CN105100008B - The method and relevant device of content distribution in content center network - Google Patents

Abstract

The embodiment of the present invention discloses a content distribution method in a content-centric network and related equipment, which are used to improve content acquisition efficiency in the content-centric network and avoid waste of link resources. The method in the embodiment of the present invention includes: after the content source requesting end device sends an interest message to the content source providing end device, it receives the encoded data packet provided by the content source providing end device, and the encoded data packet is sent by the content source providing end device The data block fragments that match the interest message generate data block fragments, and use the fountain coding algorithm to encode the data block fragments, so the content source requesting end device can simultaneously receive multiple content source providing end devices The coded data packet of the content source request device decodes the coded data packet set including the received coded data packet to obtain the data block.

Description

Method and related equipment for content distribution in content-centric network

technical field

The invention relates to the communication field, in particular to a content distribution method and related equipment in a content-centric network.

Background technique

The current Internet widely uses the TCP/IP protocol to communicate in a "host-host" manner. The original goal of the Internet was to share hardware resources. However, with the rapid development of the Internet, its applications have mainly shifted to the sharing of information such as text, pictures, and videos. Users are more concerned about the speed and reliability of information acquisition. Therefore, the traditional Internet obviously cannot meet the needs of users. Content-Centric Network (CCN) or Named Data Network (NDN) is a new architecture that replaces the current Internet. For the convenience of expression, the CCN or NDN here is collectively referred to as a content-centric network. The basic idea of content-centric network is to regard information (or content, data) itself as a "peer entity" in the network, which is to transform the current host-based network architecture into a content-based network architecture. ) structure. Compared with the current Internet, the content-centric network is a communication mode centered on the receiving end. The receiving end requests content by sending a request message, and the request message can be forwarded by each intermediate node. The node can return the data Data packet.

Currently, network coding is used in the content-centric network. The coding is used to define the feature vector of the request to explain the missing part of the requested content. The content provider determines whether the content that can be provided can meet the request according to the coding. If so, then Returns a chunk of data that is part of the missing content.

However, using this method for multi-source distribution, when multiple content providers in the network can provide the same data block, only one data block can effectively promote the receiving end to obtain the complete content requested, not only cannot Improve the efficiency of content acquisition, but also cause a waste of link resources.

Contents of the invention

Embodiments of the present invention provide a method for distributing content in a content-centric network and related equipment, which are used to improve content acquisition efficiency in the content-centric network and avoid waste of link resources.

The first aspect of the embodiments of the present invention provides a method for distributing content in a content-centric network, where the content-centric network includes a content source requester device and a content source provider device, and the method includes:

The content source requesting end device sends an interest message to the content source providing end device, and the interest message carries the information of the data block requested by the content source requesting end device;

The content source requester device receives the encoded data packet provided by the content source provider device, and the encoded data packet is divided by the content source provider device into a data block matching the interest message. The segment generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments;

The content source requesting end device decodes the encoded data packet set to obtain the data block, and the encoded data packet set includes the encoded data packet received by the content source requesting end device.

With reference to the first aspect of the embodiments of the present invention, in the first implementation manner of the first aspect of the embodiments of the present invention, the content-centric network further includes forwarding nodes,

The content source requester device sending the interest message to the content source provider device specifically includes:

The content source requester device sends the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device;

The receiving of the encoded data packet provided by the content source provider device by the content source requesting device specifically includes:

The content source requesting end device receives the encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source providing end device.

In combination with the first aspect of the embodiments of the present invention or the first implementation of the first aspect, in the second implementation of the first aspect of the embodiments of the present invention, the content source requesting device decodes the set of encoded data packets, After the step of obtaining the data block, it also includes:

The content source requesting end device stops receiving the encoded data packets, and sends out a packet sending stop notification, and the packet sending stop notification is used to make the device that receives the packet sending stop notification stop sending the encoded data corresponding to the data block packet and clear the forwarding path information of the encoded data packet.

In combination with the second implementation of the first aspect of the embodiments of the present invention, in the third implementation of the first aspect of the embodiments of the present invention, the decoding of the encoded data packet set by the content source requesting device specifically includes:

The content source requesting device decodes the set of encoded data packets by using a Gaussian elimination method.

In combination with the third implementation manner of the first aspect of the embodiments of the present invention, in the fourth implementation manner of the first aspect of the embodiments of the present invention,

The data block is one of a plurality of data blocks constituting one content;

The information of the data block is the number of the data block in the content;

The interest message also includes the content name of the content.

The second aspect of the embodiment of the present invention provides a method for distributing content in a content-centric network, including:

The forwarding node receives the interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device;

The forwarding node forwards the interest message to the content source provider device, so that the content source provider device performs fountain coding on the data block matching the interest message and returns the encoded data packet to the forwarding node. node;

The forwarding node caches the encoded data packet returned by the content source provider device in an encoding buffer area;

The forwarding node forwards the returned encoded data packet to the content source requester device, so that the content source requester device decodes the set of encoded data packets to obtain the data block, and the set of encoded data packets Include the encoded data packet received by the content source requester device.

In combination with the second aspect of the embodiments of the present invention, in the first implementation of the second aspect of the embodiments of the present invention, before the forwarding node forwards the interest message to the content source provider device, it further includes:

The forwarding node searches whether there is an encoded data packet matching the interest message in the encoding buffer;

If there is an encoded data packet that matches the Interest message in the encoded buffer, then send the matched encoded data packet to the content source requesting device.

The third aspect of the embodiment of the present invention provides a method for distributing content in a content-centric network, including:

The content source provider device receives the interest message sent by the content source requester device, and the interest message carries the information of the data block requested by the content source requester device;

The content source provider device segments the data block matching the interest message into data block fragments according to preset rules, encodes the data block fragments according to the fountain coding algorithm, and obtains encoded data packets ;

The content source provider device sends the encoded data packet to the content source requester device, so that the content source requester device decodes the encoded data packet to obtain the data block after receiving the encoded data packet.

In combination with the third aspect of the embodiments of the present invention, in the first implementation manner of the third aspect of the embodiments of the present invention, the receiving of the interest message sent by the content source requesting device by the content source provider device includes:

The content source provider device receives the interest message sent by the forwarding node, and the interest message is sent to the forwarding node by the content source requester device;

Sending the encoded data packet to the content source requesting device by the content source provider device includes:

The device provided by the content source sends the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device.

In combination with the third aspect of the embodiment of the present invention or the first implementation manner of the third aspect, in the second implementation manner of the third aspect of the embodiment of the present invention, the coded data packet contains the serial number of the data block , the data block is one of multiple data blocks forming one content;

The coded data packet also includes the content name of the content, the fountain coded identifier and a random number.

The fourth aspect of the embodiment of the present invention provides a content source requester device, which is characterized in that it includes:

A first sending module, configured to send an interest message to the content source provider device, where the interest message carries information about the data block requested by the content source requester device;

The first receiving module is configured to receive the encoded data packet provided by the content source provider device, where the encoded data packet is divided into data blocks matching the interest message by the content source provider device The segment generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments;

The decoding module is configured to decode a set of encoded data packets to obtain the data block, and the set of encoded data packets includes the encoded data packets received by the first receiving module.

In combination with the fourth aspect of the embodiments of the present invention, in the first implementation manner of the fourth aspect of the embodiments of the present invention,

The first sending module is specifically configured to send the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device;

The first receiving module is specifically configured to receive an encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source provider device.

In combination with the fourth aspect or the first implementation manner of the fourth aspect of the embodiments of the present invention, in the second implementation manner of the fourth aspect of the embodiments of the present invention, the content source requesting end device further includes:

A stop module, configured to stop receiving the encoded data packets, and issue a packet sending stop notification, the packet sending stop notification is used to make the device that receives the packet sending stop notification stop sending the encoded data packets corresponding to the data block and Clear forwarding path information of the encoded data packet.

In combination with the second implementation manner of the fourth aspect of the embodiments of the present invention, in the third implementation manner of the fourth aspect of the embodiments of the present invention,

The decoding module is specifically configured to use a Gaussian elimination method to decode the set of encoded data packets to obtain the data block.

The fifth aspect of the embodiment of the present invention provides a forwarding node, including:

The second receiving module is configured to receive an interest message sent by a content source requesting end device, where the interest message carries information about a data block requested by the content source requesting end device;

The first forwarding module is configured to forward the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns the encoded data packet to cache module;

A caching module, configured to cache the encoded data packets returned by the content source provider device in an encoding buffer area;

The second forwarding module is configured to forward the encoded data packet returned by the content source provider device to the content source requester device, so that the content source requester device decodes a set of encoded data packets to obtain the data block, the set of encoded data packets includes the encoded data packets received by the content source request end device.

With reference to the fifth aspect of the embodiments of the present invention, in the first implementation manner of the fifth aspect of the embodiments of the present invention, the forwarding node further includes:

A search module, configured to find whether there is an encoded data packet matching the interest message in the encoding buffer;

The second sending module is configured to send the matched encoded data packet to the content source requesting end device when there is an encoded data packet matching the interest message in the encoded buffer.

The sixth aspect of the embodiment of the present invention provides a content source provider device, including:

The third receiving module is configured to receive an interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device;

An encoding module, configured to generate data block fragments by segmenting the data blocks matching the interest message according to preset rules, and encode the data block fragments according to the fountain encoding algorithm to obtain encoded data packets;

The third sending module is configured to send the encoded data packet obtained by the encoding module to the content source requesting device, so that the content source requesting device decodes the encoded data packet to obtain the data block after receiving the encoded data packet .

With reference to the sixth aspect of the embodiments of the present invention, in the first embodiment of the sixth aspect of the embodiments of the present invention, the third receiving module is specifically configured to receive the Interest message sent by the forwarding node, and the Interest message The text is sent to the forwarding node by the content source requesting device;

The third sending module is specifically configured to send the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device, so that the content After receiving the encoded data packet, the source requester device decodes it to obtain the data block.

It can be seen from the above technical solutions that the embodiment of the present invention has the following advantages: in the embodiment of the present invention, after the content source requesting end device sends the interest message to the content source providing end device, it receives the encoded data packet provided by the content source providing end device , the encoded data packet is obtained by generating data block fragments by the content source provider device by segmenting the data block matching the interest message, and using the fountain coding algorithm to encode the data block fragments, so the content source The requesting end device can simultaneously receive encoded data packets sent by multiple content source providing end devices, and the content source requesting end device decodes the set of encoded data packets including the received encoded data packets. When the encoding conditions are satisfied, the content The device at the source requesting end can successfully decode and obtain the data block. Since the number of encoded data packets obtained according to the fountain encoding algorithm is much larger than the number of data blocks, and the probability that the encoded data packets are identical to each other is very small, so in a certain Within a certain period of time, the probability that the encoded data packets obtained by the content source requesting device from multiple devices are the same is much smaller than the probability that the data blocks obtained from multiple devices are the same, which increases the probability that the content source requesting device obtains valid data , reducing the time to obtain sufficient effective data, improving the content acquisition efficiency in the content-centric network, no longer transmitting a large amount of repeated data in the network link, and avoiding the waste of link resources.

Description of drawings

FIG. 1 is a schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 2 is another schematic flowchart of a content distribution method in a content-centric network in an embodiment of the present invention;

FIG. 3 is another schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 4 is a schematic diagram of a decoding process in an embodiment of the present invention;

FIG. 5 is another schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 6 is another schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 7 is another schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 8 is another schematic flowchart of a method for distributing content in a content-centric network in an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a content source requesting device in an embodiment of the present invention;

FIG. 10 is a schematic diagram of another structure of a content source requesting end device in an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a network device in an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a forwarding node in an embodiment of the present invention;

FIG. 13 is another structural schematic diagram of a forwarding node in an embodiment of the present invention;

FIG. 14 is a schematic structural diagram of a content source provider device in an embodiment of the present invention;

Fig. 15 is a schematic structural diagram of the content distribution system in the embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

The method for content distribution in the content-centric network in the embodiment of the present invention is described below from the perspectives of different executive entities:

1. Operation of the content source requester device:

Referring to Fig. 1, an embodiment of a method for content distribution in a content-centric network in an embodiment of the present invention includes:

101. The content source requester device sends an Interest message to the content source provider device;

In a content-centric network, when a content source requester device needs to request content, it sends an Interest message to the content source provider device, and requests data in units of data blocks. The Interest message carries the information requested by the content source requester device. information about the data block.

102. The content source requesting device receives the encoded data packet provided by the content source providing device;

After the content source requester device sends the interest message to the content source provider device, it receives the encoded data packet provided by the content source provider device. The encoded data packet is matched with the interest message by the content source provider device. The data block segmentation of generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments.

It can be understood that when performing fountain coding, the data block can be divided into k segments, each segment is an original packet, and then any number of encoded packets can be generated from the k original packets, and each encoded packet can become an encoded As long as the receiving end receives any subset of k(1+ε) coded packets, it can successfully (related to ε) restore all the original packets through decoding with a high probability, so as to obtain a complete data block.

It can be seen from the fountain code that there are many encoded data packets provided, and the number of content source provider devices in step 101 can be one or multiple, and the content source provider device that returns the encoded data packets in step 102 It can be one or multiple, and the specific number can be determined according to the number of content source provider devices that actually receive the Interest message and the number of content source provider devices that contain data blocks that match the Interest message. There is no limit here.

103. The content source requester device decodes the encoded data packet set to obtain the data block, and the encoded data packet set includes the encoded data packet received by the content source requester device.

After receiving the encoded data packet provided by the content source provider device, the content source requester device decodes the set of encoded data packets to obtain a data block matching the interest message. The encoded data packet set includes the content source requester device Encoded packet received.

It should be noted that there are many ways for the content source requester device to decode the set of encoded data packets. For example, the content source requester device can continuously decode the set of encoded data packets until the received encoded data packets reach a certain value. The number of encoded data packets contained in the encoded data packet set reaches a certain number before decoding is successful. The content source requesting device can also set a preset value. When the received encoded data packets reach the preset value After the value is obtained, the encoded data packet set is decoded to obtain the data block. There are other ways. For example, before decoding, it is possible to judge whether the encoded data packets in the encoded data packet set meet the decoding conditions, etc., which are not limited here. . In the embodiment of the present invention, after the content source requester device sends an interest message to the content source provider device, it receives the encoded data packet provided by the content source provider device, and the encoded data packet is shared with the content source provider device. The data block segments matching the interest message generate data block fragments, and use the fountain coding algorithm to encode the data block fragments, so the content source requesting device can receive codes sent by multiple content source provider devices at the same time The content source requester device decodes the encoded data packet set including the received encoded data packet. When the encoding condition is satisfied, the content source requester device can decode the data block successfully. According to the Fountain The number of encoded data packets obtained by the encoding algorithm is much larger than the number of data blocks, and the probability that the encoded data packets are identical to each other is very small, so within a certain period of time, the encoding obtained by the content source requesting device from multiple devices The probability of the same data packets is much smaller than the probability of the same data blocks obtained from multiple devices, which increases the probability of obtaining valid data from the content source request device, reduces the time to obtain sufficient valid data, and improves the efficiency of the content-centric network. The efficiency of content acquisition, a large amount of repeated data is no longer transmitted in the network link, and the waste of link resources is avoided.

In the above embodiment, the content source requester device sends the interest message to the content source provider device. In practical applications, the content source requester device can send the interest message to the forwarding node, and then the forwarding node forwards the interest message to the content source provider. terminal device, please refer to FIG. 2, another embodiment of the content distribution method in the content-centric network in the embodiment of the present invention includes:

201. The content source requester device sends an Interest message to the forwarding node, so that the forwarding node forwards the Interest message to the content source provider device;

In the content-centric network, when the content source requester device needs to request content, it sends an Interest message to the forwarding node, so that the forwarding node forwards the Interest message to the content source provider device, and requests data in units of data blocks. The message carries the information of the data block requested by the content source requesting end device.

It can be understood that the content source requester device can send the interest message to multiple forwarding nodes, or to all forwarding nodes connected to it, and the forwarding node can forward the interest message to multiple content source provider devices or Other forwarding nodes may also forward to some specific content source provider devices through query or path calculation, which is not limited here.

202. The content source requesting end device receives the encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source providing end device;

After the content source requester device sends the interest message to the forwarding node, it receives the encoded data packet forwarded by the forwarding node. The encoded data packet is sent to the forwarding node by the content source provider device. The encoded data packet is sent by the content source The provider device segments the data blocks that match the Interest message to generate data block fragments, and uses the fountain coding algorithm to encode the data block fragments.

It can be understood that when performing fountain coding, the data block can be divided into k segments, each segment is an original packet, and then any number of encoded packets can be generated from the k original packets, and each encoded packet can become an encoded As long as the receiving end receives any subset of k(1+ε) coded packets, it can successfully (related to ε) restore all the original packets through decoding with a high probability, so as to obtain a complete data block.

It can be seen from the fountain code that there are many encoded data packets provided, and the number of content source provider devices in step 201 can be one or multiple, and the content source provider device that returns the encoded data packets in step 202 It can be one or multiple, and the specific number can be determined according to the number of content source provider devices that actually receive the Interest message and the number of content source provider devices that contain data blocks that match the Interest message. There is no limit here. When there are multiple content source provider devices, multiple content source provider devices divide the data block into k segments according to the same rules, and each segment is an original packet, and then any number of encoded packets can be generated from the k original packets. Each encoded packet can become an encoded data packet

203. The content source requester device decodes the encoded data packet set to obtain the data block, and the encoded data packet set includes the encoded data packet received by the content source requester device.

After receiving the encoded data packet provided by the content source provider device, the content source requester device decodes the set of encoded data packets to obtain a data block matching the interest message. The encoded data packet set includes the content source requester device Encoded packet received.

It should be noted that there are many ways for the content source requester device to decode the set of encoded data packets. For example, the content source requester device can continuously decode the set of encoded data packets until the received encoded data packets reach a certain value. The number of encoded data packets contained in the encoded data packet set reaches a certain number before decoding is successful. The content source requesting device can also set a preset value. When the received encoded data packets reach the preset value After the value is obtained, the encoded data packet set is decoded to obtain the data block. There are other ways. For example, before decoding, it is possible to judge whether the encoded data packets in the encoded data packet set meet the decoding conditions, etc., which are not limited here. .

In the embodiment of the present invention, the content source requests the device interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device, and then receives the encoded data packet forwarded by the forwarding node, so that the interest The message spreads to a larger area, and more coded data packets returned by devices can be obtained, which improves the content acquisition efficiency.

In practical applications, after the content source requester device obtains the data block, it can also issue a stop sending notification to stop other devices from forwarding the encoded packets corresponding to the data block. Please refer to Figure 3, the content in the content-centric network in the embodiment of the present invention Another embodiment of the method of distributing includes:

301. The content source requester device sends an Interest message to the forwarding node, so that the forwarding node forwards the Interest message to the content source provider device;

In the content-centric network, when the content source requester device needs to request content, it sends an Interest message to the forwarding node, so that the forwarding node forwards the Interest message to the content source provider device, and requests data in units of data blocks. The message carries the information of the data block requested by the content source requesting end device.

It should be noted that the data block is one of multiple data blocks that constitute a content, the information of the data block may be the number of the data block in the content, and the interest message may also include the content of the content Name, for example, the packet header of the interest message can carry naming information defined in the format of .../content_name/chunk_number, the content_name is the content name of the content requested by the content source requester device, and the chunk_number is the requested data block in the content The information can also be carried in other naming ways in the Interest message, which is not limited here.

It can be understood that the content source requester device can send the interest message to multiple forwarding nodes, or to all forwarding nodes connected to it, and the forwarding node can forward the interest message to multiple content source provider devices or Other forwarding nodes may also forward to some specific content source provider devices through query or path calculation, which is not limited here.

302. The content source requesting end device receives the encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source providing end device;

After the content source requester device sends the interest message to the forwarding node, it receives the encoded data packet forwarded by the forwarding node. The encoded data packet is sent to the forwarding node by the content source provider device. The encoded data packet is sent by the content source The provider device segments the data blocks that match the Interest message to generate data block fragments, and uses the fountain coding algorithm to encode the data block fragments.

It can be understood that when performing fountain coding, the data block can be divided into k segments, each segment is an original packet, and then any number of encoded packets can be generated from the k original packets, and each encoded packet can become an encoded As long as the receiving end receives any subset of k(1+ε) coded packets, it can successfully (related to ε) restore all the original packets through decoding with a high probability, so as to obtain a complete data block.

It can be seen from the fountain code that there are many encoded data packets provided, and the number of content source provider devices in step 301 can be one or multiple, and the content source provider device that returns the encoded data packets in step 302 It can be one or multiple, and the specific number can be determined according to the number of content source provider devices that actually receive the Interest message and the number of content source provider devices that contain data blocks that match the Interest message. There is no limit here.

303. The content source requester device decodes the encoded data packet set to obtain the data block, and the encoded data packet set includes the encoded data packet received by the content source requester device.

After receiving the encoded data packet provided by the content source provider device, the content source requester device decodes the set of encoded data packets to obtain a data block matching the interest message. The encoded data packet set includes the content source requester device Encoded packet received.

It should be noted that there are many ways for the content source requester device to decode the set of encoded data packets. For example, the content source requester device can continuously decode the set of encoded data packets until the received encoded data packets reach a certain value. The number of encoded data packets contained in the encoded data packet set reaches a certain number before decoding is successful. The content source requesting device can also set a preset value. When the received encoded data packets reach the preset value After the value is obtained, the encoded data packet set is decoded to obtain the data block. There are other ways. For example, before decoding, it is possible to judge whether the encoded data packets in the encoded data packet set meet the decoding conditions, etc., which are not limited here. .

Among them, the content source requesting end device can use the Gaussian elimination method to decode the set of encoded data packets, and the specific decoding process can be shown in Figure 4:

401. A coding symbol is received;

402. Extract the feature vector of the encoding symbol;

403. Determine whether the feature vector is linearly independent from the received feature vector;

If it is not linearly independent, trigger step 404;

If it is linearly independent, trigger step 405;

404. Discard the feature vector;

405. Save the data packet of the encoding symbol, and add the feature vector to the encoding matrix;

406. Judging whether the number of encoding symbols is equal to the number of input symbols;

If not equal, then trigger step 401, and then receive another coding symbol;

If equal, trigger step 407;

407. Decode by using the encoding matrix and the received encoding symbols.

304. The device at the content source requesting end stops receiving the encoded data packets, and sends a packet sending stop notification.

After the content source requester device obtains the data block that matches the interest message, it stops accepting the encoded data packet and sends a packet stop notification, which is used to make the device that receives the packet stop notification stop sending the data block Correspondingly encoded data packets and clear the forwarding path information of the encoded data packets, such as PTT entries.

In the embodiment of the present invention, after the content source requester device obtains the data block, it stops receiving the encoded data packet, and sends a packet stop notification so that other devices stop sending the encoded data packet corresponding to the data block and clears the forwarding path of the encoded data packet Information saves network resources, improves the efficiency of subsequent processing of each device, and uses Gaussian elimination method for decoding, which reduces the impact of encoded data packets with a degree of 1 on the decoding success rate and improves the decoding success rate.

2. The operation of the forwarding node:

Please refer to FIG. 5, another embodiment of the content distribution method in the content-centric network in the embodiment of the present invention includes:

501. The forwarding node receives the Interest message sent by the content source requesting end device;

After the content source requester device sends an Interest message to the forwarding node, the forwarding node receives the Interest message sent by the content source requester device, and the Interest message carries the information of the data block requested by the content source requester device.

502. The forwarding node forwards the interest message to the content source provider device, so that the content source provider device performs fountain coding on the data block matching the interest message and returns the encoded data packet to the forwarding node;

After the forwarding node receives the interest message sent by the content source requesting end device, it forwards the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns The encoded data packet is sent to the forwarding node.

It can be understood that the forwarding node may also forward the interest message to the content source provider device through another forwarding node, and is not limited to directly forwarding the interest message to the content source provider device.

503. The forwarding node caches the encoded data packet returned by the content source provider device in the encoding buffer area;

The forwarding node forwards the interest packet to the content source provider device, and caches the coded data packet returned by the content source provider device into a coded buffer area, and the coded buffer area is dedicated to buffering the coded data packet.

It can be understood that, after the forwarding node receives an encoded data packet, if the same encoded data packet exists in the current encoding buffer, the forwarding node may directly discard the received same encoded data packet.

504. The forwarding node forwards the returned encoded data packet to the content source requesting end device, so that the content source requesting end device decodes the set of encoded data packets to obtain the data block.

After the forwarding node caches the encoded data packet returned by the content source provider device in the encoding buffer area, it forwards the returned encoded data packet to the content source request end device, so that the content source request end device decodes the set of encoded data packets Get the data block.

The forwarding node can directly forward the encoded data packet to the content source request device according to the reverse path of the interest message, or can search and calculate the path and then forward the encoded data packet according to the calculated path, which is not limited here.

It can be understood that the coded data packet carries the identifier of the fountain code, and the forwarding node can judge that the data packet is an encoded data packet through the identifier.

In the embodiment of the present invention, the forwarding node opens an encoding cache area dedicated to caching encoded data packets, so that the utilization rate of encoded data packets can be improved through caching, thereby improving the efficiency of content acquisition.

In the above embodiment, after the forwarding node receives the Interest message, it forwards the Interest message. In practical applications, the forwarding node can first check whether there is an encoded data packet matching the Interest message in the encoding buffer, and then perform For subsequent processing, please refer to FIG. 6. Another embodiment of the content distribution method in the content-centric network in the embodiment of the present invention includes:

601. The forwarding node receives the Interest packet sent by the content source requesting end device;

After the content source requester device sends an Interest message to the forwarding node, the forwarding node receives the Interest message sent by the content source requester device, and the Interest message carries the information of the data block requested by the content source requester device.

The information of the data chunk can be the number of the data chunk in the content, and the interest message can also include the content name of the content, for example, the header of the interest message can carry the format defined in .../content_name/chunk_number The content_name is the content name of the content requested by the content source requester device, and the chunk_number is the number of the requested data block in the content. The interest message can also carry this information in other naming methods. Here Not limited.

602. The forwarding node checks whether there is an encoded data packet matching the interest message in the encoding buffer, if it exists, trigger step 603, and if not, trigger step 604;

After the forwarding node receives the interest message sent by the content source requester device, it searches whether there is an encoded data packet matching the interest message in the encoding buffer, which is dedicated to buffering the encoded data packet;

If it exists, trigger step 603;

If not, step 604 is triggered.

It can be understood that there may also be a common buffer area in the forwarding node for caching data blocks. If there are data blocks requested by the content source requesting end device in the common buffer area of the forwarding node, the forwarding node can be used as the forwarding node at this time. A content source provider device.

603. The forwarding node sends an encoded data packet matching the Interest message to the content source requesting end device;

If the forwarding node finds that there is an encoded data packet matching the interest message in the encoding buffer, the forwarding node sends the encoded data packet matching the interest message to the content source requesting device.

604. The forwarding node forwards the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns the encoded data packet to the forwarding node;

The forwarding node sends the coded data packet matching the interest message in the code buffer to the content source request device, or after finding no coded data packet matching the interest message in the code buffer, forward Send the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns the encoded data packet to the forwarding node.

It can be understood that the forwarding node may also forward the interest message to the content source provider device through another forwarding node, and is not limited to directly forwarding the interest message to the content source provider device.

605. The forwarding node caches the encoded data packet returned by the content source provider device in the encoding buffer area;

The forwarding node forwards the interest packet to the content source provider device, and caches the coded data packet returned by the content source provider device into a coded buffer area, and the coded buffer area is dedicated to buffering the coded data packet.

It can be understood that, after the forwarding node receives an encoded data packet, if the same encoded data packet exists in the current encoding buffer, the forwarding node may directly discard the received same encoded data packet.

606. The forwarding node forwards the returned encoded data packet to the content source requesting end device, so that the content source requesting end device decodes the set of encoded data packets to obtain the data block.

After the forwarding node caches the encoded data packet returned by the content source provider device in the encoding buffer area, it forwards the returned encoded data packet to the content source request end device, so that the content source request end device decodes the set of encoded data packets Get the data block.

The forwarding node can directly forward the encoded data packet to the content source request device according to the reverse path of the interest message, or can search and calculate the path and then forward the encoded data packet according to the calculated path, which is not limited here.

It can be understood that the coded data packet carries the identifier of the fountain code, and the forwarding node can judge that the data packet is an encoded data packet through the identifier.

607. After the forwarding node receives the packet sending stop notification sent by the content source requesting device, the forwarding node stops forwarding the Interest message.

When the forwarding node receives the packet stop notification sent by the content source requesting end device, the forwarding node can terminate the forwarding of the interest message, and clear the forwarding path information of the encoded data packet, and can also clear the encoded data that matches the interest message Bag.

In the embodiment of the present invention, before forwarding the interest message, the forwarding node can check whether there is an encoded data packet matching the interest message in the encoding buffer, and if so, the encoded data packet can be sent to The content source requester device enables the requester device to obtain encoded data packets that are sufficient for decoding faster, improving the efficiency of content acquisition.

3. Operation of the content source provider device:

Referring to FIG. 7, another embodiment of the content distribution method in the content-centric network in the embodiment of the present invention includes:

701. The content source provider device receives the Interest packet sent by the content source requester device;

After the content source requester device sends an Interest message, the content source provider device receives the Interest message sent by the content source requester device, and the Interest message carries the information of the data block requested by the content source requester device.

702. The content source provider device segments the data block matching the interest message according to preset rules to generate data block fragments, encodes the data block fragments according to the fountain coding algorithm, and obtains encoded data packets;

After receiving the interest message sent by the content source requesting device, the content source provider device will segment the data block matching the interest message according to the preset rules to generate data block fragments, and the data block will be segmented according to the fountain coding algorithm. Fragmentation is encoded to obtain encoded data packets;

The preset rule is the rule of fountain encoding. Different fountain encodings may have different segmentation rules. For example, LT encoding can be used to divide the data block into K segments. K is a positive integer to ensure that all packets except the last segment have the same The size of the last paragraph is filled with zeros if the length is insufficient, or another encoding form in the fountain encoding can also be used, which is not limited here.

703. The content source provider device sends the encoded data packet to the content source requester device, so that the content source requester device decodes the encoded data packet to obtain the data block after receiving the encoded data packet.

After the content source provider device obtains the encoded data packet, it sends the encoded data packet to the content source requester device, so that after receiving the encoded data packet, the content source requester device decodes it to match the interest packet. of data blocks.

It can be understood that since the fountain encoding algorithm can continuously generate new encoded data packets, the content source provider device can continuously send newly generated encoded data packets to the content source request end device until it is sent to a certain The number of packets or the notification to stop sending packets is received, etc., to stop sending encoded data packets. The specific trigger conditions for stopping can be set according to the actual situation, and are not limited here.

In the embodiment of the present invention, after receiving the interest message, the content source provider device performs fountain coding on the data block that matches the interest message, and sends out the encoded data packet, so that multiple provider devices simultaneously send the encoded When the data packets are sent, there is no need for cooperation between providers, but the content transmission in the form of multi-node cooperation is realized. When each provider completes the content transmission, the number of packets that each content source provider device needs to send is reduced. .

In the above embodiment, the content source provider device receives the interest message sent by the content source request end device. In practical applications, the content source device can accept the interest message forwarded by the forwarding node. Please refer to FIG. 8, the implementation of the present invention Another embodiment of the content distribution method in the content-centric network in the example includes:

801. The content source provider device receives the interest message sent by the forwarding node, and the interest message is sent to the forwarding node by the content source requesting device;

After the content source requester device sends an Interest message, the content source provider device receives the Interest message sent by the forwarding node, and the Interest message is sent by the content source requester device to the forwarding node, and the Interest message carries content Information about the data block requested by the source requester device.

802. The content source provider device segments the data block matching the interest message according to preset rules to generate data block fragments, and encodes the data block fragments according to the fountain coding algorithm to obtain encoded data packets;

After receiving the interest message sent by the content source requesting device, the content source provider device will segment the data block matching the interest message according to the preset rules to generate data block fragments, and the data block will be segmented according to the fountain coding algorithm. Fragmentation is encoded to obtain encoded data packets;

The preset rule is the rule of fountain encoding. Different fountain encodings may have different segmentation rules. For example, LT encoding can be used to divide the data block into K segments. K is a positive integer to ensure that all packets except the last segment have the same The size of the last paragraph is filled with zeros if the length is insufficient, or another encoding form in the fountain encoding can also be used, which is not limited here.

803. The device provided by the content source sends the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting device, so that after receiving the encoded data packet, the content source requesting device, Decode to obtain the data block.

After the content source provider device obtains the encoded data packet, it sends the encoded data packet to the forwarding node, so that the content source requesting device decodes the encoded data packet forwarded by the forwarding node to obtain the Interest message matching data blocks.

It can be understood that since the fountain encoding algorithm can continuously generate new encoded data packets, the content source provider device can continuously send newly generated encoded data packets to the content source request end device until it is sent to a certain The number of packets or the notification to stop sending packets is received, etc., to stop sending encoded data packets. The specific trigger conditions for stopping can be set according to the actual situation, and are not limited here.

The coded data packet may contain the number of the data block matching the interest message, the data block is one of the multiple data blocks that make up a content, and the coded data packet may also include the number of the content The content name, the identifier of the fountain code and a random number, for example, the header of the coded data packet can carry the naming information defined in the format of .../content name/chunk number/LT/nonce, where content_name is the content source request device request The content name of the content, chunk_number is the number of the data block that matches the interest message, LT is the identifier of the LT code in the fountain code, nonce is a random number with a wide range of values, and multiple data blocks can be composed One content, it can be understood that each encoded data packet can also be named in other naming manners to distinguish each different encoded data packet, which is not limited here.

In the embodiment of the present invention, the content source provider device can receive the interest message forwarded by the forwarding node, and then forward the encoded data packet to the forwarding node, so that the forwarding node sends it to the content source requesting device. In this way, the forwarding node can send the interest message The message is forwarded to multiple content source provider devices, so that multiple content source provider devices provide encoded data packets at the same time, and send the encoded data packets to the forwarding nodes, so that the forwarding nodes can forward the encoded data packets to each other , so that the device at the content source requesting end can receive encoded data packets provided by multiple devices at the same time, thereby improving the efficiency of content acquisition.

For ease of understanding, combined with the operations of the above three execution subjects, the method for multi-source distribution in the content network in the embodiment of the present invention is described in detail below in a specific application scenario:

The content source requester device sends an interest message to the forwarding node. The header of the interest message carries the naming information of .../ABC/5, indicating that the data block numbered 5 in the content named ABC is requested;

The forwarding node receives the interest message, and at the same time searches the encoding buffer to obtain 2 encoded data packets that match the interest message. The forwarding node returns the 2 encoded data packets to the content source requesting device and forwards the interest message. The message is sent to another forwarding node and content source provider device;

The content source provider device receives the interest message forwarded by the forwarding node, and the content source provider device that stores the data block that matches the interest message segments and encodes the data block into encoded data packets according to the LT coding rules , the header of each encoded data packet carries the naming information of .../ABC/5/LT/nonce, and the nonce is a random number with a large value range, which is continuously sent to the forwarding node;

When the forwarding node receives the data packet with the LT mark, it recognizes it as an encoded data packet, and caches the encoded data packet in the encoding buffer area according to the local cache mechanism, such as the LRU mechanism;

The forwarding node forwards the received encoded data packet to the content source requesting device according to the reverse path of the interest message. During this process, the forwarding node does not perform any packet loss operation, and does not clear the encoded data packet during the process. Forwarding path information, such as the content of the corresponding entry in the PIT table;

The content source requester device continues to receive the encoded data packets returned by the forwarding node;

When the decoding condition is met, the content source requesting device uses the Gaussian elimination method to decode the received encoded data packet to obtain the data block 5 that matches the interest message;

The device at the content source requesting end issues a notification to stop sending packets;

After the forwarding node receives the packet stop notification, it stops forwarding the interest message, and clears all encoded data packets and forwarding path information that match the interest message;

After receiving the packet sending stop notification, the content source provider device stops encoding the data block and terminates sending the encoded data packet.

The three execution subjects in the embodiment of the present invention are described respectively below:

1. The requesting device:

Please refer to Figure 9, an embodiment of the content source requester device in the embodiment of the present invention includes:

The first sending module 901 is configured to send an interest message to the content source provider device, where the interest message carries information about the data block requested by the content source requester device;

The first receiving module 902 is configured to receive the encoded data packet provided by the content source provider device, where the encoded data packet is a data block that the content source provider device will match with the interest message Segmentation generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments;

The decoding module 903 is configured to decode a set of encoded data packets to obtain the data block, and the set of encoded data packets includes the encoded data packets received by the first receiving module 902 .

In the embodiment of the present invention, after the first sending module 901 sends the interest message to the content source provider device, the first receiving module 902 receives the encoded data packet provided by the content source provider device. The encoded data packet is provided by the content source The end device generates data block fragments by segmenting the data blocks matching the interest message, and uses the fountain coding algorithm to encode the data block fragments, so the first receiving module 902 can receive multiple content source providers at the same time For the encoded data packet sent by the device, the decoding module 903 decodes the set of encoded data packets including the received encoded data packet. When the encoding condition is met, the decoding module 903 can successfully decode the data block to obtain the data block. The number of encoded data packets obtained by the encoding algorithm is far greater than the number of data blocks, and the probability of the encoded data packets being identical to each other is very small, so within a certain period of time, the encoding obtained by the content source requesting device from multiple devices The probability of the same data packets is much smaller than the probability of the same data blocks obtained from multiple devices, which increases the probability of obtaining valid data from the content source request device, reduces the time to obtain sufficient valid data, and improves the efficiency of the content-centric network. The efficiency of content acquisition, a large amount of repeated data is no longer transmitted in the network link, and the waste of link resources is avoided.

In practical applications, after the content source requester device obtains the data block, it can also issue a stop sending notification to stop other devices from forwarding the encoded packets corresponding to the data block. Please refer to Figure 10. In the embodiment of the present invention, the content source requester device also One embodiment includes:

The first sending module 1001 is configured to send an interest message to the content source provider device, where the interest message carries information about the data block requested by the content source requester device;

The first receiving module 1002 is configured to receive the encoded data packet provided by the content source provider device, where the encoded data packet is a data block that the content source provider device will match with the interest message Segmentation generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments;

A decoding module 1003, configured to decode a set of encoded data packets to obtain the data block, and the set of encoded data packets includes the encoded data packets received by the first receiving module 1002;

In this embodiment, the first sending module 1001 may be specifically configured to send the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device;

The first receiving module 1002 may be specifically configured to receive an encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source provider device;

The content source requester device also includes:

A stop module 1004, configured to stop receiving the encoded data packets, and issue a packet sending stop notification, the packet sending stop notification is used to make the device that receives the packet sending stop notification stop sending the encoded data packets corresponding to the data block And clear the forwarding path information of the encoded data packet.

In some embodiments of the present invention, the decoding module 1003 is specifically configured to use a Gaussian elimination method to decode the set of encoded data packets to obtain the data block.

In the embodiment of the present invention, after the decoding module 1003 obtains the data block, the stop module 1004 stops receiving the encoded data packet, and sends a notification to stop sending packets so that other devices stop sending the encoded data packet corresponding to the data block and clears the forwarding of the encoded data packet. The path information saves network resources and improves the efficiency of subsequent processing of each device, and the decoding module 1003 uses Gaussian elimination method to decode, which reduces the influence of encoded data packets with a degree of 1 on the decoding success rate and improves the decoding efficiency. Success rate.

FIG. 11 is a schematic structural diagram of a network device, which may be a schematic structural diagram of a content source requesting end device, a structural schematic diagram of a forwarding node, or a structural schematic diagram of a content source providing end device.

The content source requester device in the embodiment of the present invention has been described above from the perspective of unitized functional entities. The following describes the content source requester device in the embodiment of the present invention from the perspective of hardware processing. Please refer to FIG. 11 , the present invention Another embodiment of the content source requester device in the embodiment includes:

An input device 1101, an output device 1102, a processor 1103, and a memory 1104 (the number of processors 1103 in the content source requester device can be one or more, one processor 1103 is taken as an example in FIG. 11 ). In some embodiments of the present invention, the input device 901 , the output device 1102 , the processor 1103 and the memory 1104 may be connected through a bus or in other ways, wherein connection through a bus is taken as an example in FIG. 11 .

Wherein, by calling the operation instructions stored in the memory 1104, the processor 1103 is configured to perform the following steps:

sending an interest message to the content source provider device, the interest message carrying the information of the data block requested by the content source requester device;

receiving an encoded data packet provided by the content source provider device, wherein the encoded data packet is generated by segmenting a data block matching the interest message by the content source provider device to generate a data block fragment, and obtained by encoding the data block fragments using a fountain encoding algorithm;

Decoding the set of encoded data packets to obtain the data block, the set of encoded data packets including the received encoded data packets;

In some embodiments of the present invention, the processor 1103 is specifically configured to perform the following steps:

sending the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device;

receiving an encoded data packet forwarded by the forwarding node, where the encoded data packet is sent to the forwarding node by the content source provider device;

In some embodiments of the present invention, the processor 1103 is also configured to perform the following steps:

stop receiving the encoded data packet, and issue a stop sending notification, the stop sending notification is used to make the device that receives the stop sending notification stop sending the encoded data packet corresponding to the data block and clear the encoded The forwarding path information of the data packet;

In some embodiments of the present invention, the processor 1103 is specifically configured to perform the following steps:

The coded data packet set is decoded by using a Gaussian elimination method to obtain the data block.

2. Forwarding node:

Please refer to Figure 12, an embodiment of the forwarding node in the embodiment of the present invention includes:

The second receiving module 1201 is configured to receive an interest message sent by a content source requesting end device, where the interest message carries information about a data block requested by the content source requesting end device;

The first forwarding module 1202 is configured to forward the interest message to the content source provider device, so that the content source provider device performs fountain coding on the data block matching the interest message and returns an encoded data packet To the cache module 1203;

A caching module 1203, configured to cache the encoded data packets returned by the content source provider device in an encoding buffer area;

The second forwarding module 1204 is configured to forward the encoded data packet returned by the content source provider device to the content source requester device, so that the content source requester device decodes the set of encoded data packets to obtain the A data block, the set of encoded data packets includes the encoded data packets received by the content source request end device.

In the embodiment of the present invention, the caching module 1203 opens an encoding cache area dedicated to caching encoded data packets, so that the utilization rate of encoded data packets can be improved through caching, thereby improving the efficiency of content acquisition.

In the above embodiment, after the second receiving module 1201 receives the interest message, the first forwarding module 1202 forwards the interest message. In practical applications, the forwarding node can first check whether there is an encoding cache that matches the interest message. Encoded data packets, and then perform subsequent processing, please refer to Figure 13, another embodiment of the forwarding node in the embodiment of the present invention includes:

The second receiving module 1301 is configured to receive an interest message sent by a content source requesting end device, where the interest message carries information about a data block requested by the content source requesting end device;

The first forwarding module 1302 is configured to forward the interest message to the content source provider device, so that the content source provider device performs fountain coding on the data block matching the interest message and returns an encoded data packet to the cache module;

A caching module 1303, configured to cache the encoded data packets returned by the content source provider device in an encoding buffer area;

The second forwarding module 1304 is configured to forward the encoded data packet returned by the content source provider device to the content source requester device, so that the content source requester device decodes the set of encoded data packets to obtain the A data block, wherein the set of encoded data packets includes the encoded data packets received by the content source requesting end device;

In this embodiment, the forwarding node also includes:

A search module 1305, configured to find whether there is an encoded data packet matching the interest message in the encoding buffer;

The second sending module 1306 is configured to send the matched encoded data packet to the content source requesting device when there is an encoded data packet matching the interest message in the encoded buffer.

In the embodiment of the present invention, before forwarding the interest message, the search module 1305 can search whether there is a coded data packet that matches the interest message in the encoding buffer, and if so, the second sending module 1306 can first send the message The encoded data packet is sent to the content source requesting device, so that the requesting device can obtain the encoded data packet sufficient for decoding faster, and the efficiency of content acquisition is improved.

The forwarding node in the embodiment of the present invention is described above from the perspective of unitized functional entities, and the forwarding node in the embodiment of the present invention is described below from the perspective of hardware processing. Please refer to FIG. 11, the forwarding node in the embodiment of the present invention Another embodiment includes:

An input device 1101 , an output device 1102 , a processor 1103 and a memory 1104 (there may be one or more processors 1103 in the forwarding node, one processor 1103 is taken as an example in FIG. 11 ). In some embodiments of the present invention, the input device 901 , the output device 1102 , the processor 1103 and the memory 1104 may be connected through a bus or in other ways, wherein connection through a bus is taken as an example in FIG. 11 .

Wherein, by calling the operation instructions stored in the memory 1104, the processor 1103 is configured to perform the following steps:

receiving an interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device;

Forwarding the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns the encoded data packet to the cache module;

Buffering the encoded data packets returned by the content source provider device into the encoding buffer;

Forwarding the encoded data packet returned by the content source provider device to the content source requester device, so that the content source requester device decodes the set of encoded data packets to obtain the data block, and the encoded data packet The collection includes encoded data packets received by the content source requesting device;

In some embodiments of the present invention, the processor 1103 is also configured to perform the following steps:

Finding whether there is an encoded data packet matching the Interest message in the encoded buffer;

When there is an encoded data packet matching the Interest message in the encoded buffer, sending the matched encoded data packet to the content source requesting end device.

3. Content source provider device:

Please refer to Figure 14, an embodiment of the content source provider in the embodiment of the present invention includes:

The third receiving module 1401 is configured to receive an interest message sent by the content source requester device, where the interest message carries the information of the data block requested by the content source requester device;

An encoding module 1402, configured to segment the data blocks matching the interest message into data block fragments according to preset rules, encode the data block fragments according to the fountain encoding algorithm, and obtain encoded data packets;

The third sending module 1403 is configured to send the encoded data packet obtained by the encoding module 1402 to the content source requesting end device, so that the content source requesting end device decodes the encoded data packet to obtain the data block;

In some embodiments of the present invention, the third receiving module 1401 is specifically configured to receive the interest message sent by the forwarding node, and the interest message is sent to the forwarding node by the content source requesting end device;

The third sending module 1403 is specifically configured to send the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device, so that the content After receiving the encoded data packet, the source requester device decodes it to obtain the data block.

In the embodiment of the present invention, after the third receiving module 1401 receives the interest message, the encoding module 1402 performs fountain encoding on the data block matching the interest message, and the third sending module 1403 sends out the obtained encoded data packet In this way, when multiple provider devices send encoded data packets at the same time, there is no need for cooperation among providers, but the content transmission in the form of multi-node cooperation is realized, and when each provider completes content transmission, each provider is reduced. The number of packets that the content source provider device needs to send.

The content source provider device in the embodiment of the present invention is described above from the perspective of unitized functional entities, and the content source provider device in the embodiment of the present invention is described below from the perspective of hardware processing. Please refer to FIG. 11 , the present invention Another embodiment of the content source provider device in the embodiment includes:

An input device 1101 , an output device 1102 , a processor 1103 and a memory 1104 (there may be one or more processors 1103 in the forwarding node, one processor 1103 is taken as an example in FIG. 11 ). In some embodiments of the present invention, the input device 901 , the output device 1102 , the processor 1103 and the memory 1104 may be connected through a bus or in other ways, wherein connection through a bus is taken as an example in FIG. 11 .

Wherein, by calling the operation instructions stored in the memory 1104, the processor 1103 is configured to perform the following steps:

receiving an interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device;

Segmenting the data blocks matching the interest message according to preset rules to generate data block fragments, and encoding the data block fragments according to the fountain coding algorithm to obtain encoded data packets;

The encoded data packet is sent to the content source requesting device, so that the content source requesting device decodes the encoded data packet to obtain the data block after receiving the encoded data packet.

In some embodiments of the present invention, the processor 1103 is specifically configured to perform the following steps:

receiving the interest message sent by the forwarding node, where the interest message is sent to the forwarding node by the content source requesting device;

sending the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device, so that the content source requesting end device receives the encoded data After the packet is decoded, the data block is obtained.

The following describes the content distribution system in the embodiment of the present invention, please refer to Figure 15, an embodiment of the content distribution system in the embodiment of the present invention includes:

The content source requesting end device 1501 shown in FIG. 9 or FIG. 10 , the forwarding node 1502 shown in FIG. 12 or FIG. 13 , and the content source providing end device 1503 shown in FIG. 14 .

In order to facilitate the understanding of the above embodiment, the interaction process of each device in the above content distribution system in a specific application scenario is described below:

The content source requester device 1501 sends an interest message to the forwarding node 1502. The header of the interest message carries the naming information of .../ABC/5, indicating that the data block numbered 5 in the content named ABC is requested;

The forwarding node 1502 receives the interest message, and searches the encoding buffer to obtain 2 encoded data packets matching the interest message, and the forwarding node 1502 returns the 2 encoded data packets to the content source requester device 1501, and Forwarding the interest message to another forwarding node and content source provider device 1503;

The content source provider device 1503 receives the interest message forwarded by the forwarding node 1502, and the content source provider device 1503 that stores the data block matching the interest message segments and encodes the data block into coded The header of each encoded data packet carries the naming information of .../ABC/5/LT/nonce, and the nonce is a random number with a large value range, which is continuously sent to the forwarding node 1502;

The forwarding node 1502 receives the data packet with the LT identifier and recognizes it as a coded data packet, and caches the coded data packet in the code buffer according to a local cache mechanism, such as an LRU mechanism;

The forwarding node 1502 forwards the received encoded data packet to the content source requesting device 1501 according to the reverse path of the interest message. During this process, the forwarding node 1502 does not perform any packet loss operation and does not clear the encoded data packet during the process. The forwarding path information of the data packet, such as the content of the corresponding entry in the PIT table;

The content source requester device 1501 continuously receives the encoded data packets returned by the forwarding node 1502;

When the decoding condition is satisfied, the content source requester device 1501 decodes the received encoded data packet by using the Gaussian elimination method, and obtains the data block 5 that matches the interest message;

The content source requesting end device 1501 issues a notification to stop sending packets;

After the forwarding node 1502 receives the notification to stop sending packets, it stops forwarding the interest message, and clears all encoded data packets and forwarding path information that match the interest message;

After receiving the packet sending stop notification, the content source provider device 1503 stops encoding the data block and terminates sending the encoded data packet.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, and other media that can store program codes.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (18)

1. A method for content distribution in a content-centric network, characterized in that the content-centric network includes a content source requesting end device and a content source providing end device, and the method includes: The content source requesting end device sends an interest message to the content source providing end device, and the interest message carries the information of the data block requested by the content source requesting end device; The content source requester device receives the encoded data packet provided by the content source provider device, and the encoded data packet is divided by the content source provider device into a data block matching the interest message. The segment generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments; The content source requesting end device decodes the encoded data packet set to obtain the data block, and the encoded data packet set includes the encoded data packet received by the content source requesting end device. 2. The method according to claim 1, wherein the content-centric network further includes forwarding nodes, The content source requester device sending the interest message to the content source provider device specifically includes: The content source requester device sends the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device; The receiving of the encoded data packet provided by the content source provider device by the content source requesting device specifically includes: The content source requesting end device receives the encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source providing end device. 3. The method according to claim 1 or 2, wherein the content source requesting device decodes the set of encoded data packets, and after the step of obtaining the data block, further includes: The content source requesting end device stops receiving the encoded data packets, and sends out a packet sending stop notification, and the packet sending stop notification is used to make the device that receives the packet sending stop notification stop sending the encoded data corresponding to the data block packet and clear the forwarding path information of the encoded data packet. 4. The method according to claim 3, wherein the decoding of the set of encoded data packets by the content source requesting device specifically comprises: The content source requesting device decodes the set of encoded data packets by using a Gaussian elimination method. 5. The method of claim 4, wherein, The data block is one of a plurality of data blocks constituting one content; The information of the data block is the number of the data block in the content; The interest message also includes the content name of the content. 6. A method for distributing content in a content-centric network, comprising: The forwarding node receives the interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device; The forwarding node forwards the interest message to the content source provider device, so that the content source provider device performs fountain coding on the data block matching the interest message and returns the encoded data packet to the forwarding node. node; The forwarding node caches the encoded data packet returned by the content source provider device in an encoding buffer area; The forwarding node forwards the returned encoded data packet to the content source requester device, so that the content source requester device decodes the set of encoded data packets to obtain the data block, and the set of encoded data packets Include the encoded data packet received by the content source requester device. 7. The method according to claim 6, characterized in that before the step of forwarding the interest message to the content source provider device by the forwarding node, the step further comprises: The forwarding node searches whether there is an encoded data packet matching the interest message in the encoding buffer; If there is an encoded data packet that matches the Interest message in the encoded buffer, then send the matched encoded data packet to the content source requesting device. 8. A method for distributing content in a content-centric network, comprising: The content source provider device receives the interest message sent by the content source requester device, and the interest message carries the information of the data block requested by the content source requester device; The content source provider device segments the data block matching the interest message into data block fragments according to preset rules, encodes the data block fragments according to the fountain coding algorithm, and obtains encoded data packets ; The content source provider device sends the encoded data packet to the content source requester device, so that the content source requester device decodes the encoded data packet to obtain the data block after receiving the encoded data packet. 9. The method of claim 8, wherein The interest message sent by the content source provider device to receive the content source request device includes: The content source provider device receives the interest message sent by the forwarding node, and the interest message is sent to the forwarding node by the content source requester device; Sending the encoded data packet to the content source requesting device by the content source provider device includes: The device provided by the content source sends the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device. 10. The method according to claim 8 or 9, wherein the coded data packet contains the number of the data block, and the data block is one of a plurality of data blocks forming one content; The coded data packet also includes the content name of the content, the fountain coded identifier and a random number. 11. A content source requester device, characterized in that it comprises: A first sending module, configured to send an interest message to the content source provider device, where the interest message carries information about the data block requested by the content source requester device; The first receiving module is configured to receive the encoded data packet provided by the content source provider device, where the encoded data packet is divided into data blocks matching the interest message by the content source provider device The segment generates data block fragments, and uses the fountain coding algorithm to encode the data block fragments; The decoding module is configured to decode a set of encoded data packets to obtain the data block, and the set of encoded data packets includes the encoded data packets received by the first receiving module. 12. The content source requester device according to claim 11, characterized in that: The first sending module is specifically configured to send the interest message to the forwarding node, so that the forwarding node forwards the interest message to the content source provider device; The first receiving module is specifically configured to receive an encoded data packet forwarded by the forwarding node, and the encoded data packet is sent to the forwarding node by the content source provider device. 13. The content source requesting device according to claim 11 or 12, wherein the content source requesting device further comprises: A stop module, configured to stop receiving the encoded data packets, and issue a packet sending stop notification, the packet sending stop notification is used to make the device that receives the packet sending stop notification stop sending the encoded data packets corresponding to the data block and Clear forwarding path information of the encoded data packet. 14. The content source requester device according to claim 13, characterized in that: The decoding module is specifically configured to use a Gaussian elimination method to decode the set of encoded data packets to obtain the data block. 15. A forwarding node, characterized in that, comprising: The second receiving module is configured to receive an interest message sent by a content source requesting end device, where the interest message carries information about a data block requested by the content source requesting end device; The first forwarding module is configured to forward the interest message to the content source provider device, so that the content source provider device performs fountain encoding on the data block matching the interest message and returns the encoded data packet to cache module; A caching module, configured to cache the encoded data packets returned by the content source provider device in an encoding buffer area; The second forwarding module is configured to forward the encoded data packet returned by the content source provider device to the content source requester device, so that the content source requester device decodes a set of encoded data packets to obtain the data block, the set of encoded data packets includes the encoded data packets received by the content source request end device. 16. The forwarding node according to claim 15, wherein the forwarding node further comprises: A search module, configured to find whether there is an encoded data packet matching the interest message in the encoding buffer; The second sending module is configured to send the matched encoded data packet to the content source requesting end device when there is an encoded data packet matching the interest message in the encoded buffer. 17. A content source provider device, characterized in that it comprises: The third receiving module is configured to receive an interest message sent by the content source requesting end device, the interest message carrying the information of the data block requested by the content source requesting end device; An encoding module, configured to generate data block fragments by segmenting the data blocks matching the interest message according to preset rules, and encode the data block fragments according to the fountain encoding algorithm to obtain encoded data packets; The third sending module is configured to send the encoded data packet obtained by the encoding module to the content source requesting device, so that the content source requesting device decodes the encoded data packet to obtain the data block after receiving the encoded data packet . 18. The content source provider device according to claim 17, characterized in that, The third receiving module is specifically configured to receive the interest message sent by the forwarding node, and the interest message is sent to the forwarding node by the content source requesting end device; The third sending module is specifically configured to send the encoded data packet to the forwarding node, so that the forwarding node forwards the encoded data packet to the content source requesting end device, so that the content After receiving the encoded data packet, the source requester device decodes it to obtain the data block.