JP2010257305A - Client device and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue the reception of data even when data can not be transferred in a communication network in which data are transferred between a plurality of client devices. <P>SOLUTION: The client device for receiving data transferred from one client device is provided with: a connection candidate storage means for storing information related with a plurality of client devices as candidates for transferring data to the client device; an event occurrent detection means for detecting the occurrence of a prescribed event related with one client device; an access point selection means for, when the occurrence of the prescribed event is detected by the event occurrence detection means, selecting one candidate of the information stored by the connection candidate storage means; and a data transfer requesting means for requesting the candidate selected by the access point selection means to transfer the data to the client device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique in streaming distribution.

  Conventionally, in streaming distribution, each client makes a distribution request to the streaming distribution server, and the distribution server performs streaming distribution to each client. That is, the client and the streaming distribution server perform one-to-one unicast distribution.

  In general, moving image data and the like used for streaming has a large capacity, and if the number of clients as distribution destinations increases, the network usage band increases in proportion to it, and the processing load on the distribution server increases. Further, during the distribution of content, the processing load on these networks and distribution servers is kept large.

  As a method for reducing the processing load on the network and the distribution server, a streaming distribution method using P2P (Peer to Peer) for transferring streaming data received by a client to another client is considered (Patent Literature). 1).

JP 2002-82924 A

  However, in the above streaming distribution method using P2P, it is necessary to consider that the client that has been undertaking the data transfer may stop the data transfer for some reason. In this case, there is a problem that another client that has received the streaming data via the client cannot receive the transferred data. In addition, when a client that has received data transfer receives data distribution by another route, if it takes time to change the distribution route, reception of streaming data is interrupted during the distribution route change processing. .

  Therefore, in the present invention, in a communication network that transfers data between a plurality of client devices, the client device that continues to receive data even if the client device that was transferring data cannot continue the data transfer And it aims at providing the control method.

  In one form of the disclosed client device, in a communication network having a data distribution device and a plurality of client devices, the client device is connected to one client device and receives data distributed from the data distribution device. A client device that receives the transferred data, and a candidate connection unit that holds information about the plurality of client devices as candidates for transferring the data to the client device; An event occurrence detecting means for detecting the occurrence of an event, and a connection for selecting one of the information held by the connection candidate holding means when the occurrence of the predetermined event is detected by the event occurrence detecting means Selected by the destination selection means and the connection destination selection means. To said candidate, and having a data transfer request means for requesting to transfer the data to the client device.

  In the disclosed client device, in a communication network that transfers data between a plurality of client devices, even if the client device that has performed data transfer cannot continue the data transfer, the client device may continue to receive data. it can.

It is a functional block diagram of a data distribution system including a client device according to the present embodiment. It is a block diagram of the data delivery system containing the client apparatus which concerns on this Embodiment. It is a figure which shows an example of the data structure which concerns on this Embodiment. It is a figure which shows an example of the viewer list | wrist which concerns on this Embodiment. It is a figure which shows an example of the connection destination candidate list | wrist which concerns on this Embodiment. It is a figure which shows an example of the connection core list | wrist which concerns on this Embodiment. It is a schematic diagram of an example of the reception data buffer which concerns on this Embodiment. It is a figure which shows an example of the reception data buffer management information list | wrist which concerns on this Embodiment. It is a sequence diagram which shows the flow of the delivery process in the data delivery system containing the client apparatus which concerns on this Embodiment. It is a sequence diagram which shows the flow of the parent client switching process (the 1) in the data delivery system containing the client apparatus which concerns on this Embodiment. It is a sequence diagram which shows the flow of the parent client switching process (the 2) in the data delivery system containing the client apparatus which concerns on this Embodiment. It is a sequence diagram which shows the flow of the change process of the secondary connection destination in the data delivery system containing the client apparatus which concerns on this Embodiment. It is a sequence diagram which shows the flow of a process at the time of a child client stop in the data delivery system containing the client apparatus which concerns on this Embodiment.

  The best mode for carrying out the present invention will be described with reference to the drawings.

(Operation Principle of Client Device According to this Embodiment)
The operation principle of the client device 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a functional block diagram of a data distribution system 200 including the client device 100. As shown in FIG. 1, the data distribution system 200 includes a client device 100, a data distribution device 170, one client device 180, and another client device 190.

  In the data distribution system 200, one client device 180 once receives streaming data (hereinafter simply referred to as data) distributed by the data distribution device 170, and transfers the received data to the client device 100. Other client devices 190 also receive data distributed by the data distribution device 170 and can transfer the data to the client device 100.

  As shown in FIG. 1, the client apparatus 100 includes a connection destination candidate holding unit 110, an event occurrence detection unit 120, a connection destination selection unit 130, a data transfer request unit 140, connection destination candidate information 150, and a buffer 160.

  The connection destination candidate holding unit 110 holds connection destination candidate information 150. Here, the connection destination candidate information 150 is a client device to which the client device 100 is connected among the client devices in the data distribution system 200, and requests transfer of data distributed by the data distribution device 170. This is list information of client devices that can be used. In the connection destination candidate information 150, a plurality of client devices are listed, and priority is given to each client device. As processing at the time of starting distribution in the data distribution system 200, the client apparatus 100 makes a data distribution request to the data distribution apparatus 170 and acquires the connection destination candidate information 150 from the data distribution apparatus 170. Subsequently, data transfer is requested (connected) to the one client device 180 having the highest priority in the connection destination candidate information 150, and data transfer is received from the one client device 180.

  Further, in the connection destination candidate information 150, a higher priority is given to a client device having a shorter network distance (for example, propagation delay time) from the client device 100. Further, in the connection destination candidate information 150, in addition to the network distance condition, priority may be given in consideration of the processing capability of the client device that is the connection destination and the traffic on the communication path.

  Further, the connection destination candidate information 150 is generated by another device that holds the connection state between the client devices, the processing capability of each client device, and the traffic status in the data distribution system 200, for example, the data distribution device 170, and the client The device 100 is notified. By doing so, it is not necessary for each client device in the data distribution system 200 to individually collect information for generating the connection destination candidate information 150, so that the amount of data communication in the data distribution system 200 can be kept low. it can. In addition, since it is not necessary to request a special function for each client device, the data distribution system 200 can be easily constructed.

  The buffer 160 is a buffer for temporarily storing the received data after receiving the data transferred from one client device 180. The stored data is stored for a certain time from the time of storage according to the first-in first-out rule. It is erased after elapse.

  The event occurrence detection unit 120 acquires a notification that a predetermined event has occurred from one client device 180 that is receiving data transfer. Here, the predetermined event includes that one client device 180 stops data transfer to the client device 100 for some reason such as viewing stoppage. The event occurrence detection unit 120 detects that a predetermined event has occurred in one client device 180 when the notification is acquired.

  The event occurrence detection unit 120 monitors the amount of data stored in the buffer 160, and when the amount of stored data falls below a predetermined threshold, a predetermined event on one client device 180 or a communication path. Detects that has occurred. In this manner, the event occurrence detection unit 120 can check whether data is normally transferred from one client device 180 by monitoring the amount of data stored in the buffer 160. Therefore, the event occurrence detection unit 120 determines that data is not normally transferred from one client device 180 when the amount of data stored in the buffer 160 falls below a predetermined threshold.

  In addition, the event occurrence detection unit 120 determines whether the usage rate of the buffer 160 (= “the amount of data stored in the buffer 160” / “the storage capacity of the buffer 160”) is less than a predetermined threshold value. It may be configured to detect that a predetermined event has occurred on the route. Also in this case, the connection destination selection unit 130 can confirm whether data is normally transferred from one client device 180 by monitoring the usage rate of the buffer 160.

  When the occurrence of a predetermined event related to one client device 180 is detected, the connection destination selecting unit 130 requests other clients from the connection destination candidate information 150 to transfer data on behalf of the one client device 180. One device 190 is selected. In addition, the connection destination selection unit 130 selects, from the connection destination candidate information 150, another client device 190 that is given the next priority after the one client device 180.

  The data transfer request unit 140 requests (requests) another client device 190 to transfer data to the client device 100. Then, the other client device 190 starts data transfer to the client device 100 in response to a request from the client device 100.

  Here, the streaming data transferred between the devices is moving image data or audio data, and each image data or audio data includes identification information for identifying each data. The identification information may be time information or a sequence number indicating the order of data in a series of moving image data or audio data. In another form of the data transfer request unit 140, a request (request) is made to transfer image data or audio data including specific identification information to the client device 100. By doing so, it is possible to prevent the received data from becoming discontinuous before and after the data transfer destination is switched.

  In the disclosed client device 100 based on the above operation principle, in a communication network that transfers data between a plurality of client devices, the client device that has been transferring data cannot continue the data transfer. Can continue to receive data.

  Here, the client device 100 includes a CPU (Central Processing Unit), a ROM (Read-Only Memory), an HDD (Hard Disc Drive), and the like. Each unit included in the client device 100 is realized by the CPU executing a program corresponding to each unit stored in the ROM or the HDD. In addition, each unit included in the client device 100 may realize processing related to each unit as hardware.

(Processing example by data distribution system including client device according to the present embodiment)
A processing example by the data distribution system 200 including the client device 100 will be described with reference to FIGS. As shown in FIG. 2, the data distribution system 200 includes a streaming distribution server 170, a client A 180, a client B 100, a client C 190, a client D, and a client M.

  Here, the streaming distribution server 170 is connected to the client A 180 and the client C 190 via the access points 1 and 10 and to the client M via the access points 1 and 11, respectively, and streaming data (hereinafter simply referred to as data) is connected to each client. Will be distributed. Client A 180 transfers data to client B 100, and client B 100 transfers data to client D.

  As shown in FIG. 3, the streaming distribution server 170 has a viewer list 210, and each client has a connection destination candidate list 150, a connection core list 220, a reception data buffer 160, a reception data buffer management information list. 230.

  FIG. 4 shows an example of the viewer list 210. The viewer list 210 holds “viewing client” that is an ID (IP address or the like) on the network of the data distribution client, and “route information” that is a connection path from the “browsing client” to the streaming distribution server 170. Further, in the viewer list 210, for each “browsing client”, a “connection destination candidate” determined based on a predetermined standard from other “browsing clients” is set. The “connection candidate destination” includes a “primary connection destination” that indicates a connection destination that has already been connected, and a “secondary connection destination” that indicates a connection switching destination candidate such as when the “primary connection destination” stops the connection with the streaming delivery server 170. Connected to ".

  FIG. 5 shows an example of the connection destination candidate list 150. FIG. 5 shows an example of the connection destination candidate list 150 that the client B 100 has, which has received data transfer from the client A 180 and indicates that the connection switching destination candidate is the client C 190. The connection destination candidate list 150 is held by the connection destination candidate holding unit 110.

  FIG. 6 shows an example of the connected core list 220. FIG. 6 shows an example of the connection core list 220 that the client A 180 has, and shows that the client A 180 is transferring data to the client B 100.

  FIG. 7 shows an example of the reception data buffer 160. In FIG. 7, received data including time “00:01:50” as the identification information is arranged at the beginning, and received data including time “00:02:20” is arranged at the end, and the data is temporarily stored. Indicates that Further, FIG. 7 shows that the storage area of the reception data buffer 160 has a free space.

  FIG. 8 shows an example of the received data buffer management information list 230. In FIG. 8, the identification information “00:01:50” of the leading data extracted from the reception data buffer 160, the identification information “00:02:20” of the trailing data, and the time difference between the leading data and the trailing data. Contains the threshold to apply. The threshold value is used to detect an abnormal connection with the parent client that is the data transfer source.

(1) Distribution Processing in Data Distribution System 200 Streaming data distribution processing in the data distribution system 200 will be described using the sequence diagram shown in FIG. Here, a flow of processing when the client B 100 newly requests data distribution while the client A 180 is viewing streaming from the streaming distribution server 170 will be described.

  In S10, the streaming distribution server 170 distributes data to the client A180. In S20, the client B100 requests the streaming distribution server 170 to start data distribution. In S30, the streaming delivery server 170 accepts the request from the client B100 and performs the following processing in response to the request.

  In S30, the streaming distribution server 170 collects route information between the client B100 and the streaming distribution server 170. Then, the streaming delivery server 170 registers the client B 100 as “browsing client” in the viewer list 210 as shown in FIG. 4, and registers the collected route information in “route information”. Next, the streaming delivery server 170 selects two clients that can transfer data to the client B 100 from among the clients registered in the “viewing client” in the viewer list 210 and registers them in the “connection destination candidate”. . As shown in FIG. 4, the streaming distribution server 170 selects the client A 180 and the client C 190 as clients that can transfer data to the client B 100. Thereafter, the streaming distribution server 170 registers the client A 180 as the “primary connection destination” and the client C 190 as the “secondary connection destination”.

  In S <b> 40, the streaming delivery server 170 notifies the client B 100 of the two clients registered in the “primary connection destination” and the “secondary connection destination” in the viewer list 210. That is, the streaming delivery server 170 notifies the client A 180 as “primary connection destination” and notifies the client C 190 as “secondary connection destination”.

  In S50, the client B100 receives the notification from the streaming distribution server 170, and generates the connection destination candidate list 150 based on the received notification content. That is, the client B 100 receives the notification that the “primary connection destination” is the client A 180 and the “secondary connection destination” is the client C 190, and generates and holds the connection destination candidate list 150 based on the received content as shown in FIG. To do.

  In S <b> 60, the client B <b> 100 issues a data transfer (distribution) start request to the client A <b> 180 set as “primary connection destination” in the connection destination candidate list 150. In S70, the client A 180 receives the request from the client B 100 and registers the client B 100 as a data transfer destination. That is, as shown in FIG. 6, the client A 180 registers the client B 100 as a child client that performs data transfer. In S80, the client A 180 starts data transfer to the client B 100 registered in the connected core list 220 shown in FIG.

  On the other hand, when the streaming distribution server 170 ends the distribution of data in S90, the streaming distribution server 170 distributes data including information indicating “to end the data distribution” to the client A 180 in S100. In step S <b> 110, the client A 180 transfers data including information indicating “data distribution is terminated” received from the streaming distribution server 170 to the client B 100.

  Through the processing as described above, the data distribution system 200 can distribute streaming data using so-called P2P.

(2) Parent client switching process in data distribution system 200 (part 1)
Processing for switching the parent client in the data distribution system 200 will be described using the sequence diagram shown in FIG. Here, the flow of processing for switching the data transfer source of the client B 100 to the client C 190 in a state where the client B 100 is receiving data transfer from the client A 180 as described in (1) above will be described.

  In S120 to S140, the streaming distribution server 170 distributes data to the client A 180 and the client C 190, and the client A 180 transfers data to the client B 100. In S150 and S160, the client A 180 refers to the connected core list 220 shown in FIG. 6 and notifies the client B 100 and the streaming distribution server 170 registered in the connected core list 220 of the stop of data viewing.

  After the client B 100 receives the viewing stop notification of the client A 180 in S170, the client B 100 makes a data transfer start request to the client C 190 set as “secondary connection destination” in the connection destination candidate list 150 shown in FIG. The processing in S170 corresponds to processing by the event occurrence detection unit 120, the connection destination selection unit 130, and the data transfer request unit 140.

  Further, the client B 100 notifies the client C 190 of the time information of the data at the tail end in the reception data buffer 160 shown in FIG. 7, and requests to transfer the data including the time information after the notified time information. . That is, the client B 100 notifies the time information “00:02:20” of the data at the tail in the reception data buffer 160, and the data after the data including the identification information of the time information “00:02:21”. Request to transfer. This processing corresponds to the processing by the data transfer request unit 140.

  In step S190, the client C190 receives the request from the client B100 and registers the client B100 as a data transfer destination. That is, as shown in FIG. 6, the client C190 registers the client B100 as a child client that performs data transfer by itself.

  In S200, the client C190 starts transferring data including identification information after the time information “00:02:21” to the client B100 registered in the connected list 220 shown in FIG. By doing this, even when changing the data transfer source, the client B 100 can receive continuous data without interruption.

  On the other hand, after the streaming distribution server 170 receives the viewing stop notification of the client A 180 in S210, the content that sets the client A 180 that has made the viewing stop notification in the viewer list 210 shown in FIG. To do. Specifically, the streaming delivery server 170 sets the “primary connection destination” related to the client B 100 in the viewer list 210 to the client C 190 that has been the “secondary connection destination”, and sets the “secondary connection destination” other than the client A 180. Set as appropriate from among clients.

  In S220, the streaming delivery server 170 notifies the client B100 of the two clients registered in the “primary connection destination” and the “secondary connection destination” in the viewer list 210. That is, the streaming distribution server 170 notifies the client C 190 as “primary connection destination” and notifies the newly set client as “secondary connection destination”. In S230, the client B100 receives the notification from the streaming distribution server 170, and updates the connection destination candidate list 150 based on the received notification content. The process in S230 corresponds to the process by the connection destination candidate holding unit 110.

(3) Parent client switching process in data distribution system 200 (part 2)
Processing for switching parent clients in the data distribution system 200 will be described using the sequence diagram shown in FIG. Here, the flow of processing for switching the data transfer source of the client B 100 to the client C 190 in a state where the client B 100 is receiving data transfer from the client A 180 as described in (1) above will be described.

  In S240 to S260, the streaming distribution server 170 distributes data to the client A 180 and the client C 190, and the client A 180 transfers data to the client B 100.

  In step S270, the client B 100 detects a shortage of the accumulated data amount while monitoring the amount of data accumulated in the reception data buffer 160 shown in FIG. Specifically, the client B 100 refers to the received data buffer management information list 230 shown in FIG. 8, calculates the difference between the “first time” and “last time” of the stored data, and calculates the calculated difference and the detection threshold value. And compare. When the calculated difference is smaller than the detection threshold, the client B 100 detects that the amount of accumulated data is insufficient, that is, that there is a problem in connection with the data transfer source. By doing so, the child client can continue to receive data by autonomously switching the parent client, triggered by detecting the lack of received data from the parent client.

  After the client B 100 detects a connection failure with the data transfer source client A 180 in S 280 and S 290, the client B 100 performs data transfer to the client C 190 set as “secondary connection destination” in the connection destination candidate list 150 shown in FIG. Make a start request. The processing in S280 and 290 corresponds to processing by the event occurrence detection unit 120, the connection destination selection unit 130, and the data transfer request unit 140.

  Further, the client B 100 notifies the client C 190 of the time information of the data at the tail end in the reception data buffer 160 shown in FIG. 7, and requests to transfer the data including the time information after the notified time information. . That is, the client B 100 notifies the time information “00:02:20” of the last data in the reception data buffer 160 and transfers the data including the identification information after the time information “00:02:21”. Request that. This processing corresponds to the processing by the data transfer request unit 140.

  In step S300, the client C190 receives the request from the client B100 and registers the client B100 as a data transfer destination. That is, as shown in FIG. 6, the client C190 registers the client B100 as a child client that performs data transfer by itself.

  In S310, the client C190 starts transferring data including identification information after the time information “00:02:21” to the client B100 registered in the connected core list 220 shown in FIG. By doing this, even when changing the data transfer source, the client B 100 can receive continuous data without interruption.

  In S320, the client B100 requests the streaming distribution server 170 to change the “connection destination candidate” in the viewer list 210 shown in FIG. In S330, after the streaming distribution server 170 receives the change request for the client B100, the streaming delivery server 170 notifies the client A180 of a request to stop data transfer to the client B100 that is the child client. In step S340, after the client A 180 receives the stop request from the streaming delivery server 170, the client A 180 deletes the client B 100 from the connected core list 220 shown in FIG.

  On the other hand, in S350, the streaming distribution server 170 updates the content that sets the client A 180 as the “connection destination candidate” in the viewer list 210 shown in FIG. Specifically, the streaming distribution server 170 sets the “primary connection destination” related to the client B 100 in the viewer list to the client C 190 that has been the “secondary connection destination”, and sets the “secondary connection destination” other than the client A 180. Set as appropriate from within the client.

  In S360, the streaming delivery server 170 notifies the client B100 of the two clients registered in the “primary connection destination” and the “secondary connection destination” in the viewer list 210. That is, the streaming distribution server 170 notifies the client C 190 as “primary connection destination” and notifies the newly set client as “secondary connection destination”. In S370, the client B100 receives the notification from the streaming distribution server 170, and updates the connection destination candidate list 150 based on the received notification content. The process in S370 corresponds to the process by the connection destination candidate holding unit 110.

(4) Secondary Connection Destination Change Processing in Data Distribution System 200 Processing for changing the secondary connection destination in the data distribution system 200 will be described using the sequence diagram shown in FIG. Here, as described in (1) above, the flow of processing for changing the client C 190 that is the “secondary connection destination” of the client B 100 in a state where the client B 100 is receiving data transfer from the client A 180 will be described.

  In S380 to S400, the streaming distribution server 170 distributes data to the client A 180 and the client C 190, and the client A 180 transfers data to the client B 100.

  In S410, the client C190 notifies the streaming distribution server 170 that streaming viewing is stopped. In step S420, after the streaming distribution server 170 receives the viewing stop notification of the client C190, the streaming server 170 updates the content of the client list 190 shown in FIG. Specifically, the streaming distribution server 170 appropriately sets the “secondary connection destination” related to the client B 100 in the viewer list 210 from the clients other than the client C 190.

  In S430, the streaming delivery server 170 notifies the client B100 of the two clients registered in the “primary connection destination” and the “secondary connection destination” in the viewer list 210. That is, the streaming delivery server 170 notifies the client A 180 as “primary connection destination” and notifies the newly set client as “secondary connection destination”. In S440, the client B100 receives the notification of the streaming distribution server 170, and updates the connection destination candidate list 150 based on the received notification content. The process in S440 corresponds to the process performed by the connection destination candidate holding unit 110.

(5) Child Client Stop Processing in Data Distribution System 200 Processing when the child client stops viewing in the data distribution system 200 will be described using the sequence diagram shown in FIG. Here, as described in (1) above, the flow of processing when the client B 100 stops viewing while the client B 100 receives data transfer from the client A 180 and the client B 100 is transferring data to the client D. Will be explained.

  In S450 to S470, the streaming distribution server 170 distributes data to the client A 180, the client A 180 transfers data to the client B 100, and the client B 100 transfers data to the client D. In S480-500, the client B100 refers to the connected core list 220 as shown in FIG. 6 to notify the client D of the viewing stop, and notifies the parent client A180 of the viewing stop.

  In step S510, the client A 180 receives the client B 100 viewing stop notification, deletes the client B 100 from the connected core list 220 shown in FIG. 6, and stops data transfer to the client B 100. In S520, the client B100 notifies the streaming distribution server 170 that viewing is stopped.

  In step S530, after the streaming distribution server 170 receives the viewing stop notification of the client B100, the streaming distribution server 170 updates the content that sets the client B100 that has made the viewing stop notification in the viewer list shown in FIG. Specifically, the streaming distribution server 170 sets the “primary connection destination” related to the client D100 in the viewer list 210 to the client E (not shown in FIG. 2) that has been the “secondary connection destination” in the past. The “secondary connection destination” is appropriately set from the clients other than the client B100.

  In S540, the streaming distribution server 170 notifies the client D of the two clients registered in the “primary connection destination” and the “secondary connection destination” in the viewer list 210. That is, the streaming distribution server 170 notifies the client E as the “primary connection destination” and notifies the newly set client as the “secondary connection destination”. In S550, the client D receives the notification of the streaming distribution server 170, and updates the connection destination candidate list 150 based on the received notification content. In S560, the client D can continue to receive data by performing the parent client switching process (part 1) described in (2) above.

(Summary)
In the disclosed client device, in a communication network that transfers data between a plurality of client devices, even if the client device that has performed data transfer cannot continue the data transfer, the client device may continue to receive data. it can.

In the above description, the case where there is one distribution target stream (data) has been described. However, it is also possible to apply to a multi-channel stream by configuring the above processing for each distribution target stream.
Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications are possible within the scope of the gist of the present invention described in the claims.・ Change is possible.
(Appendix 1)
In a communication network having a data distribution device and a plurality of client devices, the client is connected to one client device and receives the data distributed from the data distribution device and receives the data transferred from the one client device A device,
Connection candidate holding means for holding information related to a plurality of client devices as candidates for transferring the data to the client device;
Event occurrence detection means for detecting occurrence of a predetermined event related to the one client device;
A connection destination selecting means for selecting one of the information held by the connection candidate holding means when the event occurrence detecting means detects the occurrence of the predetermined event;
Data transfer requesting means for requesting the candidate selected by the connection destination selecting means to transfer the data to the client apparatus.
(Appendix 2)
When the data is a plurality of data having order, and each piece of data includes identification information indicating the order,
2. The client device according to appendix 1, wherein the data transfer requesting unit requests the client device to transfer the plurality of data after the data corresponding to the one identification information.
(Appendix 3)
A buffer for temporarily storing the received data;
The event occurrence detection means detects that the predetermined event has occurred when the amount of the data accumulated in the buffer is less than a predetermined threshold value. The client device according to claim 1.
(Appendix 4)
In a communication network having a data distribution device and a plurality of client devices, the client is connected to one client device and receives the data distributed from the data distribution device and receives the data transferred from the one client device An apparatus control method comprising:
A connection candidate holding unit holding information on a plurality of client devices as candidates for transferring the data to the client device;
An event occurrence detecting means for detecting occurrence of a predetermined event related to the one client device;
A connection destination selecting means, when the occurrence of the predetermined event is detected by the event occurrence detecting means, selecting one candidate among the information held by the connection candidate holding means;
A data transfer requesting unit that requests the candidate selected by the connection destination selecting unit to transfer the data to the client device.
(Appendix 5)
When the data is a plurality of data having order, and each piece of data includes identification information indicating the order,
The control method according to appendix 4, wherein the data transfer request unit requests the client device to transfer the plurality of data subsequent to the data corresponding to the one identification information.
(Appendix 6)
A buffer for temporarily storing the received data;
Any one of appendix 4 or 5, wherein the event occurrence detection means detects that the predetermined event has occurred when the amount of the data accumulated in the buffer is less than a predetermined threshold. The control method as described in one.
(Appendix 7)
In a communication network having a data distribution device and a plurality of client devices, the client is connected to one client device and receives the data transferred from the data distribution device and receives the data transferred from the one client device To the device,
A connection candidate holding unit holding information on a plurality of client devices as candidates for transferring the data to the client device;
An event occurrence detecting means for detecting occurrence of a predetermined event related to the one client device;
A connection destination selecting unit that selects one of the information held by the connection candidate holding unit when the occurrence of the predetermined event is detected by the event occurrence detection unit;
A client device control program for causing a data transfer request unit to request the candidate selected by the connection destination selection unit to transfer the data to the client device.
(Appendix 8)
When the data is a plurality of data having order, and each piece of data includes identification information indicating the order,
8. The client device control program according to appendix 7, wherein the data transfer request unit requests the client device to transfer the plurality of data after the data corresponding to the one identification information.
(Appendix 9)
A buffer for temporarily storing the received data;
The event occurrence detection means detects that the predetermined event has occurred when the amount of the data stored in the buffer is less than a predetermined threshold value. The client device control program according to claim 1.

100 Client device (Client B)
110 connection destination candidate holding means 120 event occurrence detection means 130 connection destination selection means 140 data transfer request means 150 connection destination candidate information (connection destination candidate list)
160 Buffer (Reception data buffer)
170 Data distribution device (streaming distribution server)
180 One client device (client A)
190 Other client device (client C)
200 Data Distribution System 210 Viewer List 220 Connected Core List 230 Reception Data Buffer Management Information List

Claims (4)

In a communication network having a data distribution device and a plurality of client devices, the client is connected to one client device and receives the data distributed from the data distribution device and receives the data transferred from the one client device A device,
Connection candidate holding means for holding information related to a plurality of client devices as candidates for transferring the data to the client device;
Event occurrence detection means for detecting occurrence of a predetermined event related to the one client device;
A connection destination selecting means for selecting one of the information held by the connection candidate holding means when the event occurrence detecting means detects the occurrence of the predetermined event;
Data transfer requesting means for requesting the candidate selected by the connection destination selecting means to transfer the data to the client apparatus. When the data is a plurality of data having order, and each piece of data includes identification information indicating the order,
The client device according to claim 1, wherein the data transfer request unit requests the client device to transfer the plurality of data after the data corresponding to the one identification information. A buffer for temporarily storing the received data;
4. The event occurrence detection unit detects that the predetermined event has occurred when the amount of the data accumulated in the buffer becomes smaller than a predetermined threshold. The client device according to any one of the above. In a communication network having a data distribution device and a plurality of client devices, the client is connected to one client device and receives the data distributed from the data distribution device and receives the data transferred from the one client device An apparatus control method comprising:
A connection candidate holding unit holding information on a plurality of client devices as candidates for transferring the data to the client device;
An event occurrence detecting means for detecting occurrence of a predetermined event related to the one client device;
A connection destination selecting means, when the occurrence of the predetermined event is detected by the event occurrence detecting means, selecting one candidate among the information held by the connection candidate holding means;
A data transfer requesting unit that requests the candidate selected by the connection destination selecting unit to transfer the data to the client device.

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