JP2006246242A - Hierarchically coded data transfer control system and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize rapid rate control by enabling to easily apply a network-initiative basis of a hierarchical multicast to an existing network and immediately deciding the number of transfer hierarchies for a network band usable for user, when congestion occurs. <P>SOLUTION: In this system, a receiver calculates the data-receiving state of a hierarchical content, an RTCP performs feedback transmission for a result thereof, and a control device receives the information, determines the viewing state of a user and decides the number of transfer hierarchies. Also, the control device calculates an available throughput from the data reception information for each user, decides the number of transfer hierarchies so that they may be within the throughput, sets an access list for an edge router to house the user, and controls the number of transfer hierarchies. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hierarchically encoded data transfer control system and program, and more particularly to a technique for transferring hierarchically encoded data in an IP network. The receiving device (user) determines the number of hierarchical contents being transferred. The present invention relates to a hierarchically encoded data transfer control system and program for optimizing the viewing quality for each user by controlling each.

  Compared to a distribution system using IP unicast, a content distribution system using IP multicast can reduce the load on the distribution server and reduce the amount of data flowing on the network. It is effective in the case. However, when IP multicast is used, the data packet is copied and transferred by the router, so that the content distributed from the distribution server is distributed on the multicast tree at a single distribution rate. Therefore, in a content distribution system that simply uses IP multicast, it is difficult to perform distribution with optimum quality individually to users having various access network bandwidths and users having various terminal performances. For this reason, in order to receive content of appropriate quality for each user terminal, the distribution side hierarchically encodes the original content, assigns an individual multicast address for each layer, and performs IP multicast transmission. For the multicast addresses assigned to each layer, IGMP “Internet Group Management Protocol” (Internet Group Management Protocol, Version 3, RFC 3376) and MLD “Multicast Listener Discovery” (Multicast Listener Discovery Version 2 ( MLDv2) for IPv6, RFC3810 Membership Report (IGMP Join / MLD Join) message is used to request reception to the edge router, so that users can receive content at their desired quality (distribution rate). Many hierarchical multicast schemes have been proposed.

  In addition, the user makes a reception request to all hierarchies of the hierarchized content in advance, determines the congestion status of the line at the edge router in which the user is accommodated, and determines the number of transfer hierarchies based on it. There are also different methods.

  Hierarchies that allow users to receive content at their desired quality (distribution rate) by making a reception request to an edge router using IGMP or MLD IGMP Join / MLD Join messages that are the above multicast protocols In the generalized multicast method, since control is performed by the user, it is difficult to perform explicit control from the network operator. For example, when it is desired to temporarily reduce the number of transfer tiers for a certain user, it is difficult to control. If there are multiple users under the physical port of an edge router, there is a possibility that control synchronization will occur if the rate is increased or decreased independently for each user, ensuring viewing quality for each user. There is a problem that can not be.

  On the other hand, a method in which reception requests are made in advance for all hierarchies of hierarchized content, the congestion status of the line is determined at the edge router in which the user is accommodated, and the number of transfer hierarchies is determined based on this According to the network side (for example, the network operator), it becomes possible to control the number of transfer layers, but it is necessary to provide all the edge routers with the control function or when congestion occurs. Hierarchy stop / restore operation is executed only in units of the number of hierarchies set in advance. For example, if the number of control hierarchies is set to 1, hierarchies that can be stopped for each user even when serious congestion occurs Since there is 1, there is a problem in flexibility and speed of control.

  The present invention has been made in view of the above points, and shows a method for making it easy to apply the layered multicast network-side initiative method to an existing network, and the network bandwidth available to the user when congestion occurs. It is an object of the present invention to provide a hierarchically encoded data transfer control system and program that can immediately determine the number of transfer layers and realize rapid rate control.

  FIG. 1 is a principle configuration diagram of the present invention.

The present invention (Claim 1) is a hierarchically encoded data transfer control system used to transfer hierarchically encoded data obtained by dividing and encoding data into a plurality of hierarchical levels for each hierarchical level in an IP network,
Consists of a transmission device 100, a reception device 500, and a control device 300 connected to the IP network,
The transmission device 100
A transmission-hierarchy management table 110 for storing the relationship between the layer information of the layer encoded data and the destination IP address or port number of the IP packet used for layer data transfer;
Content holding means 120 for holding content;
IP packet transmission means 130 for acquiring content data from the content holding means 120, generating one or more IP packets, and assigning and transmitting the destination IP address,
The receiving device 500
A reception-hierarchy management table 510 that stores a relationship between a destination IP address, a source IP address, or a port number of a received IP packet and hierarchical information of hierarchically encoded data;
An IP packet receiving unit 530 for identifying a hierarchy of received data based on a combination of a destination IP address and a source IP address or a port number of the received IP packet;
Reproduction means 540 for decoding and reproducing data from the received IP packet;
Reception request means 550 for making an acquisition request for hierarchically encoded data;
State transmission means 520 for transmitting the reception state of the hierarchically encoded data of the reception device as reception state information,
The control device 300
State receiving means 310 for receiving the reception state information transmitted from the receiving device 500;
State determination means 320 for determining the reception state of the reception device 500 from the received reception state information of the reception device 500 and determining the number of transfer layers;
Content distribution management means 330 for managing hierarchical content information being transferred to the receiving device by storing it in the storage means;
Control information transmission means 340 for transmitting control information to the router 600 in which the receiving device 500 is accommodated.

Further, the present invention (Claim 2) is provided in the IP packet transmitting means 130 of the transmitting device 100.
When transmitting hierarchically encoded data, the transmission-hierarchy management table 110 is referred to. When the stored IP address associated with the hierarchy of data to be transmitted is an IP multicast address, an IP packet is generated, The IP multicast address stored in the transmission-hierarchy management table 110 is assigned to the destination IP address, and the port number stored in the transmission-hierarchy management table is assigned in association with the hierarchy, and the RTP protocol is used. Means for transmitting.

Further, the present invention (Claim 3) is provided in the receiving apparatus 500.
When receiving an IP packet, the packet receiving means 530 refers to a means for identifying the hierarchy of received data by referring to the reception-hierarchy management table 510 from the destination IP address or port number of the received IP packet. Including
The status transmission means 520 calculates packet loss as the reception status of each hierarchical layer or the entire hierarchical content during reception of hierarchical data, and periodically transmits the packet loss using IP multicast using the RTCP protocol. Means for transmitting to the group address or transmitting to the control device 300 using IP unicast is included.

Further, according to the present invention (Claim 4), in the status receiving means 310 of the control device 300,
Means for making a reception request in the IP multicast protocol in order to receive the RTCP reception state information when the RTCP reception state information transmitted for each receiving device is transmitted by IP multicast;
Means for receiving RTCP reception status information transmitted by IP unicast for each receiving device,
The state determination means 320
Means for calculating a hierarchical content data reception state for each receiving device based on the received RTCP reception state information;
Means for periodically calculating the current throughput for each receiving device from the packet loss rate stored in the RTCP reception state information and the distribution rate of the content currently being managed, which is managed by the content distribution management means 330; Have.

In addition, the present invention (Claim 5)
If all packet loss rates held for each receiving device are 0, the previous calculated throughput value is compared with the currently calculated throughput value, and the larger one is stored in the storage means as a new throughput value. Means,
And a means for holding the throughput value calculated this time in the storage means as a new throughput value when the packet loss rates held for each receiving apparatus are not all zero.

Further, the present invention (Claim 6) is provided in the control device 300.
Compare the throughput maintained for each receiving device with the current delivery rate, and if the retained throughput value falls below the current delivery rate, the number of layers from the transfer layer will be adjusted so that it is within the retained throughput value. Means for determining whether to stop the transfer of the hierarchy,
If the throughput held for each receiving device is compared with the current delivery rate, and the retained throughput value exceeds the current delivery rate, it will be out of the hierarchy that is stopped within the range that does not exceed the retained throughput value. And means for determining transfer resumption of some or all layers.

In addition, the present invention (Claim 7)
Means for setting an access list for a router in which the receiving device is accommodated in order to distribute the number of transfer layers determined for each receiving device;
In the case of stopping several transfer layers, a means for setting an access list specifying an IP address or a port number corresponding to the layer to a physical or logical port in which the user is accommodated;
In the case of restoring several hierarchies that are stopped, a unit that cancels the setting of an access list corresponding to the hierarchy set in the physical or logical port in which the user is accommodated.

  The present invention (Claim 8) is a hierarchically encoded data transfer control program used to transfer hierarchically encoded data obtained by dividing data into a plurality of hierarchical levels for each hierarchical level in an IP network. A program for executing any one of the functions of items 1 to 7 on a computer.

  As described above, in the present invention, a control device for monitoring the viewing situation for each user and determining the number of transfer layers is provided on the IP network, and the hierarchical content distribution protocol between the transmission device and the reception device is provided. RTP / RTCP (RTP: A Transport Protocol for Real-Time Applications, RFC3550) is used, and a method in which a packet reception state such as a packet loss rate can be calculated by a receiving apparatus is used. As a result, the data reception state of the hierarchical content is calculated by the receiving device, the result is fed back by RTCP, and the information is received by the control device to determine the user's viewing state. Determine the number of transfer layers.

  In addition, the control device calculates the available network bandwidth (throughput) from the data reception information for each user, determines the number of transfer layers so as to be within the throughput, and the edge router that accommodates the user. Set the access list and control the number of transfer layers.

  As described above, according to the present invention, in hierarchical multicast, the data reception state of the receiving device is calculated, the result is fed back by RTCP, the information is received by the control device, and the user is calculated. Can be determined, the number of transfer layers can be determined, and rapid rate control can be performed.

  In addition, providing the control device on the IP network has an advantage that the function can be easily introduced into the existing network.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a configuration example of a network according to an embodiment of the present invention, in which a transmitting device 100 is connected to a transmitting device accommodating router 200 of an IP network, and a receiving device 500 is connected to a receiving device accommodating router 600. And Further, it is assumed that the control device 300 is connected to the control device accommodating router 400. Note that a plurality of receiving apparatuses 500 may be connected, and the control apparatus 300 may be connected to the transmitting apparatus accommodating router 200. In the present embodiment, it is assumed that receiving device 500, transmitting device 100, and control device 300 are all connected to different routers.

  FIG. 3 is a configuration diagram of a transmission apparatus according to an embodiment of the present invention.

  The transmission device 100 includes a hierarchy management table 110, a content holding unit 120, and an IP packet transmission unit 130.

  The hierarchy management table 110 in the transmission device 100 is provided in a storage unit such as a hard disk device or a memory, and as shown in FIG. 4, the configuration includes a hierarchy identifier indicating hierarchy information for each hierarchy content, a destination IP address, It shall consist of the destination port number. FIG. 4A shows an example in which a multicast address is assigned to each hierarchy, and FIG. 4B shows an example in which a multicast address is assigned to each content unit. In FIG. 4A, the hierarchy can be identified by both the transmission destination IP address and the transmission destination port number. In the case of FIG. 4B, the hierarchy can be identified by the transmission destination port number. Either of the hierarchy identification information may be used. 4 is an example for clarifying the explanation, the present invention is not limited with respect to the number of layers, and the present invention is not limited with respect to the version of the IP address.

  The content holding unit 120 in the transmission device 100 is provided in a storage unit such as a hard disk device, and transfers the stored hierarchically encoded data to the IP packet transmission unit 130. The content holding unit 120 can consider a case where the data is hierarchically encoded in real time or a case where the data previously hierarchically encoded is accumulated. Although there are a plurality of hierarchical encoding algorithms, the present invention is a system for transferring data resulting from hierarchical encoding, and the present invention is not limited to the method of hierarchical encoding itself. .

  The IP packet transmission unit 130 in the transmission device 100 converts the data received from the content holding unit 120 into an IP packet and transmits it to the IP network. At this time, referring to the hierarchy management table 110 described above, the destination address of the IP packet is acquired and transferred to the IP multicast IP network. Further, RTP is used as a media distribution protocol.

  FIG. 5 shows a configuration of a receiving apparatus according to an embodiment of the present invention.

  The receiving device 500 includes a hierarchy management table 510, a reception request unit 520, an IP packet receiving unit 530, a reproducing unit 540, and a status transmitting unit 550.

  The hierarchy management table 510 is provided in a storage means such as a hard disk device or a memory, and as shown in FIG. 6A, the hierarchy management table 510 has a hierarchy identifier indicating hierarchy information, a data request destination IP address, a reception port, and the like. The number is registered. In addition, as shown in FIG. 6B, it is conceivable that the data transmission destination IP address is registered together. 6A and 6B are examples in which an IP multicast address is assigned to each layer, but as shown in FIG. 6C, an IP multicast address is uniquely assigned for each content. In this case, the hierarchy can be identified by the reception port number. As the request destination IP address, a destination IP multicast address assigned to each layer or content is registered.

  The reception request unit 520 refers to the tier management table 510, and makes a content reception request for each tier transferred by IP multicast or for the content using a multicast protocol such as IGMP or MLD. carry out. However, the present invention does not limit the protocol used for the access request.

  The IP packet receiving unit 530 receives an IP packet from the IP network, refers to the hierarchy management table 510, identifies the hierarchy, extracts data, and transfers the data to the reproduction unit 540.

  The reproducing unit 540 decodes and reproduces the data transferred from the IP packet receiving unit 530 based on a predetermined hierarchical encoding algorithm. However, the present invention is a system for transferring hierarchically encoded data, and does not limit the present invention with respect to a method for realizing the hierarchical encoding itself.

  The status transmission unit 550 calculates the packet loss rate from the packet received by the IP packet reception unit 530, and transmits the packet loss rate to each multicast address assigned to each layer or content using RTCP. Alternatively, unicast transmission to the control device 300 or the transmission device 100 can be considered.

  FIG. 7 shows the configuration of the control device according to one embodiment of the present invention.

  The control device 300 includes a state reception unit 310, a state determination unit 320, a content distribution management unit 330, and a control information transmission unit 340.

  The state reception unit 310 receives packet reception information for each reception device 500 transmitted from the state transmission unit 550 of the reception device 500 using RTCP, and sends the packet reception information to the state determination unit 320.

  The state determination unit 320 acquires the packet loss rate for each reception device from the received reception information for each reception device 500 and passes the packet loss rate to the content distribution management unit 330.

  As shown in FIG. 8A, the content distribution management unit 330 manages the distribution state of content for each user, and includes a content type, a hierarchy identifier, an IP address and a port number assigned to the content, and a hierarchy. Each rate and transfer status, the packet loss rate, and the throughput calculated from the packet loss and the rate for each layer are held. It is assumed that the throughput holds a larger value than the past value. If the retained throughput falls below the total rate during the current transfer, the reception state is stabilized by suppressing the occurrence of packet loss of the receiving device 500 by making a decision to reduce the number of transfer layers so that it is less than the retained throughput. Make it. Note that the hierarchies to be stopped may be matched to the characteristics of the hierarchized content or stopped from the one with a high transfer rate. However, in the present invention, the transfer hierarchies are stopped and the transfer rate is optimized for each receiving device 500. Therefore, the stop hierarchy determination algorithm is not particularly defined and does not limit the present invention. On the other hand, if the retained throughput exceeds the transfer rate currently being transferred, the decision is made to optimize the reception state of the receiving terminal by increasing the number of transfer layers within a range that does not exceed the retained throughput. Do. In addition, after determining the number of transfer layers to be reduced or increased, the receiving apparatus accommodating router in which the receiving apparatus 500 is accommodated in the control information transmitting unit 340 from the user accommodating state as shown in FIG. Hierarchical transfer control is realized by transmitting predetermined control information for setting an access list for performing hierarchical transfer control to a predetermined port. Here, the port refers to either a physical port or a logical port.

  Next, the operation of the present invention will be described.

  First, the operation during normal viewing will be described based on the network configuration shown in FIG.

  FIG. 9 shows a flowchart of the operation (during normal viewing) in one embodiment of the present invention.

  Assume that the hierarchy management table 510 in the transmission apparatus 100 with the IP address “140.0.0.1” is set as shown in FIG. 10, and the content A is multicast-distributed from the IP packet transmission unit 130 in advance. It is assumed (step 101). Here, for example, when a general PIM-SM is applied to the IP multicast protocol in the core network, if there is no access request from the receiving device 500, it is discarded by the transmitting device accommodating router 200 and is not transferred to the IP network. . Note that the hierarchical contents A are all three hierarchical levels, and a multicast address is assigned to each hierarchical level. Further, the hierarchy described by the hierarchy identifier 1 of the hierarchy content A is defined as a basic hierarchy (hereinafter referred to as hierarchy 1), and the hierarchy described by the hierarchy identifiers 2 and 3 is different from each other (hierarchy 2 respectively). , Referred to as layer 3). At the time of reproduction, it is assumed that the reproduction quality is improved by receiving layer 1, layer 2, and layer 3 in order, and when the control transfer layer is controlled by the control device 300, the layer from the upper layer (from layer 3) It shall be decided to stop.

  On the other hand, it is assumed that the hierarchy management table 510 in the receiving apparatus 500 whose IP address is “130.0.0.1” is set as shown in FIG. 11, and the information of content A is already registered in the hierarchy management table 510. It is assumed that In addition, it is assumed that the receiving device 500 has already made a reception request for the content A and is receiving all three layers (step 102). The user of the receiving apparatus 500 is “user 1”.

  Further, it is assumed that the IP address of the control device 300 is “150.0.0.1” and the state of the content distribution management unit 330 is set as shown in FIG. In this case, since “user 1” is viewing content A, information is stored that “user 1” is receiving content A in all three layers. It is assumed that the stream rate of each layer of content A is 2 Mbps, and all layers are normally viewed with a packet loss rate of 0. For this reason, the throughput is 2 Mbps for each layer from the calculation result of stream rate × (1−packet loss rate) / 100. Also, the control device 300 periodically receives RTCP packets from the receiving device 500 (step 103), and updates the content monitoring table (FIG. 12) of “user 1” in the content distribution management unit 330, thereby Is monitored (step 104).

  In the present embodiment, receiving apparatus 500 multicasts RTCP packets in units of multicast addresses assigned for each reception layer, and control apparatus 300 receives the multicast addresses in advance by a multicast protocol such as IGMP or MLD. Assume that a request has been made and reception is possible.

  A case where the RTCP packet is directly transmitted from the receiving device 500 to the control device 300 is also conceivable. When the receiving device 500 is normally viewing, steps 103 and 104 are periodically repeated, and the viewing state of the “user 1” is monitored by the control device 300.

  Here, the quality of the network between the receiving device accommodating router 600 and the receiving device 500 deteriorates, a packet loss occurs in the receiving device 500, which is detected by the control device 300, and the number of transfer layers is reduced. A case where rate control is performed will be described.

  FIG. 13 is a flowchart of the operation in the embodiment of the present invention (when packet loss occurs: determination of hierarchy stop).

  It is assumed that the receiving device 500, the transmitting device 100, and the control device 300 are operating by repeating Steps 103 and 104 shown in FIG.

  Assume that the quality of the network deteriorates between the receiving device accommodating router 600 and the receiving device 500 while viewing the content A on the receiving device 500 (step 201). Here, it is assumed that the packet loss rates from layer 1 to layer 3 are all 10%, and that information is transmitted by RTCP after the occurrence of the loss (step 202).

  The control device 300 that has acquired the reception state information updates the state of the content distribution management unit 330 of the user, and calculates the current throughput from the layer rate and the packet loss rate, as shown in FIG. In this case, since the packet loss rate of each layer is 10%, the throughput for each layer is 2 Mbps × (1-0.1) = 1.8 Mbps, so the total throughput is 5.4 Mbps. Here, when the transfer rate is compared with the throughput, the value of the throughput is smaller, so it is determined that the network is in a congested state, and in order to avoid the congestion situation of the network, the transfer hierarchy of the user A decision is made to reduce the number (step 204). In this case, since the difference between the transfer rate and the throughput is 0.6 Mbps, it is determined that the network congestion can be alleviated if the transfer of one layer is stopped. The transfer stop of the hierarchy 3 is determined. Note that the method for determining the stop hierarchy may be determined from the characteristics of the hierarchical encoding and the transfer rate, and does not limit the present invention. In this embodiment, it is assumed that the transfer stop is determined from the highest layer among the layers being transferred.

  After deciding to stop the hierarchy of “user 1”, “user 1” is accommodated in which port of which router from the user accommodation information managed by the content distribution management unit 330 shown in FIG. Information is transmitted to the port of the router (step 205), and the access list is set (step 206) (in this case, the receiving device of FIG. 13) The accommodating router 600 is “router 1”, and the port to which the receiving device 500 is connected is “port 1.” The access list designates an IP address and a port number to stop forwarding of the packet. Is a router function that can).

  After that, at “port 1” of receiving device accommodating router 600 “router 1”, transfer of layer 3 is stopped, and only layer 1 and layer 2 of content A are transferred to receiving device 500, and viewing continues. Is done. In this case, as shown in FIG. 14B, the content distribution management unit 330 of the control device 300 updates the distribution state and recalculates the throughput. However, since the throughput value holds the actual value of the bandwidth that can be used by each user, when the current packet loss rate is zero, the larger one of the past and current values is held. For this reason, when 5.4 Mbps has been calculated in the past, it is currently 4 Mbps, but since the packet loss rate is 0, the past 5.4 Mbps is retained.

  On the other hand, if packet loss further occurs in layer 2 or layer 1 as a result of FIG. 13B, as shown in FIG. 14C, the throughput value at that time (= 3.8 Mbps) is updated. Subsequently, the transfer hierarchy number reduction decision is made.

  In addition, an operation in the case where the receiving apparatus 500 performs throughput control and the control apparatus 300 determines the increase in the number of transfer layers and performs rate control will be described.

  FIG. 15 is a flowchart (hierarchy restoration decision) of the operation according to the embodiment of the present invention.

  In this case, it is assumed that the receiving device 500 receives the layer 1 and the layer 2 of the content A, and the layer 3 is in a transfer stop state from the control device 300. Therefore, it is assumed that an access list for the hierarchy 3 of “user 1” is set in the receiving device accommodating router 600. In addition, it is assumed that the content B is received in the same manner and is normally received from the hierarchy 1 to the hierarchy 3. The content distribution management unit 330 of “user 1” in the control device 300 at this time is as shown in FIG. It is assumed that the packet loss rate is 0 for each layer being received, and both the transfer rate and the throughput are 10 Mbps.

  Here, as shown in FIG. 15, when “User 1” stops viewing the content B (step 301), and the subsequent reception state is transmitted by RTCP (step 302), the receiving apparatus 500 is shown in FIG. As shown in B), the content distribution management state is updated (step 303). Since the packet loss rate of each layer of the layered content A is 0 even after the update, if the high value of the past and current throughput is retained, the throughput value is maintained at 10 Mbps. become. In this case, since the current transfer rate is 4 Mbps, the throughput is higher, and if there is a hierarchy whose transfer is stopped, a decision is made to restore it. Note that transfer of the layer 3 of the content A is currently stopped, and even if the layer 3 is restored, the transfer rate is 6 Mbps, so that it does not exceed the currently held throughput. For this reason, the transfer restoration is determined (step 304), information on the setting cancellation of the currently set access list is transmitted to the receiving device accommodating router 600 (step 305), and the setting of the access list is canceled (step 305). Step 306). Thereafter, the transfer of the level 3 of the content A is started for “user 1” (step 307). When the reception state at that time is transmitted by RTCP, the state of the content distribution management unit 330 of the control device 300 is updated (step 308), and the viewing of the content A of “user 1” is continued. .

  It is to be noted that the storage unit on the computer used as each device has the hierarchy management table 110 of the transmission device 100, the hierarchy management table 510 of the reception device, and the content distribution management unit 330 of the control device 300, and FIG. It is possible to construct a program for causing a computer to execute the operation of each device shown in FIGS. 5 and 7 and install and execute the program on these computers, or distribute the program via a network.

  Also, the constructed program is stored in a hard disk device connected to a computer used as a transmission device, a reception device, or a control device, or a portable storage medium such as a flexible disk or a CD-ROM, and installed in the computer. It can also be executed or distributed.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.

  The present invention is applicable to a technique for transferring hierarchically encoded data in an IP network.

It is a principle block diagram of this invention. It is an example of a network structure in one embodiment of this invention. It is an example of a structure of the transmitter in one embodiment of this invention. It is a structural example of the hierarchy management table of the transmitter in one embodiment of this invention. It is an example of a structure of the receiver in one embodiment of this invention. It is a structural example of the hierarchy management table of the receiver in one embodiment of this invention. It is a structural example of the control apparatus in one embodiment of this invention. It is an example of a structure of the content delivery management part of the control apparatus in one embodiment of this invention. It is a flowchart (at the time of normal viewing) of the operation | movement in one embodiment of this invention. It is a figure which shows the state of the hierarchy management table of the transmitter in one embodiment of this invention. It is a figure which shows the state of the hierarchy management table of the receiver in one embodiment of this invention. It is a figure which shows the state at the time of normal viewing of the content delivery management part of the control apparatus in one embodiment of this invention. 5 is a flowchart of an operation according to an embodiment of the present invention (when packet loss occurs: hierarchy stop determination). It is a figure which shows the state at the time of a hierarchy stop decision at the time of packet loss generation | occurrence | production of the content delivery management part of the control apparatus in one embodiment of this invention. It is a flowchart (hierarchy restoration decision) of the operation | movement in one embodiment of this invention. It is a figure which shows the state at the time of the hierarchy restoration decision of the content delivery management part of the control apparatus in one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Transmission apparatus 110 Transmission-hierarchy management table 120 Content holding | maintenance means, content holding | maintenance part 130 IP packet transmission means, IP packet transmission part 200 Transmitting apparatus accommodation router 300 Control apparatus 310 State reception means, State reception part 320 State determination means, State determination Unit 330 content distribution management unit, content distribution management unit 340 control information transmission unit, control information transmission unit 400 control device accommodating router 500 reception device 510 reception-hierarchy management table, hierarchy management table 520 status transmission unit, status transmission unit 530 IP packet Receiving means, IP packet receiving section 540 Reproducing means, Reproducing section 550 Receiving request means, Receiving request section 600 Receiving device accommodating router

Claims (8)

Hierarchically encoded data obtained by dividing the data into multiple layers and encoding the IP (Internet Protocol)
A hierarchically encoded data transfer control system used for transferring layer by layer in a network,
A hierarchically encoded data transmitting apparatus (hereinafter referred to as a transmitting apparatus), a hierarchically encoded data receiving apparatus (hereinafter referred to as a receiving apparatus), and a hierarchical encoding rate control apparatus (hereinafter referred to as control) connected to the IP network. Device)), and
The transmitter is
A transmission-hierarchy management table for storing the relationship between the hierarchical information of hierarchically encoded data and the destination IP address or port number of an IP packet used for hierarchical data transfer;
Content holding means for holding content;
IP packet transmission means for acquiring content data from the content holding means, generating one or more IP packets, and assigning and transmitting a destination IP address;
The receiving device is:
A reception-hierarchy management table that stores a relationship between a destination IP address, a source IP address, or a port number of a received IP packet, and hierarchical information of hierarchically encoded data;
IP packet receiving means for identifying a hierarchy of received data based on a combination of a destination IP address and a source IP address or a port number of the received IP packet;
Reproduction means for decoding and reproducing data from the received IP packet;
A reception requesting means for requesting acquisition of hierarchically encoded data;
State transmission means for transmitting the reception state of the hierarchically encoded data of the receiving device as reception state information,
The controller is
Status receiving means for receiving the reception status information transmitted from the receiving device;
Status determination means for determining the reception status of the reception device from the received reception status information of the reception device and determining the number of transfer layers;
Content distribution management means for managing by storing the hierarchical content information being transferred to the receiving device in a storage means;
Control information transmission means for transmitting control information to a router in which the receiving apparatus is accommodated, and a hierarchically encoded data transfer control system. The IP packet transmission means of the transmission device includes:
When transmitting the hierarchically encoded data, the transmission-hierarchy management table is referred to, and if the IP address stored in association with the hierarchy of data to be transmitted is an IP multicast address, an IP packet is generated. The IP multicast address stored in the transmission-hierarchy management table is assigned to the destination IP address, and the port number stored in the transmission-hierarchy management table is assigned in association with the hierarchy, and the RTP protocol is used. The hierarchical encoded data transfer control system according to claim 1, further comprising means for transmitting the data. The IP packet receiving means of the receiving device comprises:
Means for identifying the layer of the received data by referring to the reception-layer management table from the destination IP address or the port number of the received IP packet when receiving the IP packet;
The state transmitting means includes
During reception of layered data, a packet loss is calculated as the reception state of each layer or the entire layered content, and the packet loss is periodically IP multicast group using IP multicast using RTCP (RTP Control Protocol) protocol. The hierarchically encoded data transfer control system according to claim 1, further comprising means for transmitting to an address or transmitting to the control device using IP unicast. The status receiving means of the control device includes:
Means for making a reception request in the IP multicast protocol in order to receive the RTCP reception status information when the RTCP reception status information transmitted for each receiving device is transmitted by IP multicast;
Means for receiving RTCP reception status information transmitted by IP unicast for each receiving device,
The state determination means includes
Means for calculating a hierarchical content data reception state for each receiving device based on the received RTCP reception state information;
The packet loss rate stored in the RTCP reception status information is held, and the current throughput of each receiving device is periodically determined from the distribution rate of the currently distributed content managed by the content distribution management unit. The hierarchically encoded data transfer control system according to claim 1, further comprising: The controller is
When the packet loss rates held for each receiving device are all 0, the previously calculated throughput value is compared with the currently calculated throughput value, and the larger one is stored in the storage means as a new throughput value. Means for holding;
Means for holding the throughput value calculated this time in the storage means as a new throughput value when the packet loss rate held for each receiving device is not all zero;
5. The hierarchically encoded data transfer control system according to claim 4, comprising: The controller is
The throughput held for each receiving device is compared with the current delivery rate, and if the held throughput value falls below the current delivery rate, the transfer layer is set so that it falls within the held throughput value. A means of determining transfer suspension for several tiers;
The throughput held for each receiving device is compared with the current delivery rate, and if the retained throughput value exceeds the current delivery rate, the level of the stopped layer is within a range not exceeding the retained throughput value. Among them, a means for determining transfer resumption of some or all layers,
The hierarchical encoded data transfer control system according to claim 1, comprising: The controller is
Means for setting an access list for a router in which the receiving device is accommodated in order to distribute the number of transfer layers determined for each receiving device;
In the case of stopping several transfer layers, a means for setting an access list specifying an IP address or a port number corresponding to the layer to a physical or logical port in which the user is accommodated;
In the case of recovering several stopped hierarchies, a means for canceling the setting of the access list corresponding to the hierarchy, which is set in the physical or logical port in which the user is accommodated,
7. The hierarchically encoded data transfer control system according to claim 1, comprising: A hierarchically encoded data transfer control program used for transferring hierarchically encoded data obtained by dividing data into a plurality of hierarchical levels for each hierarchical level in an IP network,
8. A hierarchically encoded data transfer control program for causing a computer to execute the function according to any one of claims 1 to 7.

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