CN1998199B - Connection mode control device, connection mode control method and connection mode control program - Google Patents

Abstract

Provided is a network control device which can surely distribute contents without affecting processing in a node below even when a relay function of one of nodes included in a network is stopped, while improving reliability of a network system itself. When controlling a node N included in a network system NS including a server S and a plurality of nodes N constituting a plurality of hierarchies and connected to each other, to each of which a content is distributed from the server S, it checks whether a content relay function of a node located in an uplink with respect to the node N in content distribution has stopped. When the stop of the relay function is detected, control is performed so that the consumption rate of the content accumulated in the lower node N in the processing performed in the node N is smaller than the consumption rate before the stop of the relay function.

Description

Connection mode control device, connection mode control method and connection mode control program

technical field

The present invention relates to the technical field of a network control device, a connection mode control device, a network control method, a connection mode control method, a network control program and a connection mode control program. More specifically, the present invention relates to a network control device for controlling a distribution mode of distribution information distributed from a distribution source in a network system while relaying distribution information step by step in relay units that are connected and constitute a multi-stage hierarchy , the technical field of a connection mode control device, a network control method, a connection mode control method, a network control program, and a connection mode control program.

Background technique

In recent years, network systems have been widely used as the speed of Internet lines for homes has increased. In the network system, a network is constructed by connecting home personal computers and the like into a tree structure with the apex being a single distribution device as a distribution source, and so-called contents such as music and movies are distributed from the distribution devices via the network as distribution information. From the point of view of connection mode, the network is called "topology". Each of the publishing devices and personal computers that make up the network is generally referred to as a "node".

For example, Patent Document 1 discloses a prior art of a network system. Patent Document 1: Japanese Patent Laid-Open No. 2003-169089.

In each node included in the existing network system represented by the network system of Japanese Patent Laid-Open No. 2003-169089, content transmitted from an upper node is temporarily stored in a buffer memory and used for playback processing and the like. This structure attempts to reduce the influence of transmission speed fluctuations in Internet circuits constituting distribution paths in the network system. For example, a FIFO (First In First Out) memory such as a ring buffer memory is used as the buffer memory.

On the other hand, in the network system, nodes constructing the system are home personal computers and the like as described above. Therefore, there may be a case where the power supply of any one node on the distribution path is turned off regardless of whether the content is being distributed or not. In this case, the function of relaying content to the lower nodes connected to the node whose power switch was turned off is stopped.

During content distribution in the network system, in the event that the relay function of any node on the distribution path stops, the topology is reconstructed to include nodes other than the node whose relay function stops (that is, rebuilding distribution path from the distribution device to the lower layer node directly connected to the node where the relay function stopped and restart distribution).

Contents of the invention

The problem to be solved by the present invention

However, in the topology reconfiguration of the existing network system, processing such as searching for the shortest path from the distribution system and performing connection switching using the search results are necessary. As a result, publishing of content to lower nodes is temporarily interrupted. In the case where the distribution is interrupted, in the lower layer node, the processing of the playback content stored in the buffer memory is continued (in other words, the data stored as the content in the buffer memory is consumed), but no new content is supplied to buffer. As a result, problems arise such that the amount of storage in the buffer gradually decreases, and in some cases, content playback processing in lower nodes is interrupted.

In the case where the relay function of any one of the nodes included in the network system is stopped, interruption of the playback process leads to deterioration of the reliability of the network system itself.

The implementation of the present invention takes these problems into consideration, and the purpose of the present invention is to propose a network control device, a network control method and a network control program for controlling the release mode in the network system, so that even if any Even when the relay function of the node is stopped, the content distribution can be reliably performed, and at the same time, the reliability of the network system itself can be improved without affecting the processing in the lower layer nodes. problem solving

In order to achieve the object, the present invention according to claim 1 relates to a network control device for controlling any one of a plurality of repeaters included in a network system including as a distribution source of distribution information A publisher and a plurality of repeaters connected to the publisher and forming a plurality of levels, and wherein the distribution information is distributed from the publisher to each repeater, the device includes: a detection device such as a CPU means for detecting a function of relaying the distribution information in any one of the repeaters located upstream in the distribution of the distribution information to a target repeater as the repeater to be controlled whether to stop; and consumption control means such as a CPU for controlling the unit time consumption which is the consumption per unit time of the distribution information stored in the target relay to be smaller than the relay The unit time consumption amount until function stop, the posting information is consumed due to use in processing executed in the target repeater when the stop of the relay function is detected.

Therefore, when the relay function in the repeater located on the upstream side in the network system is stopped, the consumption per unit time of the distribution information stored in the repeater located on the downstream side is controlled to be smaller than the consumption before the stop. quantity. As a result, it is possible to prevent interruption of processing in the downstream repeater caused when the distribution of the distribution information is interrupted while the distribution information is still being consumed at a speed similar to that before the interruption without increasing the burden on the network system itself or significant processing delays occur.

In order to achieve this object, the present invention as set forth in claim 2 relates to the network control device as set forth in claim 1, wherein the distribution information is image information, and the consumption amount control means processes by using The speed of reducing the storage amount of the image information in the cache device is slower than the reduction speed before the stop of the relay function, so as to reduce the unit time consumption, wherein the cache device is used for temporary storing the image information in the target repeater.

Therefore, in addition to the effect of the present invention according to claim 1, the distribution information is image information, and the unit is reduced by making the reduction speed of the storage amount of the image information in the buffer device slower than that before the relay function is stopped. time consumption. Therefore, a simple structure can be employed to reduce unit time consumption without performing complicated speed control processing.

In order to achieve this object, the present invention according to claim 3 relates to the network control apparatus according to claim 2, wherein said image information is dynamic image information composed of a plurality of still images, and said consumption control means passes through multiple Repeatedly outputting the same still image from the cache means reduces the reduction speed of the storage amount.

Therefore, in addition to the effect of the present invention according to claim 2, the speed of reducing the amount of memory is reduced by repeatedly outputting the same still image as a constituent of moving image information multiple times. Therefore, the unit time consumption can be reliably reduced by simple processing.

To achieve this object, the present invention according to claim 4 relates to the network control apparatus according to claim 1, wherein the distribution information is coded image information, and the consumption amount control means relays the The decoding speed of the image information in the processing in the device is slower than the decoding speed before the relay function is stopped, so as to reduce the unit time consumption.

Therefore, in addition to the effect of the present invention according to claim 1, the unit time consumption is reduced by making the speed of decoding image information in-process in the target repeater slower than the decoding speed before the relay function stops. Therefore, the unit time consumption can be reliably reduced by simple processing.

In order to achieve this object, the present invention according to claim 5 relates to the network control apparatus according to claim 1, wherein said distribution information is dynamic image information composed of a plurality of still images, and said consumption amount control means operates by making the The display time of the still image is longer than the display time before the relay function is stopped to reduce the unit time consumption.

Therefore, in addition to the effect of the present invention according to claim 1, the unit time consumption is reduced by making the display time of the still image constituting the moving image information longer than the display time before the relay function is stopped. Therefore, the unit time consumption can be reliably reduced by simple processing.

To achieve this object, the present invention according to claim 6 relates to the network control device according to any one of claims 1 to 5, wherein said distribution information is composed of a plurality of continuous unit distribution information, said distribution information The unit release information in the predetermined position in the unit release information is empty, and the information amount of the release information for processing is zero, and the device further includes: reset means such as a CPU, in sending to the target After the release of the repeater is restarted, it is used to reset the unit time consumption in the target repeater to the same as the unit time consumption before the relay function stops; and release such as CPU control means for, after resetting said unit time consumption in said target repeater, for issuing empty unit release information only to all repeaters except The repeater is the repeater located downstream in the distribution before the stop of the relay function of the repeater whose relay function is stopped.

Therefore, in addition to the effect of the present invention according to any one of claims 1 to 5, only empty unit issue information is issued to the issue located before the repeater function of the repeater whose relay function is stopped is stopped. All repeaters except those on the downstream side. Therefore, the playback time base in the repeater becomes gradually closer to the playback time base in the other repeaters. As a result, by reducing the unit time consumption in the repeater on the downstream side of the repeater whose repeater function is stopped, the difference between the playback position on the playback time base of the repeater and other repeaters can be reduced. deviation between.

In order to achieve this object, the present invention as set forth in claim 7 relates to a control method for controlling any one of a plurality of repeaters included in a network system including as a distribution source of distribution information A publisher and a plurality of repeaters connected to the publisher and forming a plurality of levels, and wherein the release information is issued from the publisher to each repeater, the method includes: a detection step, using for detecting whether a function of relaying the distribution information in any one of the relays located upstream is stopped during distribution of the distribution information to a target relay of the relay to be controlled; and a consumption amount control step of controlling the consumption amount per unit time which is the consumption amount per unit time of the distribution information stored in the target repeater to be smaller than the Consumption per unit time, the posting information is consumed due to use in processing performed in the target repeater when a stop of the relay function in the middle is detected.

Therefore, when the relay function in the repeater located on the upstream side is stopped in the network system, the consumption per unit time of the distribution information stored in the repeater located on the downstream side is controlled to be smaller than before the stop. consumption. As a result, it is possible to prevent the occurrence of processing in the downstream repeater due to the fact that the distribution of the distribution information is still consumed at a speed similar to that before the interruption when the distribution of the distribution information is interrupted without increasing the burden on the network system itself Interruptions or severe processing delays.

In order to achieve this object, the present invention as set forth in claim 8 causes a computer included in a network control device for controlling a plurality of repeaters included in the following network system to function as follows: Either, the network system includes a publisher as a distribution source of distribution information and a plurality of repeaters connected to the distribution device and forming a plurality of hierarchies, and wherein the distribution information is distributed from the distribution device To each repeater, the function is: detection means, used to detect that in any one of the upstream located in the release of the release information to the target repeater as the repeater to be controlled whether the function of relaying the distribution information in the repeater is stopped; and consumption amount control means for controlling the unit time consumption as the consumption amount per unit time of the distribution information stored in the target repeater amount so as to be smaller than the unit time consumption amount before the relay function is stopped, the distribution information due to use in the processing performed in the target repeater when the relay function is detected to be stopped It is consumed.

Therefore, when the relay function in the repeater located on the upstream side in the network system is stopped, the computer functions so that the consumption per unit time of the distribution information stored in the repeater on the downstream side becomes smaller than that in the repeater on the downstream side. The amount of time consumed per unit of time before the relay function stops. Thus, it is possible to prevent the occurrence of processing in the downstream repeater due to the fact that the distribution of the distribution information is still consumed at a speed similar to that before the interruption when the distribution of the distribution information is interrupted without increasing the burden on the network system itself. Interruptions or severe processing delays.

In order to achieve this object, the present invention as set forth in claim 9 relates to a connection mode control device for controlling a publisher serving as a distribution source of distribution information in a network system and connected to the publisher in a tree structure and A connection mode between multiple repeaters forming multiple levels, wherein the release information is published in the network system, the device includes: a retrieval device such as a CPU, when any one of the repeaters When the relay function is stopped, for retrieving any one of the repeaters other than the repeater whose relay function is stopped and capable of relaying the distribution information; connection means such as a CPU for receiving the The repeater of the distribution information is connected to the retrieved another repeater; and distribution continuation means such as a CPU for speeding up the distribution of the distribution information via the another repeater The distribution of the distribution information via another repeater of the connection is continued faster than the distribution speed before the relay function is stopped.

Therefore, when the relay function in any one of the repeaters stops, another repeater capable of relaying the published information is retrieved. When the distribution of the distribution information is continued via the retrieved another repeater, the distribution speed of the distribution information is made faster than that before the stop of the relay function. Therefore, it is possible to continue the process of distributing information in the repeater belonging to the hierarchy below the repeater whose relay function stopped.

In order to achieve this object, the present invention according to claim 10 relates to the connection mode control apparatus according to claim 9 , wherein said distribution continuation means continues distribution while gradually replacing said distribution via another repeater of said connection. The distribution speed of the distribution information is increased to the maximum value of the distribution speed prescribed in the network connecting the distributor and each repeater as an upper limit.

Therefore, distribution is continued while gradually increasing the distribution speed of the distribution information via another repeater connected to the maximum value of the distribution speed as the upper limit, so that the repeater belonging to the lower hierarchy can get the necessary information more quickly. release information.

In order to achieve this object, the present invention according to claim 11 relates to the connection mode control apparatus according to claim 9 or 10, wherein said distribution continuation means realizes the distribution by making the distribution speed faster than that before said relay function stops. Distribution is continued until the storage amount of the distribution information distributed in the repeater as a distribution destination becomes a predetermined amount.

Since the distribution is continued by making the distribution speed faster than that before the relay function stops, until the storage amount of the distributed distribution information in the repeater which is the distribution destination of the distributed distribution information becomes a predetermined amount, It is possible to reliably continue the processing of distribution information in the repeater belonging to the hierarchy below the repeater whose relay function is stopped.

In order to achieve this object, the present invention as set forth in claim 12 relates to a connection mode control device for controlling a publisher serving as a distribution source of distribution information in a network system and connected to the publisher in a tree structure and A connection mode between a plurality of repeaters forming a plurality of levels, wherein the distribution information is published in the network system, the device includes: a connection means such as a CPU for connecting the plurality of repeaters Some of the repeaters are connected to one of the repeaters, thereby forming a plurality of paths for distributing the distribution information to the one repeater; the distribution information issued to the one repeater is distributed to another repeater belonging to a hierarchy below the one repeater, the distribution information is provided for external output processing in the one repeater, and distributing the distribution information issued to the one repeater via the main path as one of the paths or the sub-path as another path to another repeater belonging to a hierarchy below the one repeater .

Therefore, a main path and a sub path are formed to connect a plurality of repeaters to one repeater, and distribution information distributed via the main path is used for external output processing in the one repeater and for distribution to Another Repeater at the level below the Repeater. The distribution information distributed via the main path or the sub-path as one of the paths is also used for distribution to yet another repeater belonging to a lower hierarchy. By connecting a plurality of lines to each node, redundancy can be increased in preparation for stopping the relay function of any one node, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being stopped.

In order to achieve this object, the present invention according to claim 13 relates to the connection mode control apparatus according to claim 12, further comprising switching means such as a CPU, when belonging to a level above the one repeater on the main path when the relay function of the repeater is stopped, for switching the distribution information distributed to the one repeater via the sub-path so as to provide it to an external output in the one repeater deal with.

Therefore, when the relay function of a repeater belonging to a layer above the one repeater on the main path stops, distribution information for switching distribution via the sub-path is provided to external output processing. Therefore, the external output processing in the one repeater is not interrupted.

To achieve this object, the present invention according to claim 14 relates to the connection mode control apparatus according to claim 13, further comprising retrieval means, when switching by said switching means is issued to the one repeater via said sub-path when said publication information of said one repeater is provided to said external output processing in said one repeater, for retrieving said publisher or a new repeater belonging to said level above said one repeater, Wherein the connection means connects the publisher or the new repeater retrieved by the retrieval means to the one repeater, thereby forming a new path.

Therefore, when switching the publication information published via the sub-path to provide it to the external output processing, the publisher or a new repeater belonging to a hierarchy above the one repeater is retrieved, and the publisher or the retrieved new middle The repeater is connected to the one repeater, thereby forming a new path. Therefore, redundancy can be ensured and maintained.

To achieve this object, the present invention according to claim 15 relates to the connection mode control apparatus according to claim 12, further comprising retrieval means, when all the When the relay function of the above repeater is stopped, it is used to retrieve the publisher or the new repeater belonging to the layer above the one repeater, wherein the connecting device transfers the published The repeater or the new repeater retrieved by the retrieval means is connected to the one repeater, thereby forming a new sub-path.

Therefore, when the relay function of a repeater belonging to a level above the one repeater on the subpath stops, a publisher or a new repeater belonging to a level above the one repeater is retrieved, and A new repeater for a publisher or retrieval is connected to this one repeater, forming a new subpath. Therefore, even when the relay function in the repeater located on the sub-path stops, a new sub-path can be formed, and redundancy can be ensured and maintained.

To achieve this object, the present invention according to claim 16 relates to the connection mode control device according to claim 14 or 15, wherein said retrieving means retrieves said publisher or said new repeater so that the one repeater Another repeater on the level to which it belongs is included in the new main path.

Therefore, a publisher or a new repeater is retrieved so that another repeater located on the level to which this one repeater belongs is included in the new main path so that publications can be received via repeaters on the same level information.

To achieve this object, the invention according to claim 17 relates to a connection mode control device according to any one of claims 9 to 16, wherein said connection means connects each repeater on a different level to the one Repeaters, thus forming multiple paths.

Therefore, since the repeaters located on different levels are connected to the one repeater, thereby forming a plurality of paths to the one repeater, even when the possibility of failure such as the stop of the relay function occurs at different levels Sufficient redundancy can also be reliably ensured even when there are differences.

In order to achieve this object, the present invention as set forth in claim 18 relates to a connection mode control method for controlling a publisher serving as a distribution source of distribution information in a network system and those connected to the publisher in a tree structure and A connection mode between multiple repeaters forming multiple levels, wherein the release information is published in the network system, the method includes: a retrieval step, when any one of the repeaters stops the relay function When, any one of the repeaters except the repeater whose relay function has been stopped and capable of relaying the release information is retrieved; in the connecting step, the relay for receiving the release information connected to the retrieved another repeater; and a publishing continuation step, as a publishing connection step of continuing to publish the publishing information via the connected another repeater, for passing through the another repeater The distribution speed of the distribution information of the repeater is faster than the distribution speed before the stop of the relay function to continue distribution.

Therefore, when the relay function in any one of the repeaters stops, another repeater capable of relaying the published information is retrieved. When continuing the distribution of the distribution information via the retrieved another repeater, the distribution speed of the distribution information is made faster than the distribution speed before the relay function is stopped. Therefore, it is possible to continue the processing of distribution information in the repeaters belonging to the hierarchy below the repeater whose relay function is stopped.

In order to achieve this object, the present invention as set forth in claim 19 relates to a connection mode control method for controlling a publisher serving as a distribution source of distribution information in a network system and those connected to the publisher in a tree structure and A connection mode between a plurality of repeaters forming a plurality of levels, wherein the release information is published in the network system, the method includes: a connecting step for connecting some of the plurality of repeaters to one of the repeaters, thereby forming a plurality of paths for distributing the distribution information to the one repeater; The distribution information of the repeater is distributed to another repeater belonging to the hierarchy below the one repeater, the distribution information is provided for the external output processing in the one repeater, and will be passed as one of the paths The main path or the sub-path of another path is distributed to another repeater belonging to a layer below the one repeater by the release information issued to the one repeater.

Therefore, a main path and a sub path are formed to connect a plurality of repeaters to one repeater, and distribution information distributed via the main path is used for external output processing in the one repeater and for distribution to Another repeater of the hierarchy below the repeater, and the distribution information distributed via the main path or the sub-path as one of the paths is also used for distribution to yet another repeater belonging to the lower hierarchy. Therefore, by using multiple lines for repeaters, redundancy can be increased in preparing to stop the repeater function of any one repeater, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being blocked. stop.

In order to achieve this object, the present invention as set forth in claim 20 causes a computer included in a control mode control device for controlling such as a distribution source of distribution information in a network system to function as A connection mode between a publisher of a node and a plurality of repeaters such as a plurality of nodes connected to the publisher in a tree structure and forming a plurality of hierarchies, wherein the distribution information is distributed in the network system , the function is: retrieval means, when the relay function of any one of the repeaters is stopped, it is used to retrieve any one of the repeaters except the repeater whose relay function has stopped and capable of relaying the distribution information; connecting means for connecting the relay receiving the distribution information to the retrieved another relay; and distribution continuation means as another relay via the connection distribution continuation means for continuing distribution of the distribution information by one repeater for continuing by making the distribution speed of the distribution information via the other repeater faster than the distribution speed before the stop of the relay function release.

Therefore, when the relay function of any one of the repeaters stops, another repeater capable of relaying the published information is retrieved. In continuing the distribution of the distribution information via another relayer retrieved, the computer acts to continue the distribution by making the distribution speed of the distribution information faster than that before the stop of the relay function. Therefore, it is possible to continue the processing of distribution information in the repeaters belonging to the hierarchy below the repeater whose relay function is stopped.

In order to achieve this object, the present invention as set forth in claim 21 causes a computer included in a connection mode control device for controlling distribution as a distribution source of distribution information in a network system to function A connection mode between a device and a plurality of repeaters connected to the publisher in a tree structure and forming a plurality of levels, wherein the distribution information is distributed in the network system, and the function is: a connection device , for connecting some of the multiple repeaters to one of the repeaters, thereby forming multiple paths for publishing the release information to the one repeater; and a release control device, for distributing the distribution information distributed to the one repeater via the main path which is one of the paths to another repeater belonging to a hierarchy below the one repeater, as an outside of the one repeater The output processing provides the distribution information, and distributes the distribution information distributed to the one repeater via the main path as one of the paths or a sub-path as another path to the ones belonging to the one repeater. Another repeater for the lower level.

Therefore, a main path and a sub path are formed to connect a plurality of repeaters to one repeater, and distribution information distributed via the main path is used for external output processing in the one repeater and for distribution to Another repeater of the hierarchy below the repeater, and the distribution information distributed via the main path or the sub-path as one of the paths is also used for distribution to yet another repeater belonging to the lower hierarchy. Therefore, by using multiple lines for repeaters, redundancy can be increased in preparing to stop the repeater function of any one repeater, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being blocked. stop.

According to the invention of claim 1, when the relay function in the repeater located on the upstream side in the network system is stopped, the consumption per unit time of the distribution information stored in the repeater located on the downstream side is controlled , so that it is less than the consumption before stopping. As a result, without increasing the burden on the network system itself, it is possible to prevent a problem in the downstream repeater caused by the interruption of the distribution of the distribution information while on the other hand the distribution information is still consumed at a speed similar to that before the interruption. Processing in is interrupted or significant processing delays occur.

Therefore, even in the case where the relay function in any one of the repeaters included in the network system is stopped, the stopped relay can be resumed without exerting a large influence on the processing in the downstream repeater. Function. Therefore, the release information can be released reliably, and at the same time, the reliability of the network system itself is improved.

In the present invention according to claim 2, in addition to the effect of the present invention of claim 1, the distribution information is image information, and by making the reduction speed of the storage amount of image information in the buffer device slower than that in the relay function The reduction speed before stopping can reduce the unit time consumption. Therefore, a simple structure can be employed to reduce unit time consumption without performing complicated speed control processing.

In the invention according to claim 3, in addition to the effect of the invention of claim 2, the reduction speed of the storage amount is slowed down by repeatedly outputting the same still image as a component of moving image information a plurality of times. Therefore, the consumption per unit time can be reliably reduced with simple processing.

In the invention according to claim 4, in addition to the effect of the invention of claim 1, by making the decoding speed of the image information in the processing in the target repeater slower than the decoding speed before the relay function stops To reduce the unit time consumption. Therefore, the consumption per unit time can be reliably reduced with simple processing.

In the invention according to claim 5, in addition to the effect of the invention of claim 1, by making the display time of a still image as a component of moving image information longer than that before the relay function is stopped. Therefore, the consumption per unit time can be reliably reduced with simple processing.

According to the present invention described in claim 6, in addition to the effect of the present invention of any one of claims 1 to 6, after the relay function is restored, the empty unit release information is released only to those other than the one whose relay function is stopped The relay function of the relay stops all relays except the one downstream in the previous release. Therefore, the playback time base in the repeater becomes gradually closer to the playback time base in the other repeaters. As a result, by reducing the unit time consumption in the repeater on the downstream side of the repeater whose repeater function is stopped, the playback position and other repeaters located on the playback time base of the repeater can be eliminated The deviation between playback positions.

According to the invention described in claim 7, when the relay function in the repeater located on the upstream side in the network system is stopped, the per unit time of the distribution information stored in the repeater located on the downstream side is controlled consumption so that it is less than the consumption before stopping. Therefore, it is possible to prevent the occurrence of processing in the downstream repeater due to the fact that the distribution of the distribution information is interrupted while the distribution of the distribution information is still consumed at a speed similar to that before the interruption without increasing the burden on the network system itself. Interruptions or severe processing delays.

Therefore, even if the relay function of any one of the repeaters included in the network system is stopped, the stopped relay function can be restored without exerting a large influence on the processing of the downstream repeater. Therefore, the release information can be released reliably, and at the same time, the reliability of the network system itself is improved.

According to the invention described in claim 8, when the relay function in the repeater located on the upstream side stops, the computer functions so that each unit of the distribution information stored in the repeater located on the downstream side The consumption of time is less than that before the relay function stops. Therefore, it is possible to prevent the occurrence of processing in the downstream repeater due to the fact that the distribution of the distribution information is still consumed at a speed similar to that before the stop, without increasing the burden on the network system itself Interruptions or severe processing delays.

Therefore, even if the relay function of any one of the repeaters included in the network system is stopped, the stopped relay function can be restored without exerting a large influence on the processing of the downstream repeater. Therefore, the release information can be released reliably, and at the same time, the reliability of the network system itself is improved.

According to the invention described in claim 9, when the relay function in any one of the repeaters is stopped, another repeater capable of relaying the distribution information is retrieved. When the distribution of the distribution information is continued via the retrieved another repeater, the distribution speed of the distribution information is made faster than the distribution speed before the stop of the relay function. As a result, it is possible to continue the processing of distribution information in the repeaters belonging to the hierarchy below the repeater whose relay function stopped.

Therefore, even another repeater connected below the repeater whose relay function is stopped can continue processing such as playback using the distribution information without being affected by the stop of the function.

According to the invention described in claim 10, in addition to the effect of the invention described in claim 9, distribution is continued while gradually increasing the distribution speed of distribution information via another repeater connected to the upper limit. The maximum publishing speed, so that repeaters belonging to lower levels can get the necessary publishing information more quickly.

According to the invention described in claim 11, in addition to the effects of the invention described in claim 9 or 10, since the distribution is continued by making the distribution speed faster than that before the relay function is stopped, until the The storage amount in the repeater of the distribution destination of the distribution information becomes a predetermined amount, so it is possible to reliably continue the processing of the distribution information in the repeater belonging to the hierarchy below the repeater whose relay function is stopped. According to the present invention described in claim 4, the main path and the sub path are formed to connect a plurality of repeaters to one repeater, the distribution information issued via the main path is used for external output processing in the one repeater, And for publishing to another repeater belonging to a hierarchy below the one repeater. The distribution information distributed via the main path or the sub-path as one of the paths is also used for distribution to yet another repeater belonging to a lower hierarchy. By connecting a plurality of lines to each node, redundancy can be increased in preparation for stopping the relay function of any one node, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being stopped.

According to the present invention described in claim 12, the main path and the sub path are formed to connect a plurality of repeaters to one repeater, the distribution information issued via the main path is used for external output processing in the one repeater, And for publishing to another repeater belonging to a hierarchy below the one repeater. The distribution information distributed via the main path or the sub-path as one of the paths is also used for distribution to yet another repeater belonging to a lower hierarchy. By connecting a plurality of lines to each node, redundancy can be increased in preparation for stopping the relay function of any one node, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being stopped.

According to the present invention described in claim 13, in addition to the effects of the present invention described in claim 12, when the repeater function of the repeater belonging to the layer above the one repeater located on the main path is stopped , to switch the publishing information published via the subpath to provide for external output processing. Therefore, the external output processing in the one repeater is not interrupted.

According to the present invention described in claim 14, in addition to the effect of the present invention described in claim 13, when the distribution information distributed via the sub-path is switched to be provided for external output processing, the one belonging to the one repeater is retrieved. Publisher or new repeater of the upper level, and connect the retrieved publisher or new repeater to the one repeater, thereby forming a new path. Therefore, redundancy can be ensured and maintained.

According to the present invention described in claim 15, in addition to the effect of the present invention described in claim 12, when the relay function of the repeater belonging to the hierarchy above the one repeater located on the sub-path is stopped , retrieve a publisher or a new repeater belonging to a layer above the one repeater, and connect the retrieved publisher or new repeater to the one repeater, thereby forming a new sub-path. Therefore, even if the relay function in the repeater located on the sub-path stops, a new sub-path can be formed, and redundancy can be ensured and maintained.

According to the present invention described in claim 16, in addition to the effect of the present invention described in claim 14 or 15, a publisher or a repeater is retrieved so that another repeater on the hierarchy to which the one repeater belongs Repeaters are included on the new main path so that publications can be received via repeaters on the same level.

According to the present invention described in claim 17, in addition to the effect of the present invention described in any one of claims 9 to 16, repeaters located on different levels are connected to the one repeater, thereby forming Multiple paths to that one repeater. Therefore, even when the probability of occurrence of a failure such as a relay function stop is different in different layers, sufficient redundancy can be reliably ensured.

According to the invention described in claim 18, when the relay function in any one of the repeaters is stopped, another repeater capable of relaying the distribution information is retrieved. When the distribution of the distribution information is continued via the retrieved another repeater, the distribution speed of the distribution information is made faster than the distribution speed before the stop of the relay function. Therefore, it is possible to continue the processing of distribution information in the repeaters belonging to the hierarchy below the repeater whose relay function is stopped.

Therefore, even another repeater connected below the repeater whose relay function is stopped can continue processing such as playback using the distribution information without being affected by the stop of the function.

According to the present invention described in claim 19, the main path and the sub path are formed to connect a plurality of repeaters to one repeater, the distribution information issued via the main path is used for external output processing in the one repeater, And for distribution to another repeater belonging to a hierarchy below the one repeater, and distribution information distributed via a main path or a subpath as one of the paths is also used for distribution to another repeater belonging to a lower hierarchy a repeater. By using a plurality of lines for repeaters, redundancy can be increased in preparation for stopping the repeater function of any one repeater, and external output processing in repeaters belonging to a lower hierarchy can be prevented from being stopped.

According to the invention described in claim 20, when the relay function in any one of the repeaters is stopped, another repeater capable of relaying the distribution information is retrieved. When continuing the distribution of the distribution information via another relayer retrieved, the computer continues the distribution by making the distribution speed of the distribution information faster than that before the stop of the relay function. Therefore, it is possible to continue the processing of distribution information in the repeaters belonging to the hierarchy below the repeater whose relay function is stopped.

Therefore, even another repeater connected below the repeater whose relay function is stopped can continue processing such as playback using the distribution information without being affected by the stop of the function.

According to the present invention recited in claim 21, the computer functions to form a main path and a sub path to connect a plurality of repeaters to one repeater, and the distribution information issued via the main path is used in the one repeater. and is used to publish to another repeater belonging to the hierarchy below the one repeater, and the publishing information published via the main path or sub-path as one of the paths is also used to publish to the repeater belonging to Yet another repeater at a lower level. By using multiple lines for multiple repeaters, redundancy can be increased in preparation for stopping the repeater function of any one repeater, and external output processing in repeaters belonging to lower hierarchies can be prevented from being blocked. stop.

Description of drawings

1A and 1B are block diagrams showing a schematic configuration of a network system according to a first embodiment. FIG. 1A is a block diagram showing a physical connection mode of a network system. FIG. 1B is a block diagram showing a connection mode of a network system as a topology. FIG. 2A shows the structure of nodes included in the network system according to the first embodiment, and FIG. 2B shows details of information stored in the storage unit 3 . Fig. 3 is a flowchart showing the overall processing in the node according to the first embodiment. 4A to 4E are flow charts (I) showing details of processing in nodes according to the first embodiment, and respectively showing upper-layer node connection processing, data reception processing, lower-layer node connection processing, exit message response processing, and Node exits processing. 5A and 5B are flowcharts (II) showing details of processing in the nodes in the first embodiment, and show data transmission processing and data playback processing, respectively. Fig. 6 is a flowchart showing data display processing in the node according to the first embodiment. 7A, 7B and 7C are diagram (I) showing the packet distribution status in the network system according to the first embodiment and diagrams (i), (ii) and (iii) respectively showing status details. 8A, 8B, and 8C are diagram (II) showing a packet issuing state in the network system according to the first embodiment, and diagrams (iv), (v) and (vi) respectively showing state details. 9A, 9B, and 9C are diagram (III) showing a packet distribution state in the network system according to the first embodiment, and diagrams (vii), (viii) and (ix) respectively showing state details. FIGS. 10A and 10B are diagrams (i) and (ii), respectively, showing details of a packet issue state in the case where node withdrawal occurs in the network system according to the first embodiment. 11A, 11B and 11C are diagrams (i), (ii) and (iii), respectively, showing the details of the packet issue state in the case of reconnection after completion of node exit in the network system according to the first embodiment . 12A, 12B, and 12C are graphs (i), (ii) and (iii), respectively, showing the situation of resuming playback delay after node exit and reconnection in the network system according to the first embodiment. Details of the package's release status. 13A, 13B, and 13C show transmission/reception of data in a node in the case of resuming playback delay after node exit and reconnection in the network system according to the first embodiment, and show node exit respectively The previous state, the state after the node exits, and the state of replay delay recovery. 14A and 14B are flowcharts showing data display processing in nodes in the first modification and the second modification of the first embodiment, respectively. Fig. 15 is a block diagram showing a schematic configuration of a network system according to the second embodiment. Fig. 16 is a block diagram showing a general structure of nodes included in the network system according to the second embodiment. 17A and 17B show the detailed structure of the node according to the second embodiment and show details of the topology table and the operation of the buffer memory, respectively. Fig. 18 is a flowchart showing a normal posting operation in the network system according to the second embodiment. Fig. 19 is a block diagram showing a schematic configuration of a network system according to the second embodiment after the relay function of some nodes is stopped. 20A, 20B and 20C are flowcharts showing the operation of the lower layer nodes when the relay function of some nodes is stopped, and showing the operation of the buffer memory. Fig. 21 shows the operation of the lower layer nodes when the relay function of some nodes is stopped. 22A and 22B show operations in the network system according to a modification of the second embodiment. FIG. 22A is a flowchart showing operations, and FIG. 22B shows operations of the buffer memory corresponding to the operations. Fig. 23 is a block diagram showing a schematic configuration of a network system according to the third embodiment. Fig. 24 is a block diagram showing a schematic configuration of a network system according to the third embodiment after the relay function of some nodes is stopped. Fig. 25 is a flowchart showing a normal distribution operation of the network system according to the third embodiment. Fig. 26 is a flowchart showing the operation of the lower layer nodes when the relay function of some nodes is stopped.

Label description

1, 100 CPU2 connection authentication unit 3 storage unit 4 input unit 5 output unit 6 message sending/receiving unit 7 data sending/receiving unit 8, 109 bus 10 first upper layer node information storage area 11 second upper layer node information storage area 12 send data number information storage area 14 received data number information storage area 15 playback speed information storage area 16 specific value storage area 17 ring buffer area 102 decoder 103 table memory 104 buffer memory 105 broadband interface 106 timer 107 speaker 108 CRTNS network system S server N, N ₁ , N ₂ , N ₃ , N ₄ , N ₅ , N ₆ , N ₇ , N ₈ , N ₉ , N ₁₀ , N ₁₁ , N _{12 , N 13} , N ₁₄ , _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 Node NT Network L, L' line LM, LM' main line LS, LS' sub-line NT, NT2 network system

Detailed ways

(I) First Embodiment Next, a first embodiment of the present invention will be described with reference to FIGS. 1A and 1B to 13A to 13C. The first embodiment to be described below relates to a case where the present invention is applied to a network control process for controlling a distribution mode of content in a network system in which content is distributed and the The network system includes: a server as a node, which is a distribution device as a distribution source of the content of distribution information; and a plurality of nodes as user terminals connected to include a plurality of levels below the server tree structure.

1A and 1B show a schematic structure of a network system according to the first embodiment. 2A and 2B are block diagrams showing detailed structures of nodes included in the network system. 3 to 6 are flowcharts each showing distribution processing performed in a node according to the present invention. 7A to 7C to 13A to 13C specifically show the posting process.

In the case of viewing the network system of the first embodiment as a physical connection mode, as shown in FIG. 1A, the network system NS is constructed so that a server S and a plurality of nodes N as user The lines L are connected to each other so as to be able to mutually transmit/receive information via a network NT such as an Internet line. In the case of looking at the network system NS shown in FIG. 1A as a topology whose vertex is the server S, as shown in FIG. 1B , two nodes N are connected to the server S via a line L, and the two nodes N are connected to Each of node N. With a topology in which the nodes N are connected in a tree shape using the server S as an apex, desired content is distributed from the server S to the node N that requires the content.

The specific structure of the node N included in the network system S will be described below with reference to FIGS. 2A and 2B.

As shown in FIG. 2A, the node N according to the first embodiment includes: a CPU 1 as detection means, consumption control means, reset means, and release control means; a connection authentication unit 2; Unit 3; input unit 4 consisting of a mouse, keyboard, etc.; output unit 5 consisting of a display for displaying images, a speaker for outputting sound, and a decoder for decoding sound; message sending/receiving unit 6 and data sending/receiving unit 7. CPU 1, connection authentication unit 2, storage unit 3, input unit 4, output unit 5, message sending/receiving unit 6 and data sending/receiving unit 7 are connected to each other via bus 8 to be able to send/receive information mutually.

The general operation is described below. First, the message sending/receiving unit 6 is functionally divided into: a part that is connected to a node N (or server S) on a higher level via a line L and sends/receives a message from a node on a higher level; A line L is connected to a node N located on a lower level and a portion that transmits/receives a message from a node located on a lower level. The message here means various control information necessary for distributing desired content in the network system NS. By receiving/sending messages, an environment for publishing actual content is formed.

On the other hand, like the message transmission/reception unit 6, the data transmission/reception unit 7 is functionally divided into: connected to and from nodes N etc. located on a higher hierarchy via a line L A section that transmits/receives data; a section that is connected to a node N located on a lower level via a line L and transmits/receives data from a node located on a lower level. The data represent data in the form of packets including audio or video constituting the content itself distributed in the network system NS. In an environment formed by transmission/reception of messages, the slave server S distributes data as content to each node.

For data in the form of packets, it is assumed that consecutive packet numbers from the head of the content are assigned to packets constituting a block of content (for example, the content of one movie or the content of one music piece). Data sent as a packet is divided into small packets whose units are smaller than a packet. In addition, for packets, consecutive packet numbers from the content header are assigned.

For example, in the case where the network system NS is a network system for distributing chargeable content, the connection authentication unit 2 passes the case where the node N enters the network system NS or the case where another node N is newly connected The so-called authentication process for determining whether the node N is a node to which content distribution is permitted under the control of the CPU 1 is performed by transmitting/receiving authentication information from the server S.

Furthermore, the storage unit 3 temporarily or rewritably stores information to be described later in a nonvolatile manner, and outputs the information to the CPU 1 if necessary.

On the other hand, when an operation such as specifying content to be played back is performed by using the node N, the input unit 4 generates an operation signal corresponding to the performed operation, and outputs the operation signal to the CPU 1. The CPU 1 receives the operation signal and controls other components of the node N, thereby performing processing of distributing and playing back desired content.

Playback processing is performed by using the output unit 5 under the control of the CPU 1.

The specific structure of the storage unit 3 will be described in detail with reference to FIG. 2B . FIG. 2B shows the storage unit 3 partitioned according to the type of stored information.

As shown in Figure 2B, the storage unit 3 is composed of the following: a first upper-level node information storage area 10, which is used to store a node that is located on the upper layer of the node N that includes the storage unit 3 on the topology shown in Figure 1B The upper-level node information of N; the second upper-level node information storage area 11 is used to store the upper-level node information of the upper-level node N located on the upper layer of the upper-level node N in topology; the lower-level node information storage area 12 is used to store the representation Connect topologically to the lower layer node information of one or more nodes N under the node N that includes the storage unit 3, the information number is equal to the lower node number; the data number information storage area 13 is sent to store and represent the information included Send data number information of the packet number of the data sent to the lower layer node; receive the data number information storage area 14, be used to store and represent the packet number information including the packet number of the data received by the node N itself that includes the storage unit 3 The playback speed information storage area 15 is used to store the playback speed information representing the playback speed in the output unit 5 of images and sounds corresponding to the received data; the specific value storage area 16 is used to store as Specific values such as the minimum storage data amount preset by the ring buffer area to be described later; and the ring buffer area 17 for temporarily storing data actually distributed as content.

The node information stored in the first upper node information storage area 10 , the second upper node information storage area 11 and the lower node information storage area 12 specifically includes an IP (Internet Protocol) global address representing the node N.

The ring buffer area 17 is a ring buffer type storage area for temporarily storing data corresponding to distributed contents in a FIFO manner. The ring buffer area 17 sequentially stores packets (and small packets) as content data and outputs the packets according to the storage order as a rule to supply them to playback processing in the output unit 5 .

Next, with reference to the flow charts shown in FIGS. 3 to 6, the process of allowing a new node N to newly enter the network system NS, receiving distribution data corresponding to content, and replaying the content according to the first embodiment, and the process of replaying the content will be described. Processing performed in a case where the function of relaying data to other nodes N connected to the new node N during which the function of relaying data to other nodes N connected to the new node N is stopped due to the withdrawal of the new node from the network system NS is as processing in each node N.

Under the situation that allows new node N to be positioned at the position of the next layer of any node N in the existing network system NS, enter node N (below will newly enter network system NS and carry out data receiving process according to the flow chart of Fig. 3 and replay processing node N is called "entry node N" to distinguish it from other nodes already connected to the network system NS) executes connecting the entry node N to the upper node N (or the node located at the uppermost layer in the network system NS Processing of the server S) on the upper layer (steps S1 and S2). When the connection request is rejected by the upper node N (No in step S2), the entry node N cannot join the existing network system NS at this time, thus completing the processing in the entry node N.

On the other hand, after the upper node N (or server S) permits entry in the determination in step S1 and the necessary connection processing is performed by the upper node N (or server S) (Yes in step S2), it is determined whether in the entering node N The operation of logging out from the network system NS in which the node N exists is performed by the input unit 4 (step S3).

When the entry node N exits from the network system NS (Yes in step S3), the exit operation is performed in the entry node N (step S4), and the processing in the entry node N is completed.

On the other hand, when the process of exiting from the network system NS is not performed but the data reception process etc. are continuously performed (No in step S3), the entry node N performs the process of receiving necessary data from the upper node N (step S5), And the received data is reproduced and the reproduced data is output by using the output unit 5 (step S9). When another node N of the connection needs it, the entry node N executes exit message response processing for disconnecting the connection between another node N connected to the entry node N and the entry node N (step S8), returns to step S3 and Data reception and playback processing are continuously performed.

In parallel with the data replay process (step S9), the entry node N performs a process of connecting another node N to the next layer of the entry node N (step S6) and transmits (relays) data to the connected lower layer node N processing (step S7).

The processing in step S1 and steps S4 to S9 in FIG. 3 will be described in detail below in order.

First, the processing of step S1 will be described in detail by using the flowchart of FIG. 4A.

As shown in Figure 4A, in the processing of step S1, at first the entry node N sends a request message to the upper node N via the line L (step S10), waits for a reply to the request from the upper node N (step S11), and confirms Reply (step S12), wherein the request message is for the entry node N to enter as a node N of the lower layer located at another node N that is a node of the upper layer.

When the entry node N is allowed to enter the network system NS in response to the reply (Yes in step S12), the entry node N stores the upper-level node information including the IP address corresponding to the upper-level node N in the storage of the entry node N. In the first upper-level node information storage area 10 in the unit 3, the upper-level node information of the upper-level node that includes an IP address corresponding to another node above the upper-level node N is stored in the storage unit 3 of the incoming node N. in the second upper layer node information storage area 11 (step S13), and proceed to step S2 as shown in FIG. 3 .

On the other hand, when the entry node N is not allowed to enter the network system NS in the determination of step S12 (NO in step S12), the entry node N cannot display its function. Also in this case, after switching to step S2 shown in FIG. 2 (No in step S2), the process of entering the node N is completed.

Next, the data receiving process in step S5 shown in FIG. 3 will be described in detail by using the flowchart shown in FIG. 4B.

As shown in FIG. 4B, in the process of step S5, firstly, the entering node N sends a message for requesting desired data to the upper layer node connected at this time via the line L (step S15), and confirms whether there is a The transmission permission reply of the message from the upper node N (step S16).

When there is a transmission permission reply (Yes in step S16), the entry node N receives a packet including data desired by the entry node N according to the reply (step S17), and proceeds to step S6 or S9 as shown in FIG. 3 . On the other hand, when no transmission permission reply is obtained from the upper node N in the determination of step S16 (NO in step S16), there is a possibility that a failure occurs on the line between the upper node N and the incoming node N. As a result, the entering node N performs the above-mentioned processing in step S1 (refer to FIG. 4A ), to eliminate the fault and can receive data, returns to the processing of step S15 again, and receives data from the upper node N connected again (step S15 or S17 ).

Next, the lower layer node connection processing in step S6 shown in FIG. 3 will be described by using the flowchart shown in FIG. 4C.

As shown in FIG. 4C, in the process of step S6, it is first determined whether a connection request message from node N connected one layer below the entry node N has been sent to the entry node N (step S20). When the connection request message has not been sent (No in step S20), the entering node N switches to step S7 in FIG. 3 . When the connection request message has been sent (Yes in step S20), by, for example, the connection authentication unit 2 included in each of the lower node N and the entry node N, the lower node N that has sent the connection request message An authentication process is performed between the entry node N (or between the lower node N and the server S via the entry node N) for determining whether the lower node N is a node N having the qualification to enter the network system NS (steps S21 and S22) .

Under the situation that the lower-level node N cannot be allowed to enter the network system NS through the authentication process (No in step S22), this fact is sent to the lower-level node N as a connection prohibition message (step S25), and the program proceeds to the state shown in FIG. Step S7 shown.

On the other hand, when the lower-level node N is allowed to enter the network system NS in the authentication process in the determination of step S22 (Yes in step S22), this fact is sent to the lower-level node N as a connection permission message (step S23), The lower layer node information including the IP address corresponding to the lower layer node N etc. is stored in the lower layer node information storage area 12 in the storage unit 3 of the incoming node N (step S24), and the program proceeds to Step S7 shown.

Next, the data transmission process in step S7 shown in FIG. 3 will be described by using the flowchart shown in FIG. 5A.

As shown in FIG. 5A, in the processing of step S7, it is first determined whether a request for sending data to be reproduced in the lower node N has been received as a request from the node N connected to the lower layer of the entry node N. The message is sent (step S35). When no message is received through the entry node N (NO in step S35), the procedure proceeds to step S8 shown in FIG. 3 .

On the other hand, when it is determined in step S35 that the message has been sent (yes in step S35), next, in response to the message, it is judged whether the packet to be sent from the entry node N is an empty packet to be described in detail below (a packet including only title information and not including entity image information constituting content, etc.) (step S36). When the packet is not an empty packet (NO in step S36), the packet that is not an empty packet is sent as content data to the lower layer node N via the line L (step S38), and the procedure proceeds to step S8 shown in FIG. 3 .

On the other hand, when it is determined in step S36 that the packet to be transmitted is an empty packet (Yes in step S36), the small packet number received by the entry node N before the processing in step S7 shown in FIG. 5A starts. It is compared with the packet number of the entity data to be sent to the lower layer node N (that is, entity data such as image data and sound data not included in the empty packet). In the case of discontinuous numbers (that is, an empty packet is received), by concatenating the packet number immediately before the empty packet with the packet number immediately after the empty packet, the packet number immediately following is arranged at the next Following the previous packet number (step S37), data constituting the contents in the packet with the arranged packet number is sent to the lower node N (step S38), and the procedure proceeds to step S8 shown in FIG. 3 .

Next, the logout message response processing in step S8 shown in FIG. 3 will be described in detail by using the flowchart of FIG. 4D.

As shown in Fig. 4D, in the process of step S8, it is first determined whether any one of the other nodes N connected to the entry node N (specifically, the upper layer node N connected to the upper layer of the entry node N) Or the lower layer node N connected to the lower layer of the entry node N) receives the message that the node N will withdraw from the network system NS (step S26). In a case where the message has not been received (NO in step S26), the procedure returns to step S3 in FIG. 3 . On the other hand, in the case where a message requesting withdrawal is received (YES in step S26), it is determined which of the node N of the upper layer and the node N of the lower layer sent the message (step S27).

When the exit request message has been sent from the upper-level node N ("upper-level node" in step S27), according to the upper-level node stored in the second upper-level node information storage area 11 in the storage unit 3 of the entry node N The node information of the upper layer node of N, the upper layer node connection processing in the above step S1 is performed on the upper layer node N connected to the upper layer node N (that is, the node N that sends the exit request message), thereby recovering topology (step S1), and the procedure returns to step S3 in FIG. 3 .

On the other hand, when an exit request message has been sent from the lower node N (“lower node” in step S27), the lower node information in the storage unit 3 of the entry node N is deleted from the lower node information storage area 12 The node information of the lower node N stored in the area 12 is stored (step S28), and the procedure returns to step S3 in FIG. 3 .

Next, the node exit processing in step S4 shown in FIG. 3 (processing in which the entry node N itself exits from the network system NS) will be described in detail with reference to the flowchart of FIG. 4E.

As shown in FIG. 4E, in the process of step S4, the above-mentioned exit request message (see FIG. 4D) is first sent to the upper node N connected to the upper layer of the entry node N (step S30). Next, the above-mentioned exit request message is similarly transmitted to the lower layer node N connected to the lower layer of the entry node N (step S31). After sending the message, the entry node N performs the process of exiting from the network system NS.

Finally, the data playback processing in step S9 shown in FIG. 3 will be described in detail by using the flowchart shown in FIG. 5B.

As shown in FIG. 5B, in the process of step S9, the replay flag entering the node N (that is, the replay flag indicating whether replay processing using the output unit 5 is being executed) is first checked (step S40). When the playback flag is "off" (that is, playback processing is not currently being executed in the output unit 5) (OFF in step S40), it is next determined whether an amount equal to or data larger than a specific value "t" which is a specific value of a preset storage capacity (step S45).

When there is no data stored in the ring buffer area 17 whose data amount is equal to or greater than the certain value "t" (NO in step S45), if the data playback processing is performed in this state (in other words, the ring buffer is consumed data in the area 17), the ring buffer area 17 enters a so-called underrun state, and there is a possibility that playback of images, playback of music, and the like are interrupted. As a result, in order to further store data, the procedure returns to step S3 via step S8 shown in FIG. 3 .

On the other hand, when it is determined in step S45 that the amount of data equal to or greater than the certain value "t" has been stored (YES in step S45), the playback flag which has been "off" is set to "on". (step S46), in a manner similar to the prior art, carry out the processing of replaying stored data (for example, in the case of image information, the processing of displaying image information) (step S47), and the program proceeds to Step S8.

On the other hand, when the playback flag is "on" in the determination of step S40 (that is, when playback processing is currently being performed in the output unit 5) (NO in step S40), similar to the step S40 The above determination in S45 determines whether or not data equal to or greater than a certain value "t" is currently stored in the ring buffer area 17 (step S41). When the amount of data equal to or greater than the specific value "t" has been stored (YES in step S41), then in a manner similar to step S47, the playback mode such as the display speed of the image data is set to Set to normal mode (step S42). Playback processing is executed according to this setting (step S44). Thereafter, the procedure proceeds to step S8 shown in FIG. 3 .

Conversely, when it is determined in step S41 that data of an amount equal to or greater than the specific value "t" has not been stored (NO in step S41), the data playback mode is changed according to the stored amount (step S43), and according to the setting to execute playback processing (step S44), and the program proceeds to the processing of step S8 shown in FIG. 3 .

When the setting of the playback mode is changed in step S43, when data equal to or greater than the specified value "t" has not been stored, the playback mode is set so that by reducing the data in the playback process in step S44 The reduction speed of the storage amount of the ring buffer area 17 is reduced by reducing the consumption amount (that is, the consumption amount per unit time of the data stored in the ring buffer area 17). Specifically, for example, the amount of data read from the ring buffer area 17 per unit time is set so as to be reduced to about 4/5 of the maximum value of the normal amount. More specifically, there is a method of controlling the amount of reading so that the same packet is read twice at a cycle such as once every 5 packets. In this case, when the relay function in the upper node N is not stopped, it is sufficient to set the period to zero, and shorten the period as the storage amount in the ring buffer area 17 decreases.

The degree of reduction in the amount of data read from the ring buffer area 17 per unit time may be such that the user cannot visually perceive the reduction. To this extent the value of 4/5 can be changed.

Next, the data display processing in step S44 shown in FIG. 5B will be specifically described by using the flowchart of FIG. 6 . The data display processing is based on the preset condition of changing the setting of the speed of reading data from the ring buffer area 17 in the processing of step S43.

As shown in FIG. 6, in the processing of step S44, first, data as image information is read from the ring buffer area 17 according to the reading amount per unit time (reading speed) set in the processing of step S43. (step S50). The read data is decoded in the output unit 5 (step S51) and the decoded data is displayed on an unshown display or the like (step S52). Also in the case of sound information, data is read from the ring buffer area 17 at a reading speed set in a manner similar to that in the case of image information (step S50). The read data is decoded and decoded data is generated from a not-shown speaker or the like (steps S51 and S52).

Next, a series of network control processing will be described more specifically with reference to FIGS. 7A to 7C to FIGS. 13A to 13C including flows of packets constituted by data as contents.

In FIGS. 7A to 7C to 12A to 12C, it is assumed that in the topology whose vertex is the server S, two nodes _N1 and _N2 are connected on the first level one level below the server S. Two nodes _N3 and _N4 are connected one level below node _N1 . Two nodes _N5 and _N6 are connected one layer below node _N2 . Two nodes N ₇ and N ₈ , two nodes N ₉ and N ₁₀ , two nodes N ₁₁ and N ₁₂ and two nodes N ₁₃ and N ₁₄ are respectively connected at nodes N ₃ , N ₄ , N ₅ and N ₆ for the next layer. Next, in the network system NS having the connection mode as shown in the topology having this structure, the image data prestored in the server S as content is distributed to the lower nodes _N1 to _N14 in the form of packets and the node _N1 Processing performed in the case where the node N ₄ in the N ₁₄ withdraws from the network system NS.

Furthermore, it is assumed that each of the server S and the nodes N ₁ to N ₆ has the ring buffer area 17 and also performs relaying of the packet P to other lower-level nodes (each having the ring buffer area 17) while storing the packet P as Data processing (refer to steps S7 and S9 in FIG. 3). In FIGS. 7A to 7C to FIGS. 13A to 13C, one package P is represented as one box (□), and a numeral in each box indicates a package number.

Furthermore, in FIGS. 7A to 7C to FIGS. 12A to 12C, the ring buffer area 17 in each of the nodes _N1 to _N14 is represented as one row. However, in packet input/output processing, the right and left ends of each ring buffer area 17 are connected in a ring. Provide a packet to replay processing. Every time a packet is distributed to the node N of the lower layer, the oldest packet among the packets stored in the ring buffer area 17 is replaced with a new packet distributed from the node N of the upper layer. In this way, the above-mentioned FIFO buffer memory is realized.

The downward hollow arrow for showing the ring buffer area 17 in the server S in FIGS. 7A to 7C to FIGS. 13A to 13C indicates the timing when the packet represented by the box whose left end is pointed by the arrow is sent from the server S . The upward solid arrow shown for the ring buffer area 17 in each node N in FIGS. 8A to 8C to FIGS. 13A to 13C indicates that the image data stored in the location pointed to by the arrow in each packet is displayed at this time. Also, "-" displayed in the display (frame) of the packet in the ring cache area 17 of any one of the server S and the node N indicates that no data is stored in the ring cache area 17 corresponding to the packet.

Assume now that in each of the examples shown in FIGS. 7A and 7B to FIGS. 13A and 13B , a certain value "t" in each node N (specifically, the lower limit of the insufficient storage amount in the ring buffer area 17 The value "t") corresponds to three packets.

First, before the packages are released, the packages to be released are stored in the ring buffer area 17 as shown in FIG. 7A in order of release. These packets are to be distributed numerically to nodes N ₁ to N ₄ connected on the lower layer. Specifically, as shown in FIG. 7A, at the point in time when the packet _P0 is output from the server S, the packet _P0 (with the packet number "0") is sent to the line L connecting the server S and the nodes _N1 and _N2 . superior. Thereafter, the transmitted P ₀ is stored in the ring buffer area 17 in each node N while being relayed by the node N located on the lower hierarchy after the lapse of time as shown in FIGS. 7B and 7C .

When the packet P ₀ is distributed to the nodes N ₇ to N ₁₄ connected on the bottom of the network system NS, then next, as shown in FIG. 8A , transmission of the packet P to be distributed after the packet P ₀ starts.

For example, when image data of three packages are stored in nodes N ₇ to N ₁₄ connected on the bottom of the network system NS as shown in _FIG . to start image playback processing in nodes _N1 to _N14 .

After finishing playback processing of one packet using packet P ₀ in each of nodes N ₁ to N ₁₄ as shown in FIG. 8C , playback processing using next packet P ₁ starts in nodes N ₁ to N ₁₄ , and publishes the fourth packet P ₄ from server S.

By repeating the above-described processing, packets as image data are sequentially issued and played back while being stored in (or erased from) the ring buffer area 17 in a FIFO manner. Assume that in each of the nodes N ₁ to N ₁₄ in the first embodiment, as shown in FIG. 9A , the packets stored just one packet before the packet currently being played back are sequentially updated.

As shown in Figures 9B and 9C, after all the packets to be distributed in the server S are distributed, the ring buffer areas 17 in the nodes N ₁ to N ₁₄ become empty in turn, and all distributions in the network system NS are completed deal with.

10A and 10B to 13A to 13C to describe the processing performed in the case where the node N ₄ in the network system NS stops its relay function due to, for example, a power outage and withdraws from the network system NS itself.

As shown in FIG. 10A , it is assumed that when the process of replaying, for example, the image data included in the packet P ₁ is completed and at the same time the packet P ₅ is sent from the server S to each of the nodes N ₁ to N ₁₄ , the node N ₄ due to For the above reason, it exits from the network system NS (refer to FIG. 4D ). After the exit, the distribution of the package P ₅ to the lower nodes N ₉ and N ₁₀ is naturally disconnected. In this case, as shown in FIG. 10B , the processing of reconnecting the node N ₁₀ to the node N ₁ which is the upper node N at present and the processing of reconnecting the node N ₉ to the reconnected N ₁₀ are performed (refer to FIG. Step S1) in 4D, and re-publish the package P ₅ that has not been released before the release timing. As a result, in the ring buffer area 17 included in each of the nodes N ₉ to N ₁₀ , compared with the other nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ , the rewriting timing is delayed by only one packet. As a result, there are only two packets (packets _P3 and _P4 ) that have not been subjected to playback processing as shown in FIG. 10B, and so-called data delay occurs (No in step S41 in FIG. 5B). Afterwards, until posting of all packets is completed, replay in nodes N ₉ to N ₁₀ is continued in nodes N ₉ and N ₁₀ , delaying only one packet from other nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ state.

Therefore, in the first embodiment, as indicated by the hatched arrows in FIGS. 11A and 11B , in the nodes _N9 and _N10 , the speed at which data is read from the ring buffer area 17 after the time point at which data delay occurs is made to be slower than in the other nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ (NO in step S41 in FIG. 5B and step S50 in FIG. 6 ). Finally, as shown in FIG. 11C , the number of packets to be subjected to playback processing returns to 3 as a specific value (packets P ₄ to P ₆ in the case of FIG. 11C ).

As is apparent from a comparison between the state of the ring buffer area 17 in node _N9 and the state of the ring buffer area 17 in node _N8 in FIG. The package number is restored to 3. The packet to be reproduced in the node N ₈ is the packet P ₅ , but the packet to be reproduced in the node N ₉ is the packet P ₄ . Since _the upper node N ₄ withdraws from the network system NS, when comparing the replay timing on the time base of a series of packets P, a _so -called replay _delay ( That is, the playback timing of the same content in node N deviates). Therefore, for example, in the case where the user of the node _N9 and the user of the node _N8 play a so-called online game, occurrence of a playback delay in these two nodes disturbs the normal use state of the node N.

As a result, in the network control process of the first embodiment, a null packet is issued from the server S to all nodes belonging to the network system NS except for the node N whose replay delay occurs due to the withdrawal of the upper node N from the network system NS , so that the content playback timings of all nodes N included in the network system NS are synchronized with each other.

In the first embodiment, as shown in FIG. 12A , in the content stored in the ring buffer area 17 of the server S before distribution, empty packets P ₀₀ are inserted at predetermined timing or intervals in anticipation of occurrence of playback delay in the future. into other packages.

As shown in FIGS. 12A and 12B , in the case where playback delay occurs in, for example, nodes N ₉ and N ₁₀ , a null packet is issued to all nodes except nodes N ₉ and N ₁₀ , that is, nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ (refer to FIG. 5A ). As a result, as shown in FIG. 12C , the timing of replaying the distributed packets in all the nodes N ₁ to N ₁₄ included in the network system NS becomes the same, and the playback delay in the nodes N ₁ to N ₁₄ is eliminated. .

13A to 13C are specifically described in the node N connected in the node N ₉ and N ₁₀ above and below the transmission/reception timing of the packet transmission / reception, and the execution of a series of network control processing. 13A to 13C show packet transmission/reception states in nodes N connected one layer above and below nodes _N9 and _N10 . The horizontal axis represents the distribution time using its left end as the content distribution start time and the vertical axis represents the packet number in the distributed package (specifically, the lower end of the vertical axis corresponds to the packet whose packet number is "0" in the package _P0 ).

In the case where the relay function of the node N ₄ connected _to the node of the upper layer in Figs. _7A to _7C to Figs. The operation proceeds to the node of the next layer while receiving the packet from the node _N4 . Although the next layer node N is not connected to the node N ₉ or N ₁₀ in FIGS. 7A to 7C to FIGS. 12A to 12C, in order to fully explain the function of each node N included in the network system NS, assume Another node N in 13C is connected to the next layer of node N ₉ or N ₁₀ .

In parallel with the relay function, the node N ₉ or N ₁₀ stores the packets P distributed from the node N ₄ in the ring buffer area 17 in the distribution order (refer to FIGS. 8A to 8C and FIGS. 9A to 9C ). At the point of time when three packs P are stored, the node _N9 or _N10 performs processing such as decoding and displaying the data stored in the pack P through the output unit 5 (below, the processing includes when the data is image data) display processing and sound output processing when the data is sound data). In the example shown in FIG. 13A, when the first package _P0 shown in FIGS. 7A to _7C to _{FIGS .} The time when the ring buffer area 17 is in corresponds to the left end of the horizontal axis. From the time on the left end, subsequent packages _P1 and _P2 are similarly issued and stored in the ring buffer area 17 . The time period from this time until decoding and displaying etc. of the data stored in the packet P ₀ is started is time T ₀ shown in FIG. 13A . The storage amount in the ring buffer area 17 (the amount of three packets in the first embodiment) corresponds to the amount indicated by the symbol "M" in FIGS. 13A and 13B.

After the data in each packet P is decoded and displayed, the portion of the ring buffer area 17 in which the packet P has been recorded is overwritten with the subsequent packet P issued after the packet. In the example shown in FIG. 12A , it starts from decoding and displaying the data in the packet P ₀ until the data in the subsequent packet P ₄ is stored (overwritten) in the ring buffer area 17. part of the package P ₀ , time T is required.

Next, as described above with reference to FIGS. 10A and 10B , in the case where the upper layer node N ₄ of the nodes N ₉ and N ₁₀ withdraws from the network system NS and the subsequent function stops, for the time since the stop until completion as shown in FIG. During the period of reconstruction of the topology shown in 10B and resuming distribution of packets P, no packets P were distributed to nodes N ₉ and N ₁₀ . Therefore, during the non-publishing period, although time elapses, no packet P is distributed from the upper node N. In the nodes N ₉ and N ₁₀ , as shown in FIG. 13B , a graph showing the distribution state of the packet P from the upper node and the relay state of the packet P to the lower node includes a flat part corresponding to the non-release period . As a result, the amount of storage in the ring cache area 17 is reduced. The gradients of the graphs before and after the non-publishing period are the same (that is, the publishing speed and the relaying speed of the package P).

Next, in the first embodiment, in the case where there is a non-release period, the speed of reading data from the ring buffer area 17 is reduced and underflow is prevented from occurring in the ring buffer area 17 (refer to the steps in FIG. 5B ). S43 and S44). Therefore, from the point of time when the non-distribution period is started, the speed of decoding and displaying data, etc. is reduced, as indicated by a thick solid line in FIG. 13B . When the storage amount in the ring buffer area 17 becomes three packs or more, the speed of decoding and display, etc. is reset to the initial speed as shown in FIG. 13B. The storage amount in the ring buffer area 17 is "M" at the start of distribution in a similar manner to the case shown in 13A, and temporarily becomes smaller than "M" due to the occurrence of a non-distribution period. However, the speed of reading data from the ring buffer area 17 becomes slower, so that after the elapse of time T3 in which the data reading speed is slow, the storage amount becomes the initial storage amount "M" again.

In FIG. 13B , in the non-issue period, the overwrite write process in the ring buffer area 17 stops.

As shown in FIGS. 12A to 12C , after the node N ₄ exits, playback delays occur in the nodes N ₉ and N ₁₀ different from the other nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ . In the first embodiment, as shown in FIGS. 12A to 12C , a package P ₀₀ is mixed in content in advance and distributed only to other nodes N ₁ to N ₈ and nodes N ₁₁ to N ₁₄ .

Therefore, when viewed from the positions of nodes N ₉ and N ₁₀ , as shown in FIG. 13C , at the point in time when an empty packet P ₀₀ is issued to other nodes N ₁ to N ₈ and other nodes N ₁₁ to N ₁₄ (shown as "null data" in FIG. 13C ), the content is distributed by passing the empty packet P ₀₀ as described in step S37 in FIG. 5A . As a result, the continuity of packet numbers in the nodes N ₉ and N ₁₀ is interrupted in the case of viewing continuous content stored in the original server S. As a result, the small packet number (indicated by the label "PK" in FIG. 13C ) of an amount corresponding to the empty packet P ₀₀ is delivered to increase the distribution amount at the point of issuance of the empty packet P ₀₀ as shown in FIG. 13C , And similarly relay it to the lower node N. Therefore, the packet number provided for processing such as decoding and displaying is similarly passed and changed in incremented state.

As described above, in the network control process according to the first embodiment, when the relay function in the node N located on the upper layer side in the network system NS is stopped, the consumption speed of the content data stored in the lower layer node N is controlled slower than it was before stopping. As a result, when the distribution of content data is interrupted, it is possible to prevent interrupt processing or serious damage from occurring in the lower layer node N due to consumption of content data at a speed similar to that before the stop without imposing a burden on the network system NS itself. Processing delay.

Therefore, even in the case where the relay function is stopped in any one of the nodes N included in the network system NS, the stopped relay function can be restarted without exerting a large influence on the processing in the lower node N. Therefore, content data can be distributed reliably while improving the reliability of the network system NS itself.

Since the content data is image data and the content data consumption speed is reduced by making the reduction speed of the image data storage amount in the ring buffer area 17 slower than that before the relay function is stopped, it is possible to reduce the speed without performing complicated speed control processing. In the case of a simple structure to reduce the consumption rate.

Furthermore, by repeatedly outputting the same still image for forming moving image data a plurality of times, the reduction speed of the storage amount in the ring buffer area 17 is reduced so that the consumption speed can be reliably reduced by simple processing.

In addition, when the stop of the relay function is detected, the consumption speed is controlled to 4/5 of the consumption speed that was at the maximum value before the relay function was stopped, so that it can be possible without exerting a large influence on the processing in the node N Reduce consumption rate. The reduction in consumption speed is not limited to 4/5, and may eventually be a reduction in reading speed that cannot be perceived by viewers (users of node N).

Since the empty packet P ₀₀ is issued after resetting the relay function of all nodes N except the node N whose relay function was stopped before the stop of the relay function, at the time of replay in other nodes N Basically, the delay occurs gradually. As a result, replay on the replay time base that occurs between this node and all other nodes N due to a decrease in elapsed time per unit time in a node N located below the node N whose relay function has stopped can be eliminated The offset of the position.

II. Modification of First Embodiment A modification of the first embodiment will now be described with reference to FIGS. 14A and 14B.

In the foregoing first embodiment, as a method of reducing the consumption speed of data stored in the ring buffer area 17, a method of reducing the speed of reading data from the ring buffer area 17 itself is used. In addition to this method, the following two methods can be adopted as a method of reducing the consumption rate.

As a first modification, not the speed of reading data from the ring buffer area 17 itself, but the decoding speed of the output unit 5 of the data read from the ring buffer area 17 may be reduced. More specifically, in the process of step S43 in FIG. 5B , the data decoding speed in the output unit 5 is set to be reduced to about 4/5 of the speed at the maximum value in the normal state. For example, when the relay function in the upper node N is not stopped, it is sufficient to set the frame rate at the time of decoding still image data for forming moving image data to 30 frames per second, and when the ring buffer area When the storage capacity in 17 is reduced, setting the frame rate at 29 frames per second is enough. The more the amount of storage in the ring buffer area 17 is reduced, the lower the frame rate is set.

In the case of changing the frame rate in the process of step S43, as the process in step S44 performed subsequently, as shown in FIG. Step S53). The read data is decoded in the output unit 5 by using the frame rate set in step S43 (step S54), and the decoded data is displayed on a display not shown in the figure or the like (step S52 ). In addition, in the case of sound information, data is read from the ring buffer area 17 at a reading speed similar to that in the case of image information (step S53), and the read data is decoded at the set frame rate. , and generate decoded data from a speaker not shown in the figure or the like (steps S54 and S52).

As described above, according to the first amendment, the data consumption speed in the ring buffer area 17 is reduced by making the data decoding speed in process in the node N slower than the decoding speed before the relay function stops. Therefore, the consumption rate can be reliably reduced by simple processing.

Next, as a second embodiment, in the case where the content data is moving image data, not the reading speed itself from the ring buffer area 17 and the decoding speed in the output unit 5, but the output unit 5 of the decoded data The display speed in can be reduced. More specifically, in the processing of step S43 in FIG. 5B , the display time for each of a plurality of pieces of still image data forming the moving image data decoded in the output unit 5 is increased to the normal About 5/4 of the time the display is at maximum in the state. Specifically, when the relay function in the upper layer function in the upper layer node N is not stopped, the display time of the still image data corresponding to one still image (that is, the display time of each still image) is set It is sufficient to set the display time to 1/30 second, and it is sufficient to set the display time to 1/29 second when the storage amount in the ring buffer area 17 decreases. As the amount of storage in the ring buffer area 17 decreases, it is sufficient to make the display time longer.

In the case where the display time as described above is changed in the processing of step S43, as the processing in step S44 performed subsequently, as shown in FIG. data (step S53). The read data is decoded in the output unit 5 by using the normal frame rate (step S55). Thereafter, the decoded data is displayed on a display not shown in the figure or the like at the display time per still image set in step S43 (step S56).

As described above, according to the second revision, the consumption in the ring buffer area 17 is reduced by making the display time of the still image corresponding to the still image data used to form the moving image data longer than the display time before the relay function is stopped. speed. Therefore, the consumption speed can be reduced more reliably by simple processing.

It is also possible to record on an information recording medium such as a floppy disk or a hard disk to the extent corresponding to the flowcharts of FIGS. program, thereby causing the computer to function as the CPU 1 according to the first embodiment.

(III) Second Embodiment (A) Embodiment First, a second embodiment according to the present invention will be described with reference to FIGS. 15 to 22A and 22B.

Fig. 15 is a block diagram showing a schematic configuration of a network system according to the second embodiment. Fig. 16 is a block diagram showing a general structure of nodes included in the network system. 17A and 17B show the detailed structure of the node. Fig. 18 is a flowchart showing a conventional posting operation in a network system. Fig. 19 is a block diagram showing a schematic structure of a network system after the relay function of some nodes is stopped. 20A, 20B and 20C are flowcharts showing operations in the lower layer nodes when the relay function is stopped. Fig. 21 shows the operation of the lower layer node when the relay function is stopped. 22A and 22B show operations in the revised network system according to the second embodiment.

As shown in FIG. 15, the network system NT according to the second embodiment is formed by a tree structure using nodes 0-1 as distribution devices as vertices. The network system NT includes nodes 1-1, 1-2, and 1-3 as nodes constituting the first hierarchy, nodes 2-1 and 2-2 as nodes constituting the second hierarchy, nodes 3-1, 3-2 , 3-3, and 3-4 as nodes constituting the third level, and nodes 4-1, 4-2, and 4-3 as nodes constituting the fourth level. Nodes are connected to each other via a line L which is a wired circuit or a wireless circuit to be able to mutually transmit/receive information using nodes 0-1 as vertices. As specific examples of nodes, node 0-1 located at the highest layer corresponds to a server as a content distribution source, for example, and all nodes other than node 0-1 are, for example, personal computers for home use. Nodes can be home set-top boxes or routers.

In the network system NT shown in FIG. 15 , content distributed from nodes 0-1 and desired by node users is distributed via line L through other nodes included in a hierarchy higher than the node. Apparently, content is distributed in digital state in so-called packages. In addition, packs are issued that are assigned consecutive pack numbers indicating the order of playback or storage in the buffer memory 104 (refer to FIG. 16 ) or the like.

The specific structure of each node will be described below with reference to FIG. 16 and FIGS. 17A and 17B. Next, the detailed structure of the node 3-2 in the network system NT shown in FIG. 15 will be described. The detailed structure of each of the other nodes is the same as that of node 3-2.

As shown in Figure 16, node 3-2 has CPU 100, as retrieval device, connection device, release relay device, release control device and switching device; Decoder 102; Table memory 103; Buffer memory 104; Broadband interface 105; Timing 106; a speaker 107; and a CRT (cathode ray tube) 108 as a display device. CPU 100, decoder 102, table memory 103, buffer memory 104, broadband interface 105 and timer 106 are connected to each other via bus 109.

The operation is described next. The broadband connection 105 is directly connected to line L. As shown in FIG. 15, the broadband interface 105 in the node 3-2 is connected to the broadband interface 105 included in the node 2-1 on the upper level via the line L, and is also connected to the next level via the line L. The broadband interface 105 included in the nodes 4-1 to 4-3. Transmission/reception of content and transmission/reception of control information required for content transmission/reception can be performed in units of packets in a node.

In the table memory 103 which is a nonvolatile memory, a topology table as shown in FIG. 17A is stored. In the topology table T, in addition to the layer information representing the hierarchy, it also includes a node number and an IP (Internet Protocol) address in the network system N, wherein the node number is used to store the topology table T according to the table memory 103 The position of the node in the network system NT is used to identify other nodes located on a higher or lower level. Since the topology table T shown in FIG. 17A corresponds to node 3-2, it includes the layer of node 1-1 on a level (layer 2) two layers higher than node 3-2 as shown in FIG. 15 information, the node number of node 1-1, and the IP address of node 1-1 (eg "100.100.10.10").

Similarly, the topology table T includes: the layer information of the node 2-1 located on the layer (layer 1) above the node 3-2, the node number of the node 2-1, and the IP address of the node 2-1 (for example, "100.100.10.21"); the layer information of node 4-1, the node number of node 4-1, and the IP address of node 4-1 (e.g. "100.100.10.30"); the layer information of node 4-2, the node number of node 4-2, and the IP address of node 4-2 (e.g. "100.100.10.31"); and the layer information of the node 4-3, the node number of the node 4-3, and the IP address of the node 4-3 ( For example "100.100.10.32");

Referring to FIG. 16, the buffer memory 104 which is a volatile memory is a ring buffer memory in a so-called FIFO (First In First Out) format. The buffer memory 104 only stores the data corresponding to the distributed content according to the distribution order through the preset recording capacity, reads the data according to the stored order under the control of the CPU 100, and transfers the read data via the bus 109 output to the decoder 102.

Next, the operation of the buffer memory 104 in the case where the network system NT is in a normal state will be described with reference to FIG. 17B.

As described above, the buffer memory 104 is structured in a ring shape. For example, content data is input clockwise via broadband interface 105 as conceptually shown in the upper half of FIG. 17B , and data is output clockwise to decoder 102 as conceptually shown in the lower half of FIG. 17B . In the example shown in FIG. 17B, the data in the hatched portion is actually stored content data. In parallel to outputting data to the decoder 102 as indicated by the arrow in the lower half of FIG. 17B , new data is input from the broadband interface 105 and stored in the direction indicated by the arrow in the upper half of FIG. 17B . In a normal state, the data input amount and the data output amount in the buffer memory 104 per unit time are the same, and the storage amount in the buffer memory 104 is kept constant (more specifically, half the storage amount of the buffer memory 104)

On the other hand, when the arrival time of a packet as data fluctuates in such a case where the topology in the network system NT changes, the fluctuation can be absorbed by the buffer memory 104 . In the case where the decoder 102 decodes a predetermined amount of data all at once or when the topology is disconnected for some reason, the buffer memory 104 plays a role of always storing the predetermined amount of data so that the buffer memory 104 does not become empty, and playback processing in decoder 102 is not interrupted.

Referring again to FIG. 16, the timer 106 performs counting for detecting the stop of the relay function in any one node in the network system NT, as described below.

The decoder 102 decodes content data output from the buffer memory 104 via the bus 109 , outputs images in the data to the CRT 108 that displays the images, and outputs sound in the data via the speaker 107 .

Next, connect the new node to the network system NT. Operations started and performed in a normal state including new nodes and published content are described all at once by using FIG. 18 . FIG. 18 is a flowchart showing an example of a case where the node 3-1 is newly connected to the node 2-1 in the network system NT so as to obtain the network system NT shown in FIG. 15 and distribute content to the node 3-1 . In the embodiment described below, it is assumed that the total storage capacity of the buffer memory 104 is 64 kilobytes corresponding to the data amount of 16 packets.

When the node 3-1 newly enters the network system NT by being physically connected to the node 2-1, first the CPU 100 in the node 3-1 sets the buffer memory 104 in the node 3-1 (below in each figure, Buffer memory 104 itself may be appropriately referred to as a "ring cache"). The CPU 100 in the node 3 sets a speed parameter indicating the playback speed in the decoder 102 (shown as "speed Reg" in the figure) to be the same as the normal playback speed, and sets The IP address is set in the node 2-1 on the upper layer (when the node 3-1 is connected to the node 2-1, the IP address of the node 2-1 is obtained by the node 3-1). In order to calculate the address for storing data in the buffer memory 104, the CPU 100 counts the input counter (16 bits) for counting the number of bytes of the input data issued from the node 2-1 and the input counter (16 bits) representing the value reset by the decoder 102. Each of the output counters (16 bits) of the put data amount is initialized to "zero" (step S101).

The address for storing the data input to the buffer memory 104 is "the head address in the buffer memory 104 and the value of the input counter", and the address for reading data into the decoder 102 is "the address of the head in the buffer memory 104". head address + output counter value".

After completing necessary initialization processing, next CPU 100 in node 3-1 refers to topology table T in table memory 103 and sends a start message for requesting start of content data transmission to node 2-1 (step S102).

Next, the CPU 1 in the node 2-1 for receiving the start message (step S115) determines whether the received message is a start message (step S116). Because the currently received message is a start message (Y in the step S116), the CPU 1 returns to the node 3-1 (step S117) the packet number of the data currently played back by the node 2-1 as the start packet number.

When the node 3-1 gets the start packet number from the node 2-1, the node 3-1 stores it in the area corresponding to the packet number on the buffer memory 104 (step S103) and uses the data request for requesting the actual content data The message is sent to node 2-1 (step S104). The data request message includes information indicating the packet number of the data to be sent to the node 3-1 and the distribution speed (parameter "speed Reg" in the node 2-1).

The node 2-1 having received the data request message (step S115) determines again whether the received message is a start message (step S116). Since the currently received message is a data request message (N in step S116), the node 2-1 determines whether the received message is a message requesting a topology table T (step S118).

The determination operation in step S118 (and the process of transmitting the topology table T from the node 2-1 in the case of "Y" in step S118) is performed so that when the relay function in any one of the nodes in the network system NT stops , prepare for a case where another node connected under the node whose relay function is stopped acquires the topology of the network system NT. This operation is meaningless processing in the processing between the current node 3-1 and the node 2-1 (therefore, the processing of transmitting the topology table T from the node 2-1 (step S119) is naturally not performed).

Since the currently received message in the determination of step S118 is a data request message rather than a topology request message (N in step S118), it is next determined whether the received message is a data request message (step S120). Since the currently received message is a data request message (Y in step S120), the data of one packet is sent (via line L) to the node 3-1 at the playback speed (currently 1X) specified in the data request message (step S121). When it is determined in step S120 that the message received from node 3-1 is not any one of start message, topology table request message and data request message (N in step S120), the preset error message is returned to node 3-1 (step S122).

In parallel with these operations, the node 3-1 is set to start counting in the timer 106 in the node 3-1 in synchronization with the output of the data request message, and when the count becomes "0", a timer interrupt instruction is generated (step S105). The node 3-1 waits until a predetermined time elapses in the count of the timer 106 (step S106). When the data from the node 2-1 does not arrive within the predetermined time (N in step S106), a timer interrupt instruction is executed, and reconnection processing is performed on the node 2-1.

On the other hand, when the data from the node 2-1 arrives within the predetermined time (Y in step S106), it is determined whether the arrived data is correctly transmitted (step S107). If the data is correctly transmitted (Y in step S107), execution of the timer interrupt instruction is prohibited (step S108), and one packet of received data is stored in the buffer memory 104. In connection with this operation, the value of the input counter and the packet number stored in the buffer memory 104 are only updated for one packet, and in addition only the velocity parameter (step S109) is increased by the current acceleration (set in the initialization process in step S101). ).

It is determined whether the amount of data stored in the buffer memory 104 and not output to the decoder 102 becomes eight packs (that is, half the storage amount of the buffer memory 104) (step S110). When the amount is less than eight packets (Y in step S110), the node 3-1 returns to step S104 to receive the next packet and repeat the above processing. On the other hand, when the amount of data stored in the buffer memory 104 becomes eight packs (N in step S110), the speed parameter and the acceleration are reset to initial values (step S111), and data output to the decoder is started. node 102 (step S112), and returns to the processing in step S104 to continue receiving subsequent data from the node 2-1.

By repeating the processing in steps S104 to S110, the speed issued from the node 2-1 is increased at the current acceleration (0.2 times the initial value) until the data amount corresponding to eight packets is stored in the buffer memory 104 and the buffer memory 104 is charged at a high speed until data reception becomes an error (Y in step S107). On the other hand, when an error occurs in data reception (Y in step S107), the subsequent distribution speed is reduced by only 0.5 times the acceleration (step S113) to reliably perform data transmission, and then continue distribution.

In the process of step S112, when the data amount of eight packets is stored in the buffer memory 104 and the data is output to the decoder 102, the decoder 102 acquires the data from the buffer memory 104 according to the value of the output counter in the buffer memory 104 at this time. The address of the data output by the memory 104 (step S125), the data is decoded and reproduced by only one packet (step S126), and the value of the output counter in the buffer memory 104 is incremented by only one packet (step S127). The processing is repeated only by the amount of eight packets, thereby performing data playback processing.

As described above, by executing the data distribution of the node 2-1 and the playback processing in the node 3-1, the data playback processing in the node 3-1 is performed while keeping the amount of data in the buffer memory 104 constant.

Next, the processing performed in the case where the content relay function in the node 2-1 stops due to reasons such as the power switch being turned off in the network system NT as shown in FIG. 15 will be specifically described with reference to FIGS. 19 to 21 cut off

In the network system NT according to the second embodiment, when the relay function in the node 2-1 stops due to the above reasons, as shown in FIG. 19, the nodes 3-1 and 3 connected to the initial node 2-1 -2 Automatically perform a topology reconfiguration operation for connecting to the node 1-1 located on the upper layer of the node 2-1 via the line L', and continue distribution of content.

First, general operations in the nodes 3-1 and 3-2 in the case where the relay function in the node 2-1 is stopped as shown in FIG. 19 will be described.

When the relay function in node 2-1 is stopped as shown in FIG. 19, even after a predetermined time elapses in the processing of step S106 as shown in FIG. The CPU 100 in each of the (since the issuance in the normal state is continued, so the processing described with reference to FIG. 18 is repeated) cannot receive data from the node 2-1 either. When the data cannot be received even after the predetermined time elapses (N in step S106), the CPU 100 in each of the nodes 3-1 and 3-2 recognizes the The trunking function is stopped and the topology is disconnected.

Afterwards, when a topology disconnection is recognized, the topology is restructured with reference to the topology table T stored in the table memory 103 so as to connect the nodes 3-1 and 3-2 to two higher Node 1-1 on the level of the hierarchy. The node 2-1 is deleted from the topology table T in the table memory 103 in each of the nodes 3-1 and 3-2, and at the same time the layer information of the node 1-1 is updated to "1". After that, each of nodes 3-1 and 3-2 sends a topology request message to node 1-1 (refer to steps S118 and S119 in FIG. 18), and obtains a new topology table T from node 1-1. According to the obtained topology table T, identify the node on the upper level of node 1-1 as node 0-1, and at the same time add the IP address and node number of node 0-1 whose layer information is "2" into the topology table T (in each of the nodes 3-1 and 3-2), thereby completing the reconstruction of the topology.

Afterwards, each of the nodes 3-1 and 3-2 requests the node 1-1 to send a packet following the packet whose packet number is obtained at that time (refer to step S104 in FIG. 18 ), and the node 1-1 receives the request and sends The data is then sent to nodes 3-1 and 3-2 as new destinations.

Changes in the buffer memory 104 in the node 1-1 and each of the nodes 3-1 and 3-2 during reconfiguration of the topology will be described below with reference to FIGS. 20A to 20C.

As described above, when the relay function of the node 2-1 stops, the nodes 3-1 and 3-2 located on the layer below the node 2-1 cannot receive data from the node 2-1, so the node 3-1 The amount of data in the buffer memory 104 in each of 1 and 3-2 decreases. Meanwhile, decoders 102 in nodes 3-1 and 3-2 continue to read data from buffer memory 104 for playback processing. Therefore, as shown in FIG. 20A, the data in each buffer memory 104 continues to decrease.

On the other hand, the node 1-1 located on the upper layer of the node 2-1 cannot transfer data to the node located on the lower layer, so that the amount of data in the buffer memory 104 in the node 1-1 continues to increase, as Figure 20B.

After the topology has been reconstructed, the nodes 3-1 and 3-2 newly connected on the level below the node 1-1 must restore their buffer memory 104 to the normal state (that is, the state where the data is stored halfway) as soon as possible. ). If data cannot continue to be received from upper nodes and decoders 102 in nodes 3-1 and 3-2 continue to read data from buffer memory 104, then finally buffer memory 104 becomes empty and nodes 3-1 and 3-2 Replay processing in was interrupted.

As a result, in the second embodiment, the nodes 3-1 and 3-2 trying to realize the early recovery of the storage amounts in their buffer memories 104 transmit control signals (commands) for increasing the issue speed to newly connected nodes 1-1. For example, node 1-1 for receiving instructions issues data to buffer memories 104 in nodes 3-1 and 3-2 at an issue speed twice the normal playback processing speed in nodes 3-1 and 3-2 , as shown in Figure 20C. Through this operation, the storage amount in the buffer memory 104 returns to the normal state almost simultaneously with the time required to reconfigure the topology.

As a mode of increasing the distribution speed, more specifically, the maximum value of the distribution speed is determined by the transmission processing capability of the CPU 100 in each node related to the so-called bandwidth (frequency band) of the lines L and L'. Considering general redundancy, a speed of about twice the normal replay processing speed described above is appropriate.

As another mode of changing the issuing speed, for example, instead of immediately doubling the issuing speed, the node 1-1 may continuously increase the issuing speed at a predetermined rate until the following control signals are sent from the nodes 3-1 and 3-2, This control signal is used to notify the fact that the storage amount in the buffer memory 104 in each of the nodes 3-1 and 3-2 has reached a predetermined amount. Since the limit of the increase in the release speed depends on the output capability of the node 1-1 and the bandwidth of the line L' used to connect the nodes 3-1 and 3-2, it is grasped by exchanging necessary messages between the node and another controller Whether a packet from a node on a higher level reaches a node on a lower level. Increase the publishing speed to the highest allowable speed, and transmit packets at increasing speeds. In this way, the storage amount in each buffer memory 104 can be recovered in the shortest time. The node 3-2 transmits the packet to the lower nodes 4-1 and 4-2 at the same speed as the speed at which the packet is received from the node 1-1.

Next, when the relay function of the node 2-1 in the network system NT according to the second embodiment is stopped and the nodes 3-1 and 3-2 located on the lower hierarchy are connected again Operations performed when reaching the node 1-1 to reconstruct the topology of the network system NT as shown in FIG. 19 . Next, the reconnection operation in the node 3-1 of the two nodes 3-1 and 3-2 connected to the node 2-1 will be described. In addition, the reconnection operation in the node 3-2 is similarly performed.

Until the relay function of the node 2-1 stops, the processing shown in FIG. 18 is repeated in the node 3-1. When the data from the node 2-1 has not arrived even after a predetermined time elapses in the processing of step S106 shown in FIG. The function is stopped and the reconnection of the tree structure is started.

Specifically, as shown in FIG. 21, when the data from the node 2-1 cannot be received within a predetermined time, a timer interrupt instruction is generated in the node 3-1 (refer to step S105 in FIG. 18 ), and from In the topology table T in the table memory 103, the node 1-1 located on the layer above the node 2-1 is obtained, that is, the IP address of the node 1-1 whose layer information is viewed as "2" from the node 3-1 (step S130), and delete the information in the topology table T related to the node 2-1. After that, the node 3-1 sends a topology table request message for acquiring the topology table T in the node 1-1 to the node 1-1 indicated by the IP address (step S131).

During the topology reconfiguration process, in the node 1-1 located on the higher hierarchy, the same operation as that performed in the node 2-1 shown in FIG. 4 (steps S115 to S122 in FIG. 18 ) is performed. operation (steps S135 to S142 in FIG. 21). The type of the message sent from the node 3-1 is determined (steps S136, S137 and S140) and processing according to the determined message type is performed (S139, S138, S141 and S142).

In the node 101 that has performed this process, when receiving the topology table request message from the node 3-1 (step S135) and determining that the message is a topology table request message (Y in step S137), the node 1-1 will The topology table T stored in the table memory 103 is sent to the node 3-1 (step S138).

The node 3-1 for receiving the topology table T (step S132) updates the existing topology table T with the topology table T acquired from the node 1-1 (step S133). More specifically, node 3-1 identifies node 0-1 and adds the IP address and node number of node 0-1.

After that, in order to restore the storage capacity in the buffer memory 104 in the node 3-1 at high speed, the speed parameter is set to "1", the acceleration is set to 0.2, and a data request message is sent from the node 3-1 to the node 1-1 (step S134). After that, the node 3-1 returns to step S1105 shown in FIG. 18 and repeats the operations in steps S105 to S112 which are the normal state.

Until the amount of one packet of data corresponding to the data request message is received from the node 1-1, the data in the buffer memory 104 is continuously decoded and continuously reduced (refer to FIG. 20A ). When data starts to be distributed from node 1-1 (steps S140 and S141), the distribution speed is gradually increased while the data is distributed, until the data amount corresponding to eight packets is stored in the buffer memory 104 (step S109 in FIG. 18 ) . After storing the data amount corresponding to eight packets, the buffer memory 104 in the node 3-1 starts functioning in the normal state (refer to FIG. 17B ).

As described above, in the process of controlling the connection mode in the network system NT according to the second embodiment, when the relay function in any one node stops, another node capable of relaying content is retrieved. When content distribution is continued via another node retrieved, the distribution speed is made higher than that before the relay function was stopped. Therefore, the processing of the content can be continued in the node belonging to the layer below the node whose relay function was stopped.

Since distribution is continued while gradually increasing the speed of content distribution via another node newly connected to the upper limit speed which is the maximum value of the distribution speed, nodes belonging to a lower hierarchy can acquire necessary content more quickly. It is also possible to detect the amount of unreplayed data stored in the buffer of the node after the relay function is stopped and the topology is reconstructed, and control the publishing speed to the highest speed according to the detected unreplayed data amount time.

(B) Modification of Second Embodiment Next, a modification of the second embodiment will be described with reference to FIG. 22 . Fig. 22 is a flowchart showing the revised operation.

In the second embodiment described above, when the relay function of the node 2-1 stops, another node (node 1-1) located on a higher hierarchy is retrieved and distribution of content is resumed from this node. In the following revision, multiple new nodes are retrieved and distribution of content continues from multiple nodes at the same time.

In the case that the node 3-1 according to this revision cannot receive data from the node 2-1 within a predetermined time as shown in FIG. 22A, steps S130 to S133 as shown in FIG. 21 are performed to update the Topology table T.

While receiving the data released by node 2-1, determine the storage capacity (number of packets) in the buffer memory 104 at this moment and the required storage capacity (eight packets) in the buffer memory 104 under the normal state. Whether the difference is greater than two packets (that is, whether further data storage is necessary) (step S145). When the difference is greater than two packets (i.e. when further data storage is necessary, Y in step S145), a new data request message is sent to node 1-1, the packet number to be received is updated, and the data The request message is sent to the node 0-1 located one level above the node 1-1 (step S146). It is determined whether data of one packet each from nodes 1-1 and 0-1, that is, data of two packets in total have been received (step S147). When the data of two packets has not been received (N in step S147), the node 3-1 waits until the data of two packets is received. On the other hand, when the data of two packets has been received (Y in step S147), the data of two packets is stored in the buffer memory 104, the input counter is updated only for two packets, and the packet number to be received is updated ( Step S148), and the node 3-1 returns to Step S145.

On the other hand, when it is determined in step S145 that the difference is not greater than two packets (that is, further data storage is unnecessary, N in step S145), it is determined whether the difference is greater than one packet (that is, whether it is unnecessary Supplement data urgently) (step S149). When the difference is not greater than one packet (that is to say, the storage capacity in the current buffer memory 104 is in a normal state) (N in step S149), node 3-1 returns to step S111 among Fig. 4, and continues to receive normally deal with.

On the other hand, when the difference is larger than one packet (that is to say, the storage amount in the current buffer memory 104 is close to the normal state and there is no need to urgently supplement data) (Y in step S149), the node 3-1 sends the new data request message Send to the node 1-1 (step S150) and wait until a predetermined time elapses in the count of the timer 6 in the node 3-1 (step S151). If the data from the node 2-1 does not arrive within the predetermined time (N in step S151), a timer interrupt instruction is executed, and data connection processing is executed again for the node 1-1.

On the other hand, when the data from the node 1-1 arrives within a predetermined time (Y in step S151), the data amount of one packet received is stored in the buffer memory 104, and the value of the input counter is stored in the buffer memory 104. The number of packets in the buffer memory 104 is updated by the amount of only one packet (step S152), and the node 3-1 returns to step S145.

When it is determined in step S147 that data from node 0-1 cannot be received (Y in step S147), another node connected to node 0-1 (in the case of FIG. 15, node 1- 2 or 1-3), send a data request message to another node, and check whether the data can be published.

Through the above processing, as shown in FIG. 22B, data is input from a plurality of routers to the buffer memory 104 in the node 3-1, and the necessary storage amount can be quickly restored.

In a manner similar to node 3-1, node 3-2 receives data from a plurality of routers, and restores to the necessary amount of storage. The nodes 4-1 and 4-2 under the node 3-2 located on the next layer of the node 2-1 whose relay function stopped also receive data from a plurality of routers, and quickly restore the necessary storage capacity. The nodes 4-1 and 4-2 under the node 3-2 located on the lower layer of the node 2-1 whose relay function is stopped may not receive data from a plurality of routers, and the node 3-2 may receive data at a rate higher than The speed of the speed in the normal state in the second embodiment distributes data to the lower-level nodes 4-1 and 4-2.

In the above description, by connecting nodes located on different hierarchies to nodes for distributing data, multiple paths to nodes are formed. As a result, sufficient redundancy can be reliably ensured even in a case where the probability of occurrence of a failure such as a relay function stop varies among different hierarchies.

(IV) Third Embodiment A third embodiment as another embodiment according to the present invention will now be described with reference to FIGS. 23 to 26 .

23 and 24 are block diagrams each showing a schematic configuration of a network system according to the third embodiment, and FIGS. 25 and 26 are flowcharts showing operations of the network system.

In the second embodiment described above, the case has been described where the relay function in the node is stopped during reception of content distributed via only one line L. In the third embodiment described below, a node is provided in advance with two routes; a main route and a sub route, and receives posted content.

As shown in FIG. 23, in a similar manner to the second embodiment, a network system NT2 according to the third embodiment is formed by a tree structure whose vertices are nodes 0-1 as distribution devices. The network system NT2 includes nodes 1-1, 1-2, and 1-3 as nodes constituting the first hierarchy, nodes 2-1 and 2-2 as nodes constituting the second hierarchy, nodes 3-1, 3-2 , 3-3, and 3-4 as nodes constituting the third level, and nodes 4-1 and 4-2 as nodes constituting the fourth level. Nodes are connected to each other via a main line LM which is a wired circuit or a wireless circuit to be able to mutually transmit/receive information using nodes 0-1 as vertices. A specific example of each node is similar to that in the second embodiment.

In addition, in the network system NT2 according to the third embodiment, each node belonging to the second or lower hierarchy is connected to a node of a hierarchy above the node of the hierarchy to which the main line LM is connected by using the sub-line LS. In the normal distribution state, only content distributed via the main line LM is provided to playback processing in each node. Content distributed via the sub-line LS is temporarily received without being used for playback processing, and then distributed to another node located on the next hierarchy. Also, it is sufficient to receive content distributed from the sub-line LS and distribute content from the main line to lower nodes.

The detailed structure of the node according to the third embodiment differs from the node according to the second embodiment (see FIG. 2 ) in that two table memories 103, two buffer memories 104 and two timers 106 are provided, each of which One is for the main line LM and the other is for the sub-line LS. In a manner similar to the second embodiment, a CPU 100, a decoder 102, a broadband interface 105, a speaker 107, and a CRT 108 are provided. Furthermore, in the topology table T stored in each table memory of a node, unlike the second embodiment, an identifier is added for indicating whether the topology table is the topology table T for the main line LM or for The topology table T of the sub-line LS.

For example, when the relay function in the node 2-1 belonging to the network system NT2 in the state shown in FIG. Each of each automatically reconnects the main line LM and the sub-line LS into the main line LM' and the sub-line LS' respectively, as shown in FIG. 24 , and continues to receive published content. In this case, in FIG. 23, the node 3-1 is connected to the node 2-1 via the main line LM, and is connected to the node 0-1 via the sub line LS. After the relay function in the node 2-1 stops, the node 3-1 connects the main line LM' to the node 1-1, and the connection of the sub line LS to the node 0-1 remains unchanged. On the other hand, in FIG. 23, the node 3-2 is connected to the node 2-1 via the main line LM, and is connected to the node 1-1 via the sub line LS. After the relay function in the node 2-1 stops, the node 3-2 connects the main line LM' to the node 3-1 on the same level, and the connection of the sub line LS to the node 1-1 remains unchanged. In this way, the rules are strictly followed so that the main line LM is connected to the nearest node, and the sub-line LS is connected to a node located on a level one level above the node to which the main line LM is connected.

For the nodes 4-1 and 4-2 belonging to the fourth level, the node to which the sub-line LS is connected loses the relay function in Fig. 23, so the main line LM remains unchanged and only the sub-line LS' is connected to the new node (In the case of FIG. 24, the node to which the sub-line LS' is connected is the node 3-1).

Next, the topology reconfiguration operation performed in the nodes 3-1, 3-2, 4-1, and 4-2 in the case where 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. 3-2 starts connecting to a node located on a higher hierarchy than node 2-1. During the counting of the timer 106, in the connected router, the node 3-1 stores the data distributed from the node 0-1 in the buffer memory 4, and the node 3-2 stores the data distributed from the node 1-1 In the buffer memory 4, and distribute the data 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 memory 4, and the data distributed from the sub-line LS is distributed to the lower layer nodes.

The node 3-1 or 3-2 (node 3-1 in the case of Fig. 24) having a higher speed is connected to the node 1-1. The node 3-1 connects the new main line LM' to the node 1-1, furthermore, maintains the connection to the node 0-1 via the original sub line LS, and receives the content distributed from the node 0-1 (backup distribution).

On the other hand, the node 3-2 which cannot be connected to the node 1-1 is connected to the node 3-1 which currently belongs to the lower layer of the node 1-1 via the main line LM' while maintaining the original sub-line with the node 1-1. LS. In this case, node 3-2 can be directly reconnected to node 0-1. However, many nodes are currently connected to nodes 0-1, so the main line LM' is actually connected to node 3-1.

For nodes 4-1 and 4-2 located on lower levels, the original sub-line LS is disconnected. As a result, the nodes 4-1 and 4-2 inquire about the node 3-2 belonging to the upper layer of the node to which the sub-line LS' is to be newly connected. As a result, it can be recognized that a new main line LM' is formed between nodes 3-2 and 3-1, so that node 4-1 or 4-2 which has inquired node 3-2 first forms a new sub-line to node 3-1 LS'.

Next, operations performed when a new node is connected to the network system NT2 according to the third embodiment and distribution of content is started and executed in a normal state including the new node will be described all at once with reference to FIG. 25 . FIG. 25 is a flow chart showing a case where the node 3-1 is newly connected to the node 2-1 in the network system NT2 to obtain the network system NT2 as shown in FIG. 23, and distribution of content is performed to the node 3-1. example of.

In at least one of the nodes in the network system NT2 according to the third embodiment, which is another node via the main line LM or the sub line LS, the processing in the flowchart shown in the upper right part is always executed. The node to connect to at a lower level.

Specifically, whenever a message is sent from a node located on a lower hierarchy (step S170), the type of the message is sequentially determined (step S171, S173, S175, S177, or S179).

When the received message is a start message (Y in step S171), the packet number of the data currently being played back by the node is sent back as the start packet number (step S117).

When the received message is a topology data table request message (Y in step S173), in the topology table T provided for the node at present, according to the type of the circuit connected to the node for sending back the topology data table request message The topology table T of (main line or sub-line) is sent back (step S174).

When the received message is a data request message (Y in step S175), data of one packet is transmitted at the playback speed specified in the data request message (step S176).

When the received message is the new node support request information that inquires about the possibility of using the sub-line LS to distribute data (Y in step S177), it is determined whether it is possible to use Sub-line L to publish. Reply with an "Allow" message if possible. On the other hand, if it is not possible, a "prohibited" message is replied (step S178).

When the received message is a forced connection request message indicating that the new sub-line LS is used to force the distribution of data (Y in step S179), in a manner similar to the case of step S177, the Another node's association to determine whether it is possible to use the sub-line LS for publication. Reply with an "Allow" message if possible. On the other hand, if it is not possible, data publication is stopped. Publishing is to a node (step S180) that is layer information in the topology table T according to the type of line to which the node that has sent the mandatory connection request information is connected among the topology tables currently provided to the node Nodes that are "-1".

When the received message is not any of the above messages (N in step S179), a preset error message is sent back to the node that has sent the message (step S181).

In each node that continuously performs the above processing, data from a node whose layer information is "1" in the topology table T corresponding to the main line LM is decoded by the decoder 102 and the decoded data is output. On the other hand, data from a node whose layer information is "1" in the topology table T corresponding to the sub-line LS is distributed to another node located on a lower layer without being decoded.

In the network system NT2 operating in this state, when the node 3-1 newly enters the network system NT2 by physically connecting to the node 2-1, first the CPU 100 in the new node 3-1 sets the Two buffer memories 104 (for the main line LM and the sub-line LS), set the IP address of the node representing the data supply source, and set the nodes 0-1 located on the upper level on the sub-line LS (when When node 3-1 is connected to node 2-1, node 3-1 acquires IP addresses of both nodes from node 2-1). In order to calculate the address at which data is stored in each buffer memory 104, the input counter 1 (16 bits), the input counter 2 (16 bits) and the output counter 1 (16 bits) are initialized to "0". The input counter 1 counts the number of bytes of received data issued by the slave nodes 0-1 via the main line LM. The input counter 2 counts the number of bytes of received data issued from the node 0-1 via the sub-line LS. The output counter shows the amount of data reproduced by the decoder 102 . Also, at this time, a buffer address indicating "ring buffer 1" (in FIGS. 25 and 26, appropriately indicated as "ring buffer ADR") is set in the buffer memory 104 corresponding to the main line LM (step S160) .

After completing necessary initialization processing, the CPU 100 in the node 3-1 refers to the topology table T in the table memory 3, and sends a start message for requesting the nodes 2-1 and 0-1 to start transmission of content data ( Step S161).

Next, the CPU 100 in the nodes 2-1 and 0-1 that have received the start message sends the packet number of the data currently replayed by the nodes 2-1 and 0-1 as the start packet number to the node 3-1 (step S172).

Node 3-1 obtains the starting packet number from nodes 2-1 and 0-1, stores it in the corresponding packet number area on the buffer memory 104 corresponding to the line (step S162), and will be used to request the actual content data The data request message is sent to nodes 2-1 and 0-1 (step S 163). The data request information includes packet number information of data to be transmitted from the nodes 3-1 and 2-1 (for replay processing) and the node 0-1 (for immediately distributing data to a lower layer).

Nodes 2-1 and 0-1 having received the data request message ("Y" in step S170 and in S175) at the playback speed specified in the data request message (via the main line LM and sub-line LS) The data amount of one packet is sent to the node 3-1 (step S176).

In parallel with this operation, the node 3-1 is set to output a data request message, while counting is started by the timer in the node 3-1, and a timer interrupt instruction is independently generated when the count becomes "0" (step S164 ). The node 3-1 waits until a predetermined time elapses every count of the timer 106 (step S165). When the data from the nodes 2-1 and 0-1 do not arrive within the predetermined time (N in step S165), the node 3-1 executes the timer interrupt instruction, and executes the connection again to the nodes 2-1 and 0-1 deal with.

On the other hand, when the data from the nodes 2-1 and 0-1 arrive within the predetermined time (Y in step S165), the node 3-1 prohibits the execution of the timer interrupt command (step S166), and will communicate with the received An amount corresponding to one packet of data is stored in the buffer memory 104 . Accompanying this processing, the values of the input counters 1 and 2 and the packet number stored in the buffer memory 104 are updated by only one packet.

The node 3-1 determines whether the amount of data stored in each buffer memory 104 and not yet output to the decoder 102 becomes four packs (ie, 1/4 storage amount of the buffer memory 104) (step S168). When the amount is less than four packets (Y in step S168), node 3-1 returns to step S163 to receive subsequent packets from nodes 2-1 and 0-1, and repeats the above-described processing. On the other hand, when the amount of data stored in each buffer memory 104 becomes four packs (N in step S168), only the data acquired via the main line LM is output to the decoder 102 (step S169), And return to the processing in step S163 to receive the following data from nodes 2-1 and 0-1.

In the process of step S169, when storing the data amount of four packets in the buffer memory 104 corresponding to the main line LM and outputting it to the decoder 102, the decoder 102 repeats only by the amount of four packets The following operations are performed, thereby performing data replay processing. In these operations, the decoder 102 acquires the buffer address representing the buffer memory 104 at this time and the address of the data output from the buffer memory 104 according to the value of the output counter in the buffer memory 104 indicated by the buffer address (step S182), only The data is decoded and played back in one pack (step S183), and the value of the output counter in the buffer memory 104 is incremented by only one pack (step S184).

By performing data distribution from node 2-1, playback processing in node 3-1, and distribution from node 0-1 using the sub-line LS as described above, data playback processing in node 3-1 is performed, while The amount of data in each buffer memory 104 is kept constant.

Next, referring to FIG. 26, it will be specifically described the processing performed when the content relay function in the node 2-1 is stopped due to reasons such as the power switch being turned off in the network system NT2 shown in FIG.

In the network system NT2 according to the third embodiment, when the relay function in the node 2-1 stops due to the above reasons, as shown in FIG. 24, the nodes 3-1 and 3-1 connected to the original node 2-1 2 and the nodes 4-1 and 4-2 automatically perform the topology reconfiguration operation, and continue publishing of content through the topology in the mode as shown in FIG. 24 .

When the relay function in node 2-1 is stopped as shown in FIG. 25, even after a predetermined time elapses in the processing of step S165 as shown in FIG. The CPU 100 in each of 2 (since the issuance in the normal state as shown in FIG. 25 is continued, so the processing described with reference to FIG. 25 is repeated) cannot receive data from the node 2-1 either. When the data cannot be received even after the predetermined time has elapsed (N in step S165), the CPU 100 in each of the nodes 3-1 and 3-2 recognizes that in the node 2-1 located on the upper level The trunking function is stopped and the topology is disconnected.

Afterwards, when topology disconnection is recognized, an interrupt instruction as shown in FIG. 26 is executed with reference to the topology table T stored in the table memory 103 , and the topology is reconstructed as shown in FIG. 24 .

Specifically, as shown in FIG. 26, when an interrupt instruction is executed, it is determined whether the timer 106 whose predetermined time has elapsed is the timer 106 corresponding to the main line LM (represented as "timer 1" in FIG. 26) ) (step S190). When it is the timer 106 corresponding to the main line LM (Y in step S190), the value of the buffer address is changed to a value for representing the buffer memory 104 corresponding to the sub-line LS, so as to be connected to the sub-line LS The corresponding buffer memory 104 is set to output data to the buffer memory 104 of the decoder 102 (step S191). Next, a topology table request message corresponding to the main line LM is sent to a node whose layer information value is "2" (node 1-1 in the case of FIG. 24 ) in the main line LM (steps S192 and S194), and obtain the topology table T (step S195) corresponding to the main line LM from the topology table T in the node.

By using the obtained topology table T, the topology table T in the nodes 3-1 and 3-2 corresponding to the main line LM is updated (step S196).

Next, the new node support request message queries the node whether the sub-line LS can be connected to a node (in the case of FIG. 24, node 0-1) whose layer information is "2" in the updated topology table T (step S197 ).

Check whether the reply of the new node support request message is "allowed" (step S198). If "allow" (Y in step S198), then the IP address of the node to which the sub-line LS was connected before the relay function was stopped is rewritten to the IP address of the node to which the main line LM is currently connected, and the sub-line LM The IP address of the node to which the line LS is newly connected (node 0-1 in the case of FIG. The address is written into the topology table T (step S199).

On the other hand, when it is determined in step S198 that the reply of the new node support request message is "forbidden" (N in step S198), the forced connection request message is sent to the node 0- Node 1-1 on the hierarchy below 1 (step S200).

When node 1-1 receives the mandatory connection message and sub-line LS can be connected in node 1-1, the connection is allowed in node 1-1, and the topology table T in node 3-1 is updated (step S201). When it is not possible, distribution of data from node 0-1 to node 1-1 stops. The node 1-1 to which transmission of data is stopped performs the above-described processing, thereby reconfiguring the topology.

On the other hand, when it is determined in step S190 that the interrupt instruction is executed in the timer 106 corresponding to the sub-line LS (N in step S190), the relay function of the node 2-1 at the upper level has an effect on the main line LM. to operate. Therefore, the topology table request message corresponding to the main line LM is sent to the node 2-1 (steps S193 and S194), the topology table T in the node 2-1 is obtained (step S195), and the processing of step S196 and subsequent steps is performed .

As described above, in the network system NT2 of the third embodiment, the main line LM and the sub-line LS are formed to connect a plurality of nodes to one node. Data distributed via the main line LM is used for playback processing in this one node and the like and distributed to other nodes belonging to lower levels. On the other hand, data distributed via the sub-line LS is intended for distribution to other nodes belonging to a lower hierarchy. By connecting a plurality of lines to each node, redundancy can be increased in preparation for stopping the relay function in any node, and it is possible to prevent stop of replay processing and the like in nodes belonging to a lower hierarchy.

When the relay function in a node belonging to a higher hierarchy stops on the main line LM to one node, the data issued via the sub-line LS is switched for replay processing and the like for replay in the one node Processing such classes is not interrupted.

Also, when data distributed via the sub-line LS is switched for playback processing or the like, any node belonging to a higher hierarchy is retrieved, and a new sub-line is formed by connecting to the retrieved node LS. Therefore, even when the sub-line LS is used as the main line LM, a new sub-line LS is formed, and redundancy can be ensured and maintained.

Furthermore, when the relay function in a node belonging to a higher hierarchy stops on a sub-line LS to a node, any node belonging to a higher hierarchy is retrieved, and by connecting to the retrieved node, A new sub-line LS is formed. Therefore, even when the relay function in the node on the sub-line LS stops, a new sub-line LS is formed, and redundancy can be ensured and maintained.

Since nodes of a higher hierarchy are retrieved so that another node on the hierarchy to which the one node belongs is included in the new main line LM, provision of distribution information can be retrieved via nodes located in the same hierarchy.

In each of the foregoing embodiments, as a method of detecting the stop of the relay function in any one node, in addition to the above-mentioned method, the node may periodically detect whether there is a response to a node of a higher or lower hierarchy. For example, when the relay function of the node 2-1 itself stops in each embodiment, the stop may be notified to the node 101 located at a higher level, or the nodes 3-1 and 3-2 located at a lower level .

The series of connection mode control processes described above may also be performed under the control of another server device located outside the network system NT or NT2. In this case, the server device has connection mode information of nodes in the network system NT or NT2. By sending inquiries to the server device from the nodes 3-1 and 3-2, the node 1-1 located on the upper hierarchy of the node 2-1 whose relay function has been stopped is identified.

Furthermore, the decoder 102, the CRT 108, etc. for playing back content may also be configured to connect playback devices, etc., at other locations than the nodes via another network.

In addition, it is also possible to record the programs corresponding to the flowcharts of Figs. 18, 21, 22, 25, and 26 on an information recording medium such as a floppy disk or a hard disk, or obtain the program via the Internet or the like and record it, and pass it on to an ordinary computer. The program is read and executed, thereby causing the computer to function as the CPU 100 according to the embodiments.

Industrial applicability

As described above, the present application can be applied to the field of distributing contents by using a network system having a tree structure. In particular, when the present invention is applied to the field of content distribution, such as movies and music, which are played in real time and inconvenient for distribution interruption, significant effects can be obtained.

Claims (11)

1. connection mode control appliance; Be used for being controlled at network system and be connected to the connection mode between said distributor and a plurality of repeaters that form a plurality of levels as the distributor of the issue source that releases news with tree structure; Wherein said releasing news issued in said network system, and this equipment comprises:

Indexing unit when the relay function in any one said repeater stops, being used to retrieve any one the said repeater except the said repeater that relay function has stopped and can relaying is said releasing news;

Jockey is used for being connected to said another repeater that retrieves with receiving the said said repeater that releases news; And

Issue continues device, is used for through making the said issue speed that releases news via said another repeater continue the said issue that releases news via another repeater of said connection faster than the issue speed before stopping at said relay function.

2. connection mode control appliance as claimed in claim 1; Wherein said issue continues device and proceeds issue; To bring up to simultaneously the maximum of the said issue speed of in the said network that connects said distributor and each repeater, stipulating gradually via the said issue speed that releases news of another repeater of said connection, as the upper limit.

3. according to claim 1 or claim 2 connection mode control appliance; Wherein said issue continues device and proceeds issue through making issue speed faster than the issue speed before stopping at said relay function, up to becoming scheduled volume as the said memory space that releases news that is published in the said repeater of issue destination.

4. connection mode control appliance; Be used for being controlled at network system and be connected to the connection mode between said distributor and a plurality of repeaters that form a plurality of levels as the distributor of the issue source that releases news with tree structure; Wherein said releasing news issued in said network system, and this equipment comprises:

Jockey, some that are used for said a plurality of repeaters are connected to a repeater in the said repeater, thereby form said releasing news are published to the mulitpath of the said repeater in the said repeater; And

The issue control device; Said the releasing news that is used for being distributed to via the main path as one of path a said repeater of said repeater is published to said the releasing news of resetting in another repeater of the level under the said repeater that belongs in the said repeater, the said repeater in said repeater, and will be via being published to another repeater of the level under the said repeater that belongs in the said repeater as the said main path in one of path or as said the releasing news that the subpath of another paths is distributed to the said repeater in the said repeater.

5. connection mode control appliance as claimed in claim 4; Further comprise switching device shifter; When the said relay function of the said repeater of the level on the said repeater in the said repeater on belonging to said main path stops; Be used for switching to the said of a said repeater that is distributed to said repeater via subpath and release news, reset thereby it is offered in the said repeater in the said repeater.

6. connection mode control appliance as claimed in claim 5; Further comprise indexing unit; Offer playback time in this repeater when switching to through said switching device shifter that be distributed to this repeater via said subpath said releases news so that with it; Be used to retrieve the new repeater that said distributor perhaps belongs to the said level on this repeater

Wherein said jockey is connected to this repeater with the said new repeater that said distributor is perhaps retrieved by said indexing unit, thereby forms new path.

7. connection mode control appliance as claimed in claim 4; Further comprise indexing unit; When the said relay function of the said repeater of the said level on the said repeater in the said repeater on belonging to subpath stops; The new repeater of the said level on the said repeater that is used for retrieving said distributor or belonging to said repeater

Wherein said jockey is connected to the said repeater in the said repeater with said distributor or by the said new repeater that said indexing unit retrieves, thereby forms new subpath.

8. like claim 6 or 7 described connection mode control appliances, wherein said indexing unit is retrieved said distributor or said new repeater, so that another repeater on the said level under this repeater is included in the new main path.

9. connection mode control appliance as claimed in claim 4, wherein said jockey is connected to this repeater with each repeater on the different levels, thereby forms mulitpath.

10. connection mode control method; Be used for being controlled at network system and be connected to the connection mode between said distributor and a plurality of repeaters that form a plurality of levels as the distributor of the issue source that releases news with tree structure; Wherein said releasing news issued in said network system, and this method comprises:

Searching step, when the relay function in any one said repeater stops, retrieval except the said repeater that relay function has stopped any one said repeater and can relaying is said release news;

Connection Step will be used to receive the said said repeater that releases news and be connected to said another repeater that retrieves; And

Issue continues step; Continue the said issue Connection Step that releases news of issue as another repeater, be used for through making the said issue speed that releases news continue issue faster than the issue speed before stopping at said relay function via said another repeater via said connection.

11. connection mode control method; Be used for being controlled at network system and be connected to the connection mode between said distributor and a plurality of repeaters that form a plurality of levels as the distributor of the issue source that releases news with tree structure; Wherein said releasing news issued in said network system, and this method comprises:

Connection Step, some that are used for said a plurality of repeaters are connected to a repeater in the said repeater, thereby form said releasing news are published to the mulitpath of the said repeater in the said repeater; And

The issue controlled step; Said the releasing news that is used for being distributed to via the main path as one of path a said repeater of said repeater is published to said the releasing news of resetting in another repeater of the level under the said repeater that belongs in the said repeater, the said repeater in said repeater, and will be via being published to another repeater of the level under the said repeater that belongs in the said repeater as the said main path in one of path or as said the releasing news that the subpath of another paths is distributed to the said repeater in the said repeater.

Images