KR100802331B1 - Content delivery system and method using user terminal - Google Patents

Abstract

The present invention relates to a content delivery network (CDN) technology, and to a content delivery system and method using a user terminal. The system of the present invention stores the terminal information table and ranking information of each user terminal, a list of all contents and contents to be provided, and a list of contents downloaded by each client, and updates the ranking information according to log data. CDN operator system; A plurality of user terminals receiving and storing contents from the CDN operator system and transmitting the contents at the request of each client; And receiving information of content to be downloaded by the client from the CDN provider system and ranking information on the content, mapping each block of the content to each user terminal according to the ranking information, and then displaying the content to each user terminal. It includes a client that requests and downloads the block transmission and transmits log data to the CDN operator system.

Description

CONTENT DELIVERY SYSTEM AND METHOD USING USER TERMINAL}

The present invention relates to a content delivery network (CDN) technology, and more particularly, to a content delivery system and method using a user terminal.

In general, a content delivery network (CDN) is a solution to a bottleneck problem occurring in a server and a network. The content delivery network (CDN) is a fast and reliable method for distributing content through a cache server strategically installed in each network. It is a network infrastructure that provides a network access environment and can accommodate a large number of users through distributed processing to a content provider (CP). In other words, the CDN technology installs multiple cache servers in the neighboring network close to the content consumer to remove the communication load, content transmission speed, and quality deterioration caused by transmitting content remotely from the content server's central server to the client. It is a kind of content distribution technology that responds to a request from a nearby cache server.

As shown in FIG. 1, the conventional CDN includes a client terminal 10 connected through the Internet, a content server 20 of a content provider, and a cache server 30 installed in an ISP provider. When the client terminal 10 requests content from the content server 20, the content server 20 finds a cache server 30 that can provide an optimal service to the client terminal 10, and the corresponding cache server 30. IP address of the (①, ②), accordingly, the client terminal 10 receives the desired content by accessing the cache server 30 through the reset (Request redirection) (③, ④).

As described above, in a conventional content delivery network (CDN), a CDN provider delivers content to each client. In this case, the content to be transmitted is large in size (units of gigabytes). Must be able to send to

However, in the case of a typical CDN service provider, it is not possible to secure a network capable of transmitting such a large amount of content in a short time, and thus has no choice but to transmit content through an ISP. In this case, the CDN provider uploads and stores the contents to be transmitted to each of the ISP's delivery servers, and each of the ISP's delivery servers transmits the stored contents when the client requests the set time or the client. As a result, CDN operators inevitably had to pay high costs for content delivery.

Accordingly, there is a demand for a method of transmitting content to each client at a level of using an ISP while reducing the cost of the CDN service provider.

On the other hand, with the development of wired and wireless Internet technology, each user (individual) accesses the Internet using a variety of terminals to use the online service. For the general user, the actual use time of the terminal and the Internet is only a few hours a day. . As a result, the user's terminal and the network resources allocated to the user remain idle for most of the time. And according to the current ISP billing method, unlike the conventional telephone-modem connection method, the user charges the monthly fee instead of the billing according to the usage time, so each user spends only a few hours a day using the actual Internet. However, each user has to pay a flat fee monthly.

Accordingly, there is a demand for a method of properly utilizing resources of a user terminal and a network not used during idle time.

The present invention has been proposed to meet the above necessity, and an object of the present invention is to provide a CDN service provider with a terminal in idle state of each user, rather than through an ISP as in the prior art. It is to provide a content delivery system and method that can reduce the cost burden of the CDN provider by transmitting using a storage device) and network resources.

In addition, another object of the present invention is to distribute and store each content to a plurality of terminals and network resources of a plurality of users and then to each client content delivery system and method that can deliver content as quickly and effectively as a conventional transmission method through an ISP To provide.

In addition, another object of the present invention is to provide a revenue to the user by paying a reward for the use of resources to each user to induce the user's participation, through which the content delivery system and method that can gradually improve the content delivery efficiency To provide.

In order to achieve the above object, the system of the present invention stores a terminal information table and ranking information of each user terminal, a list of all contents and contents to be provided, and a list of contents downloaded by each client, and log data. A CDN operator system for updating the ranking information according to; A plurality of user terminals receiving and storing contents from the CDN operator system and transmitting the contents at the request of each client; And receiving information of content to be downloaded by the client from the CDN provider system and ranking information on the content, mapping each block of the content to each user terminal according to the ranking information, and then displaying the content to each user terminal. It is characterized in that it comprises a client for requesting and downloading the block transmission, and transmitting log data to the CDN operator system.

If the bottleneck occurs in a specific block while receiving each block of content from the user terminal, the client requests transmission of a subblock to another user terminal for the block in which the bottleneck occurs and downloads the block and the subblock of the content. A block is one identified by indexing information.

In addition, the user terminal and the client are divided by region, and each region receives and stores the entire contents from the CDN operator system, and has a local CDN server that transmits the contents when the client requests the contents to be transmitted. This is to ensure the quality of service (QoS) for transmission.

In addition, the local CDN server receives the log data from the client of the region, analyzes and reports the result to the CDN provider system, the CDN provider system updates the ranking information according to the report of each local CDN server.

In order to achieve the above object, the method of the present invention includes a first step of reporting an idle state to a CDN operator system when each user terminal is in a state capable of transmitting content; A second step of reporting to the CDN provider system when each client is turned on, and checking whether there is content to be transmitted and requesting transmission of the corresponding content at a set transmission request time point; A third step of transmitting, by the CDN service provider system, information of content to be transmitted by the corresponding client and ranking information about the corresponding content to the requesting client; A fourth step of the client mapping each block of the corresponding content in the order of the respective user terminals according to the ranking information, accessing the corresponding user terminal using the access information included in the ranking information, and requesting block transmission of the contents; A fifth step of transmitting, by the user terminal, each block of the requested content to the corresponding client; And the client determines whether the entire block of the corresponding content has been received, repeats the fourth and fifth steps until the entire block is received, and when reception of the entire block is completed, logs to the CDN provider system. And a sixth step of transmitting data.

The content transmission method may further include a seventh step of updating the ranking information by analyzing the log data and reflecting the learning data in the ranking information by the CDN service provider system, and the transmission request time point of the second step is the client. Either when the power is on, at a scheduled time, at regular intervals, or when the client is idle.

In the fifth step, the client sets a reference speed for downloading of each block, monitors the transmission speed of each user terminal, and if the transmission speed of a specific user terminal falls below the reference speed, the bottleneck occurs in the corresponding user terminal. In response to the determination, the request for transmission of the block being transmitted by the corresponding user terminal to the remaining user terminals in sub-block units, and the corresponding user terminals transmit the block having the bottleneck to the sub block.

The reference speed is not set uniformly because the transmission speed of each user terminal is different, and is set differently according to the ranking of each user terminal. In this case, the ranking information is a priority according to the transmission speed of each user terminal, and the ranking of the corresponding content generated by extracting the user terminal storing the content to be transmitted by the client requesting transmission from the overall ranking information. King information, and the ranking information includes access information for accessing each user terminal.

On the other hand, in order to achieve the above object, another method of the present invention comprises a first step of reporting the idle state to the CDN operator system when each user terminal is in a state capable of transmitting content; A second step of reporting to the CDN provider system when each client is turned on, and checking whether there is content to be transmitted and requesting transmission of the corresponding content at a set transmission request time point; A third step of transmitting, by the CDN service provider system, a client requesting transmission of information of content to be transmitted by the client and ranking information about the content; The client mapping each block of the corresponding content in the order of the respective user terminals of the ranking information, and accessing the corresponding user terminal or the local CDN server using the access information included in the ranking information to request block transmission of the content; 4 steps; A fifth step of transmitting, by the user terminal or the local CDN server, each block of the requested content to the corresponding client; The client determines whether the entire block of the corresponding content has been received, repeats the fourth step and the fifth step until the entire block is received, and when reception of the entire block is completed, logs to the local CDN server. A sixth step of transmitting data; And analyzing, by the local CDN server, log data, generating a result report and transmitting the result report to the CDN provider system, wherein the CDN provider system reflects the result report in ranking information to update the ranking information. It is characterized by one.

According to the present invention, by configuring the content delivery network using the user terminals distributed during idle time without using the user terminal, the cost of the content delivery of the CDN service provider can be greatly reduced, and each user is compensated for resource usage. Therefore, each user can generate additional revenue from content transmission by using their own idle user terminal without any equipment or effort.

In addition, by distributing and storing each content through a plurality of users' terminals and network resources, and transmitting the content to each client, the content can be transmitted as quickly and effectively as a conventional ISP, and the user's participation is encouraged by rewarding the user. The content delivery efficiency can be continuously improved.

In addition, by dividing and managing the content into blocks / subblocks of small size, the indexing information can be minimized to optimize the management information, and the content can be easily distributed and stored in each user terminal. In addition, it is possible to quickly transfer a large amount of content between the CDN operator system, the user terminal, and the client, and even if a bottleneck occurs during the transmission of the content, the bottleneck problem may be solved by transmitting the block / subblock unit of small size.

In addition, by distributing regional CDN servers, which are centralized P2P servers in each region, in each region, when the service quality of each user terminal is degraded, the optimal quality of service can be provided by transmitting contents to the client through the local CDN server. have.

In addition, the network resources can be used efficiently, and the contents requested by the clients can be transmitted quickly.

The technical problems achieved by the present invention and the practice of the present invention will be more clearly understood by the preferred embodiments of the present invention described below. The following examples are merely illustrated to illustrate the present invention and are not intended to limit the scope of the present invention.

First, the present invention uses a conventional peer-to-peer (P2P) model, but by using the terminal of each user as a transport server of the ISP in the time when each user does not use the terminal and network to reduce the cost of CDN operators And providing a revenue model to the user. At this time, the user terminal is installed with an agent for interworking with the CDN provider system to store the contents provided by the CDN provider system in some storage areas of the storage device of the user terminal and to transmit the content to each client requesting the content. In addition, the present invention aims at a hybrid P2P which is intermediate between a centralized type and a distributed type, and can efficiently guarantee a user's service quality. Specifically, in the present invention, control is centrally performed by the CDN operator system, and data is managed in a user terminal or a local CDN server, so that a hybrid P2P is directed.

Preferably, the Web-based Distributed Authoring and Versioning (WebDAV) protocol of HTTP method is used instead of the TCP method generally used as a content transmission method of the present invention.

WebDAV is an extension of the HTTP protocol developed to make the World Wide Web a readable and writable medium. Specifically, WebDAV is a protocol written mainly for HTTP to obtain a web page or download a file. In other words, WebDAV is an extended protocol of HTTP that enables distributed authoring on the web by supplementing the weak point of editing a web page or uploading a file. WebDAV adds a write attribute to the read attribute of HTTP, allowing you to create, change, and move remote server documents, allowing you to collaborate on documents and even use them on the web as needed. It also allows you to send, receive and modify / delete files on the web via the HTTP protocol rather than via FTP.

In the present invention, by using the WebDAV protocol as a content transmission method, it is possible to improve the readability of the metadata and to provide a smooth service even under easy access control and NAT (Network Address Translation) environment. Specifically, in case of FTP transmission, restrictions are placed in the process of converting IP between the external network and the internal network by the firewall or NAT, and in order to solve this problem, hole punching or connecting to the terminal in the router is performed. You need a mapping to do this. Hole punching means that the router exchanges packets with the other party in advance for the purpose of P2P communication in order to create a routing table and creates a routing table in each router. However, WebDAV uses port 80, which is used by most web browsers and is not blocked by firewalls. Therefore, in the present invention, it is possible to provide a service without using a firewall or NAT by using the WebDAV protocol. Meanwhile, in order to use the WebDAV protocol, a WebDAV server is applied to the CDN operator system according to the present invention and a WebDAV client is applied to the agent of the user terminal.

On the other hand, since the present invention is based on P2P, as a result, the client and the user terminal have the same configuration, and are merely conceptually divided for convenience of description. In other words, the client and the user terminal may be conceptually divided according to whether the content is downloaded or transmitted, and even while the client downloads the content, the client and the user terminal may transmit content previously stored in the corresponding client or content currently being downloaded to another client or the user terminal.

First embodiment

2 is a schematic diagram showing a content delivery system according to a first embodiment of the present invention.

As shown in FIG. 2, the content delivery system according to the first embodiment of the present invention includes one CDN operator system 100, a plurality of user terminals 110, and a plurality of clients connected to each other via a network. 120).

Referring to FIG. 2, the CDN provider system 100 is a centralized system for providing content requested by the client 120. The terminal information table, ranking information, and CDN provider system 100 of each user terminal 110 are provided. Stores a complete list of contents, a list of contents downloaded by each client 120, and the like. At this time, since the client 120 and the user terminal 110 are the same object, the client 120 and the user terminal 110 may be configured to include the content list together in the terminal information table. The entire content list of the CDN operator system 100 and the content list downloaded by each client 120 include identification information (content ID) of each content.

The terminal information table is a table for storing and managing information of each user terminal 110, and the configuration thereof is shown in Table 1, for example.

User ID Terminal type Storage Affiliation Area  Save content  Transmission time xxx-123-yyy  PC  1G     A  Miryang 21:00-23:00 xxx-122-yyy  Set top box  500M     C The sun is full (some) 12: 00 ~ 14: 00 xxx-121-ttt Set top box  2G     B  Seoul Hymn 01: 30 ~ 04: 20 ........ ..... ..... ... .... .....

As shown in Table 1, the terminal information table includes the user ID, terminal type, storage capacity of the user terminal (size of the storage area in which the content is stored), affiliation region, and identification information (ID, name) of contents stored in the content storage area of the user terminal. Etc.) and a transmission time, which is an idle time of the user terminal, may be recorded. Additionally, activation of the user terminal, user information (name or ID), and account information for settlement may be recorded. In this case, user information or account information may be managed separately in a separate table. In addition, the storage capacity may be the total size of the storage area in which the content is stored in the user terminal or a capacity contracted in advance for storing the content in the user terminal and transmitting the content to the client.

The ranking information is generated based on learning data based on the speed at which each user terminal 110 previously transmits the content to the client 120, and the priority information according to the transmission speeds of all user terminals. The ranking information includes access information for the client 120 to access each user terminal 110. The ranking information may reflect not only the bandwidth of each user terminal 0 110 but also local proximity to each client 120.

Meanwhile, the content according to the present invention is managed by dividing it into blocks of a predetermined size, and each block is managed by dividing it into sub-blocks of a smaller size, and when the client 120 downloads the content, each block or sub-block unit is used. You can download it as Each block and subblock is identified by indexing information. Preferably, the size of each block is about 8 Mb (23 power of 2), and the size of the sub block is 32 Kb (15 power of 2). Accordingly, by dividing a large amount of content into block / sub block units, the CDN operator system 100 and the agent of the user terminal 110 may manage the content more easily. Here, the size of the block and the sub-block is set to 8Mb and 32Kb, respectively, in order to optimize the management information by minimizing the indexing information for managing each index. Specifically, since each block has a size of 8Mb (23 powers of 2), it can be managed by allocating 3 bytes as indexing information. Since each subblock is 32Kb (15 powers of 2), it is 2Bytes as indexing information. Can be assigned to manage.

One file managed in this manner can be managed with indexing information (5 bytes) up to a file size up to 8Mb × 32Kb = 256Gb. In addition, by dividing one content into small block / sub block units, it is possible to distribute and store the content, and to easily and quickly perform content transmission between the CDN operator system 100, the user terminal 110, and the client 120. Can be. Specifically, compared to transmitting one content from one user terminal to a client, a large amount of content can be transmitted in a short time by dividing it from several user terminals in block units and simultaneously transmitting the same to the client. In addition, if a bottleneck occurs in a specific block in transmitting content from each user terminal 110 to the client 120, the bottleneck problem may be smoothed by transmitting the corresponding block in units of smaller sub-blocks through the remaining user terminals. It is possible to provide a transmission efficiency.

The user terminal 110 receives and stores the content from the CDN operator system 100 and transmits the corresponding content at the request of each client 120 (eg, set-top box, PC, mobile phone, PDA, etc.). As an example, an agent is provided for storing contents transmitted from the CDN operator system 100 in a storage area of the storage device. The agent of the user terminal 110 may be downloaded and installed from the CDN operator system 100.

The client 120 is a terminal (eg, a set-top box, a PC, a mobile phone, a PDA, etc.) that requests and downloads content from each user terminal 110 in block units, and an agent for content transmission request and download is installed. . The agent of the client 120 may also download and install from the CDN operator system 100. In this case, the agent of the client 120 and the user terminal 110 may be configured in the same manner.

The agent of the client 120 receives information (including identification information) of the content (eg, newly updated content) to be downloaded by the client 120 from the CDN operator system 100 and ranking information on the corresponding content. After mapping each block of the corresponding content and each user terminal 110 according to the ranking information, the user terminal 110 requests the transmission of each block of the corresponding content and downloads it.

In addition, when a bottleneck occurs in a specific block during reception of each block, the agent of the client 120 requests the user terminal 110 to transmit a subblock to the block in which the bottleneck occurs and downloads it. At this time, identification of each block and subblock is made by indexing information.

3 is a flowchart illustrating the overall operation of the content delivery system according to a first embodiment of the present invention.

Prior to the content transmission, the CDN operator system 100 according to the present invention receives information about user terminals 110 and the client 120 using the service according to the present invention through a predetermined service subscription procedure or registration procedure. Storage and management. For example, the CDN provider system 100 stores a terminal information table of each user terminal 110, ranking information, a complete list of contents of the CDN provider, a list of contents downloaded by the client 120, and the like.

The overall operation of the content delivery system according to the first embodiment of the present invention will be described with reference to FIG. 3.

First step (S1): Each user terminal 110 reports the idle state to the CDN operator system 100 when it is in a state capable of transmitting content. In detail, the agent of the user terminal 110 monitors the use state of the user terminal 110 and the network, and if there is no use for a predetermined time, determines that it is idle and reports it to the CDN operator system 100. In this case, the idle state monitoring of the user terminal 110 may be processed in conjunction with the power saving mode / screen protection mode provided by the general operating system. Meanwhile, the CDN operator system 100 may determine the idle state of the user terminal 110 through information (transmission time) registered in advance in the terminal information table.

Second step (S2): The agent of the client 120 reports this to the CDN operator system 100 when the client is powered on, and checks whether there is content to be transmitted and requests the transmission of the corresponding content at the set transmission request time. do. At this time, the content request time of the client 120, when the first client is powered on, the second client scheduled the content transmission in advance, the third periodic time interval, the fourth client's agent monitors the client's use It may be set to an idle state (eg, idle state for 30 minutes or more) without using a certain time.

In particular, referring to the case of transmitting content in a fourth idle state, in order to download the content, the client 120 typically maps each user terminal 110 according to the ranking information received from the CDN operator system 100. An operation of requesting transmission of each block of the corresponding content is performed. If the client requests and downloads content to each user terminal 110 when the client is in operation (for example, playing stored content), the client ( A load may be generated at 120 to deteriorate the performance, which may result in a deterioration in the quality of service for an operation currently being performed. Therefore, it is possible to secure a certain quality of service by preferably downloading the content when the client is idle.

In addition, in the case of downloading the content at the second scheduled time and the third periodic time interval, even if the power of the client 120 is off at that time, it is activated through a wake-up procedure to process the content transmission request. have. In other words, for example, when the power switch on the rear side of the set-top box (STB) is off, the power is completely turned off as if the power cable is removed. When the power switch is off, it is a kind of sleep mode rather than a complete off state. Therefore, in the latter case, when a timer is provided in the set-top box (STB), the agent of the client 120 automatically uses a separate scheduler to automatically set the power of the set-top box (STB) to a reservation time or a periodically set time. After turning on, the content can be downloaded. On the other hand, when the timer is not provided in the set-top box (STB), when the CDN operator system 100 is a predetermined time or periodically set time, a separate signal for waking up the set-top box (STB) After transmitting the power of the set-top box (STB) (on), the content may be downloaded.

Third Step (S3): The CDN provider system 100 transmits the information of the content to be transmitted by the client 120 and the ranking information for the corresponding content to the client 120 requesting the transmission.

In this case, the content information is updated in the CDN operator system 100 and is content that the client 120 has not yet received. The content information may be extracted by comparing the entire content list with the content list of each client 120. The transmitted content information may include identification information (ID), name, capacity, and the like of the content, and may include indexing information about the block and the sub block. In this case, the indexing information is a kind of identification for identifying a block that is requested to be transmitted or transmitted between the client 120 and the user terminal 110 when the client 120 requests each user terminal 110 to transmit a block unit of content. Information. On the other hand, since the indexing information for the block and the sub-blocks are preset and used in common between the CDN operator system 100, the client 120, and the user terminal 110, the CDN operator system 100 to separate indexing information It may not transmit. In this case, the agent of the client 120 may determine how many blocks the corresponding content is made through the total capacity of the corresponding content.

In addition, the ranking information is priority information according to the transmission speed of each user terminal 110 generated through the learning data, the CDN operator system 100 stores the corresponding content of the ranking information of the entire user terminal 110 The ranking information of the user terminal 110 is extracted and transmitted. In detail, the CDN operator system 100 generates and manages overall ranking information based on learning data for all registered user terminals 110. The CDN operator system 100 extracts the user terminal 110 that stores the content to be transmitted by the client 120 that has requested the transmission from the overall ranking information, and generates and transmits the ranking information for the corresponding content. The ranking information transmitted to the client 120 may be performed by matching the overall ranking information with the terminal information table. The ranking information includes access information for connecting the user terminal 110 to the client 120 such as an IP.

Meanwhile, the ranking information should of course include at least one source node (a component for transmitting content such as a user terminal). Specifically, when the system of the present invention is applied for the first time or newly updated contents, no user terminal 110 holds the corresponding contents, and only the CDN service provider system 100 stores the corresponding contents. The information will contain only one source node, i.e. the CDN provider system (and thus the ranking information cannot be null). In this case, the client 120 downloads the content from the CDN operator system 100. Thereafter, as the download of the content continues, the number of user terminals 110 holding the corresponding contents will increase, and the number of user terminals 110 included in the ranking information will also increase. However, since the client 120 downloads the content, the meaning is not the overall ranking information of the user terminal 110 but the top few, so that the ranking information may be hundreds or tens of thousands of the user terminals 110 having the corresponding content. Only a few of the highest ranked user terminal list is transmitted. At this time, the number of ranking information transmitted (the number of user terminals included in the ranking information) is adjusted according to the performance of the client. This is because requesting and receiving content from each user terminal 110 also generates a load when the performance of the client 120 decreases. Therefore, the number of ranking information is determined by the learning data, but preferably 10 to 15 pieces.

The ranking information may be generated and managed for each content or generated and managed for each block of each content. This is because each user terminal 110 may not have the entire block of each content but only some of them. Preferably, when the type of content is initially small, the ranking information is managed for each block, and when there are more types of content, the CDN provider system 100 generates a load, so that the ranking information for each content is generated and managed. It may be.

Fourth Step (S4): The client 120 maps each block of the corresponding content in the order of the respective user terminals 110 of the ranking information, and uses the access information included in the ranking information to the respective user terminals 110. Connect and request transmission of each block. At this time, each block is identified by indexing information.

Fifth Step (S5): Each user terminal 110 transmits each block of the requested content to the corresponding client 120. At this time, the client 120 sets the reference speed for the download of each block, and monitors the transmission speed of each user terminal 110. When the transmission speed of the specific user terminal is lower than the reference speed, the client 120 determines that the bottleneck has occurred in the corresponding user terminal 110, and the remaining user terminal 110 with respect to the block that the user terminal 110 is transmitting. Request transmission in sub-block units. On the other hand, since the transmission speed of each user terminal 110 is different, the reference speed may not be uniformly set, but may be set differently according to the ranking of each user terminal 110. On the other hand, if the overall network speed of the user terminal 110 or a failure occurs, the CDN operator system 100 may transmit the content directly to the client 120 to ensure the stability of the service quality.

On the other hand, if each user terminal 110 does not hold the entire block for each content, but only a part of the block, the block requested by the client 120 in the fourth step (S4) may not exist in the user terminal 110. have. In this case, the user terminal 110 responds that there is no block requested by the client 120, and the client 120 uses the remaining user terminal 110 of the ranking information except for the user terminal 110 to download. Proceed.

Sixth Step S6: The client 120 determines whether all blocks of the corresponding content have been received, and repeats the fourth step S4 and the fifth step S5 until all the blocks are received.

Seventh Step S7: When the reception of the entire block is completed, the client 120 transmits log data to the CDN operator system 100. The log data includes a transmission speed of each user terminal, and includes a block (indexing information) in which the bottleneck occurs and information on the corresponding user terminal, that is, an error report when the bottleneck occurs.

Eighth Step (S8): The CDN operator system 100 analyzes the log data and updates the ranking information by reflecting the learning data in the ranking information. In addition, the CDN operator system 100 statistically manages the content transmission history of each user terminal 110.

Thereafter, when the client 120 pays the content usage fee, the CDN service provider pays a part of the profits from the content transmission by paying the registered user. That is, the CDN operator system 100 calculates the resource usage of the user by using the number of contents transmission and the amount of transmission of each user terminal 120, and then pays the compensation accordingly. In this case, the reward paid to the user may be made in various forms such as cash or points.

Next, a detailed embodiment of each step will be described in detail.

4 is a detailed flowchart illustrating a process (S2, S3) of transferring content information between the client 120 and the CDN operator system 100 according to the present invention, (a) shows that the CDN operator system 100 is a client ( 120 is an example of transmitting ranking information individually for each content to be downloaded, and (b) is an example in which the CDN provider system transmits the ranking information for the entire contents of the content list to be downloaded by the client. That is, FIG. 4 is a detailed flowchart of a process in which the client 120 wakes up and requests and receives information of content to be downloaded by accessing the CDN operator system 100.

In FIG. 4, it is assumed that the content to be downloaded by the client 120 is A, B, C, ....

First, as shown in FIG. 4A, when the client 120 wakes up and accesses the CDN provider system 100 to inquire content to be downloaded, the CDN provider system 100 ) Transmits the information of the first content (content A) among the content to be downloaded by the client 120 and the ranking information for the corresponding content (S41, S42). The client 120 downloads the content A from each user terminal 110 using the content A information and the ranking information (S43).

After the download is completed, when the client 120 transmits log data to the CDN operator system 100 to report the completion of the download of the content A, the CDN provider system 100 transmits the content that the client 120 should download next (content B). Information and ranking information for the content B are transmitted (S44 and S45).

This process is repeated until the client downloads the entire content to be downloaded. As shown in FIG. 4A, the CDN provider system 100 concentrates the cost of generating ranking information for each content and controlling the download of each content.

In contrast, FIG. 4B illustrates an embodiment in which a cost for controlling generation and download of ranking information for each content is distributed to each client 120. That is, as shown in (b) of FIG. 4, when the client 120 wakes up and accesses the CDN provider system 100 to inquire content to be downloaded, the CDN provider system 100 ) Transmits the list of contents (A, B, C, ...) and overall ranking information to be downloaded by the client (S41, S46).

The client 120 extracts ranking information on the first content (content A) of the content list and downloads the content A from each user terminal 110 (S47). Thereafter, the client 120 extracts ranking information about the next content (content B) from the content list and downloads the content B from each user terminal 110 (S48). At this time, the CDN provider system 100 is a list of the user terminal 110 having each content with the content list, the overall ranking information, so that the client 120 can extract the ranking information for each content from the overall ranking information It is desirable to send it.

When the download of the entire contents of the content list is completed, the client 120 transmits log data and reports the download completion (S49). Meanwhile, the log data may be transmitted and the download completion may be reported whenever transmission of each content is completed.

5 is an example of the configuration of a data packet in block-based transmission of content according to the present invention. That is, FIG. 5 illustrates a configuration of a data packet exchanged between the client 120 and the user terminal 110 in order to transmit content in units of blocks. In the overall process of FIG. Corresponds to step 5 (S5).

Referring to FIG. 5, when the client 120 requests a block transmission to the user terminal 110 by transmitting a data packet including a content ID and indexing information, the user terminal 110 requests a block transmission. Send a block of content. In this case, the indexing information is indexing information on a block for which the client requests transmission. At this time, the data packet transmitted by the user terminal 110 in response to the client request can be configured in two ways as shown in (a) and (b) of FIG.

First, as shown in FIG. 5A, in response to a request of the client 120, the user terminal 110 stores a data packet including contents ID, indexing information, a requested block, and a checksum. send. In this case, the contents ID and the indexing information may have the same value as the information included in the data packet transmitted from the client and may be included in the header. However, in this case, since the block of content transmitted from the user terminal 110 is a block requested to be transmitted from the client 120, the client 120 does not transmit the content ID and the indexing information. The block transmitted by the terminal 110 may identify which block is what content. Therefore, as shown in FIG. 5B, the user terminal 110 may transmit only the requested block.

FIG. 6 is a detailed flowchart illustrating a processing process when a bottleneck occurs during content transmission according to the present invention. In the fifth step S5 of FIG. 3, each user terminal 110 transmits a specific block. This is a diagram showing the treatment process when a bottleneck occurs in

First, the client 120 sets a certain reference rate (for example, 2Mbps) in requesting the user terminal 110 to transmit each block of content. In this case, since the transmission speed of each user terminal 110 is different, the reference speed may not be uniformly set, but may be set differently according to the ranking of each user terminal 110. Subsequently, the client 120 checks the transmission speed of each block while receiving each block of content from each user terminal 110 and determines that the bottleneck occurs when it is lower than the set reference speed (S5-1).

Subsequently, the client 120 requests the remaining user terminal 110 to transmit the corresponding block in sub-block units except for the corresponding user terminal 110 for the block in which the bottleneck occurs (S5-2). At this time, the sub block is also identified using the indexing information. Specifically, the client 120 maps the sub-blocks of the block in which the bottleneck occurs to the respective user terminals according to the ranking information for the remaining user terminals except for the user terminal in which the bottleneck occurs. Request the transfer. Meanwhile, in requesting transmission of a subblock to each user terminal 110, preferably, the transmission is requested for the remaining subblocks except for the portion already received from the user terminal having the bottleneck.

Accordingly, each user terminal 110 stops the transmission of the block being transmitted, and transmits each sub block of the block in which the bottleneck occurs (S5-3). In this way, steps S5-2 and S5-3 of requesting and transmitting transmissions in subblock units are repeated until all subblocks of the corresponding block are transmitted (S5-4).

When the transmission of all sub blocks of the block is completed, the client 120 requests the transmission of the block being transmitted to each user terminal 110 (S5-5), and each user terminal 110 transmits the block being transmitted. (S5-6).

Meanwhile, except for the bottleneck in which the bottleneck occurs in mapping the user terminal 110 to the remaining blocks, the remaining user terminal 110 may request transmission.

7 is a schematic diagram illustrating a process in which a client maps each block according to the ranking information according to the present invention, in which the client requests and receives the transmission of each block from the user terminal.

Referring to FIG. 7, the ranking information is made up of SN1, SN15, SN6, SN24, SN31, SN10, SN22, SN2, SN34, and SN41 from 1 to 10, and the content is composed of blocks B1 to Bn.

When the ranking information includes 10 user nodes (SNs) from 1 to 10, the agent of the client 120 may block 1 of the content, and B1 of the content may be assigned to the 1st user terminal SN1. The transfer request is made, and the second block B2 requests the transfer to the user terminal SN15 having the second rank. In this way, blocks 1 to 10 are mapped to the rankings 1 to 10 user terminals 110 to request transmission. At this time, since the ranking information is a fast transmission speed according to the learning data, in the general case, B1 transmitted by SN1 will be completed first, followed by B2, B3, ..., B10. will be. The agent of the client 120 sequentially requests transmission of the next blocks B11, B12, ... from the corresponding user terminal 110 as soon as the transmission of each block is completed.

Meanwhile, a bottleneck may occur due to a sudden network problem or a problem of a specific user terminal (over-connecting or degrading performance) during the transmission of the method as shown in FIG. 7. To this end, after setting the reference speed, the client 120 monitors the transmission speed of each user terminal 110 and determines that the bottleneck occurs in the corresponding user terminal when it falls below the reference speed. That is, in the case where 10 user terminals 110 transmit blocks 1 to 10 as shown in FIG. 7, it is assumed that a bottleneck occurs in the user terminal SN31 transmitting block 5 as shown in FIG. 8. The explanation is as follows. Block 5 in Figure 8 is composed of subblocks of SB1 ~ SBm.

Referring to FIG. 8, when a bottleneck occurs in the user terminal 110 transmitting a specific block, the agent of the client 120 may subblock the remaining user terminal 110 with respect to the block that the user terminal 110 is transmitting. Request transmission in units.

Specifically, when a bottleneck occurs in 'SN31' in FIG. 8, nine sub-blocks of block 5 (B5) are requested to be transmitted to nine user terminals 110 except for 'SN31'. In this case, although FIG. 8 illustrates that the user terminal requests from the first subblock SB1, the transmission is requested to the remaining subblocks except for the subblock in which the transmission is completed.

Each user terminal 110 stops the transmission of the block being transmitted, and then transmits the requested subblock. This is because it is preferable that each block is sequentially received for the corresponding content, so that the transmission of the block having the bottleneck is first processed.

Meanwhile, in this case, the blocks B1 to B4 before the block bottleneck are transmitted by the respective user terminals SN1, SN15, SN6, and SN24, and the remaining user terminals SN10, SN22, SN2, SN34, After requesting transmission of the subblock to SN41, SN1, SN15, SN6, and SN24 may perform subblock transmission of block 5 after completing the transmission of the block being transmitted. Thereafter, when the entire subblock transmission of the fifth block is completed, each user terminal 110 transmits each block that is being transmitted.

Thereafter, the bottleneck user terminal SN31 may be excluded from transmission of each block thereafter, and the bottleneck occurrence and processing thereof are included in the log data of the client 120 and transmitted to the CDN operator system 100.

Second embodiment

9 is an overall configuration diagram of a content delivery system according to a second embodiment of the present invention.

As shown in FIG. 9, the content delivery system according to the second embodiment of the present invention divides a user terminal and a client in units of a predetermined region, and includes a local CDN server in each region. At this time, it is preferable to set the standard of each region in POP unit (a kind of telephone station unit in public telephone network). As described above, according to the second embodiment of the present invention, the system of the first embodiment is configured in each region, and the central CDN operator system connects and controls each region.

Referring to FIG. 9, the content delivery system of the second embodiment is divided into three local systems L1 to L3, and each local system L1 to L3 is connected to a central CDN provider system 100. In addition, each of the local systems L1 to L3 has a plurality of user terminals 210 and clients 220 connected to at least one local CDN server 204.

The configuration and operation of the CDN operator system 200, the user terminal 210 and the client 220 of the second embodiment are described in detail in the configuration and operation of the CDN operator system 100, the user terminal 110 and the client 120 of the first embodiment. Same operation.

In the second embodiment, the local CDN server 204 does not control the user terminal 210 or the client 220 like the CDN operator system 200, but instead transmits the content to the client 220 like the user terminal 210. Perform the function of sending. That is, in the second embodiment, the local CDN server 204 having excellent performance is provided in each region to ensure QoS for content delivery. Therefore, the ranking information of the CDN operator system 200 includes each local CDN server 204 together with each user terminal 210. At this time, the local CDN server 204 to store all the content provided by the CDN operator system 200.

On the other hand, when the user terminal 210 and the client 220 of each region concentrates on the central CDN operator system 200, the CDN operator system 200 of the first embodiment may be overloaded because the CDN operator system 200 may be overloaded. Analyzing log data of the client during the operation of may be performed by each local CDN server 204 in the second embodiment. That is, the local CDN server 204 receives and analyzes log data from each client 220, reports the result to the CDN provider system 200, and the CDN provider system 200 reflects the ranking information in the ranking information. The load on the CDN operator system 200 may be reduced.

10 is a flowchart illustrating an operation procedure of a content delivery system according to a second embodiment of the present invention.

Referring to FIG. 10, when the user terminal 210 is in a state capable of transmitting content in the eleventh step S11, the user terminal 210 reports an idle state to the CDN provider system 200, and the client (in step S12). 220 also reports to the CDN operator system 200 when it wakes up and requests whether there is content to be transmitted.

In a thirteenth step S13, the CDN provider system 200 transmits information of content to be transmitted by the client 220 and ranking information about the content. In this case, the ranking information includes not only the user terminal 210 but also the local CDN server 204, and the user terminal 220 and the local CDN server 204 of other regions as well as the region to which the client 220 belongs. Can be. The ranking information is generated by the learning data, and since the transmission speed will be high when the region is near, the ranking information may include the client 220 and the adjacent user terminal 210 and the local CDN server 204 in the same region. This is big.

In operation 14 (S14), the client 220 requests transmission of each block of the corresponding content to each user terminal 210 or the local CDN server 204 according to the ranking information, and in operation 15, each user The terminal 210 or the local CDN server 220 transmits each block of the requested content.

In the sixteenth step S16, the client 220 determines whether all blocks of the corresponding content are received, and repeats the fourteenth step S14 and the fifteenth step S15 until all the blocks are received.

In the seventeenth step S17, when the reception of the entire block is completed, the client 220 transmits log data to the corresponding local CDN server 204. In this case, the log data includes a transmission speed of each user terminal, and includes an error report including information on a block (indexing information) where the bottleneck occurs and information on the corresponding user terminal (or a local CDN server) when the bottleneck occurs.

The local CDN server 204 analyzes log data to generate a result report (self ranking information) in the eighteenth step S18 to the twentieth step S20, and transmits the result report (self ranking information) to the CDN operator system 200. The CDN operator system 200 updates the ranking information by reflecting the result report in the ranking information. Therefore, in the second embodiment, the cost of log collection can be distributed from the center to the region. In addition, the CDN operator system 200 statistically manages the content transmission history of each user terminal 210, and when the client 220 pays the content usage fee, the CDN provider system 200 pays a part of the profits from the content delivery.

On the other hand, the basic configuration of the content delivery system according to the second embodiment of the present invention shown in Figures 9 and 10, specifically, the content information transfer process between the client and the CDN operator system of Figure 4, the configuration of the data packet of Figure 5, The bottleneck treatment process of FIG. 6 and the block / subblock mapping process of FIGS. 7 and 8 are commonly applied to the first embodiment.

The present invention has been described above with reference to one embodiment shown in the drawings, but those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

1 is a schematic diagram illustrating a conventional content delivery network (CDN);

2 is a schematic diagram showing a content delivery network configuration according to a first embodiment of the present invention;

3 is an overall flowchart illustrating a content delivery procedure according to a first embodiment of the present invention;

4 is a detailed flowchart illustrating a process of delivering content information between a client and a CDN operator system according to the present invention;

5 is a configuration example of a data packet in block-based transmission of content according to the present invention;

6 is a detailed flowchart illustrating a processing process when a bottleneck occurs in content transmission according to the present invention;

7 is a schematic diagram illustrating a process in which a client maps each block according to ranking information according to the present invention;

8 is a schematic diagram illustrating a process in which a client maps each subblock according to ranking information when a bottleneck occurs in a specific block in the mapping example shown in FIG. 7;

9 is a schematic diagram showing a configuration of a content delivery network according to a second embodiment of the present invention;

10 is a flowchart illustrating a content delivery procedure according to a second embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

100,200: CDN operator system 204: local CDN server

110,210: user terminal 120,220: client

Claims (18)

Contents using a user terminal for distributing and storing a plurality of contents divided into blocks of a predetermined size in a plurality of user terminals, and transmitting the requested contents in units of blocks when the client requests the transmission of the contents. As a transmission system, The terminal information table for storing the information of each user terminal including the ID of the content stored in each user terminal, ranking information that is generated through the learning data and priority information according to the transmission speed of the entire user terminal, to each client A CDN provider system for storing a list of all contents that can be provided and a list of contents downloaded by each client, and updating the ranking information by learning data; A plurality of the user terminals receiving and storing the respective contents from the CDN operator system and transmitting the contents requested by each client in block units; And Receive content information including the ID of the content to be downloaded from the CDN operator system and ranking information for the content to be downloaded, and each block constituting the content to be downloaded according to the received ranking information and the ranking And mapping each user terminal included in the information, and then requesting and downloading a transmission of each block of the content to each mapped user terminal. The method of claim 1, The client transmits log data including the transmission rate of each of the user terminals that transmitted the block of the content and an error report about the block in which the bottle occurred, to the CDN provider system; And the CDN provider system updates the ranking information by reflecting the log data. The method of claim 1, The CDN operator system, The user terminal characterized in that the mapping of the ranking information for all the user terminal and the terminal information table, the ranking information of a predetermined number of user terminals storing the content to be downloaded by the client is extracted and transmitted to the client Content Delivery System The method of claim 1, The client, And for each user terminal included in the received ranking information, map each block constituting content to be downloaded according to the ranking of the ranking information in order. The method of claim 1, And the ranking information includes access information for the client to access each of the user terminals. The method of claim 1, Wherein each block is divided and managed into sub-blocks having a predetermined size, and each block and each sub-block are indexed and managed according to indexing information, respectively. The method of claim 6, The size of each block is 8Mb, the size of each sub-block is 32Kb, 3 bytes are allocated as the indexing information of each block, and 2 bytes are allocated as the indexing information of each sub-block. The method of claim 6, The client, When a bottleneck occurs in a specific block while receiving each block of the content from each user terminal, the user terminal transmitting the block in which the bottleneck occurs among the user terminals included in the ranking information with respect to the block in which the bottleneck occurs. Content mapping using the user terminal, after mapping each sub-block not downloaded among the block having the bottleneck for the remaining user terminal except for the request to download and request the transmission of each sub block to the mapped user terminal system. The method of claim 1, In each of the user terminal, an agent for receiving the respective content from the CDN operator system is stored in the storage area of the user terminal and transmitting a block of the content requested by the client, WebDAV client is applied to the agent of each user terminal, WebDAV server is applied to the CDN provider system, characterized in that the content delivery system using a user terminal. The method of claim 1, Each of the user terminal and each client is divided by region, The local content delivery system, the local CDN server for receiving and storing the entire content from the CDN operator system, and receives the transmission of the content from the client to transmit each block of the content with each user terminal for each region Content delivery system using a user terminal comprising a. The method of claim 10, Each regional CDN server receives log data including an error report of the transmission speed and the bottleneck of each user terminal and each local CDN server that transmitted the block of content from a client of the region to which the local CDN server belongs. Analyze the log data, generate a result report including its own ranking information, and transmit the result report to the CDN operator system; And the CDN service provider system updates the ranking information by reflecting the result report. CDN provider system for providing a plurality of content is divided into blocks of a predetermined size; A plurality of user terminals receiving and storing each content from the CDN operator system and transmitting the stored content at the request of a client; And a client for requesting and downloading the contents to the respective user terminals and downloading the contents, wherein the contents are distributed and stored in the plurality of user terminals, and the contents requested by the client are transmitted through the respective user terminals. A content transmission method using a user terminal to transmit in block units, A first step of the CDN operator system indicating priority information according to transmission speeds of all user terminals and generating ranking information through learning data including access information for accessing each user terminal; A second step of reporting an idle state to the CDN provider system when the user terminal is able to transmit the stored content; A third step of reporting to the CDN operator system when each client is turned on, checking whether there is content to be downloaded, and requesting transmission of the corresponding content at a preset transmission request time when there is content to be downloaded; A fourth step of transmitting, by the CDN operator system, information of content to be downloaded by the client and ranking information about the content to be downloaded to the client; The client maps each block constituting the content to be downloaded according to the order of the ranking information to each user terminal included in the received ranking information in order, and uses the access information included in the ranking information. A fifth step of requesting transmission of the mapped block by accessing each user terminal; A sixth step in which each user terminal transmits each block of content requested to be transmitted to the client; And And a seventh step of repeating the fifth step and the sixth step until the entire block constituting the content to be downloaded by the client is downloaded. The method of claim 12, When the client completes the download of all the blocks constituting the content to be downloaded, the log data including the transmission rate of the respective user terminal that transmitted each block of the content and an error report for the block in which the bottleneck occurred An eighth step of transmitting to the CDN operator system; And And the ninth step of the CDN operator system updating the ranking information by reflecting the log data. The method of claim 12, The transmission request time of the third step, When the client is powered on, the user terminal is any one selected from the time in which the client scheduled the transmission of the content in advance, periodically set a predetermined time and when the client is idle for a certain time Content transmission method using. The method of claim 12, Each block constituting the content is indexed and managed by indexing information, In the fifth step, the client transmits a data packet including the ID of the content and the indexing information of the mapped block to each user terminal to request transmission of each block, In the fifth step, each of the user terminal, the content ID transmitted from the client and the indexing information of the block, and the content transmission method using a user terminal, characterized in that for transmitting a data packet including the requested block. The method of claim 12, And a tenth step of setting, by the client, a reference speed for downloading of each block of content to be downloaded. The sixth step, Step 6-1 of the client monitoring a transmission rate of each user terminal transmitting each block of the content; Step 6-2 of the client determining that the bottleneck occurs in the user terminal when the transmission speed of the specific user terminal among the user terminals is lower than the reference speed; The client maps each sub-block not downloaded among the blocks transmitted by the bottleneck user terminal to the remaining user terminals except for the bottleneck user terminal among the user terminals included in the ranking information. 6-3, requesting each user terminal to transmit the respective subblocks; And And a sixth to fourth step of transmitting each sub-block requested for transmission by the remaining user terminals except for the user terminal in which the bottleneck has occurred. The method of claim 12, The fourth step, The CDN operator system maps the ID of the content stored by each user terminal to the terminal information table and the ranking information of all the user terminals, and stores the content to be downloaded by the client to a predetermined number of user terminals. And a step 4-1 of generating ranking information for the user terminal. CDN provider system for providing a plurality of content is divided into blocks of a predetermined size; A plurality of user terminals receiving and storing each content from the CDN operator system and transmitting the stored content at the request of a client; A client requesting and downloading the contents to the respective user terminals; And a local CDN server that receives and stores the entire contents from the CDN operator system, and transmits the contents stored together with the respective user terminals at the request of the client. In a content delivery system in which local CDN servers are divided and arranged in predetermined area units, each content is distributed and stored in the plurality of user terminals and local CDN servers, and then the content requested by the client is transmitted to each of the user terminals and the local CDN. A content transmission method using a user terminal for transmitting in block units through a server, The CDN provider system generates priority information based on the transmission speeds of the entire user terminals and the entire local CDN servers and includes ranking information including access information for accessing the respective user terminals and the local CDN servers through the training data. A first step of making; A second step of reporting an idle state to the CDN provider system when the user terminal is able to transmit the stored content; A third step of reporting to the CDN operator system when each client is turned on, checking whether there is content to be downloaded, and requesting transmission of the corresponding content at a preset transmission request time when there is content to be downloaded; A fourth step of transmitting, by the CDN operator system, information of content to be downloaded by the client and ranking information about the content to be downloaded to the client; The client maps each block constituting content to be downloaded according to the order of the ranking information to each user terminal and each local CDN server included in the received ranking information in order, and includes the ranking information. A fifth step of requesting transmission of the mapped block by accessing each user terminal and each local CDN server using the accessed access information; A sixth step of transmitting each block of content requested to be transmitted by the user terminal and each local CDN server to the client; A seventh step of repeating the fifth and sixth steps until the entire block constituting the content to be downloaded by the client is downloaded; When the client completes the download of all blocks constituting the content to be downloaded, the client reports an error report about the transmission speed and bottlenecks of the respective user terminals and the local CDN servers that transmitted each block of the content. An eighth step of transmitting log data, including the log data, to a local CDN server of a region to which the client belongs; A ninth step of the local CDN server analyzing the log data to generate a result report including its ranking information and transmitting the result report to the CDN operator system; And And a tenth step in which the CDN provider system updates the ranking information by reflecting the result report.

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