus is stopped. When searching for one of the distribution device or a new relay device belonging to a higher hierarchy with respect to the one relay device, and connecting the searched distribution device or relay device to the one relay device Since a new sub route is formed, a new sub route can be formed and redundancy can be ensured and maintained even if the relay function in the relay device that has been on the sub route is stopped.

  According to the invention described in claim 8, in addition to the effect of the invention described in claim 6 or 7, another relay apparatus in the hierarchy to which one relay apparatus belongs is newly added. Since the distribution device or the relay device is searched so as to be included in the main route, distribution information can be supplied via the relay device in the same hierarchy.

  According to the invention described in claim 9, in addition to the effect of the invention described in any one of claims 1 to 8, by connecting each relay device in a different hierarchy to one relay device. Since a plurality of routes to the one relay device are formed, sufficient redundancy can be surely ensured even if the possibility of occurrence of a failure such as a relay function stop differs for each layer.

  According to the invention described in claim 10, when the relay function in any of the relay devices is stopped, another relay device capable of relaying distribution information is searched, and the other relay device searched for is searched for. When continuing to distribute the distribution information, the distribution information is distributed at a higher speed than before the relay function is stopped, so that the distribution is continued. Therefore, the relay function belongs to a lower hierarchy with respect to the relay device in which the relay function has stopped. Processing of distribution information in the relay device can be continued.

  Therefore, even if another relay device is connected to a lower level of the relay device whose relay function is stopped, it is possible to continue the process such as reproduction using the distribution information without the influence of the function stop.

  According to the eleventh aspect of the present invention, the main route and the sub route are formed so that a plurality of relay devices are connected to one relay device, and the distribution information distributed via the main route is the one of the ones. Used for external output processing in other relay devices and distribution to other relay devices belonging to a lower hierarchy, distribution information distributed via the main route or sub route that is one route belongs to the lower hierarchy Because it is used for distribution to other relay devices, it is possible to increase the redundancy in preparation for the stop of the relay function in any relay device by multiplexing the route in each relay device, and to the lower hierarchy It is possible to prevent the external output process from stopping in the relay device to which it belongs.

  According to the twelfth aspect of the present invention, when the relay function in any of the relay devices is stopped, another relay device capable of relaying the distribution information is searched, and the other relay device searched for is searched for. When continuing the distribution of distribution information, the computer functions so that the distribution information is distributed at a higher speed than before the relay function is stopped and the distribution is continued. It is possible to continue the distribution information processing in the relay device belonging to the hierarchy.

  Therefore, even if another relay device is connected to a lower level of the relay device whose relay function is stopped, it is possible to continue the process such as reproduction using the distribution information without the influence of the function stop.

  According to the invention described in claim 13, the main route and the sub route are formed so as to connect a plurality of relay devices to one relay device, and the distribution information distributed via the main route is Used for external output processing in other relay devices and distribution to other relay devices belonging to a lower hierarchy, distribution information distributed via the main route or sub route that is one route belongs to the lower hierarchy Since the computer functions to be used for distribution to other relay devices, multiplexing the routes in each relay device can increase redundancy in preparation for stopping the relay function in any of the relay devices. It is possible to prevent the external output process from being stopped in the relay apparatus belonging to the lower hierarchy.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. In the embodiment described below, a node as a distribution device that is a distribution source of content as distribution information and a plurality of other nodes connected to the node as a tree structure while forming a plurality of hierarchies In the embodiment, the present invention is applied to the control process of the connection mode between the nodes in the network system in which content is distributed.

(I) First Embodiment (A) Embodiment First, a first embodiment according to the present invention will be described with reference to FIGS.

  1 is a block diagram showing a schematic configuration of the network system according to the first embodiment, FIG. 2 is a block diagram showing an overall configuration of one node included in the network system, and FIG. FIG. 4 is a flowchart showing a normal distribution operation in the network system, and FIG. 5 shows a schematic configuration of the network system after the relay function in some nodes is stopped. FIG. 6 is a flowchart showing the operation of the lower node when the relay function stops, FIG. 7 shows the operation of the lower node when the relay function stops, and FIG. 8 shows the first embodiment. It is a figure which shows the operation | movement in the network system which concerns on a modified form of.

  As shown in FIG. 1, the network system NT according to the first embodiment is formed by a tree structure having nodes 0-1 as distribution devices as vertices, and the node 1-1 is configured as a node constituting the first hierarchy. 1-2 and 1-3, nodes 2-1 and 2-2 are included as nodes constituting the second hierarchy, and nodes 3-1, 3-2 are included as nodes constituting the third hierarchy. 3-3 and 3-4, and further include nodes 4-1, 4-2 and 4-3 as nodes constituting the fourth hierarchy. The nodes are connected to each other by a line L that is a wired line or a wireless line with the node 0-1 as a vertex. Here, in a specific example of each node, the highest node 0-1 corresponds to, for example, a server that is a content distribution source, and all other nodes other than the node 0-1 are, for example, It is comprised by the personal computer etc. with which each household was equipped. The node may be a set top box or router in the home.

  In the network system NT shown in FIG. 1, the contents desired by the user of each node with the node 0-1 as the distribution source are included in the hierarchy above the node on the line L. It is delivered via the node. At this time, it goes without saying that the content is distributed in a digitized state, and is distributed in units of so-called packets. Furthermore, each packet is distributed with a packet number of a serial number indicating the order of reproduction and storage in the buffer memory 4 (see FIG. 2).

  Next, a specific configuration of each node will be described with reference to FIGS. In the following description, the detailed configuration of the node 3-2 in the network system NT shown in FIG. 1 is shown, but the detailed configuration of the other nodes is exactly the same as that of the node 3-2.

  As shown in FIG. 2, the node 3-2 includes a CPU 1, a decoder 2, a table memory 3, a buffer memory 4, a broadband as search means, connection means, distribution continuation means, distribution control means, and switching means. The interface 5, the timer 6, the speaker 7, and a CRT (Cathode Ray Tube) 8 as a display means are configured. The CPU 1, the decoder 2, the table memory 3, the buffer memory 4, the broadband interface 5, and the timer 6. Are connected to each other via a bus 9.

  Next, the operation will be described.

  First, the broadband interface 5 is directly connected to the line L. In the case of the node 3-2, as shown in FIG. 1, the broadband interface included in the node 2-1 in the upper hierarchy as shown in FIG. 5 is also connected via the line L. Similarly, the broadband interface 5 included in each of the nodes 4-1 to 4-3 in the lower hierarchy is also connected via the line L. In addition, content can be exchanged between nodes and control information necessary for that can be exchanged in units of packets.

  Next, a topology table T as illustrated in FIG. 3A is stored in the table memory 3 which is a nonvolatile memory. At this time, the topology table T identifies each of the other nodes in the upper or lower hierarchy according to the position in the network system NT of the node including the table memory 3 in which the topology table T is stored. A node number to be used and an IP (internet protocol) address in the network system NT are included together with level information representing a hierarchy. Since the topology table T illustrated in FIG. 3A corresponds to the node 3-2, the contents include two upper layers as viewed from the node 3-2 as shown in FIG. Level information indicating the node 1-1 at (level “2”), a node number of the node 1-1, an IP address indicating the node 1-1 (for example, “100.100.10.10”), and the like. ,It is included.

  Similarly, level information indicating the node 2-1 in the hierarchy one level higher than the node 3-2 (level “1”), the node number of the node 2-1, and the IP indicating the node 2-1. Address (for example, “100.100.10.21”), level information indicating the node 4-1 in the hierarchy one level lower than the node 3-2 (level “−1”), the node 4- 1 node number and IP address (for example, “100.100.10.30”) indicating the node 4-1, and level information indicating the node 4-2 in the same lower hierarchy (level-1). , The node number of the node 4-2 and the IP address (for example, “100.100.10.31”) indicating the node 4-2, and a hierarchy one level lower than the node 3-2 (level “−1”). Level indicating node 4-3 in ")" Broadcast, the IP address indicating the node number and the node 4-3 of the node 4-3 (e.g., "100.100.10.32"), are included.

  Returning to FIG. 2, the buffer memory 4 that is a volatile memory is composed of a ring buffer memory in a so-called FiFO (First In First Out) format, and data corresponding to the distributed content is Only the preset recording capacity is stored in the order of distribution, and it is read in the order of storage under the control of the CPU 1 and output to the decoder 2 via the bus 9.

  Here, the operation of the buffer memory 4 when the network system NT is in the normal state will be described with reference to FIG.

  As described above, the buffer memory 4 is configured in a ring shape. For example, as conceptually shown in the upper half of FIG. 3B, content data is input clockwise via the broadband interface 5. As shown conceptually in the lower half of FIG. 3B, the data is output to the decoder 2 in a clockwise direction. In the example shown in FIG. 3B, the hatched portion of the data is the portion where the content data is actually accumulated, and this data is the decoder 2 as indicated by the arrow in the lower half of FIG. In parallel with this, new data is input from the broadband interface 5 and stored as indicated by arrows in the upper half of FIG. In the normal state, the input amount and output amount of data to the buffer memory 4 per unit time are the same, and the accumulation amount in the buffer memory 4 is substantially constant (more specifically, half of the buffer memory 4). The accumulated amount).

  On the other hand, when the arrival time of the packet as the data changes when the topology in the network system NT is changed, the buffer memory 4 can absorb the change. Further, when the decoder 2 itself tries to decode a certain amount of data collectively or when the topology is cut for some reason, the buffer memory 4 is emptied so that the reproduction process in the decoder 2 is not interrupted. The buffer memory 4 functions so as to always store a certain amount of data.

  Next, referring back to FIG. 2, the timer 6 measures the time for detecting that the relay function in any node in the network system NT is stopped, as will be described later.

  Further, the decoder 2 decodes the content data output from the buffer memory 4 via the bus 9, outputs an image of the data to the CRT 8, and displays the sound for the sound of the speaker 7. Sounds through.

  Next, an operation in which a new node is connected to the network system NT and content distribution is started and executed in a normal state including the new node will be described with reference to FIG. In FIG. 4, the node 3-1 is newly connected to the node 2-1 in the network system NT, and the network system NT shown in FIG. It is a flowchart which shows the example in the case of performing. In the embodiment described below, the total storage capacity of the buffer memory 4 is 64 kilobytes, which corresponds to the data amount for the 16 packets.

  When the node 3-1 is newly connected to the network system NT by being physically connected to the node 2-1, the CPU 1 of the node 3-1 first has a buffer memory 4 (hereinafter referred to as “buffer memory 4”). In each figure, the buffer memory 4 itself is appropriately set as “ring buffer”) and a speed parameter indicating the reproduction speed in the decoder 2 (hereinafter, the speed parameter is indicated as “speed Reg” in each figure), The normal playback speed is set to one time, and the IP address of the node indicating the data supply source is set to the node 2-1 immediately above (the IP address of this node 2-1 is the node 3-1). Is acquired by the node 3-1 when the node is connected to the node 2-1. Then, in order to calculate an address for storing data in the buffer memory 4, an input counter (16 bits) for counting the number of bytes received from the data distributed from the node 2-1, and the data regenerated by the decoder 2 The output counters (16 bits) representing the quantities are initialized as “0”, respectively (step S1).

  Here, the storage address of the data input to the buffer memory 4 is “the start address of the buffer memory 4 + the value of the input counter”, and the read address in the data read to the decoder 2 is “the start address of the buffer memory 4 + output” Counter value ".

  When the necessary initialization process is completed, the CPU 1 in the node 3-1 next refers to the topology table T in the table memory 3 and requests the data node 2-1 to start transferring content data. A start message is transmitted (step S2).

  Next, the CPU 1 in the node 2-1 having received the start message (step S15) checks whether or not the message received at that time is a start message (step S16). Since it is a start message (step S16; Y), the packet number of the data currently being reproduced by the node 2-1 is returned to the node 3-1 again as the start packet number (step S17).

  As a result, when the node 3-1 acquires the start packet number from the node 2-1, it stores it in the corresponding packet number area on the buffer memory 4 (step S3), and this time the actual content data is stored. The requested data request message is transmitted to the node 2-1 (step S4). Here, the data request message includes information indicating the packet number of data to be transmitted to the node 3-1, and the distribution rate magnification (contents of the parameter “rate Reg” in the node 2-1). It is.

  The node 2-1 that has received the data request message (step S15) checks again whether or not the received message is a start message (step S16), and the data request message is currently received. Therefore (step S16; N), it is next confirmed whether or not the received message is a message requesting the topology table T (step S18).

  Here, the confirmation operation in step S18 (and the transmission process of the topology table T from the node 2-1 when it is “Y” (step S19)) is performed in any one of the network systems NT as described later. When the relay function of the node stops, it is executed in preparation for another node connected to the lower hierarchy of the node where the relay function stops newly acquiring the topology as the network system NT. This is a process that does not make sense in the process between the current node 3-1 and the node 2-1. (Thus, the transmission process of the topology table T from the node 2-1 (step S19) is also performed. , Of course, not executed).

  In the determination in step S18, since the data request message currently received is not the topology table request message (step S18; N), it is next confirmed whether or not the received message is a data request message ( In step S20), since the data request message is currently received (step S20; Y), the data for one packet is obtained at the reproduction rate specified in the data request message (currently one). Transmit to the node 3-1 (via the line L) (step S21). In the determination of step S20, when the message received from the node 3-1 at that time is not any of the start message, the topology table request message, or the data request message (step S20; N), it is set in advance. Is returned to the node 3-1 (step S22).

  In parallel with these, the node 3-1 starts timing the timer 6 in the node 3-1 simultaneously with outputting the data request message, and generates a timer interrupt instruction when the time reaches “0”. It has been set (step S5). The timer 6 waits until a predetermined time elapses (step S6). If data from the node 2-1 does not arrive within the predetermined time (step S6; N), the timer interrupt instruction is Then, the connection process described above is performed again on the node 2-1.

  On the other hand, when the data from the node 2-1 arrives within the predetermined time (step S6; Y), it is confirmed whether or not the arrived data has been correctly transmitted (step S7), and is correctly transmitted. If it has been received (step S7; Y), the execution of the timer interrupt instruction is prohibited (step S8), and one packet of the received data is stored in the buffer memory 4. Accordingly, the value of the input counter and the number of the packet already stored in the buffer memory 4 are updated by one packet, and the speed parameter is set for the current acceleration (set in the initialization process in step S1). (Step S9).

  Then, it is confirmed whether or not the amount of data stored in the buffer memory 4 and not output to the decoder 2 has become eight packets (that is, half the storage amount of the buffer memory 4) (step S10). If it is less than the packet (step S10; Y), the process returns to step S4 and repeats the above-described processing to receive the next packet. On the other hand, the amount of data stored in the buffer memory 4 is as much as eight packets. When this occurs (step S10; N), the speed parameter and its acceleration are returned to the initial values (step S11), and data output to the decoder 2 is started (step S12). The process returns to step S4 to receive from 1.

  By repeating the processes of steps S4 to S10 described above, until the data for eight packets is accumulated in the buffer memory 4, the distribution speed from the node 2-1 is the acceleration at that time (initial value 0.2). The buffer memory 4 is filled at high speed until data reception becomes an error (step S7; Y). On the other hand, when an error occurs in data reception (step S7; Y), the subsequent delivery speed is reduced by 0.5 times the acceleration at that time (step S13) to ensure data transmission. After that, the subsequent distribution is continued.

  In the process of step S12, when data for eight packets is accumulated in the buffer memory 4 and the data is output to the decoder 2, the decoder 2 outputs the data in the buffer memory 4 at that time. Based on the value of the counter, the address of the data output from the buffer memory 4 is acquired (step S25), the data is decoded and reproduced for one packet (step S26), and the output counter of the buffer memory 4 is further decoded. Incrementing the value by one packet (step S27) is repeated by eight packets to perform data reproduction processing.

  As described above, the data distribution from the node 2-1 and the reproduction process in the node 3-1 are executed, so that the data reproduction process in the node 3-1 can be performed while keeping the data amount in the buffer memory 4 constant. Will be executed.

  Next, in the network system NT shown in FIG. 1, for example, the processing when the content relay function in the node 2-1 is exhibited due to, for example, the power switch being turned off is specifically shown in FIGS. Will be described.

  That is, in the network system NT according to the first embodiment, when the relay function in the node 2-1 is stopped for the reason described above, as shown in FIG. 5, it is connected to the original node 2-1. The nodes 3-1 and 3-2 automatically execute the topology reconfiguration operation, and respectively connect the line L ′ to the node 1-1 in the hierarchy one level higher than the node 2-1. Connect themselves and continue to distribute content.

  First, the overall operation in the nodes 3-1 and 3-2 when the relay function in the node 2-1 is stopped as shown in FIG. 5 will be described.

  As shown in FIG. 5, when the relay function in the node 2-1 is stopped, the CPU 1 in the nodes 3-1 and 3-2 in the lower hierarchy (the distribution in the normal state has been continued. In the case where the processing described above is repeated), data from the node 2-1 cannot be received even if a predetermined time elapses in the processing of step S6 shown in FIG. Then, when the CPU 1 in the nodes 3-1 and 3-2 cannot receive the data even after the predetermined time has elapsed (step S6; N), the node 2-in the hierarchy immediately above each of the nodes 3-1 and 3-2. It is recognized that the relay function in 1 is stopped and the topology so far is disconnected.

  Then, referring to the topology table T stored in the table memory 3 when the disconnection of the topology is recognized, each of the nodes 3-1 and 3-2 is in the two upper layers as viewed from each. A new line L ′ is formed and connected to the existing node 1-1 to reconstruct the topology. As a result, the node 2-1 is deleted from the topology table T in the table memory 3 in the nodes 3-1 and 3-2 until then, and the level information of the newly connected node 1-1 is changed to “ Update to “1”. Thereafter, the nodes 3-1 and 3-2 respectively transmit a topology table request message (see steps S18 and S19 in FIG. 4) to the node 1-1, and obtain a new topology table T from the node 1-1. To do. Then, based on the acquired topology table T, the node 0-1 that recognizes that the node that is one level higher than the node 1-1 is the node 0-1 and that has the level information “2” at the same time. 1 is added to the topology table T of each (nodes 3-1 and 3-2) to complete the reconstruction of the topology.

  Thereafter, each of the nodes 3-1 and 3-2 requests the node 1-1 to transmit a packet having a packet number subsequent to the packet acquired so far (see step S4 in FIG. 4). In response to this, transmission of subsequent data is started to the nodes 3-1 and 3-2 which are new transmission destinations.

  Here, changes in the buffer memory 4 in the node 1-1 and the nodes 3-1 and 3-2 during the above-described topology reconstruction will be described with reference to FIG.

  As described above, in the nodes 3-1 and 3-2, which are in the reminiscent of the node 2-1 in which the relay function is stopped, the data from the node 2-1 cannot be received when the relay function is stopped. The amount of data stored in each buffer memory 4 decreases. On the other hand, the decoders 2 of the nodes 3-1 and 3-2 continue to read data for reproduction processing from the buffer memory 4. Therefore, as shown in FIG. 6A, the data in each buffer memory 4 is decreasing.

  On the other hand, in the node 1-1 that is one level higher than the node 2-1, data cannot be transferred to the node in the lower level, so as shown in FIG. However, the amount of data in the buffer memory 4 is only increasing.

  As a result, after the topology is reconstructed, the nodes 3-1 and 3-2 newly connected to the lower hierarchy with respect to the node 1-1 can regain their normal buffer memories 4 as quickly as possible. It must recover to the state (ie, the state where data is accumulated up to half of each). If data cannot be received continuously from a higher-level node, and each decoder 2 continues to extract data from the buffer memory 4, each buffer memory 4 is eventually emptied. This is because the reproduction processing in each of the nodes 3-1 and 3-2 is interrupted.

  Therefore, in the first embodiment, the nodes 3-1 and 3-2, which are to recover the accumulated amount in the buffer memory 4 early, improve the delivery speed with respect to the newly connected node 1-1. A control signal (command) is sent to the effect. Then, the node 1-1 that has received the command, for example, as shown in FIG. 6 (c), at a distribution speed that is twice the normal reproduction processing speed at the nodes 3-1 and 3-2, Data is distributed to 1 and 3-2 (internal buffer memory 4). As a result, the accumulated amount in the buffer memory 4 is restored to the normal state in approximately the same time as the time required for the reconstruction of the topology.

  At this time, more specifically, as an aspect of improving the delivery speed, the maximum value of the delivery speed is determined by the transfer processing capability of the CPU 1 in each node related to the so-called bands (frequency bands) as the lines L and L ′. However, considering the general redundancy, it is appropriate that the normal reproduction processing speed is about twice as described above.

  Here, as another aspect of changing the delivery speed, for example, instead of suddenly doubling, the accumulation amount in the buffer memory 4 in the nodes 3-1 and 3-2 reaches a predetermined amount set in advance. Until the control signal to the effect is transmitted from the nodes 3-1 and 3-2, the node 1-1 can be configured to continue to improve the distribution speed at a certain rate. In addition, since the delivery speed is limited due to the output capability of the node 1-1 and the bandwidth of the line L ′ connecting the nodes 3-1 and 3-2, the packet is transferred from the upper layer node to the lower layer. If the message is received by exchanging the necessary messages with each other or with other control devices, the delivery speed can be increased to the maximum speed that can be used at that time. It is also possible to restore the accumulated amount in each buffer memory 4 in the shortest time. Node 3-2 transmits to lower nodes 4-1 and 4-2 at the same speed as received from node 1-1.

  Next, as shown in FIG. 5, in the network system NT according to the first embodiment, the relay function of the node 2-1 is stopped, so that the nodes 3-1 and 3-2 in the lower hierarchy are The operation of restructuring the topology as the network system NT by reconnecting to the node 1-1 will be described with reference to the flowchart of FIG. In the following description, of the two nodes 3-1 and 3-2 connected to the node 2-1, the reconnection operation in the node 3-1 will be described. The connection operation is executed in exactly the same way.

  Until the relay function of the node 2-1 stops, the process shown in FIG. 4 described above is repeated in the node 3-1. Then, when the data from the node 2-1 does not arrive even after a predetermined time has elapsed in the process of step S6 shown in FIG. 4, the relay function in the node 2-1 of the higher hierarchy is received in the node 3-1. Determines that has stopped, and starts reconnecting the tree structure.

  Specifically, as shown in FIG. 7, when data from the node 2-1 cannot be received within the predetermined time, a timer interrupt command is generated in the node 3-1 (see step S5 in FIG. 4), From the topology table T in the table memory 3, the IP address of the node 1-1 that is one level higher than the node 2-1, that is, the node 1-1 whose level information is "2" as viewed from the node 3-1, is obtained (step The information in the topology table T regarding the node 2-1 is deleted together with S30). Next, the node 3-1 transmits a topology table request message to the node 1-1 in order to acquire the topology table T in the node 1-1 to the node 1-1 indicated by the IP address. (Step S31).

  Here, during the topology restructuring process, the upper layer node 1-1 operates in exactly the same manner as the operation in the node 2-1 shown in FIG. 4 (steps S15 to S22 in FIG. 4) (FIG. 7). Steps S35 to S42) are executed, the type of message transmitted from the node 3-1 is discriminated (steps S36, S37 and S40), and the processing corresponding to the discriminated message type (step S39, S40). S38, S41 and S42) are executed.

  Then, the node 1-1 in which such processing is executed receives the topology table request message from the node 3-1 (step S35), and if it is determined that the message is the topology table request message (step S35) Step S37; Y), the node 1-1 transmits the topology table T stored in the table memory 3 to the node 3-1 (step S38).

  Receiving this (step S32), the node 3-1 updates the topology table T it had so far using the topology table T obtained from the node 1-1 (step S33). More specifically, the node 0-1 is recognized and the IP address and node number are added for the node 0-1.

  Thereafter, in order to recover the accumulated amount in the buffer memory 4 in the node 3-1 at high speed, the speed parameter is set to “1” and the acceleration is set to 0.2. 1 transmits a data request message (step S34). Thereafter, the process returns to step S5 shown in FIG. 4 and the operations in steps S5 to S12 described above are repeated in the normal state.

  Here, until the data corresponding to the data request message is received from the node 1-1 for one packet, the data in the buffer memory 4 continues to be reduced because it continues to be decoded (see FIG. 6A). When the data starts to be distributed from the node 1-1 (steps S40 and S41), the data is distributed while gradually increasing the distribution speed until the data is accumulated in the buffer memory 4 for eight packets. (Step S9 in FIG. 4). When only 8 packets are accumulated, the buffer memory 4 of the node 3-1 starts to function as a normal state thereafter (see FIG. 3B).

  As described above, according to the connection mode control process in the network system NT according to the first embodiment, when the relay function in any node is stopped, another node capable of relaying content is searched, When continuing the distribution of content via the other searched nodes, the distribution speed is made higher than before the relay function is stopped, so the distribution is continued. It is possible to continue the content processing in the nodes belonging to the hierarchy.

In addition, since the content distribution speed through other newly connected nodes is continuously increased to a speed up to the maximum value of the distribution speed, the distribution is continued. Necessary content can be acquired.
After the relay device stops and the topology is reconstructed, the amount of unreproduced data stored in the buffer of the node is detected, and the delivery speed is the maximum speed according to the detected amount of unreproduced data You may make it control the time until it reaches.

(B) Modified Embodiment Next, a modified embodiment of the first embodiment described above will be described with reference to FIG. FIG. 8 is a flowchart showing the operation of the modified embodiment.

  In the above-described first embodiment, when the relay function in the node 2-1 is stopped, one other node (node 1-1) in the higher hierarchy is searched for, and content is newly created from the one node. However, in the modification described below, a plurality of new nodes are searched, and content distribution from the plurality of nodes is continued at the same time.

  That is, in the node 3-1 according to the modification, as shown in FIG. 8A, first, when data from the node 2-1 cannot be received within the predetermined time, steps S 30 to S 33 shown in FIG. To update the topology table T in the node 3-1.

  Then, while receiving the data distribution from the node 2-1, the difference between the storage amount (number of packets) at that time in the buffer memory 4 and the necessary storage amount (eight packets) in the buffer memory 4 in the normal state is two packets. It is checked whether or not it has become larger (that is, whether or not further data needs to be accumulated) (step S45), and when the difference becomes larger than two packets (that is, further data is accumulated). In step S45; Y), first, a new data request message is transmitted to the node 1-1 and the number of the packet to be received is updated. A data request message is transmitted to a certain node 0-1 (step S46). Then, it is confirmed whether or not data for one packet and a total of two packets have been received from the nodes 1-1 and 0-1 respectively (step S47). When two packets have not been received yet (step S47). N) Wait until reception, and when two packets have been received (step S47; Y), store the data for the two packets in the buffer memory 4 and update only two packets of the input counter. The number of the packet to be received is updated (step S48), and the process returns to step S45.

  On the other hand, if the difference is not larger than two packets in the determination in step S45 (that is, when no further data accumulation is required; step S45; N), whether or not the difference is larger than one packet next. (That is, whether it is not necessary to replenish data so urgently) (step S49), and the difference is not larger than one packet (that is, the accumulated amount of the buffer memory 4 is in the normal state) (Step S49; N), the process returns to Step S11 in FIG. 4 and normal reception processing is continued.

  On the other hand, when the difference is larger than one packet (that is, the accumulated amount of the buffer memory 4 is close to the normal state and it is not necessary to replenish data so urgently) (step S49; Y), the node 1-1 is set. In response to this, a new data request message is transmitted (step S50), and a wait is made until a predetermined time elapses in the time count of the timer 6 in the node 3-1 (step S51). If the data does not arrive (step S51; N), the timer interrupt instruction is executed, and the connection process described above is performed again on the node 1-1.

  On the other hand, when data from the node 1-1 arrives within the predetermined time (step S51; Y), one packet of the received data is stored in the buffer memory 4, and the value of the input counter and the buffer memory 4 are stored. The packet number already stored therein is updated by one packet (step S52), and the process returns to step S45.

  In addition, when the data from the node 0-1 cannot be received in the determination in the above step S47 (step S47; Y), the node 0-1 is connected to another node ( In the case of FIG. 1, the node 1-2 or 1-3) may be inquired, and a data request message may be sequentially transmitted to the other nodes to confirm the possibility of distribution.

  According to the above processing, as shown in FIG. 8B, data is input from the plurality of routes to the buffer memory 4 in the node 3-1, and the required accumulation amount is promptly restored. be able to.

  Similarly to the node 3-1, the node 3-2 inputs data from a plurality of routes and quickly recovers the necessary storage amount. Then, the nodes 4-1 and 4-2 lower than the node 3-2 immediately below the node 2-1 where the relay function is stopped also input data from a plurality of routes and quickly recover to the necessary accumulation amount. . In addition, the nodes 4-1 and 4-2 that are lower than the node 3-2 immediately below the node 2-1 in which the relay function is stopped do not input data from a plurality of routes, and the node 3-2 The nodes 4-1 and 4-2 may be distributed at a higher speed than usual as in the first embodiment.

  According to the above-described modification, a plurality of paths to the node are formed by connecting nodes in different layers to the node receiving the distribution, so that a failure such as a relay function stoppage is generated for each layer. Even when the possibility of occurrence is different, sufficient redundancy can be ensured.

(II) Second Embodiment Next, a second embodiment which is another embodiment according to the present application will be described with reference to FIGS.

  9 and 10 are block diagrams showing the schematic configuration of the network system according to the second embodiment, and FIGS. 11 and 12 are flowcharts showing the operation of the network system.

  In the above-described first embodiment, the case where the relay function in one node is stopped when content distribution is originally received via only one line L has been described. However, the second embodiment described below will be described. In this case, one node is provided with two routes of a main route and a sub route in advance to receive content distribution.

  That is, as shown in FIG. 9, the network system NT2 according to the second embodiment is formed by a tree structure having nodes 0-1 as distribution devices as vertices as in the case of the first embodiment. Nodes 1-1, 1-2, and 1-3 are included as nodes constituting one layer, nodes 2-1 and 2-2 are included as nodes constituting a second layer, and a third layer is formed. Nodes 3-1, 3-2, 3-3, and 3-4 are included as nodes to be performed, and nodes 4-1 and 4-2 are further included as nodes constituting the fourth hierarchy. The nodes are connected to each other by a main line LM that is a wired line or a wireless line with the node 0-1 as a vertex. Here, a specific example of each node is the same as that in the first embodiment.

  In addition, in the network system NT2 according to the second embodiment, in addition to the main line LM, each of the nodes belonging to the second and lower layers is a node immediately above which the main line LM is connected. It is connected to a node that is one level higher than that using the sub line LS. In the normal distribution state, only the content distributed via the main line LM is subjected to reproduction processing in each node, and the content distributed via the sub-line LS is reproduced after receiving it once. It is distributed to other nodes in the lower hierarchy without using them. Note that the content distributed from the sub line LS may only be received, and the content from the main line LM may be distributed to the lower nodes.

  The detailed configuration of each node according to the second embodiment is different from the detailed configuration of each node according to the first embodiment (see FIG. 2). Two buffer memories 4 and two timers 6 are provided, one for each main line LM and one for the sub-line LS. Further, the CPU 1, the decoder 2, the broadband interface 5, the speaker 7 and the CRT 8 are provided one by one as in the first embodiment. Further, in the topology table T stored in each table memory 3 in one node, it is the topology table T for the main line LM or the secondary table LM as compared with the case of the first embodiment. An identifier indicating whether the topology table T is for the line LS is added.

  Then, in the network system NT2 in the state shown in FIG. 9, when the relay function in the node 2-1 belonging to the network system NT2 stops, for example, as shown in FIG. Each node 3-1 and 3-2 automatically reconnects the main line LM and the sub line LS as the main line LM ′ and the sub line LS ′ as shown in FIG. Receive. In this case, the node 3-1 connected the main line LM to the node 2-1 and connected the sub line LS to the node 0-1 in FIG. 9, but the relay function in the node 2-1 has stopped. Later, the main line LM ′ is connected to the node 1-1, and the sub-line LS is connected to the node 0-1 as it is. On the other hand, the node 3-2 connected the main line LM to the node 2-1 and connected the sub line LS to the node 1-1 in FIG. 9, but after the relay function in the node 2-1 was stopped. Connects the main line LM ′ to the node 3-1 in the same hierarchy, and connects the sub-line LS to the node 1-1 as it is. As a result, the rule of connecting the main line LM to the nearest node and connecting the sub-line LS to the node of the immediately higher hierarchy when viewed through the node to which the main line LM is connected is maintained.

  Also, the nodes 4-1 and 4-2 belonging to the fourth hierarchy lose their relay functions at the connection destinations of the sub-lines LS connected in FIG. 9, so that each main line LM As it is, only the sub line LS ′ is connected (in the case shown in FIG. 10, the connection destination is the node 3-1).

  Next, the topology restructuring operation executed in the nodes 3-1, 3-2, 4-1, and 4-2 when the relay function in the node 2-1 is actually stopped will be described.

  When the relay function in the node 2-1 is stopped as shown in FIG. 10, first, the nodes 3-1 and 3-2 that are immediately below the node 2-1 are connected to the node according to the time measured by the timer 6 described in the first embodiment. Connection to a node in a higher hierarchy than 2-1 is started. During the time measurement by the timer 6, the connected route, in this case, the node 3-1 stores the data distributed from the node 0-1 in the buffer 4, and the node 3-2 is distributed from the node 1-1. Is stored in the buffer 4 and distributed to the lower nodes 4-1 and 4-2. After the topology is reconstructed, the data distributed from the main line LM is stored in the buffer 4, and the data distributed from the sub line LS is distributed to the lower nodes.

  Then, the faster one of the nodes 3-1 and 3-2 (in the case of FIG. 10, the node 3-1) is connected to the node 1-1. As a result, the node 3-1 connects the new main line LM ′ to the node 1-1, and in addition, the original sub-line LS maintains the connection with the node 0-1 and distributes content ( Backup distribution) is received from node 0-1.

  On the other hand, the node 3-2 that could not connect to the node 1-1 maintains the original sub-line LS with the node 1-1, and currently has a lower hierarchy than the node 1-1. The main line LM ′ is connected to the node 3-1 belonging to. In this case, it is conceivable to reconnect the node 3-2 directly to the node 0-1. However, since there are a large number of nodes connected to the node 0-1, at present, the node 3-1 is realistically connected to the node 3-1. Thus, the main line LM ′ is connected.

  On the other hand, for the nodes 4-1 and 4-2 that are in the lower hierarchy, the original subline LS is disconnected, so the connection destination of the new subline LS ′ belongs to the immediately higher hierarchy. Queries the node 3-2. As a result, since both can recognize that the node 3-2 has formed a new main line LM ′ with the node 3-1, the nodes 4-1 and 4-2 quickly inquire the node 3-2. In this order, a new sub-line LS ′ is formed with the node 3-1.

  Next, a new node is connected to the network system NT2 according to the second embodiment, and the operations that are started and executed in the normal state including the new node are collectively shown in FIG. I will explain. In FIG. 11, the node 3-1 is newly connected to the node 2-1 in the network system NT2, and the network system NT2 shown in FIG. It is a flowchart which shows the example in the case of performing.

  First, among the nodes in the network system NT2 according to the second embodiment, at a node in which other nodes are connected to at least the lower hierarchy by the main line LM or the sub line LS, the flowchart shown in the upper right of FIG. The process indicated by is always executed.

  That is, when any message is always transmitted from a node in a lower hierarchy (step S70), the type of the message is sequentially determined (step S71, S73, S75, S77 or S79).

  When the received message is the start message (step S71; Y), the packet number of the data currently being reproduced by the node is returned as the start packet number (step S17).

  When the received message is the topology data table request message (step S73; Y), the node that has transmitted the topology data table request message is connected among the topology tables T currently included in the node. A topology table T corresponding to the type of line (main line or sub line) is returned (step S74).

  Further, when the received message is the data request message (step S75; Y), data for one packet is transmitted at the reproduction rate specified in the data request message (step S76).

  Further, when the received message is a new node support request message for inquiring about the possibility of data distribution using the sub-line LS (step S77; Y), with other nodes distributed at that time On the basis of the relationship, whether or not distribution using the sub-line LS is possible is determined, and if possible, a response indicating “permitted” is returned. On the other hand, if the distribution is impossible, “not permitted” "Is sent back (step S78).

  Furthermore, when the received message is a forced connection request message for forcibly distributing data using the sub line LS (step S79; Y), the distribution is performed at that time as in the case of step S77. Based on the relationship with the other nodes, whether the distribution using the sub line LS is possible or not is determined, and if possible, a response of “permitted” is returned, while the distribution is impossible. In this case, the level information in the topology table T corresponding to the type of the line to which the node that has transmitted the forced connection request message is connected is “−1” in the topology table T currently included in the node. The distribution of data to the node is stopped (step S80).

  Further, when the received message is not one of the above messages (step S79; N), a preset error message is returned to the node that transmitted the message (step S81).

  In each node on which the above processing is continuously executed, data from a node whose level information in the topology table T corresponding to the main line LM is “1” is decoded and output by the decoder 2, Data from a node whose level information in the topology table T corresponding to the sub line LS is “1” is distributed to other nodes in the lower hierarchy without being decoded.

  In the network system NT2 operating in this state, when the node 3-1 is physically connected to the node 2-1 and newly joins the network system NT2, first, the new node 3-1 The CPU 1 sets two buffer memories 4 (for the main line LM and the sub line LS) in the node 3-1, and sets the IP address of the node indicating the data supply source on the main line LM. Is set to the node 2-1 at the node 2-1 and the node 0-1 immediately above the subline LS is set (the IP addresses of these two nodes are that the node 3-1 is connected to the node 2-1 (At this point, the node 3-1 is acquired from the node 2-1). An input counter 1 (16 bits) that counts the number of bytes received from the node 2-1 via the main line LM in order to calculate an address for storing data in each buffer memory 4. An input counter 2 (16 bits) for counting the number of bytes received from the node 0-1 via the sub line LS and an output counter (16 bits) representing the amount of data reproduced by the decoder 2, The buffer memory 4 is initialized as “0” and outputs the data stored in the decoder 2 (that is, the buffer memory 4 corresponding to the main line LM at that time. In FIGS. 11 and 12). The buffer address indicating the ring buffer 4 as “ring buffer 1” (appropriately shown in FIGS. 11 and 12). Are shown as "ring buffer ADR"), it sets the buffer memory 4 corresponds to the main line LM at that time (step S60).

  When the necessary initialization processing is completed, the CPU 1 in the node 3-1 next refers to the topology table T in each table memory 3, and stores content data for the node 2-1 and the node 0-1. A start message requesting the start of transfer is transmitted (step S61).

  Next, each CPU 1 in the node 2-1 and the node 0-1 that has received the start message (step S70) sets the packet number of the data currently being reproduced by the node 2-1 and the node 0-1, Each is returned as a start packet number to the node 3-1 again (step S72).

  Thus, when the node 3-1 acquires the start packet number from the node 2-1 and the node 0-1, these are stored in the corresponding packet number areas on the buffer memory 4 corresponding to the respective lines (step S1). S62) This time, a data request message for requesting actual content data is transmitted to each of the node 2-1 and the node 0-1 (step S63). Here, in the data request message, the packet number of data to be transmitted from the node 2-1 (for reproduction processing) and the node 0-1 (distributed as it is to the lower layer) to the node 3-1. Contains information to indicate.

  Then, the node 2-1 and the node 0-1 that have received the data request message (steps S70, S75; Y) receive the data for one packet at the reproduction rate magnification specified in each data request message. Transmit to 3-1 (via the main line LM and the sub line LS, respectively) (step S76).

  In parallel with these, the node 3-1 starts timing each timer 6 in the node 3-1 at the same time as outputting each data request message, and each time count becomes “0”. Thus, a timer interrupt instruction is set to be generated (step S64). Then, each timer 6 waits until a predetermined time elapses (step S65), and if data from the nodes 2-1 and 0-1 does not arrive within the predetermined time (step S65; N) ) The timer interrupt instruction is executed, and the connection process described above is performed again for the nodes 2-1 and 0-1.

  On the other hand, when the data from the node 2-1 and the node 0-1 arrives within the predetermined time (step S65; Y), the execution of the timer interrupt instruction in each is prohibited (step S66), and each received data Each of the packets is stored in the corresponding buffer memory 4. Accordingly, the values of the input counters 1 and 2 and the number of the packet already stored in the buffer memory 4 are updated by one packet (step S67).

  Then, it is confirmed whether or not the amount of data stored in each buffer memory 4 and not output to the decoder 2 has become four packets (that is, one-fourth storage amount of each buffer memory 4). (Step S68), if it is less than four packets (Step S68; Y), return to Step S63 to repeat reception of the next packet from the nodes 2-1 and 0-1, respectively, and repeat the above-described processing. On the other hand, when the amount of data stored in each buffer memory 4 has reached 4 packets (step S68; N), only the data acquired via the main line LM is output to the decoder 2. (Step S69), the process returns to Step S63 to receive the subsequent data from the nodes 2-1 and 0-1.

  In the process of step S69, when the data for four packets is stored in the buffer memory 4 corresponding to the main line LM and the data is output to the decoder 2, the decoder 2 The address of the data output from the buffer memory 4 is obtained based on the buffer address indicating the buffer memory 4 and the value of the output counter in the buffer memory 4 indicated by the buffer address (step S82). Data decoding is performed by decoding and reproducing only the amount of packets (step S83), and further incrementing the value of the output counter in each buffer memory 4 by one packet (step S84) for four packets.

  As described above, the data distribution from the node 2-1 and the reproduction process in the node 3-1 and the distribution using the sub line LS from the node 0-1 are executed, so that the data amount in each buffer memory 4 is reduced. The reproduction process of the data in the node 3-1 is executed while keeping constant.

  Next, in the network system NT2 shown in FIG. 9, the processing when the content relay function in the node 2-1 is exhibited due to, for example, the power switch being turned off will be specifically described with reference to FIG. explain.

  In the network system NT2 according to the second embodiment, when the relay function in the node 2-1 is stopped for the reason described above, the node connected to the original node 2-1 as shown in FIG. 3-1 and 3-2, and 4-1 and 4-2 automatically execute the topology reconfiguration operation, and continue to distribute the content with the topology of the aspect shown in FIG. 10.

  As shown in FIG. 11, when the relay function in the node 2-1 is stopped, the CPU 1 in the nodes 3-1 and 3-2 in the lower hierarchy (the distribution in the normal state shown in FIG. 11 was continued. 11 is repeated), even if a predetermined time elapses in the process of step S65 shown in FIG. 11, data from the node 2-1 cannot be received. Then, when the CPU 1 in the nodes 3-1 and 3-2 cannot receive data even after the predetermined time has elapsed (step S65; N), the node 2 in the nearest higher hierarchy thereby It is recognized that the relay function in 1 is stopped and the topology so far is disconnected.

  After that, when the disconnection of the topology is recognized, the interrupt instruction shown in FIG. 12 is executed, and each topology table T stored in each table memory 3 is referred to, and the topology is changed as shown in FIG. Rebuild.

That is, as shown in FIG. 12, when an interrupt instruction is executed, whether or not the timer 6 for which a predetermined time has elapsed is the timer 6 corresponding to the main line LM (shown as “timer 1” in FIG. 12). (Step S90), if it is the timer 6 corresponding to the main line LM (step S90; Y), the buffer memory 4 corresponding to the sub-line LS is sent to the decoder 2 from which data is to be output. In order to set in the memory 4, the value of the buffer address is changed to a value indicating the buffer memory 4 corresponding to the sub line LS (step S91).
Next, a topology table request message corresponding to the main line LM is transmitted to the node (level 1-1 in the case of FIG. 10) whose level information value is “2” in the main line LM (step S92, S94), the node corresponding to the internal main line LM in the topology table T of the node is acquired (step S95).

  Then, each topology table T in the nodes 3-1 and 3-2 corresponding to the main line LM is updated using the acquired topology table T (step S96).

  Next, the node is inquired whether or not the sub-line LS can be connected to a node (level 0 in FIG. 10) whose level information is “2” in the updated topology table T. The above-mentioned new node support request message is transmitted (step S97).

  Then, it is confirmed whether or not the response content to the new node support request message is “permitted” (step S98). If it is “permitted” (step S98; Y), the sub line LS is set before stopping the relay function. Is rewritten to the effect that the main line LM is currently connected, and the node (node 0-1 in the case of FIG. 10) to which the sub line LS is newly connected is rewritten. The IP address is described in the topology table T as the IP address of the node whose level information is “2” in the topology table T corresponding to the current (new) sub line LS (step S99).

  On the other hand, if it is determined in step S98 that the response content to the new node support request message is “non-permitted” (step S98; N), the latest lower level as viewed from the node 0-1 to which the sub-line LS was originally connected. The forcible connection request message is transmitted to the node 1-1 of the hierarchy (step S100).

  When the node 1-1 receives the forcible connection message and can connect the sub-line LS in the node 1-1, the node 1-1 allows the connection as it is, and the node 3-1 The topology table T is updated (step S101), and if it is not possible, the distribution of data from the node 0-1 to the node 1-1 is stopped. Here, the node 1-1 in which the transfer of the data is stopped performs the above-described processing itself to reconstruct the topology.

  On the other hand, if it is determined in step S90 that the interrupt instruction is executed by the timer 6 corresponding to the sub line LS (step S90; N), the node 2- Therefore, the topology table request message corresponding to the main line LM is transmitted to the node 2-1 (steps S93 and S94), and the node 2-1 Of the topology table T corresponding to the inner sub-line LS is acquired (step S95), and the processes after step S96 described above are executed.

  As described above, according to the network system NT2 of the second embodiment, the main line LM and the sub line LS are formed so as to connect a plurality of nodes to one node, respectively, and the main line LM is connected via the main line LM. The distributed data is used for reproduction processing in the one node and distribution to other nodes belonging to the lower hierarchy, while the data distributed via the sub line LS belongs to the lower hierarchy. Since it is used for distribution to other nodes, redundancy can be increased in preparation for the suspension of the relay function in any node by multiplexing the lines in each node, and in nodes belonging to lower layers It is possible to prevent the reproduction process or the like from being stopped.

  In addition, when the relay function in a node belonging to a higher hierarchy on the main line LM is stopped for one node, switching is performed so that data distributed via the sub line LS is used for reproduction processing or the like. Therefore, the reproduction process or the like in the one node is not interrupted.

  Further, when the data distributed via the sub line LS is switched to be used for reproduction processing or the like, any one of the nodes belonging to the higher hierarchy is searched and the searched nodes are connected. Therefore, even if the previous sub line LS is handled as the main line LM, the new sub line LS can be formed to ensure and maintain redundancy.

  Furthermore, when the relay function in the node belonging to the upper layer on the sub-line LS is stopped for one node, any node belonging to the upper layer is searched, and the searched node To form a new sub-line LS, so even if the relay function at the node on the previous sub-line LS stops, a new sub-line LS is formed to ensure and maintain redundancy. can do.

  In addition, since other nodes in the hierarchy to which the one node belongs are searched for nodes in the upper hierarchy so that they are included in the new main line LM, distribution information is transmitted via the nodes in the same hierarchy. Can be supplied.

  In each of the embodiments described above, as a method for detecting that the relay function in any node has been stopped, in addition to the above, each node periodically has a higher hierarchy or lower level than that node. For example, when the node 2-1 in each of the above embodiments stops the relay function, the node 1-1 in the higher hierarchy Alternatively, it may be configured to notify the nodes 3-1 and 3-2 in the lower hierarchy.

  The series of connection mode control processes described above can also be performed under the control of another server apparatus external to the network system NT or NT2. In this case, the server device has information indicating the connection mode of each node in the network system NT or NT2, and the nodes 3-1 and 3-2 make an inquiry to the server device, so that the relay function Is configured to recognize the node 1-1 at a higher level than the node 2-1.

  Further, the decoder 2 and the CRT 8 for reproducing the content can be configured to connect the reproduction device and the like at a place other than the node via another network.

  Furthermore, the programs corresponding to the flowcharts of FIGS. 4, 7, 8, 11, and 12 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. In addition, by reading and executing these with a general-purpose computer, the computer can be caused to function as the CPU 1 according to each embodiment.

  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 showing a schematic configuration of a network system according to a first embodiment. It is a block diagram which shows the whole structure of the one node contained in the network system which concerns on 1st Embodiment. It is a figure which shows the detailed structure of the node which concerns on 1st Embodiment, (a) is a figure which illustrates the content of the topology table, (b) is a figure explaining operation | movement of a buffer memory. It is a flowchart which shows the normal delivery operation | movement in the network system which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the network system which concerns on 1st Embodiment after the relay function in some nodes stops. It is a flowchart which shows the operation | movement in the low-order node at the time of the relay function stop in some nodes, (a), (b) and (c) is a figure explaining operation | movement of a buffer memory, respectively. It is a figure which shows operation | movement of the low-order node at the time of the relay function stop in some nodes. It is a figure which shows the operation | movement in the network system which concerns on the modification of 1st Embodiment, (a) is a flowchart which shows the said operation | movement, (b) is a figure explaining operation | movement of the buffer memory corresponding to the said operation | movement. . It is a block diagram which shows schematic structure of the network system which concerns on 2nd Embodiment. It is a block diagram which shows schematic structure of the network system which concerns on 2nd Embodiment after the relay function in some nodes stops. It is a flowchart which shows the normal delivery operation | movement in the network system which concerns on 2nd Embodiment. It is a flowchart which shows the operation | movement in the low-order node at the time of the relay function stop in some nodes.

Explanation of symbols

1 CPU
2 Decoder 3 Table memory 4 Buffer memory 5 Broadband interface 6 Timer 7 Speaker 8 CRT
0-1, 1-1, 1-2, 1-3, 2-1, 2-2, 3-1, 3-2, 3-3, 3-4, 4-1, 4-2, 4- 3 nodes L, L 'line LM, LM' main line LS, LS 'sub line NT, NT2 network system

Claims (13)

The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. In a connection mode control device for controlling a connection mode between the distribution device and the relay device,
When a relay function in any of the relay devices is stopped, a search is made for another relay device other than the relay device for which the relay function is stopped and capable of relaying the distribution information Search means;
Connection means for connecting the relay device to be distributed with the distribution information to the other relay device searched;
A distribution continuation means for continuing the distribution of the distribution information via the other connected relay device, wherein the distribution speed of the distribution information via the other relay device is set to be higher than before the suspension of the relay function; A delivery continuation means for accelerating and continuing the delivery;
A connection mode control device comprising: In the connection form control device according to claim 1,
The distribution continuation means limits the distribution speed of the distribution information via the other connected relay device to an upper limit of a maximum distribution speed defined in the network connecting the distribution device and each of the relay devices. A connection mode control device that continues the distribution while sequentially increasing the speed to a predetermined speed. In the connection form control device according to claim 1 or 2,
The distribution continuation means continues the distribution at a speed faster than before the stop of the relay function until the storage amount of the distributed distribution information in the relay device as the distribution destination reaches a predetermined amount set in advance. A connection mode control device characterized in that: The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. In a connection mode control device that controls a connection mode between the distribution device and the plurality of relay devices,
Connecting means for connecting a plurality of other relay devices to the one relay device to form a plurality of routes through which the distribution information is distributed to the one relay device;
The distribution information distributed to the one relay device via the main route which is one of the routes is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device. In addition, the distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is subjected to external output processing in the one relay device, A delivery control means for delivering to another relay device belonging to the lower hierarchy with respect to one relay device;
A connection mode control device comprising: In the connection mode control device according to claim 4,
When the relay function in the relay device belonging to the higher hierarchy on the main route with respect to the one relay device is stopped, the distribution delivered to the one relay device via the sub route A connection mode control device further comprising switching means for switching information to be provided to the external output processing in the one relay device. In the connection mode control device according to claim 5,
When the distribution information distributed to the one relay device via the sub route is switched by the switching means so as to be used for the external output processing in the one relay device, the distribution device or Searching means for searching for any one of the new relay devices belonging to the higher hierarchy with respect to the one relay device,
The connection means is configured to connect the one searched by the search means to the one relay device to form a new route. In the connection mode control device according to claim 4,
When the relay function in the relay device belonging to the higher hierarchy on the sub route with respect to the one relay device stops, the distribution device or the one relay device belongs to the higher hierarchy. A search means for searching for any one of the new relay devices,
The connection means is configured to connect the one searched by the search means to the one relay device to form a new sub route. In the connection mode control device according to any one of claims 6 and 7,
The search means is characterized in that the other relay device in the hierarchy to which the one relay device belongs searches for the one so that it is included in the new main route. apparatus. In the connection mode control device according to any one of claims 1 to 8,
The connection mode control apparatus according to claim 1, wherein the connection unit forms a plurality of the paths by connecting the relay apparatuses in the different layers to the one relay apparatus. The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. In a connection mode control method for controlling a connection mode between a distribution device and the relay device,
When a relay function in any of the relay devices is stopped, a search is made for another relay device other than the relay device for which the relay function is stopped and capable of relaying the distribution information The search process;
A connection step of connecting the relay device to be distributed with the distribution information to the other relay device searched;
A distribution connection step of continuing distribution of the distribution information via the other connected relay device, wherein the distribution speed of the distribution information via the other relay device is set higher than before the suspension of the relay function; A delivery continuation process for accelerating and continuing the delivery;
The connection mode control method characterized by including. The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. In a connection mode control method for controlling a connection mode between a distribution device and the plurality of relay devices,
Connecting a plurality of other relay devices to one relay device, thereby forming a plurality of routes through which the distribution information is distributed to the one relay device;
The distribution information distributed to the one relay device via the main route which is one of the routes is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device. In addition, the distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is subjected to external output processing in the one relay device, A delivery control step of delivering to another relay device belonging to the lower hierarchy with respect to one relay device;
The connection mode control method characterized by including. The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. A computer included in a connection mode control device for controlling a connection mode between the distribution device and the relay device;
When a relay function in any of the relay devices is stopped, a search is made for another relay device other than the relay device for which the relay function is stopped and capable of relaying the distribution information Search means,
Connection means for connecting the relay device to be distributed with the distribution information to the other relay device searched; and
A distribution continuation means for continuing the distribution of the distribution information via the other connected relay device, wherein the distribution speed of the distribution information via the other relay device is set to be higher than before the suspension of the relay function; A delivery continuation means for continuing the delivery by speeding up;
It is made to function as a connection mode control program. The network system in which the distribution information is distributed including 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 as a tree structure while forming a plurality of hierarchies. A computer included in a connection mode control device that controls a connection mode between the distribution device and the plurality of relay devices;
Connecting means for forming a plurality of routes through which the distribution information is distributed to the one relay device by connecting a plurality of other relay devices to the one relay device; and
The distribution information distributed to the one relay device via the main route which is one of the routes is distributed to the other relay device belonging to the lower hierarchy with respect to the one relay device. In addition, the distribution information distributed to the one relay device via the main route that is the one route or the sub route that is the other route is subjected to external output processing in the one relay device, A delivery control means for delivering to another relay device belonging to the lower hierarchy with respect to one relay device;
It is made to function as a connection mode control program.

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