KR20130135736A - Method, system and computer-readable recording medium for transmitting contents by using unique indentifier of contents - Google Patents

Abstract

According to one aspect of the present invention, the present invention provides a method for transmitting content using a unique content identifier. The present invention includes a step where a delivery node receives a request for content from a client; a step where the delivery node sends the URL data of the content included in the request to a master node; a step where the delivery node receives data about a unique identifier corresponding the URL data of the content from the master node and determines whether the content is stored in the delivery node by referring to the data about the received identifier; and a step where if it is determined that the content is stored in the delivery node, the delivery node sends the content to the client or if it is determined that the content is not stored in the delivery node, the delivery node receives the content to send the content to the client. [Reference numerals] (10) Communication network;(250) Master node;(300) Transmission node

Description

METHOOD, SYSTEM AND COMPUTER-READABLE RECORDING MEDIUM FOR TRANSMITTING CONTENTS BY USING UNIQUE INDENTIFIER OF CONTENTS}

The present invention relates to a method, a system and a computer-readable recording medium for transmitting content using a content unique identifier. More particularly, the present invention relates to a network by storing and transmitting content based on a unique identifier uniquely generated for each content. A method, system and computer readable recording medium are provided that enable reducing traffic and improving the quality of content providing services.

The Uniform Resource Locator (URL) is an indicator indicating the location of content distributed on the World Wide Web. The user can access the corresponding content on the web by entering a specific URL into his web browser. In this case, the web server provides content corresponding to a specific URL. Since the URL is an indicator indicating the location of the content and is not an identifier for identifying the content itself, several different contents may correspond to one URL, and different contents may correspond to each other. One same content may correspond to several URLs.

First, as the former case, a web page including the top news of the current time is provided through the URL "http://news.yahoo.com/", in which case "http: // news. Even if the same URL of yahoo.com/ "is used, the contents of the news provided may vary depending on the time of access, so that different content may correspond to one URL. Next, in the latter case, the URL "http://www1.youtube.com/fileid=1234", the URL "http://www2.youtube.com/fileid=1234" and "http: // cache1. For example, the same video with identifier "1234" is provided through three different URLs of youtube.com/fileid=1234. In this case, one content corresponds to several different URLs. .

In general, a content delivery system operating on the web may include a client requesting content to a server and a server providing content in response to a request from the client. In this case, when a plurality of clients request content at the same time, the server may be overloaded, and the content providing quality may be lowered, and a bottleneck may occur in the communication network from the server to the client, thereby causing a problem in that the content providing speed is reduced. .

In the prior art to solve this problem, a predetermined delivery server is placed in a position close to the client on the transmission path between the server and the client, and the delivery server stores the frequently requested popular content from the client to the server. When a request from the server occurs, the transfer server transfers the contents stored by the server on behalf of the server. Here, as a method of storing content in the delivery server, a method of storing content selected in advance by an administrator or a corresponding system, and a method of receiving and storing the content from the server when the content is requested by the client (aka caching) (Caching) method. In general, since the content that has been requested from the client is highly likely to be requested again, the method of storing the content requested by the client has a greater traffic reduction effect and is widely used than the method of storing the content arbitrarily designated by the administrator.

Hereinafter, the prior art of identifying content using a URL and storing and transmitting the content using a caching method will be described in more detail.

According to the related art, a transmission server located on a transmission path of a client and a server may receive a request for content from a client. Next, the delivery server compares the URL information of the content included in the request received from the client with the URL information of the content that is being stored, and determines whether the content has the content (ie, storing). Can be. Next, if it is determined that the content requested from the client is stored in the delivery server, the delivery server may transmit the content stored by the client as a response to the request from the client, and the content requested from the client is transmitted to the delivery server. If it is determined that it is not stored therein, the delivery server may send a request from the client to the server and transmit the content from the server as a response to the request to the client and store it in its storage space. Here, the storage space of the transmission server may be managed by a Least Recently Used (LRU) algorithm, a First Input First Output (FIFO) algorithm, or the like.

However, in the prior art as described above, the following problems may occur because the URL is used to specify the content existing on the communication network.

First, a problem may occur that storage space of the transmission server is wasted. In other words, if the URL corresponding to the content is different, the transmission server using the URL as an identifier for the content must store the content duplicated for each URL even though the URL includes the same content. Therefore, the storage space of the transmission server is insufficient. Problems may occur. In particular, in the case of content provided by a file sharing service such as video, audio, application, software update file, and web hard, it is common to have a plurality of different URLs corresponding to one content.

Next, a problem may occur in which reusability of content is degraded. In detail, when a user accesses different contents through the same URL, the transmitting node should delete previously stored contents and store newly received contents, which means deterioration of content reusability. For example, if different content A and content B are specified by the same URL, if the content request comes from the user in the order of Content A-Content B-Content A-Content B, it is inefficient to receive new content every time. Will occur. In addition, when a plurality of different contents correspond to one URL (for example, even when the same URL responds to different contents depending on the type of browser or the header value of a request from a client), the URL may be changed. It is difficult for the delivery server used as the identifier to correctly identify the content. Although attempts have been made to solve this problem by identifying, storing, and transmitting a number of different pieces of content by using both the value of the pre-specified header and the URL as identifiers, in order to identify the content, specific URLs and There is a limitation in that it is not easy to operate in that the value of the header must be obtained, and the content may not be identified only by the URL and the value of the header.

Next, a problem may occur that the requested content may not be transmitted correctly. In other words, it is assumed that the transmission server located on the transmission path between the client and the server transmits the content stored in the client to the client using only the URL as an identifier for the content without receiving confirmation from the server in order to improve transmission efficiency. In this case, the wrong content may be transmitted to the client only if the URL matches only the content actually requested by the client.

Next, a problem may occur when transmitting contents in a wireless communication network. Specifically, unlike a wired communication network in which a client terminal is fixedly located at a specific point on a communication network, in a wireless communication network, as the client terminal moves in a physical space, the position of the client terminal on the communication network changes and accordingly, the communication network to which the client terminal belongs. This hand-over may occur. When the handover occurs in the client, the client that was receiving content from the first delivery server connected with the client before the handover needs to receive content from the second delivery server connected with the client after the handover. In this case, if the URL is used as the identifier of the content, it cannot be guaranteed that the content transmitted from the first delivery server and the content to be transmitted from the second delivery server are the same. Accordingly, the second delivery server receives the content that has been transmitted from the first delivery server to the client while taking the decrease in the transmission efficiency, and transmits the content to the client again, or accepts the content that the client has while taking a mistransmission. Problems that can only be sent to the user may occur.

The problems of the prior art mentioned above are due to the fact that the URL used as a means of identifying the content is merely an address on the network where the content can be obtained, and is not an identifier capable of uniquely identifying the content itself. Can be.

Accordingly, there is a need for a technique for accurately and efficiently transmitting content in a wireless communication network in which handover may occur.

It is an object of the present invention to solve all the problems described above.

In addition, another object of the present invention is to identify content using a unique identifier rather than a URL in transmitting and storing the content, thereby accurately identifying the content existing on the web.

In order to accomplish the above object, a representative structure of the present invention is as follows.

According to an aspect of the present invention, there is provided a method for delivering content using a content unique identifier, wherein (a) a delivery node receives a request for content from a client, and (b) Transmitting information on the URL of the content included in the request to a master node; (c) the transmitting node sends information on a unique identifier corresponding to the information on the URL of the content. Determining whether the content is stored in the transmitting node with reference to the information on the received unique identifier, and (d) determining that the content is stored in the transmitting node. When the transmitting node transmits the content stored in the transmitting node to the client, the content is transmitted to the client. If it is determined that not stored in the node, the method in which the transmitting node transmits the contents received from the master node comprises transmitting to the client is provided.

According to another aspect of the present invention, there is provided a method for delivering content using a content unique identifier, the method comprising: (a) information regarding a URL of content requested by a client from a delivery node to a master node; (B) the master node determines a unique identifier corresponding to the information about the URL of the content with reference to the mapping information between the URL and the unique identifier, and sends the determined unique identifier to the transmitting node. Transmitting, and (c) the master node transmitting the content to the transmitting node if it is determined that the content is not stored in the transmitting node.

According to another aspect of the present invention, there is provided a method for delivering content using a content unique identifier, wherein (a) a delivery node receives a request for content from a client, and (b) the delivery node. A) transmitting information on the URL of the content included in the request to a master node, (c) the master node receiving information on the URL of the content from the transmitting node; (D) determining, by the master node, a unique identifier corresponding to the information about the URL of the content with reference to the mapping information between the URL and the unique identifier, and transmitting the determined unique identifier to the transmitting node. Step (e) wherein the transmitting node refers to the information about the determined unique identifier transmitted from the master node, and the content is transmitted to the transmitting node. And (f) if it is determined that the content is stored in the transmitting node, the transmitting node transmits the content stored in the transmitting node to the client, and the content is stored in the transmitting node. If it is determined that it is not stored in the transmitting node, the master node transmits the content to the transmitting node, and the transmitting node transmits the content received from the master node to the client.

According to another aspect of the invention, a method for transmitting content using a content unique identifier, the method comprising: (a) a node receiving a request for content from a client, (b) the node: Determining a unique identifier corresponding to the information about the URL of the content included in the request, with reference to the mapping information between the URL and the unique identifier, (c) the node comprising: information about the URL of the content; Determining whether the content is stored in the node with reference to information on a corresponding unique identifier; and (d) if the content is determined to be stored in the node, the node is stored in the node. Transmits the content to the client and determines that the content is not stored in the node, the node transmits the content to the server. The method comprising transmitting to the client is provided with a receiving transfer site of the content.

According to still another aspect of the present invention, there is provided a system for transmitting content using a content unique identifier, comprising: a content request processor for receiving a request for content from a client; and information about a URL of the content included in the request. Transmits to a master node, receives information about a unique identifier corresponding to information on the URL of the content from the master node, and transmits the content with reference to the information on the received unique identifier. Is determined that the content is stored in the transmitting node, the content is stored in the transmitting node to the client, and the content is not stored in the transmitting node. If determined, the controller from the master node The system including a content-specific identifier management unit for sending to the client is provided with a receiving transfer Massachusetts.

According to another aspect of the invention, a system for delivering content using a content unique identifier, comprising: receiving information about a URL of content requested by a client from a delivery node, between the URL and the unique identifier; A content unique identifier manager for determining a unique identifier corresponding to the information about the URL of the content and transmitting the determined unique identifier to the transmitting node with reference to the mapping information of the content, and the content is not stored in the transmitting node If not determined, a system including a content request processing unit for transmitting the content to the transmitting node is provided.

According to still another aspect of the present invention, there is provided a system for transmitting content using a content unique identifier, the system comprising: receiving a request for content from a client, and receiving information about a URL of the content included in the request; and determining whether the content is stored in the transmitting node with reference to the information on the determined unique identifier transmitted from the master node, and if it is determined that the content is stored in the transmitting node. From the transmission node and the transmission node for transmitting the content stored in the transmission node to the client, and if it is determined that the content is not stored in the transmission node to transmit the content received from the master node to the client To the URL of the content Receiving a piece of information, referring to mapping information between the URL and the unique identifier, determining a unique identifier corresponding to the information about the URL of the content, and transmitting the determined unique identifier to the transmitting node; If it is determined that it is not stored in the transmitting node is provided a system including a master node for transmitting the content to the transmitting node.

According to another aspect of the present invention, a system for transmitting content using a content unique identifier, the content request processing unit for receiving a request for content from a client, and mapping information between the URL and the unique identifier, Determine whether the content is stored in the node by determining a unique identifier corresponding to the information about the URL of the content included in the request, and referring to the information about the unique identifier corresponding to the information about the URL of the content; Determine that the content is stored in the node, and transmit the content stored in the node to the client, and if the content is not stored in the node, receive the content from the server. Content-specific expression to send to the client A system is provided comprising a star management unit.

In addition, there is provided another method, system, and computer readable recording medium for recording a computer program for carrying out the method for implementing the present invention.

According to the present invention, by using the unique identifier to accurately identify the content existing on the web, it is possible to save the storage space of the server that stores the content, increase the reusability of the content and handover in a wireless communication network Even if it occurs, the effect of being able to transmit the content accurately is achieved.

In addition, according to the present invention, since the contents of the data constituting the content are managed to have different unique identifiers, the effect of being able to accurately identify each content even when various contents are downloaded through one URL is achieved. do.

In addition, according to the present invention, since the content can be accurately identified using the unique identifier, when the existing URL is used as the identifier (for example, a specific URL for a certain time (Time To Live, TTL) for the specific content) By setting it to be used as an identifier, it is possible to drastically reduce the mistransmission of content, as compared to the case where the URL can be used as an identifier for the content, and re-validation that was involved when using an existing URL as an identifier. To ensure the correct delivery of content without having to perform a process (e.g., authenticating whether a particular URL is still valid as an identifier for a particular content after a certain amount of time). Effect is achieved.

In addition, according to the present invention, even when a handover occurs in the client of the wireless communication network, the effect that the content transmission can be performed normally is achieved.

1 is a diagram schematically showing the overall configuration of a system for transmitting content using a content unique identifier according to the present invention.
2 is a diagram illustrating an internal configuration of a master node 200 according to an embodiment of the present invention.
3 is a diagram illustrating an internal configuration of a transmission node 300 according to an embodiment of the present invention.
4 to 7 are diagrams illustrating a process of transmitting content according to an embodiment of the present invention.
8 is a diagram exemplarily illustrating a process of supporting handover in transmitting content using a content unique identifier according to an embodiment of the present invention.
9 is a diagram exemplarily illustrating a mapping table between a URL and a unique identifier or a mapping table between a URL and a request header and a unique identifier according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

Configuration of the entire system

1 is a diagram schematically showing the overall configuration of a system for transmitting content using a content unique identifier according to the present invention.

As shown in FIG. 1, the entire system of the present invention includes a communication network 10, a server 100, a master node 200, a delivery node 300, and a client 400. It can be configured to include.

First, the communication network 10 can be configured without regard to its communication mode such as wired and wireless, and can be connected to the Internet (World Wide Web), publicly known WLAN (Wireless LAN), CDMA (Code Division Multiple Access), WCDMA Division Multiple Access) or GSM (Global System for Mobile communications) communication network.

Next, according to an embodiment of the present invention, the server 100 may communicate with the client 400 through the communication network 10 in which the master node 200, the transmitting node 300, and the like exist, and the client 400. At the request of), a function of providing various types of information can be performed. For example, the server 100 may be an operation server of an Internet search portal site, and the information provided to the client 400 may be various information about a web page, an image, a video, an audio, and the like that match a query. .

Next, according to an embodiment of the present invention, the master node 200 may receive a content from the server 100 and store it in its own storage device or transmit the content to the transmitting node 300 to be described later. have. In addition, the master node 200 according to an embodiment of the present invention may generate a unique identifier for the content and perform a mapping between the URL and the unique identifier of the corresponding content. Here, according to an embodiment of the present invention, in the mapping with the content unique identifier, the request header of the content together with the information about the URL of the content, that is, the header included in the content request from the client 400. More information may be used. That is, when multiple contents correspond to one URL, the master node 200 may perform mapping between the information about the URL and the request header of the contents and the information about the unique identifier. In addition, the master node 200 according to an embodiment of the present invention from the transmitting node 300 to be described later with reference to the mapping information between the URL (or URL and request header) and the unique identifier of the content that it manages A unique identifier corresponding to the received URL (or URL and request header) may be determined and transmitted to the corresponding transmission node 300. In addition, the master node 200 according to an embodiment of the present invention may perform a function of transmitting a content corresponding to a specific unique identifier to the corresponding transmission node 300 in response to a request of the transmitting node 300. In addition, the master node 200 according to an embodiment of the present invention is a transmission node 300B connected to the client 400 after the handover or when a handover occurs in the client 400 or The transmitting node 300A, which is connected with the client 400 before the handover, may transmit the content corresponding to the specific unique identifier to the client 400, and for this purpose, a function of transmitting predetermined indication information to the corresponding transmitting node. Can be performed.

2 is a diagram illustrating an internal configuration of a master node 200 according to an embodiment of the present invention.

As shown in FIG. 2, the master node 200 according to an embodiment of the present invention may include a content unique identifier manager 210, a content request processor 220, a handover processor 230, and a transceiver 240. It can be configured to include. According to an embodiment of the present invention, the content unique identifier management unit 210, the content request processing unit 220, the handover processing unit 230 and the transmission and reception unit 240 are at least some of the program modules to communicate with the external system Can be. Such program modules may be included in the master node 200 in the form of operating systems, application modules, and other program modules, and may be physically stored on various known storage devices. In addition, at least some of these program modules may be stored in a remote storage device that can communicate with the master node 200. These program modules include, but are not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types as described below in accordance with the present invention.

Next, the transmitting node 300 according to an embodiment of the present invention is the master node 200 to the URL (or URL and request header) of the content included in the request for the content received from the client 400 to be described later Request a unique identifier corresponding to the corresponding URL (or URL and request header), and receive a unique identifier corresponding to the URL (or URL and request header) of the corresponding content from the master node 200. Can be. In addition, the transmitting node 300 according to an embodiment of the present invention has a function of determining whether it is storing the content requested from the client 400 with reference to the unique identifier received from the master node 200. Can be done. In addition, when the transmission node 300 according to an embodiment of the present invention determines that the user is storing the corresponding content, the transmission node 300 transmits the corresponding content to the client 400, and the user stores the corresponding content. If it is determined that they are not doing so, the corresponding content may be received from the master node 200 and stored in its own storage device and then transmitted to the client 400. In addition, according to an embodiment of the present invention, the transport node 300B connected to the client 400 after the handover or the transport node 300A connected to the client 400 before the handover is assigned to a specific unique identifier. The corresponding content may be transmitted to the client 400.

3 is a diagram illustrating an internal configuration of a transmission node 300 according to an embodiment of the present invention.

As shown in FIG. 3, the transmitting node 300 according to an embodiment of the present invention may include a content unique identifier manager 310, a content request processor 320, a handover processor 330, and a transceiver 340. It can be configured to include. According to an embodiment of the present invention, the content unique identifier management unit 310, the content request processing unit 320, the handover processing unit 330 and the transmission and reception unit 340 are program modules that at least some of them communicate with an external system. Can be. Such program modules may be included in the transmission node 300 in the form of operating systems, application modules, and other program modules, and may be physically stored on various known storage devices. In addition, at least some of these program modules may be stored in a remote storage device capable of communicating with the transmitting node 300. These program modules include, but are not limited to, routines, subroutines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types as described below in accordance with the present invention.

Next, according to an embodiment of the present invention, the client 400 is a device having a function to communicate with each other by connecting to a communication network, a personal computer (for example, a laptop computer, etc.), PDA, tablet computer, As long as a device having memory means and a microprocessor, such as a smart phone or a mobile phone, can be a client 400 according to the present invention. According to an embodiment of the present invention, the client 400 may move in a physical space as a mobile communication terminal, and thus a hand-over phenomenon may occur in which a communication network to which the client 400 belongs is changed. .

Concrete Example

Hereinafter, a specific embodiment of transmitting content using a unique identifier of the content according to an embodiment of the present invention will be described in detail.

In the present invention, a unique identifier or a content unique identifier (CUID) of the content refers to an identifier uniquely corresponding to each content. If the content unique identifier is the same, the content of the data constituting the content is the same, and the content unique identifier is the same. If different, the content of the data constituting the content is also different.

Specifically, according to an embodiment of the present invention, the content unique identifier may be generated by a predefined algorithm, and the applicable algorithm may be Message Digest 4 (MD4), Message Digest 5 (MD5) and SHA ( Secure Hash Algorithm).

In addition, according to an embodiment of the present invention, the administrator of the content delivery system may be generated so as to satisfy the desired error tolerance level, more specifically, the probability that a predetermined probability that the unique identifier of the content uniquely corresponds to the corresponding content It can be abnormal.

In addition, according to an embodiment of the present invention, the content unique identifier may be generated based on at least some of the data constituting the content, if allowed by the administrator of the content delivery system, the entire content constituting the content The data may be generated based on only some data (for example, initial data of a predetermined size), not data, and may be generated to include length (ie, size) information of all data constituting the corresponding content. That is, in this case, if some data of two contents to be compared are the same and the total length is the same, the two contents may be determined to be the same as a whole.

Meanwhile, according to an embodiment of the present invention, as a means for identifying the content, a URL (or a URL and a request header) specifying a location from which the content can be obtained in addition to the content unique identifier can be used as an auxiliary, thereby making the content unique identifier. If the content cannot be identified by using, the content may be identified by using a URL (or a URL and a request header).

(1) Operation of Server 100 and Client 400

According to an embodiment of the present invention, the server 100 is a web server operating according to a standard communication technology and may provide content corresponding to the URL (or URL and request header) of the content requested from the outside.

According to an embodiment of the present invention, the client 400 may request content by using a URL (or URL and request header) to the outside as a client operating according to a standard communication technology.

(2) operation of the master node 200

First, according to an embodiment of the present invention, the master node 200 refers to at least one unit node located on the communication path between the server 100 and the client 400, from the transmission node 300 As a response to the request, the user may perform a function of transmitting the content stored in the terminal or the content received from the server 100 to the transmitting node 300.

In addition, according to an embodiment of the present invention, the master node 200 may perform a function of generating a unique identifier of the content, and mapping between the URL (or URL and request header) and the unique identifier of the content. The content unique identifier corresponding to the URL (or URL and request header) received from the transmitting node 300 can be determined and transmitted to the transmitting node 300 based on the mapping information. A note can perform a function. According to an embodiment of the present invention, in the mapping with the content unique identifier, the request header of the content, that is, the information included in the content request from the client 400, together with the information about the URL of the content More can be used. That is, when multiple contents correspond to one URL, the master node 200 may perform mapping between the information about the URL and the request header of the contents and the information about the unique identifier.

9 is a diagram exemplarily illustrating a mapping table between a URL and a unique identifier or a mapping table between a URL and a request header and a unique identifier according to an embodiment of the present invention.

9, the URL "http://apple.com/apple" may correspond to the unique identifier "0x01", and the URLs "http://apple.com/banana", "http: // apple. com / orange "and" http://apple.com/mango "are both URLs pointing to the same content and may correspond to the unique identifier" 0x02 ", and the URL" http://apple.com/movie/avatar " URLs pointing to different content according to the request headers "User-Agent = iphone", "User-Agent = ipad" and "User-Agent = ipad", respectively, unique identifiers "0x03", "0x04" and "0x05" May correspond to.

In addition, the master node 200 according to an embodiment of the present invention stores the previously negotiated content in its own storage device and generates a unique identifier for the corresponding content, thereby generating a unique identifier from the subsequent transmission node 300. In response to the content request through the server, it may perform a function of transmitting the content stored by the user to the transmitting node 300.

In addition, the master node 200 according to an embodiment of the present invention requests the server 100 for the content requested from the transmitting node 300, and responds to the content received from the server 100 in response thereto. It may perform a function of transmitting to the transmission node 300 while storing in the storage device of the. At this time, the master node 200 also generates and maintains a unique identifier for the corresponding content received from the server 100, thereby transmitting a unique identifier of the content to the delivery server 300 in response to the request or subsequent request. can do.

However, in the above embodiment, the master node 200 may be performed by the server 100 without directly performing a function of storing or transmitting content, and generates a unique identifier of the content or a URL of the content. (Or URL and request header) may be configured to perform only the function of managing the mapping information between the unique identifier.

Meanwhile, according to an embodiment of the present invention, the master node 200 may exist independently on the communication path between the server 100 and the transmitting node 300, or may be present in the server 100 or the transmitting node 300. It may be configured to be included. In general, when the master node 200 exists independently, it is advantageous in speeding up the transmission speed of the content, and the master node 200 is configured while being included in the server 100 or the transmitting node 300. It is advantageous in that the content delivery system can be easily configured with fewer components.

(3) operation of the transmitting node

According to an embodiment of the present invention, when the content node receives the content request from the client 400, the transmitting node 300 identifies the corresponding content by using the content unique identifier and transmits the corresponding content to the client 400. can do. More specifically, it is as follows.

First, according to an embodiment of the present invention, the transmitting node 300 may identify the content based on the content unique identifier and not the URL (or URL and request header). Since the request for a web server generally includes only information about the URL (or URL and request header) of the corresponding content, the transmitting node 300 maps information between the URL (or URL and request header) and the unique identifier of the content. The master node 200 that manages the request may transmit a unique identifier corresponding to the URL (or URL and request header) of the content requested from the client 400.

Next, according to an embodiment of the present invention, the transmitting node 300 may receive information about the unique identifier corresponding to the URL (or URL and request header) of the content from the master node 200. In addition, the transmitting node 300 may determine whether the user has the corresponding content (that is, storing) by referring to the information about the unique identifier received from the master node 200, and the content is owned by the corresponding node. If it is determined that the user has the content can be sent to the client 400, if it is determined that he does not have the content, the content is received from the master node 200 and the client 400 again ) Can be sent.

Meanwhile, according to another embodiment of the present invention, the transmitting node 300 may request the master node 200 to transmit both information about the unique identifier of the content and the corresponding content itself, and the content from the master node 200. Both the information about the unique identifier and the data constituting the content itself can be received. For example, when the transmitting node 300 and the master node 200 communicate through an HTTP packet, they first receive a header including information on a content unique identifier, and then receive data constituting the content itself later. Can be. That is, the transmitting node 300 first receives only the information about the unique identifier of the content from the master node 200 and determines whether the corresponding content is owned, and if it is determined that the user has the corresponding content, the master node 200. After ending the session with the (200) can send the corresponding content to the client (400), if it is determined that he does not have the content, and receives the content from the master node (200) It can be sent to the client 400 along with the storage in the storage device.

Meanwhile, according to another embodiment of the present invention, the transmitting node 300 does not receive the information about the unique identifier of the content from the master node 200, and includes the URL (or URL and the request included in the request from the client 400). When only the content corresponding to the information on the header) can be transmitted, the transmitting node 300 may generate a unique identifier of the corresponding content and transmit the corresponding content to the client 400.

Meanwhile, according to another embodiment of the present invention, when the content unique identifier is generated based on the initial data having a predetermined size constituting the content, the transmitting node 300 may identify the unique identifier and the master node of the content that it has. By comparing the first data constituting the content being transmitted from the 200, it is possible to determine whether the user has the content being transmitted from the master node 200, and if it is determined that he has the corresponding content, the master The session with the node 200 may be terminated, and the corresponding content that is owned by the node 200 may be transmitted to the client 400. As a result, it is not necessary to receive the entire content from the master node 200, thereby increasing content transmission efficiency.

Meanwhile, according to another embodiment of the present invention, the transmitting node 300 may perform a function of identifying and transmitting the content by using the URL (or URL and request header) of the content as an identifier. In detail, the transmitting node 300 may determine a URL (or URL and URL) for content (which may be designated by an administrator or the like) determined to be able to normally identify the content even if only the URL (or URL and request header) uses the identifier. The content may be identified using the request header) as an identifier. If the transmitting node 300 stores the content requested from the client 400, the transmitting node 300 stores its own content using only the URL (or URL and request header) without receiving the content unique identifier or the content itself from the master node 200. Since the content stored in the device can be identified and the identified content can be directly transmitted to the client 400, the content transmission efficiency can be improved.

4 to 7 are diagrams illustrating a process of transmitting content according to an embodiment of the present invention.

First, in FIG. 4, when the client 400 requests content (S410), the transmitting node 300 transmits information regarding a URL (or URL and request header) of the content requested from the client 400 to the master node 200. In step S420, a request may be made to transmit a corresponding content unique identifier. Accordingly, the master node 200 refers to the mapping information between the URL (or URL and request header) managed by the master and the content unique identifier, and corresponds to a unique identifier corresponding to the URL (or URL and request header) of the corresponding content. And transmit the same to the transmitting node 300 (S430), the transmitting node 300 identifies the corresponding content among the contents stored by the user using the content unique identifier received from the master node 200. The identified corresponding content may be transmitted to the client 400 (S440).

Next, in FIG. 5, when the client 400 requests the content (S510), the transmitting node 300 transmits information regarding the URL (or URL and request header) of the requested content from the client 400 to the master node ( In step S520, a request may be made to transmit a corresponding content unique identifier while transmitting to the corresponding content unique identifier. Accordingly, the master node 200 refers to the mapping information between the URL (or URL and request header) managed by the master and the content unique identifier, and corresponds to a unique identifier corresponding to the URL (or URL and request header) of the corresponding content. If it is determined that does not have a can request to the server 100 to transmit the corresponding content (S530). Accordingly, the server 100 may transmit the corresponding content to the master node 200 (S540), and the master node generates a unique identifier of the corresponding content using the corresponding content received from the server 100. The generated content unique identifier may be transmitted to the transmitting node 300 (S550), and the transmitting node 300 identifies the corresponding content among the contents stored by the user using the content unique identifier received from the master node 200. The corresponding content identified as described above may be transmitted to the client 400 (S560).

Next, in FIG. 6, when the client 400 requests content (S610), the transmitting node 300 transmits information regarding the URL (or URL and request header) of the requested content from the client 400 to the master node ( In step S620, the request for transmitting the corresponding content unique identifier may be made while transmitting to the server 200). Accordingly, the master node 200 refers to the mapping information between the URL (or URL and request header) managed by the master and the content unique identifier, and corresponds to a unique identifier corresponding to the URL (or URL and request header) of the corresponding content. And transmit the same to the transmitting node 300 (S630), the transmitting node 300 identifies the corresponding content among the contents stored by the user using the content unique identifier received from the master node 200. If it is determined that the user does not store the corresponding content, the master node 200 may request to transmit the corresponding content (S640). Accordingly, the master node 200 may transmit the corresponding content to the transmitting node 300 (S650), and the transmitting node 200 stores the corresponding content received from the master node 300 in its storage device. In addition, it can be transmitted to the client 400 (S660).

Next, in FIG. 7, when the client 400 requests content (S710), the transmitting node 300 transmits information about the URL (or URL and request header) of the requested content from the client 400 to the master node ( In step S720, a request may be made to transmit a corresponding content unique identifier while transmitting to the corresponding content unique identifier. Accordingly, the master node 200 refers to the mapping information between the URL (or URL and request header) managed by the master and the content unique identifier, and corresponds to a unique identifier corresponding to the URL (or URL and request header) of the corresponding content. If it is determined that does not have the server 100 can request to transmit the content (S730). Accordingly, the server 100 may transmit the corresponding content to the master node 200 (S740), and the master node generates a unique identifier of the corresponding content using the corresponding content received from the server 100. The generated content unique identifier may be transmitted to the transmitting node 300 (S750), and the transmitting node 300 identifies the corresponding content among the contents stored by the user using the content unique identifier received from the master node 200. If it is determined that the user does not store the corresponding content, the master node 200 may request to transmit the corresponding content (S760). Accordingly, the master node 200 may transmit the corresponding content to the transmitting node 300 (S770), and the transmitting node 200 stores the corresponding content received from the master node 300 in its storage device. In addition, it can be transmitted to the client 400 (S780).

(4) Handover support in wireless communication network

In a wireless communication network in which the client 400 may physically move, a position change on the communication network 10 of the client 400 may be changed, that is, a handover may occur.

According to an embodiment of the present invention, the handover may be effectively processed by identifying the content using the content unique identifier.

8 is a diagram exemplarily illustrating a process of supporting handover in transmitting content using a content unique identifier according to an embodiment of the present invention.

Referring to FIG. 8, (i) the client 400 is connected to the second transmission node 300B as a result of being handed over while belonging to the first communication network 20A connected to the first transmission node 300A. And (ii) as a result of being handed over in the state where the client 400 belongs to the first communication network 20A connected to the first transmitting node 300A. It may be assumed that it belongs to the third communication network 20C which is not connected. In the above two cases, the process of supporting handover will be described in more detail as follows.

First, it may be assumed that (i) the client 400 belongs to the second communication network 20A connected to the second transmission node 300B as a result of the handover. In this case, the client 400 may stop receiving the content from the first transmission node 300A and receive the content from the second transmission node 300B in terms of transmission efficiency. According to the prior art of identifying content using a URL (or URL and request header), it is possible to guarantee that the content transmitted from the first transmitting node 300A and the content to be transmitted from the second transmitting node 300B are the same. However, according to the present invention for identifying content using a content unique identifier, the client 400 connects the same content as the content received from the first transmitting node 300A connected before the handover after handover. 2 can be transmitted from the transmission node (300B). Of course, this is possible under the assumption that both the first transmitting node 300A and the second transmitting node 300B have corresponding contents. A process of processing handover that occurs while transmitting content will be described in more detail as follows.

According to an embodiment of the present invention, the client 400 included in the first communication network 20A may request content from the first transmitting node 300A. Accordingly, the first transmitting node 300A transmits information about the URL (or URL and request header) of the corresponding content included in the content request from the client 400 to the master node 200, and transmits the information to the unique identifier of the corresponding content. You can ask us to send you information about it. Next, the first transmitting node 300A may identify the corresponding content by using the information about the unique identifier of the corresponding content received from the master node 200, and transmit the corresponding content to the client 400. Can be. Meanwhile, as the handover occurs in the client 400 while the first transmitting node 300A transmits the corresponding content to the client 400, the first communication network in which the client 400 is connected to the first transmitting node 300A. At 20A, a second communication network 30A connected to the second transmission node 300B may be moved. At this time, the master node 200 detects that a handover has occurred in the client 400, and the client 400 transmits the content that was being transmitted from the first transmitting node 300A to the client 400. 2 may transmit to the node 300B. Accordingly, when the second transmission node 300B has the corresponding content, the second transmission node 300B may transmit the corresponding content to the client 400, and the second transmission node 300B may transmit the corresponding content. When the content does not have the corresponding content, the second transmission node 300B may receive the content from the master node 200 and transmit the content to the client 400 again.

Next, it may be assumed that (ii) the client 400 belongs to the third communication network 20C which is not connected to any transmitting node as a result of the handover. In this case, the master node 200 may detect that a handover has occurred in the client 400, and may transmit content, which the client 400 is receiving from the first transmitting node 300A, to the client 400. In detail, when the master node 200 has the corresponding content, the master node 200 transmits the corresponding content to the client 400, and when the master node 400 does not have the corresponding content, the master node 200. Receives the corresponding content from the server 100 can be sent back to the client 400.

Meanwhile, according to another embodiment of the present invention, as a result of the handover, the second transmission node 300B connected to the client 400 does not have the content that the client 400 was receiving from the first transmission node 300A. In the case where the client is not connected to any transmitting node as a result of handover, the master node 200 uses corresponding network technology such as tunneling technology to the corresponding content from the first transmitting node 300A to the client 400. Can continue the transmission of.

For example, a case in which a tunneling technique is used will be described in detail as follows. The handover occurs in the client 400 while the content is being transmitted, and the second transport node 300B connected to the client 400 after the handover was being received by the client 400 from the first transport node 300A. If the content does not have content, the master node 200 may use a tunneling technique to open a tunnel to the first transmission node 300A to which the client 400 is connected prior to the handover. In this case, the master node 200 may allow the packet received from the client 400 (that is, the packet related to the content request) to be transmitted to the first transmitting node 300A through a tunnel, and correspondingly, the first transmitting node. 300A may transmit a packet (ie, a packet constituting the requested content) in response to a request from the client 400 to the master node 200 through a tunnel. In addition, a packet tunneled from the first transmission node 300A and transmitted to the master node 200 through a tunnel formed between the first transmission node 300A and the master node 200 (that is, a packet constituting content) It may be transmitted to the second transmitting node 300B or the client 400. As described above, according to another embodiment of the present invention, even if a handover occurs in the client 400, the client 400 continuously transmits content from the first transmitting node 300A which was connected before the handover occurred. I can receive it.

However, in the present invention, a technique used to continuously transmit the content from the first transmitting node 300A to the client 400 is not necessarily limited to the tunneling technique, and may achieve the object of the present invention. It is noted that other techniques may be applied within the scope.

(4) Extensive Embodiment

Hereinafter, an extended embodiment of the present invention will be described.

According to another embodiment of the present invention, when the client 400 requests the content, the client 400 may provide not only the URL (or URL and request header) of the content but also information about the unique identifier. For example, the client 400 may request to transmit content having a URL of "A", a header value of "B", and a content unique identifier of "X", so that the transmitting node 300 may transmit a master node. Without having to request the unique identifier of the corresponding content to the 200, the content unique identifier having the content “X” may be identified and the thus identified content may be transmitted to the client 400. Of course, if the transmitting node 300 does not have the content with the content unique identifier "X" may receive the content from the master node 200 or the server 100 and deliver it to the client.

Meanwhile, according to another embodiment of the present invention, the server 100 may be configured to perform at least some functions of the above-described master node. Specifically, the server 100 may further perform a function of generating a unique identifier of the content, a function of managing mapping information between the URL (or URL and request header) and the unique identifier of the content, in addition to the basic function of transmitting the content. Can be. In this case, the transmitting node 300 may directly communicate with the server 100 without having to communicate with the master node 200 to directly receive the content unique identifier or the content itself from the server 100, thereby improving content transmission efficiency. To increase.

Meanwhile, according to another embodiment of the present invention, the server 100 performs a function related to content transmission of the master node 200 and transmits a function related to content generation and management of the content unique identifier of the master node 200. By performing the operation 300, a content delivery system can be configured without using a separate master node 200. In this case, it is advantageous in that the content delivery system can be easily configured with fewer components.

On the other hand, in the above embodiment, by having the master node 200 and the transmitting node 300 in a hierarchical relationship on the communication path between the server 100 and the client 400 has the following advantageous effects Can be achieved.

First, the transmitting node 200 located in close proximity to the client 400 on the communication network 10 directly transmits its own content to the client 400, and the content is not owned by the master node 200. By receiving the transmission to the client 400 it is possible to accelerate the content delivery speed. In this case, the storage space of the master node 300 is set relatively large and the storage space of the transmission node 200 is set relatively small so that the plurality of transmission nodes 300 are stored in the storage space of the master node 200. When the content can be shared, compared with the case where the master node 200 does not exist, it is possible to increase the content storage efficiency while reducing the cost of preparing the storage space of the entire system.

Next, the communication between the server 100 and the master node 200 or the communication between the transmission node 300 and the client 400 should comply with a communication standard, but between the master node 200 and the transmission node 300. In communication, a proprietary communication technology can be applied without having to comply with a communication standard. For example, if there is a bottleneck section between the server 100 and the client 400, the master node and the transmitting node are placed at the front end of the bottleneck section, and various content compression techniques are used for communication between the master node and the transmitting node. (For example, a real-time compression technique, a compression technique using a dictionary, etc.) can be applied, thereby achieving an effect of increasing the efficiency of content transmission.

The embodiments of the present invention described above can be implemented in the form of program instructions that can be executed through various computer components and recorded on a computer-readable recording medium. The computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination. Program instructions recorded on the computer-readable recording medium may be those specially designed and configured for the present invention, or may be known and available to those skilled in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs, DVDs, and magneto-optical media such as floptical disks. media), and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules for performing the processing according to the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Accordingly, the spirit of the present invention should not be limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the appended claims, fall within the scope of the spirit of the present invention. I will say.

10: Network
20A: first network
20B: second network
20C: tertiary network
100: Server
200: master node
210: content unique identifier management unit
220: content transmission processing unit
230: handover processing unit
240: transceiver
300: transport node
310: content unique identifier management unit
320: content transmission processing unit
330: handover processing unit
340: transceiver
300A: first transport node
300B: second transport node
400: client

Claims (39)

A method for transmitting content using a content unique identifier,
(a) the delivery node receives a request for content from a client,
(b) the transmitting node transmitting information on a URL of the content included in the request to a master node;
(c) the transmitting node receives information on the unique identifier corresponding to the information on the URL of the content from the master node, and the content is transmitted to the transmitting node with reference to the information on the received unique identifier. Determining whether it is stored, and
(d) if it is determined that the content is stored in the transmitting node, the transmitting node transmits the content stored in the transmitting node to the client, and if it is determined that the content is not stored in the transmitting node The transmission node receiving the content from the master node and transmitting the content to the client
≪ / RTI > A method for transmitting content using a content unique identifier,
(a) receiving, by a master node, information regarding a URL of content requested by a client from a delivery node,
(b) the master node determining a unique identifier corresponding to the information about the URL of the content with reference to the mapping information between the URL and the unique identifier, and transmitting the determined unique identifier to the transmitting node; and
(c) the master node transmitting the content to the transmitting node if it is determined that the contents are not stored in the transmitting node;
≪ / RTI > A method for transmitting content using a content unique identifier,
(a) the delivery node receives a request for content from a client,
(b) the transmitting node transmitting information on a URL of the content included in the request to a master node;
(c) the master node receiving information regarding the URL of the content from the transmitting node,
(d) determining, by the master node, a unique identifier corresponding to the information about the URL of the content with reference to the mapping information between the URL and the unique identifier, and transmitting the determined unique identifier to the transmitting node;
(e) determining, by the transmitting node, whether the content is stored in the transmitting node with reference to the information about the determined unique identifier transmitted from the master node; and
(f) if it is determined that the content is stored in the transmitting node, the transmitting node transmits the content stored in the transmitting node to the client, and if it is determined that the content is not stored in the transmitting node, Transmitting, by the master node, the content to the transmitting node, and transmitting, by the transmitting node, content received from the master node to the client;
≪ / RTI > A method for transmitting content using a content unique identifier,
(a) the node receiving a request for content from a client,
(b) determining, by the node, a unique identifier corresponding to the information about the URL of the content included in the request with reference to the mapping information between the URL and the unique identifier;
(c) determining, by the node, whether the content is stored in the node with reference to the information about the unique identifier corresponding to the information about the URL of the content; and
(d) if it is determined that the content is stored in the node, the node transmits the content stored in the node to the client; if it is determined that the content is not stored in the node, the node sends a server. Receiving the content from the client and transmitting the content to the client
≪ / RTI > 5. The method according to any one of claims 1 to 4,
The unique identifier of the content is generated based on at least some of the data constituting the content. The method of claim 5,
The unique identifier of the content is generated based on the first data of a predetermined size among the data constituting the content. 5. The method according to any one of claims 1 to 4,
And the unique identifier of the content includes information about the size of the content. 5. The method according to any one of claims 1 to 4,
The unique identifier of the content is a probability that uniquely corresponding to the content is a predetermined probability or more. 5. The method according to any one of claims 1 to 4,
The unique identifier of the content is generated by at least one algorithm of Message Digest 4 (MD4), Message Digest 5 (MD5) and Secure Hash Algorithm (SHA). 5. The method according to any one of claims 1 to 4,
In determining a unique identifier of content requested from the client, both information about a URL of the content included in the request and information about a header. The method of claim 1,
(e) if a handover occurs in the client, stopping transmitting the content to the client;
≪ / RTI > The method of claim 1,
(e) Determining that the content has not been stored in the second transmission node connected to the client after the handover based on the information on the determined unique identifier that has occurred in the client. And when the transmitting node transmits the content stored by the transmitting node to the client or the second transmitting node.
≪ / RTI > 3. The method of claim 2,
In the step (b)
If a unique identifier corresponding to the information about the URL of the content is stored in the master node, the master node determines the unique identifier stored in the master node as a unique identifier corresponding to the information about the URL of the content, If a unique identifier corresponding to the information about the URL of the content is not stored in the master node, the master node receives the content corresponding to the information about the URL of the content from the server and is unique based on the transmitted content. Generating an identifier and determining the generated unique identifier as a unique identifier corresponding to information about the URL of the content. The method of claim 13,
In the step (b)
Updating the mapping information between the URL and the unique identifier with reference to the generated unique identifier. 3. The method of claim 2,
(d) When a handover occurs in the client, the master node transmits the content corresponding to the determined unique identifier to the client by a second transmitting node connected to the client after the handover. Steps to get
≪ / RTI > 3. The method of claim 2,
(d) A handover occurs in the client, and it is determined that the content is not stored in the second transmission node connected to the client after the handover based on the information on the determined unique identifier. And if the master node causes the content stored in the first transmission node that was connected with the client before the handover, to be transmitted to the client or the second transmission node.
≪ / RTI > The method of claim 3,
(f) if a hand-over occurs in the client, the first transmitting node connected to the client before the handover stops transmitting the content to the client, and after the handover, Transmitting, by the second transmitting node connected to the client, the content to the client;
≪ / RTI > 18. The method of claim 17,
In the step (f)
If it is determined that the content is not stored in the second transmitting node based on the determined unique identifier, the master node transmits the content to the second transmitting node, and the second transmitting node transmits the content. A method for transmitting content received from a master node to the client. The method of claim 3,
(f) if a handover occurs in the client and it is determined that the content is not stored in the second transmitting node based on the information on the determined unique identifier, the client before the handover. A first transmission node connected to the second transmission node transmits the content stored by the first transmission node to the client, or the second transmission node connects the content stored by the first transmission node to the client after the handover. Transmitting to the client the content received from the first transmitting node by the second transmitting node.
≪ / RTI > A system for transmitting content using a content unique identifier, the system comprising:
A content request processor for receiving a request for content from a client, and
Transmitting information about the URL of the content included in the request to a master node, receiving information about a unique identifier corresponding to the information about the URL of the content from the master node, and receiving the transmitted unique It is determined whether the content is stored in the transmitting node with reference to the information on the identifier, and if it is determined that the content is stored in the transmitting node, and transmits the content stored in the transmitting node to the client. And a content unique identifier manager configured to receive the content from the master node and transmit the content to the client if it is determined that the content is not stored in the transmitting node.
/ RTI > A system for transmitting content using a content unique identifier, the system comprising:
Receiving information about the URL of the content requested by the client from a delivery node, referring to the mapping information between the URL and the unique identifier, and determining a unique identifier corresponding to the information about the URL of the content; A content unique identifier manager for transmitting the determined unique identifier to the transmitting node;
Content request processing unit for transmitting the content to the transmission node if it is determined that the content is not stored in the transmission node
/ RTI > A system for transmitting content using a content unique identifier, the system comprising:
Receiving a request for content from a client, transmitting information about a URL of the content included in the request to a master node, and referring to the information about the determined unique identifier transmitted from the master node. It is determined whether the content is stored in the transmitting node, and if it is determined that the content is stored in the transmitting node, the content stored in the transmitting node is transmitted to the client, and the content is transmitted to the transmitting node. A transmission node for transmitting the content received from the master node to the client if it is determined that the information is not stored;
Receiving information about the URL of the content from the transmitting node, referring to mapping information between the URL and the unique identifier, determining a unique identifier corresponding to the information about the URL of the content, and transmitting the determined unique identifier A master node for transmitting the content to the transmitting node if it is determined that the content is not stored in the transmitting node.
/ RTI > A system for transmitting content using a content unique identifier, the system comprising:
A content request processor for receiving a request for content from a client, and
With reference to the mapping information between the URL and the unique identifier, a unique identifier corresponding to the information about the URL of the content included in the request is determined, and information about the unique identifier corresponding to the information about the URL of the content is determined. By reference, it is determined whether the content is stored in the node, and if it is determined that the content is stored in the node, the content stored in the node is transmitted to the client, and the content is stored in the node. If not determined, the content unique identifier management unit receives the content from the server and transmits the content to the client
/ RTI > 24. The method according to any one of claims 20 to 23,
The unique identifier of the content is generated based on at least some of the data constituting the content. 25. The method of claim 24,
The unique identifier of the content is generated based on the first data of a predetermined size of the data constituting the content. 24. The method according to any one of claims 20 to 23,
The unique identifier of the content includes information regarding the size of the content. 24. The method according to any one of claims 20 to 23,
And a unique identifier of the content is a probability corresponding to the content uniquely or more than a preset probability. 24. The method according to any one of claims 20 to 23,
The unique identifier of the content is generated by at least one algorithm of Message Digest 4 (MD4), Message Digest 5 (MD5) and Secure Hash Algorithm (SHA). 24. The method according to any one of claims 20 to 23,
And determining information about the URL of the content included in the request and information on the header in determining the unique identifier of the content requested from the client. 21. The method of claim 20,
And stop transmitting the content to the client when a hand-over occurs in the client. 21. The method of claim 20,
If a handover occurs in the client and it is determined that the content is not stored in the second transmission node connected with the client after the handover based on the determined information on the unique identifier, And transmits the stored content to the client or the second transmission node. The method of claim 21,
If a unique identifier corresponding to the information about the URL of the content is stored in the master node, the unique identifier stored in the master node is determined as the unique identifier corresponding to the information about the URL of the content, and the URL of the content. If a unique identifier corresponding to the information about the information is not stored in the master node, the server receives the content corresponding to the information about the URL of the content from the server, generates a unique identifier based on the transmitted content, and generates the unique And determine an identifier as a unique identifier corresponding to the information about the URL of the content. 33. The method of claim 32,
And update the mapping information between the URL and the unique identifier with reference to the generated unique identifier. The method of claim 21,
And if a hand-over occurs in the client, after the handover, a second transmitting node connected with the client transmits the content corresponding to the determined unique identifier to the client. The method of claim 21,
If a handover occurs in the client and it is determined that the content is not stored in the second transmitting node connected with the client after the handover based on the determined unique identifier information, the And the content stored in the first transmitting node connected with the client before the handover is transmitted to the client or the second transmitting node. The method of claim 22,
When a handover occurs in the client, the transmitting node, which was connected with the client before the handover, stops transmitting the content to the client, and connects with the client after the handover. And a second transmitting node transmits the content to the client. 37. The method of claim 36,
If it is determined that the content is not stored in the second transmitting node based on the determined unique identifier, the master node transmits the content to the second transmitting node, and the second transmitting node transmits the content. A system for transmitting the content received from the master node to the client. The method of claim 22,
If a handover occurs in the client and it is determined that the content is not stored in the second transmission node based on the determined unique identifier information, the client is connected with the client before the handover. The first transmitting node which was present transmits the content stored by the first transmitting node to the client, or the first transmitting node transmits the content stored by the first transmitting node to the second transmitting node connected with the client after the handover. And transmit, by the second transmitting node, the content received from the first transmitting node to the client. A computer-readable recording medium having recorded thereon a computer program for executing the method according to any one of claims 1 to 4.

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