KR101888982B1 - Method for providing content caching service in adapted streaming service and local caching device thereof - Google Patents

Abstract

The present invention relates to a content caching service providing method considering an adaptive content providing method capable of providing a caching service more efficiently for adaptive content transmitted with different resolutions according to link quality or terminal performance, The local caching device encodes content of a specific resolution to generate two or more pieces of content data having different resolutions to further reduce traffic in a section between the content providing device and the local caching device, .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a content caching service providing method for providing adaptive content,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a content caching service providing method and a local caching apparatus for preventing traffic duplication on a network to reduce traffic, The present invention relates to a content caching service providing method and a local caching device for providing an adaptive content service that can provide a caching service more efficiently with respect to content transmitted according to a content transmission method.

The traffic of the mobile communication network is increasingly increasing due to the spread of smart phones with improved performance in recent years and the rapid increase of content providers based thereon. Accordingly, web downloading, video, audio ), Video (image), application (application), etc., due to the degradation of the transmission speed of service quality issues are becoming a problem.

Particularly, according to the development of content transmission technology, it is possible to transfer a large-capacity file in an online video service such as VOD (Video On Demand) and Live Streaming, music streaming, file upload, file download, Various services are also provided.

However, such content providing services may be different in frequency depending on their popularity, but they are typically characterized by delivering redundant content to users in the same domain or the same wireless coverage. As a result, Is increasing.

In this way, since the traffic load of the communication network is further increased, duplication of contents is prevented. Therefore, efforts are being made to reduce the traffic by preventing such duplication. As a related technology, CDN (Contents Delivery Network) The content is stored in a plurality of local caching devices distributed on a network and distributed to a load balancer such as a GLB (Global Load Balance) server, An optimal cache server is selected from a plurality of cache servers, and the requested content is delivered to the user terminal through the selected cache server.

These CDNs are implemented to solve problems such as data loss, bottlenecks, transmission speed degradation and data inconsistency on the Internet based on the Internet network.

The content caching technique is a technique for selectively caching content to a plurality of local caching devices distributed on the network in such a CDN service. Such content caching should be performed in consideration of the storage space of the local caching device, It is also necessary to consider the time required to determine the content matching the content requested by the user out of the cached contents and the cache hit rate which is the ratio of the content requested by the user to the cached contents.

In particular, in the case of an adaptive content transmission method (for example, HTTP Live Streaming (HLS)) in which different resolutions are transmitted according to link quality or terminal performance, the same content is encoded into two or more contents having different resolutions Divides each content into a plurality of chunks, and selectively transmits content having an appropriate resolution according to link quality or terminal performance.

The present invention relates to a content caching service providing method for providing an adaptive content providing a caching service more efficiently for adaptive content transmitted with different resolutions according to link quality or terminal performance, and a local caching device .

Particularly, the present invention can reduce traffic in a section between a content providing apparatus and a local caching apparatus more effectively by generating two or more pieces of content data having different resolutions by encoding contents of a specific resolution, A method of providing a content caching service for providing adaptive content and a local caching device for providing the content caching service.

The present invention provides a means for solving the above-mentioned problems, comprising: a storage unit for storing a part or all of content served from one or more content providing apparatuses to one or more terminal apparatuses; A communication interface unit connected to a communication network for transferring data between the at least one content providing apparatus and at least one terminal apparatus and transmitting and receiving data through the communication network; And a control unit that encodes the content stored in the storage unit into two or more content data having different resolutions and stores the encoded content in the storage unit, And a control unit for controlling the local caching apparatus to transmit the local caching information to the terminal apparatus.

In the local caching apparatus according to the present invention, the two or more pieces of content data are each divided into a plurality of chunk data.

In the local caching apparatus according to the present invention, the controller may determine whether the encoding is performed according to a criterion including at least one of popularity and time.

In the local caching apparatus according to the present invention, the controller may delete one or more low-resolution content data from two or more content data having different resolutions when a request for the content is not present for a predetermined time or more.

In the local caching apparatus according to the present invention, the control unit may perform the encoding at the time of caching the content in the storage unit or at the time when the content is requested.

In the local caching apparatus according to the present invention, the controller may obtain information on two or more different resolutions to be encoded from an index file for providing playback information of the content or a transmission history for the content.

In addition, the present invention provides another method for solving the above-mentioned problems, comprising the steps of: storing, by the local caching apparatus, part or all of contents served from the content providing apparatus to the terminal apparatus; Encoding the content into two or more content data having different resolutions; And selectively transmitting one of two or more pieces of content data having different resolutions to the terminal apparatus according to a request from the terminal apparatus.

The method of providing a content caching service according to the present invention may further include acquiring information on at least one resolution to be encoded from an index file of the content or a transmission history of the content prior to the encoding step.

The method of providing a content caching service according to the present invention may further include determining whether the content is encoded according to a criterion including at least one of popularity and time prior to the encoding step, And a step of determining whether or not the received data is valid.

A method of providing a content caching service according to the present invention includes counting a time until a request for the content occurs after a content is transmitted to the terminal device, and when the time exceeds a predetermined time, And deleting one or more low resolution contents from the two or more contents data having the low resolution.

The present invention supports an adaptive content transmission method in which the same content is encoded into a plurality of content data having different resolutions to selectively provide content data of an appropriate resolution according to link quality or terminal performance, And transmits at least two pieces of content data having different resolutions selectively to the terminal device in response to a request from the terminal device, It is possible to further reduce traffic in a section between the providing apparatus and the local caching apparatus and to provide a content caching service more efficiently.

1 is a block diagram schematically illustrating a content caching service system according to an embodiment of the present invention.
2 is a detailed block diagram for explaining a distributed configuration of a local caching apparatus in a content caching service system according to an embodiment of the present invention.
3 is a schematic diagram for explaining the structure of the adaptive content applied to the present invention.
4 is a flowchart illustrating a process of providing adaptive content according to an existing content caching service.
5 is a flowchart illustrating an adaptive content providing process in a content caching service according to an embodiment of the present invention.
6 is a block diagram showing a configuration of a local caching apparatus according to an embodiment of the present invention.
7 is a flowchart illustrating a content caching service method according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, detailed description of well-known functions or constructions that may obscure the subject matter of the present invention will be omitted. It should be noted that the same constituent elements are denoted by the same reference numerals as possible throughout the drawings.

In order to facilitate understanding of the present invention, terms used in the following description are defined as follows.

The 'flow information' is information defining a flow of transmitting a specific content to a terminal device. The flow information includes IP address information of a destination receiving the specific content, port information of the destination, and IP address information of a source providing the specific content . ≪ / RTI > The flow information may be a combination of at least one of IP address information, port information, and protocol field information of the source and destination. In one embodiment of the present invention, the flow information includes a combination of IP address information of a destination receiving specific contents, port information of a destination, and IP address information of a source providing the specific contents.

The 'content address information' is information indicating the location of the content provided by the content providing apparatus on the network. The content address information includes, for example, a protocol type, a domain name or IP address of the content providing apparatus, Locator).

The 'content classification information' is information for distinguishing contents stored in the local caching device from each other, specifically, information formed by extracting at least a part of contents or processing (for example, hash calculation) the contents. That is, the content classification information is generated based on at least a part of the content, and is information that can identify the content. For example, the content classification information may include at least one of prefix information having a predetermined length, a hash value obtained by calculating the prefix information using a predetermined hash function, and metadata of the content.

'Cache hit' means that there is a content requested in the storage means. In the present invention, among the contents stored in the local caching device, contents matching the contents requested by the terminal device exist . By referring to the definitions of the above-mentioned terms, embodiments of the present invention described below can be understood more clearly.

1 is a block diagram schematically illustrating a content caching service system according to an embodiment of the present invention.

Referring to FIG. 1, a content caching service according to the present invention is based on a terminal device 100, a local caching device 200, and a content providing device 300 connected through a network 400.

The terminal apparatus 100 is a user apparatus connected to the network 400 and using content provided through the network 400. The user apparatus 100 requests specific content from the content providing apparatus 300 and transmits the request to the content providing apparatus 300 300 or the local caching device 200 and uses the content. Such a terminal device 100 may be any electronic / information communication device including a communication function such as a desktop PC, a notebook computer, a tablet PC, a smart phone, a PDA (Personal Digital Assistant), an Internet TV May also be included.

The local caching device 200 is distributed on the network 400 and stores the content provided by the content providing device 300 for a predetermined time or a predetermined period of time. When the content is requested from the terminal device 100, And provides the content stored in place of the content providing apparatus 300 to the terminal apparatus 100. [ To this end, the local caching device 200 performs a caching operation for copying and storing a part or all of the content provided to the terminal device 100 from the content providing device 300 using various caching techniques. The local caching device 200 transmits the content address information or the content request message included in the content request message to the content providing device 300 upon receiving the content request message of the terminal device 100 It is determined whether the content requested by the terminal device 100 is stored based on a part of the content transmitted from the content providing device 300. Here, the local caching device 200 compares the flow information included in the content request message with the previously cached flow information, and if the content matches the content information of the content requested by the terminal device 100, And if the content is not identical, receives a part of the content requested by the terminal device 100 from the content providing device 300 and transmits the content to the terminal device 100 using a part of the received content as a key, It is possible to determine whether or not the requested content is stored.

When the content is stored, the local caching device 200 transmits the content stored on behalf of the content providing device 300 to the terminal device 100, and the terminal device 100 If the requested content is not stored, the content receiving apparatus 300 receives the content from the content providing apparatus 300 and transmits the received content to the terminal apparatus 100, and caches the same content so that the requested content can be provided.

In particular, in one embodiment of the present invention, the local caching device 200 encodes the stored content into two or more pieces of content data having different resolutions for the purpose of providing adaptive content, And selectively transmits one of two or more contents having different resolutions to the terminal device 100 according to a request from the terminal device 100.

The detailed configuration and operation of the above-described local caching device 200 will be described later in more detail.

In the embodiment of the present invention, the local caching device 200 is shown as one, but the local caching devices 200 may be distributed over the network 400, as shown in FIG.

Next, the content providing apparatus 300 is a service apparatus for providing various contents including arbitrary contents such as a moving picture file, an audio file, a web page, etc. through the network 400. At this time, May be provided in a streaming or download manner. For example, the content providing apparatus 300 may include a video sharing site for uploading, viewing, or sharing a paid or free video, an application store for freely trading mobile contents, and a broadcasting service through the Internet The IPTV service may be a server device.

In an embodiment of the present invention, the content providing apparatus 300 may provide an adaptive content transmission service. Specifically, the same content is encoded into two or more contents having different resolutions. Particularly, the contents are divided into a plurality of chunks and stored. Then, 100).

The network 400 connecting the terminal device 100, the local caching device 200, and the content providing device 300 may include a communication network that is currently used or can be used in the future, . In detail, the network 400 may include an IP-based wired / wireless communication network such as an Internet network. In addition, the network 400 may include not only a mobile communication network such as an LTE (Long Term Evolution) network, a WCDMA network, but also various types of wireless networks such as a Wi-Fi network and a mobile network . In this case, the local caching apparatus 200 according to the present invention can be used for content duplication transmission and traffic reduction in the mobile network.

The local caching device 200 according to the present invention is distributed to the above-described network 400, in particular, distributed to the edge of the network 400. [

2 is a block diagram illustrating a detailed configuration of the network 400 for explaining an arrangement structure of a local caching apparatus 200 in a content caching service providing system according to an embodiment of the present invention.

2, the network 400 includes a core network 430 connecting one or more wireless or wired access networks 410 and 420 to which the user's terminal 100 is connected, and the wireless or wired access networks 410 and 420 .

The wireless access network 410 refers to a subscriber network capable of transmitting and receiving data to and from the terminal device 100 in various wireless communication systems. The wireless access network 410 may include a mobile communication network and a Wi-Fi network. 420 denotes a subscriber network that is connected to the terminal 100 by wire and transmits and receives data, and may include a wired access network such as an optical communication FTTH.

The local caching device 200 (200a, 200b) may be distributed to the edge nodes of the network 400 described above. More specifically, the core network 100 is connected to switching devices (e.g., routers) 431a, 431b, and 431c connected to the respective wireless / wired access networks 410 and 420 of the core network 100, The content caching service can be provided to the terminal device 100 connected to the access networks 410 and 420.

Particularly, in case of applying a content caching service according to the present invention to a mobile network such as a mobile communication network, the local caching device 200 may include a base station (BS), a base transceiver station (BTS) B, and eNode B, and a base station controller such as a base station controller (BSC) and a radio network controller (RNC). In this case, (For example, a switching device) of a mobile communication system, and can support content transmission to a mobile terminal device connected to each radio access network.

FIG. 3 is a schematic diagram illustrating a structure of an adaptive content in order to facilitate understanding of a content caching service according to the present invention. Referring to FIG.

Referring to FIG. 3, according to an adaptive content transmission method such as HTTP Live Streaming (HLS), an arbitrary content 10 may include two or more content data 11, 12, and 13 encoded at different resolutions . In an embodiment of the present invention, the content data 11, 12, and 13 may include content data 11, 12, and 13 having a resolution of 1024K, 720K, and 480K, for example. In this case, the content 10 can be provided at resolutions of 1024K, 720K and 480K depending on the link quality or the terminal performance.

Each of the content data 11, 12, and 13 encoded at different resolutions is divided into chunk data A1 to A3, B1 to B3, and C1 to C3 of a predetermined size. Here, the size of one chunk data may be set to about 10 seconds, for example, when it is assumed to be moving picture contents.

The contents 10 having various resolutions are transmitted in units of chunks, and content data having a proper resolution is selectively transmitted according to either the performance or link quality of the terminal device 100. [

Accordingly, in the case of non-adaptive content, a GET message is transmitted about once in relation to the content itself, but in the case of adaptive content, a content request is generated in units of chunks, so that a relatively large number of GET messages are generated .

FIG. 4 is a diagram illustrating an existing content caching service process for the above-described adaptive content. Referring to FIG. 4, when a terminal device receives streaming content 10, And if the link quality is lowered, it is possible to request the low-resolution data C2 as the data of the next reproduction order. In the next step, the higher-intermediate-resolution data B3 may be requested.

At this time, the local caching device confirms whether or not each requested content data is stored. Assuming that all the data of the content 10 are not stored, the local caching device is arranged in the order of A1, C2, B3 Requests contents to the contents providing apparatus, and sequentially transmits the transmitted data A1, C2, B3 to the terminal apparatus.

As described above, in the case of the adaptive content, not only the content is requested in units of chunks, but the resolution of the requested data can be changed according to the link quality or terminal performance. Accordingly, the existing local caching apparatus must receive and store all content data having different resolutions from the content providing apparatus.

In order to more efficiently service such adaptive content, the local caching device 200 in an embodiment of the present invention is configured to receive the data A1 of the content 10 from the terminal device 100, (11) A1 to A3 of the content (10), and stores the received data (11) A1 to A3 in the content (10). Then, data B1 to B3 and C1 to C3 of lower resolution are encoded and generated from the stored high-resolution data (11) A1 to A3. As described above, the local caching apparatus 200 generates all the data of different resolutions that may be requested in the future for the adaptive content 10, so that data of different resolutions can be generated at the request of the terminal device 100 When requested, the data can be directly served from the local caching device 200 to the terminal device 100.

The number of data requests and responses received in the interval between the content providing apparatus 300 and the local caching apparatus 200 can be greatly reduced and thus the number of times between the content providing apparatus 300 and the local caching apparatus 200 It is possible to reduce the occurrence of unnecessary traffic for the interval of < RTI ID = 0.0 >

Hereinafter, the configuration of the local caching apparatus 200 of the present invention and the content caching service providing method thereof will be described in more detail.

6 is a block diagram illustrating a configuration of a local caching apparatus 200 according to an embodiment of the present invention.

6, a local caching apparatus 200 according to an embodiment of the present invention may include a communication interface unit 210, a control unit 220, and a storage unit 230.

The communication interface unit 210 is connected to the network 400 and is a means for transmitting and receiving data through the network 400. [ Particularly, according to an embodiment of the present invention, the communication interface unit 210 is connected to a network 400 that transmits data between one or more content providing apparatuses 300 and one or more terminal apparatuses 100, 400 to send and receive data to and from the one or more content providing apparatuses 300 and one or more terminal apparatuses 100. The communication interface unit 210 may include at least one communication module that processes wired or wireless transmission and reception according to the type of the connected network 400. [

The storage unit 230 stores a part or all of contents to be served from one or more content providing apparatuses 300 to one or more terminal apparatuses 100. In an embodiment of the present invention, the storage unit 230 may store not only the content data received from the content providing apparatus 300 but also the content data received from the local caching apparatus 200, Can be stored.

The control unit 220 controls the overall operation of the caching service by the local caching device 200. Basically when the content request message of the terminal device 100 is received through the communication interface 210, It is checked whether the content requested by the device 100 is stored in the storage unit 230. If the content is stored (cache hit), the content is fetched from the storage unit 230 in place of the content providing apparatus 300 If the content is not stored, the content is received from the content providing device 300 and is delivered to the terminal device 100, and the received content is stored in the storage unit 230 .

At this time, whether or not the content requested by the terminal device 100 is stored is determined as follows.

That is, when the content is requested from the terminal device 100, the controller 220 controls the terminal device 100 to provide the stored content on behalf of the content providing device 300. For this, the control unit 220 controls the caching operation of copying and storing a part or all of the content provided to the terminal device 100 from the content providing device 300 using various caching techniques. Upon receiving the content request message of the terminal device 100, the controller 220 transmits the content address information or the content request message included in the content request message to the content providing device 300, It is determined whether the content requested by the terminal device 100 is stored based on a part of the content transmitted from the content providing device 300. In addition, the control unit 220 compares the flow information included in the content request message with the previously cached flow information, and if the flow information matches the content information of the content requested by the terminal apparatus 100, And if not, receives a part of the content requested by the terminal device 100 from the content providing device 300 and transmits the content requested by the terminal device 100 May determine whether the requested content is stored. Here, the flow information is information for identifying the flow of providing content to the terminal device 100 by content, and may be set by matching the source address information and the destination address information. In one embodiment of the present invention, The source address information may be set as IP address information (e.g., Sever1_IP, Server2_IP) as a source of the content, that is, address information of the content providing apparatus 300. Destination address information may be a destination of the content, (E.g., UE_IP) and port information (UE_Port) of the terminal device 100 as the address information of the terminal device 100 in FIG.

Also. The previously cached flow information is cached for the specific chunk data of a specific resolution with respect to the adaptive content including the content data of various resolutions divided into a plurality of chunk data, Flow information " That is, it means flow information for adaptive contents in which specific chunk data of a specific resolution has been cache hit and content transmission is still in progress.

The control unit 220 receives a part of the content requested by the terminal device 100 from the content providing device 300 and transmits the content requested by the terminal device 100 with a part of the received content as a key The terminal device 100 transmits the content received from the content providing device 300 to the terminal device 100 while determining whether to store the content, . If it is determined that the content is stored in the local caching device 200, the local caching device 200 may fetch the subsequent data from the storage 230 and transmit the data to the terminal device 100.

To this end, the control unit 220 includes a flow information table for recording flow information related to previously cached content, and a content information table for storing at least a part of each content stored in the storage unit 230 And a second field for recording at least one content address information corresponding to the content matched with the content identification information. The source-destination address information table and the content- It is possible to determine whether the content is stored by referring to the content address management table.

If the content is not stored in the storage unit 230 as a result of the determination of whether the content requested by the terminal device 100 is stored, the control unit 220 continuously transmits content And transmits it to the terminal device and stores it in the storage unit 230.

On the other hand, if the content requested by the terminal device 100 is stored as a result of determining whether the content requested by the terminal device 100 is stored, the controller 220 transmits the content It may request a transmission interruption. According to this, the traffic of the section from the content providing apparatus 300 to the local caching apparatus 200 is reduced. Here, the message requesting the interruption of the content transmission may be an HTTP RST (Reset) message.

In particular, in one embodiment of the present invention, the control unit 220 encodes content stored in the storage unit 230 into two or more content data having different resolutions for the adaptive content transmission service, And controls the terminal apparatus 100 to selectively transmit one of two or more content data having different resolutions to the terminal apparatus 100 according to a request from the terminal apparatus 100. [ For this, the control unit 220 may further include an encoding module 221 that can encode specific contents at different resolutions.

Here, the two or more pieces of content data having different resolutions are divided into a plurality of chunk data and can be served in chunks.

In addition, the controller 220 may determine whether the content is encoded according to a criterion including at least one of popularity and time before performing the encoding. For example, it is possible to perform encoding only on contents whose number of times of requesting a content for a predetermined time period is equal to or greater than a reference value. In this case, the popularity may be defined as a user's request rate for the content. More specifically, the popularity may be calculated as a frequency of a request for a corresponding content occurring during a predetermined time.

In addition, the control unit 220 may select one of two or more content data having different resolutions and transmit it to the terminal device 100, count the elapsed time until a next content request is generated, If the content is not requested for more than the time, one or more low-resolution content data may be deleted from two or more content data having different resolutions. Accordingly, the local caching device 200 can use the storage space of the limited storage unit 230 more efficiently.

In addition, when the control unit 220 encodes two or more content data having different resolutions, the control unit 220 determines whether the content is requested from the terminal device 100 or caches the content in the storage unit 230 , And perform the encoding. That is, before the content data of different resolution is requested from the terminal device 100, encoding is performed at the different resolutions so that the terminal device 100 can promptly service the content data at a later time.

In the case of encoding two or more pieces of content data having different resolutions, the controller 220 receives information on two or more different resolutions to be encoded from the content providing apparatus 300, Or from the transfer history of the content. The index file is information provided prior to the data of the actual content when the adaptive content is requested. The index file displays a list of segments to be played by the terminal device 100 and related information, and the terminal device 100 The segments can be reproduced in combination. Also, the transmission history of the content means a request and transmission history of a plurality of chunk data requested in association with the same content. By analyzing the resolution of the plurality of chunk data, it is possible to obtain two or more different resolutions to be encoded for the content Can be confirmed.

Next, a content caching service process according to an embodiment of the present invention will be described with reference to FIG.

Here, it is assumed that the local caching device 200 stores a part or all of contents to be served from the content providing device 300 to the terminal device 100. [ Here, the content may be stored in a plurality of local caching devices 200 in accordance with a predetermined criterion in the content providing device 300, or may be stored in a mirroring method in which the local caching device 200 receives and stores the mirrored traffic, Or a caching method in which the local caching device 200 stores contents requested by the terminal device 100 according to a preset cache policy.

Referring to FIG. 7, the local caching apparatus 200 receives a content request message transmitted from the terminal device 100 to the content providing apparatus 300 (S105).

Upon receipt of the content request message transmitted from the terminal device 100, the local caching device 200 determines whether the content is stored therein, that is, whether or not the content is cached (S110). Here, the cache hit determination may be made based on the content address information (e.g., URL information) of the content requested by the terminal device 100 or a content part of the content requested by the terminal device 100 (for example, Information) stored in the storage unit 230 as a key. The local caching apparatus 200 may further transmit the content request message to the content providing apparatus 300 and receive a part of the requested content corresponding to the content request message have. At this time, the local caching device 200 further extracts the flow information of the content request message, and determines whether the content address information or a part of the content content is included in the content request message according to whether the flow information matches the previously- It is possible to determine whether the content is stored or not.

If the content requested by the terminal device 100 is not stored in the storage unit 230 of the local caching device 200 as a result of the determination, the local caching device 200 transmits the content to the content providing device 300 (S120).

In addition, the local caching device 200 transmits the content received from the content providing device 300 or stored in the storage 230 to the terminal device 100 (S125).

In addition, the local caching apparatus 200 determines whether encoding of the stored content is performed (S130). Here, as a criterion of whether to perform the encoding, one or more of the popularity (request frequency) and the time for the content may be included.

If it is determined that the encoding is to be performed according to the above-described criteria, the local caching device 200 encodes the stored content into two or more pieces of content data having different resolutions and stores the encoded content in step S135. More specifically, the local caching device 200 can encode content having a resolution lower than the resolution of the stored content, and encodes the data having such a different resolution, The local caching device 200 can directly service the content without requesting the content providing device 300. [

In addition, the local caching device 200 may count the time until a request for the content occurs after the content is transmitted to the terminal device 100, and if the time exceeds the predetermined time That is, if a request for the corresponding content does not occur for a predetermined time, one or more low resolution contents can be deleted from two or more contents having different resolutions. Accordingly, the storage unit 230 having a limited size can be used more efficiently.

The method of providing a content caching service according to an exemplary embodiment of the present invention may be implemented in the form of software readable by various computer means and recorded in a computer-readable recording medium. Here, the recording medium may include program commands, data files, data structures, and the like, alone or in combination. Program instructions to be recorded on a recording medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. For example, the recording medium may be an optical recording medium such as a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, a compact disk read only memory (CD-ROM), a digital video disk (DVD) Includes a hardware device that is specially configured to store and execute program instructions such as a magneto-optical medium such as a floppy disk and a ROM, a random access memory (RAM), a flash memory, do. Examples of program instructions may include machine language code such as those generated by a compiler, as well as high-level language code that may be executed by a computer using an interpreter or the like. Such a hardware device may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be apparent to those skilled in the art. Furthermore, although specific terms are used in this specification and the drawings, they are used in a generic sense only to facilitate the description of the invention and to facilitate understanding of the invention, and are not intended to limit the scope of the invention.

The present invention supports an adaptive content transmission method in which the same content is encoded into a plurality of contents having different resolutions to provide content of appropriate resolution according to link quality or terminal performance, The content providing apparatus and the content providing apparatus may be configured so that two or more contents having different resolutions are generated and stored in advance by encoding the contents and then selectively transmitted to two or more contents having different resolutions according to a request from the terminal apparatus, It is possible to further reduce the traffic in the interval between the caching devices and to provide the content caching service more efficiently.

100: terminal device 200: local caching device
210: communication interface unit 220:
221: encoding module 230:
300: Content providing apparatus 400: Network

Claims (10)

A local caching apparatus, which is disposed in a network connecting one or more content providing apparatuses and one or more terminal apparatuses and transmits a content requested by the terminal apparatus to the content providing apparatus on behalf of the content providing apparatus,
A storage unit for storing a part or all of contents transmitted from the one or more contents providing apparatuses to one or more terminal apparatuses;
A communication interface unit connected to the network for transferring data between the at least one content providing apparatus and at least one terminal apparatus, and transmitting and receiving data through the network; And
Receiving a part or all of the content transmitted from the one or more content providing apparatuses to the one or more terminal apparatuses through the communication interface unit and storing the received content in the storage unit and transmitting the content stored in the storage unit to two or more content A control unit for selectively transmitting one of two or more pieces of content data having different resolutions to the terminal apparatus in response to a request from the terminal apparatus after storing the encoded data in the storage unit;
The local caching device comprising: The method according to claim 1,
Wherein the at least two pieces of content data having different resolutions are divided into a plurality of chunk data. The apparatus of claim 1, wherein the control unit
And determines whether or not the encoding is performed according to a criterion including at least one of a popularity and a time. The apparatus of claim 1, wherein the control unit
And deletes one or more pieces of low-resolution content data from the two or more pieces of content data having different resolutions when the request for the content is not received for a predetermined time or more. The apparatus of claim 1, wherein the control unit
Wherein the encoding unit performs the encoding at a time when the content is requested from the terminal or when the content is cached in the storage unit. The apparatus of claim 1, wherein the control unit
And acquires information on two or more different resolutions to be encoded from an index file for providing reproduction information of the content or a transmission history for the content. A local caching apparatus, which is disposed in a network connecting one or more content providing apparatuses and one or more terminal apparatuses and transmits a content requested by the terminal apparatus to the content providing apparatus on behalf of the content providing apparatus,
Storing a part or all of the content served from the content providing apparatus to the terminal apparatus;
Encoding the stored content into two or more pieces of content data having different resolutions and storing the encoded content; And
And selectively transmitting one of two or more pieces of content data having different resolutions to the terminal apparatus in response to a request of the terminal apparatus. 8. The method of claim 7,
Further comprising the step of acquiring information on at least one resolution to be encoded from the index file of the content or the transfer history of the content prior to the encoding step. 8. The method of claim 7,
Determining whether or not the content is encoded according to a criterion including at least one of popularity and time before the encoding step, and performing the encoding step according to the determination result A method for providing a content caching service. 8. The method of claim 7,
The method comprising the steps of: counting a time until a request for the content occurs after transmitting the content to the terminal device; and when the time exceeds the predetermined time, Further comprising the step of deleting one or more content caching services.

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