KR102519390B1 - Method for distributing a content and apparatus thereof - Google Patents

Abstract

The present invention relates to a cache device capable of providing MMT content to a client device in place of a content server when the cache device caches MMT content requested by a client device, and a method for transmitting MMT content in the cache device. As a result, it can be more easily applied to a content delivery system that operates based on MMT.

Description

Cache device, MMT content transmission method in the cache device

The present invention relates to a method for transmitting content, and more particularly, when the cache device is caching MMT content requested by a client device, the cache device may provide the MMT content to the client device instead of a content server. , MMT content transmission method in the cache device.

Recently, with the improvement of performance of user terminals such as smart phones and the development of mobile communication technology, users access web servers provided by content providers (CP; Contents Providers) through user terminals anytime and anywhere to take photos and videos. Various contents such as , audio, and applications can be used.

However, while the number of web servers provided by content providers (CPs) is limited, the number of users who want to access web servers is rapidly increasing, resulting in various problems such as data loss, bottlenecks, transmission delays, and instability such as data disconnection. has occurred

What has been introduced to solve these problems is a CDN (Contents Delivery Network) service.

CDN service is a service for stably delivering various types of contents such as photos, movies, and music videos to user terminals. Some or all of the frequent contents are copied and stored in advance in a cache device distributed in multiple ISP (Internet Service Provider) interconnection points (PoP: Point of Presence), in particular, a cache device distributed in the vicinity of the user terminal, and then the user When there is a request for the service, the path of the cache device located closest to the user is returned, so that the user terminal accesses the cache device through the returned path and then receives content.

Such a CDN service has an advantage in that a cache device located closest to a user provides content to a user terminal, thereby improving a response speed to a content request from a user terminal and providing content more stably.

However, CDN services up to now operate based on HTTP. Therefore, since the cache device supporting the CDN service also performs an operation based on HTTP, there is a problem in that caching of MMT contents is impossible.

Korean Patent Publication No. 10-2011-0092869, published on March 25, 2013 (Name: CDN service method and system through wireless network)

The present invention has been proposed to solve the above conventional problems, and a message format is newly defined so that a cache device supporting the provision of a CDN service can provide a caching service for MMT-based content.

Accordingly, the content server of the present invention adds and transmits a message to the MMT content so that the cache device can cache it, and the cache device that monitors the MMT content caches the MMT content. An object of the present invention is to provide a cache device capable of providing MMT content instead of a server and a method for transmitting MMT content in the cache device.

However, the object of the present invention is not limited to the above object, and other objects not mentioned will be clearly understood from the description below.

In the cache device capable of monitoring information between an MMT transmitting entity that wants to transmit MMT content and an MMT receiving entity that wants to receive MMT content according to the present invention to achieve the above object, The cache device includes a storage unit for storing MMT (MPEG Media Transport) content divided into MPU (Media Processing Unit) units; and whether or not the MMT content requested by the MMT receiving subject is stored in the storage unit is checked, and if it is determined that the MMT content is stored, the MMT content stored in the storage unit is received. It may be configured to include; a control unit for controlling transmission to a subject.

In this case, the control unit may determine that the MMT content is stored when a continuous hit occurs more than a predetermined number of times by performing an inspection in units of the MPU.

In addition, the controller may determine an asset ID through a hash value of the MPU, and if an MPU having the same asset ID exists more than the preset number of times, it may be determined that the MMT content is stored.

In addition, if it is determined that the MMT content is stored, the control unit may control transmission of the MMT content stored in the storage unit to the MMT receiving entity, and at the same time block delivery of the MMT content transmitted from the MMT transmitting entity. can

In addition, when the MMT content is not stored, the control unit checks the cache information message corresponding to the MMT content delivered from the MMT transmitting entity, and if it is determined that the MMT content is cacheable, the MMT transmitting entity reports the MMT receiving entity. The MMT content delivered to may be controlled to be stored in the storage unit.

In addition, the cache information message includes information on a caching policy for each MPU of the MMT content, and the control unit checks the caching policy for each MPU and controls only cacheable MPUs to be copied and stored in the storage unit.

In this case, the cache information message may include an asset ID, a cache policy (cacheable), an expiration time (expire_time), and a maximum reference time (Max_age).

MMT in a cache device capable of monitoring information between an MMT transmitting entity that wants to transmit MMT content and an MMT receiving entity that wants to receive MMT content according to the present invention to achieve the above object. In a content transmission method, the step of checking whether the cache device stores MMT (MPEG Media Transport) content requested by the MMT receiving subject in units of MPU (Media Processing Unit); and if it is determined that the MMT content is stored, controlling the stored MMT content to be transmitted to the MMT receiving subject.

At this time, if it is determined that the MMT content is not stored, a cache information message of the MMT content delivered from the MMT sending subject is checked, and when it is determined that the MMT content is cacheable, the message transmitted from the MMT sending subject to the MMT receiving subject is checked. Copying and storing the MMT content; may be further included.

Additionally, the present invention may provide a computer readable recording medium recording a program for executing the method as described above.

A computer program stored in a computer readable recording medium of the present invention for achieving the above object is an MMT sending entity capable of transmitting MMT content to an MMT receiving entity that wants to receive MMT content. Configuring a cache information message including an asset ID, a cache policy (cacheable), an expiration time (expire_time), and a maximum reference time (Max_age); may be executed.

According to the cache device and the MMT content transmission method in the cache device of the present invention, when a content server transmits MMT content to a client device, a message is defined, added, and transmitted so that the cache device can cache, and the cache device confirms the message. can cache the MMT content, and through this, it can be more easily applied to a content delivery system operating based on MMT.

In addition, it is determined in units of MPUs whether the cache device is caching the MMT content requested by the client device, and if it is determined that the MMT content is being cached, the MMT content is sequentially streamed from the MPU next to the last MPU transmitted. By transmitting, it is possible to provide more rapid MMT contents.

In addition, various effects other than the above effects may be disclosed directly or implicitly in detailed descriptions according to embodiments of the present invention to be described later.

1 is an exemplary system diagram for explaining a content delivery system according to an embodiment of the present invention.
2 is an exemplary diagram for explaining MMT content according to an embodiment of the present invention.
3 is an exemplary diagram for explaining a content transmission path according to an embodiment of the present invention.
4 is a block diagram showing the main configuration of a cache device according to an embodiment of the present invention.
5 to 8 are data flow diagrams for explaining an MMT content transmission method according to an embodiment of the present invention.

Hereinafter, a preferred embodiment in which a person skilled in the art can easily practice the present invention will be described in detail with reference to the accompanying drawings. However, in the detailed description of the operating principle of the preferred embodiment of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. This is to more clearly convey the core of the present invention without obscuring it by omitting unnecessary description. In addition, since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description, but this is not intended to limit the present invention to specific embodiments, It should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Additionally, when an element is referred to as being “connected” or “connected” to another element, it means that it is logically or physically connected or capable of being connected. In other words, it should be understood that a component may be directly connected or connected to another component, but another component may exist in the middle, or may be indirectly connected or connected.

In addition, terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "include" or "having" described in this specification are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or the other It should be understood that the above does not preclude the possibility of the presence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof.

Now, a cache device according to an embodiment of the present invention and a method for transmitting MMT content in the cache device will be described in detail with reference to drawings. At this time, the same reference numerals are used for parts having similar functions and actions throughout the drawings, and overlapping descriptions thereof will be omitted.

Prior to the description, the client device described in the specification of the present invention may be implemented in various forms. For example, mobile terminals such as smart phones, tablet PCs, personal digital assistants (PDAs), portable multimedia players (PMPs), and MP3 players, as well as smart TVs and desktop computers. A fixed terminal such as a fixed terminal can be used, and any device can be applied to the client device of the present invention, as long as it is a user's device capable of requesting MMT content from a content server through a network and receiving and using the MMT content.

In addition, the content server described in the specification of the present invention is for providing various types of content, for example, content such as photos, videos, audio, applications, etc. to a client device, and at least one It receives and manages the content, transmits the corresponding content according to the request of the client device, and preferably provides the content under an agreement with the communication service provider providing the CDN service. Such a content server may exemplify a web server or a web application server (WAS).

In addition, any content described above may be included in the content of the present invention as long as it can be expressed as a specific address (eg, URL) on a network. For example, if the entire web site is expressed as one URL, it can be distributed as one content through a CDN service. In particular, the contents of the present invention may be defined according to the MPEG Media Transport (MMT) protocol.

Hereinafter, a content delivery system supporting the content transmission method according to an embodiment of the present invention will be described.

1 is a system diagram for explaining a content delivery system according to an embodiment of the present invention, and FIG. 2 is an example diagram for explaining MMT content according to an embodiment of the present invention. 3 is an exemplary view for explaining a content transmission path according to an embodiment of the present invention.

Referring to FIG. 1 , a content delivery system 1000 according to an embodiment of the present invention includes a client device 100, a network 300 including a plurality of cache devices 350 and a cache controller 340, and a content server. It may be configured to include (200).

First, the client device 100 may request specific content from the content server 200 through the network 300 according to a user's request, and may receive and use content provided from the content server 200 . In particular, the client device 100 of the present invention is a user's device capable of supporting the MMT (MPEG Media Transport) protocol, and MPEG media transport streaming data (hereinafter referred to as 'MMT content') to the content server 200 ), and refers to a device capable of receiving and playing the MMT content transmitted by the content server 200.

The client device 100 confirms a request for specific MMT content from the user. The request for the specific MMT content may be made through an input such as URL (Uniform Resource Locator) for the specific content or a user input for executing an application capable of playing the MMT content. Thereafter, the client device 100 accesses a name server such as a Domain Name Server (DNS) to acquire address information (IP address) of the content server 200 providing the corresponding MMT content. Then, the client device 100 requests and receives MMT content from the corresponding content server 200 .

The content server 200 is for providing various content such as photos, videos, audios, and applications to the client device 100, and receives at least one content from a content provider (CP). It manages and provides content to a plurality of client devices 100 through the network 300 . In particular, the content server 200 of the present invention can provide content in the form of MMT content to the client device 100, and interlocks with a separate MMT streaming server (not shown) to the MMT streaming server (not shown). Content may be provided, and the MMT streaming server (not shown) may convert the MMT content form and transmit it to the client device 100 . In the following description, it is assumed that the content server 200 directly provides MMT content for convenience, but it should be noted that, as described above, it may operate in conjunction with a separate MMT streaming server (not shown).

In addition, the content server 200 of the present invention may include and transmit a cache information message to the MMT content so that the cache device 350 through which the MMT content is transmitted to the client device 100 may cache the MMT content. . At this time, when the content server 200 of the present invention interworks with an MMT streaming server (not shown), the MMT streaming server (not shown) can compose the message.

The plurality of cache devices 350 and the cache controller 340 distributed on the network 300 serve to control the flow of content between the client device 100 and the content server 200 . At this time, the plurality of cache devices 350 are located between the access network 330 and the core network 320, and the cache controller 340 is preferably located between the core network 320 and the Internet network 310, It is not limited thereto, and if it is possible to control the flow of content between the client device 100 and the content server 200, the plurality of cache devices 350 and the cache controller 340 may be placed on the network 300 in various forms. can be placed.

The cache device 350 stores some or all of the content serviced from the content server 200 in advance according to a preset content distribution policy. Subsequently, when a request for MMT content requested by the client device 100 transmitted from the content server 200 is detected, a cache device caching the MMT content included in the corresponding content response message among the plurality of cache devices 350, MMT content can be transmitted to the client device 100 instead of the content server 200 .

In particular, the cache device 350 according to an embodiment of the present invention may store MMT content divided into media processing units (MPUs; hereinafter referred to as 'MPUs') units.

If more specifically described with reference to Figure 2 for the MMT content of the present invention, the asset 505 of the present invention may be composed of at least one or more MPU (506). Here, the asset 505 means an element of a package that encapsulates encoded media data such as audio, video, or web page data having timed or non-timed properties, and means the largest logical data unit. These assets 505 refer to data entities that include data with the same transfer characteristics. For example, if the MMT package is the largest entity among the data models defined in the MMT functional area and means one independent content such as a movie, the asset 505 includes audio data, video data, It means an element such as script data, and an MMT package, which is a set of the assets 505, can be one content.

The asset 505 includes a plurality of MPUs 506, and the plurality of MPUs 506 refer to logical data objects including the same asset ID. This MPU (506) is coded media data that can be processed completely and independently, the processing of the MPU may mean encapsulation into a package or packetization for delivery. This MPU 506 may include one or more access units for timed data. Here, an access unit (AU) is the smallest data entity capable of having time information. MPU 506 may also be configured to include a portion of data without access unit boundaries for non-timed data. This MPU 506 is a coded media data unit that can be processed completely and independently, and may be composed of a header 507 and coded data 508. In addition, the MPU 506 of the present invention may be further configured as a Media Fragment Unit (MFU).

The MMT contents of the present invention will be described on the assumption that they are applied and operated based on the MPU. That is, the content server 200 may sequentially deliver MMT content in units of MPUs to the client device 100, and the client device 100 may receive and reproduce MMT content in units of MPUs received in sequence. However, the MMT content of the present invention is not necessarily limited to the MPU unit, and the processing of the present invention may be performed in a media fragment unit unit according to a system implementation method.

As described above, the cache device 350 of the present invention may divide and store MMT contents in units of MPUs, and may store some or all of the contents. The cache device 250 monitors information transmitted and received between the client device 100 and the content server 200, and when the MMT content requested by the client device 100 is not being cached, the flow of ① in FIG. Likewise, the content server 200 may transmit MMT content according to the request of the client device 100 .

However, when the MMT content requested by the client device 100 is being cached by itself, the cache device 350 of the present invention replaces the content server 200 with the MMT content it is caching as in the flow of ②. It can be transmitted to the client device 100.

In addition, since the cache device 350 of the present invention does not cache the MMT content requested by the client device 100, the content server 200 transmits the MMT content according to the request of the client device 100 as in the flow of ①. In this case, the cache device 350 checks the cache information message included in the MMT content, and if the corresponding MMT content is in a cacheable state, the MMT content can be copied and cached. At this time, the client device 100 of the present invention may cache the MMT content delivered in units of MPUs in units of MPUs.

A more detailed operation of the cache device 350 will be described later, and the content providing system 1000 of the present invention manages a plurality of cache devices 350 distributed on a network 300 and manages a plurality of cache devices ( It may be configured to include a cache controller 340 capable of controlling the content delivery process by 350). The cache controller 340 of the present invention is located between the cache device 350 and the content server 200, and may play a role of controlling the flow of MMT content.

In addition, the network 300 in which the plurality of cache devices 350 of the present invention are distributed and disposed at main points means a communication network for transmitting and receiving information between the client device 100 and the content server 200, in particular, Rather than a single communication network type, various types of communication networks implemented using various types of wired and wireless communication technologies such as intranet networks, mobile communication networks, and satellite communication networks may be mixed types.

Here, the network 300 may include a plurality of wired/wireless access networks 330 and a mobile network including the core network 320 and an external network, for example, the Internet network 310 . Here, the wired/wireless access network 330 constituting the mobile network is an access network that performs wired/wireless communication with the client device 100, for example, a plurality of base station (BS), base transceiver station (BTS), NodeB, eNodeB It may be implemented with a base station of, and a base station controller such as a base station controller (BSC) and a radio network controller (RNC).

In another method, the digital signal processing unit and the radio signal processing unit integrally implemented in the base station are divided into digital units (hereinafter referred to as DUs) and radio units (hereinafter referred to as RUs), and a plurality of It may be configured by installing a plurality of RUs (not shown) in each area of , and connecting the plurality of RUs (not shown) to a centralized DU (not shown).

In addition, the core network 320 constituting a mobile network together with the wired/wireless access network 330 serves to connect the wired/wireless access network 330 and an external network, for example, the Internet network 310 .

As described above, the core network 320 is a network system that performs major functions for mobile communication services such as mobility control and switching between wired and wireless access networks 330, and is a network system that performs circuit switching or packet switching. ), and manages and controls the packet flow within the mobile network. In addition, the core network 320 may manage inter-frequency mobility, and perform a role for interworking with traffic within the access network 330 and the core network 320 and with other networks, for example, the Internet network 310 . The core network 320 may further include a Mobile Switching Center (MSC), a Home Location Register (HLR), a Mobile Mobility Entity (MME), and a Home Subscriber Server (HSS) in addition to the above configuration.

In addition, the internet network 310 refers to a common open communication network in which information is exchanged according to the TCP/IP protocol, that is, a public network, and is connected to the content server 200 to provide content from the content server 200. may be provided to the client device 100 via the core network 320 and the wired/wireless access network 330, or may be provided to a plurality of cache devices 350 according to a preset distribution policy.

The structure of the network 300 of the present invention has been briefly described above, and the network 300 is combined with the cache device 350 to store computing resources such as hardware and software, and provides computing resources required by clients to corresponding A cloud computing network that can be provided to the terminal may be included. Here, cloud computing refers to a computer environment in which information is permanently stored in a server on the Internet and temporarily stored in client terminals such as desktops, tablet computers, laptops, netbooks, and smartphones. It refers to a computer environment access network that stores information in a server on the Internet and makes it available anytime and anywhere through various IT devices. The network 300 includes a closed network such as a local area network (LAN) and a wide area network (WAN) and an open network such as the Internet, as well as code division multiple access (CDMA) and wideband code division (WCDMA). Multiple Access), GSM (Global System for Mobile Communications), LTE (Long Term Evolution), and EPC (Evolved Packet Core), which are recently attracting attention, as well as next-generation networks and cloud computing networks to be implemented in the future.

Hereinafter, the main configuration and operating method of the cache device 350 according to an embodiment of the present invention will be described with reference to FIG. 4 .

4 is a block diagram showing the main configuration of a cache device according to an embodiment of the present invention.

1 and 4 , a cache device 350 according to an embodiment of the present invention may include a communication unit 351, a control unit 352, and a storage unit 353.

First, the communication unit 351 monitors various data transmitted and received through the core network 320 or the Internet network 310, or serves to transmit and receive them. In particular, the communication unit 351 of the present invention can monitor and detect information transmitted and received between the client device 100 and the content server 200. For this purpose, although the communication unit 351 is not shown, the mirroring module and injection modules may be included. The mirroring module copies data transmitted through the core network 320 or the Internet network 310 and transfers it to the control unit 352 . The injection module transmits data received from the controller 352 to the cache controller 340 or the client device 100 through the core network 320 or the Internet network 310 . Therefore, the communication unit 351 confirms a content request transmitted from the client device 100 to the content server 200 through a connection with the client device 100, or the content server 200 transmits the content request to the client device 100. You can check the MMT contents that you do.

The control unit 352 serves to control overall operations of the cache device 350 . The controller 350 of the present invention includes a caching determination module 352a and a caching control module 352b.

First, the caching determination module 352a checks a request for MMT content transmitted from the client device 100 to the content server 200 or MMT content transmitted from the content server 200 to the client device 100, and the corresponding It can play a role of determining whether it is caching MMT content.

At this time, the caching determination module 352a of the present invention determines whether the cache is hit in units of MPUs. And if more than a predetermined number of consecutive hits occur, the caching determination module 352a guides the caching control module 352b to transmit the MMT content to the client device 100 on behalf of the content server 200. .

In addition, when it is determined that the MMT content transmitted from the content server 200 to the client device 100 is not being cached, the caching determination module 352a checks the cache information message included in the MMT content, and the MMT content You can check if is in a cacheable state.

A cache information (CAI) message included in the MMT content of the present invention may be configured as shown in Table 1 below.

Syntax V alues No . of bits Mnemonic CAI_message() {
message_id
version
length

message_payload{
asset _ id (){
asset _ id _ scheme
asset _ id _ length
for (j=0; j<N; j++) {
asset _ id _ byte
}
}
cacheable
expires
max_age

}
}






N




16
8
16



32
8



One
64
64

uimsbf
uimsbf
uimsbf



uimsbf
uimsbf



bslbf
uimsbf
uimsbf

In the message, asset_ID means an asset ID for identifying an asset.

Cacheable means a 1-bit flag representing a cacheable policy. At this time, if the flag is set, the corresponding MMT content cannot be cached.

expire_time means the expiration time of the cached MMT content, and may be composed of 64 bits. Through this, the control unit 352 of the cache device 350 can determine the storage period of the corresponding MMT content.

Max_age means the maximum reference time (max age) representing the criterion for validating the cached MMT content. may be delivered to the MMT receiving entity instead of the MMT transmitting entity, and after 1200 seconds, the MMT transmitting entity, such as the content server 200, is queried for validation of the corresponding MMT content. MMT content may be delivered to an MMT receiving entity on behalf of the content server 200 .

In addition, the cache information message may further include information about the content server 200, for example, a host_name field.

In addition, the cache information message of the present invention described above may be delivered through an MMT signaling message separate from the MMT contents, or may be included in the MMT contents and delivered.

The caching control module 352b blocks communication between the client device 100 and the content server 200 when it is determined that the caching determination module 352a is caching MMT content, and the storage unit 352b blocks communication between the client device 100 and the content server 200. A process of transferring MMT contents stored in 353 to the client device 100 through the communication unit 351 may be performed.

That is, when the caching control module 352b of the present invention confirms that it is caching the MMT content in a situation where the MMT content is received from the content server 200, further MMT content is delivered to the client device 100. It can block the content server 200 and transmit the MMT content to the client device 100 on behalf of the content server 200 . At this time, since the caching control module 352b of the present invention is caching the MMT content in units of MPUs, the MPU identification information of the last delivered MMT content is checked and sequentially starting with the MPU corresponding to the next MPU identification information. It can be controlled to be transmitted to the client device 100.

In addition, the caching control module 352b of the present invention stores MMT for the content server 200 from the client device 100 when the storage unit 353 stores the entirety of any one asset or MMT package. When the content transmission request is confirmed, the corresponding MMT content may be directly transmitted to the client device 100 .

In addition, the caching control module 352b of the present invention uses the cache information message included in the MMT content when the MMT content transmitted from the content server 200 to the client device 100 is not being cached. It is possible to determine whether to cache for , and support the caching process.

In addition, when the caching control module 352b of the present invention intends to transmit the MMT content it is caching to the client device 100, the caching information message may be included in the MMT content and transmitted.

That is, the caching information message indicating whether or not caching of the present invention corresponds to the MMT content when an MMT sending entity that wants to transmit MMT content transmits the MMT content to an MMT receiving entity that wants to receive the MMT content. It can be transmitted by being included in the MMT content, or transmitted through a separate MMT signaling message corresponding to the MMT content.

The MMT content 353a stored in the storage unit 353 may be divided into units of MPUs, stored and managed, and may serve to store and manage caching information messages.

The storage unit 353 may temporarily store various data generated during execution of the application program, including an application program required for function operation according to an embodiment of the present invention. In particular, the storage unit 353 according to an embodiment of the present invention may store the MMT contents 353a, and in this case, the MMT contents 353a may be divided and stored in units of MPUs.

This storage unit 353 may largely include a program area and a data area. The program area stores information such as an operating system (OS) for driving the cache device 350 . The data area is an area where data generated according to the use of the cache device 350 is stored, and as described above, various commands for processing the MMT content 353a may be stored. The storage unit 353 may include a flash memory, a hard disk, a multimedia card micro type memory (eg SD or XD memory, etc.), RAM, ROM ( ROM) may be configured to include a storage medium.

Above, the main configuration of the cache device 350 according to an embodiment of the present invention has been described.

Hereinafter, a content transmission method according to an embodiment of the present invention will be described with reference to FIGS. 5 to 8 .

5 to 8 are data flow diagrams for explaining an MMT content transmission method according to an embodiment of the present invention.

First, in order to transmit content in the cache device 350 of the present invention, the cache device 350 must store MMT content in advance.

Referring to FIG. 5, the client device 100 may request MMT content from the content server 200 (S103) in a state in which a connection is made to the content server 200 (S101). Upon receiving this, the content server 200 transmits the MMT content to the client device 100 (S105).

The MMT content delivered by the content server 200 to the client device 100 may be streamed and transmitted in units of MPUs. That is, the content server 200 of the present invention may sequentially transmit MMT content to the terminal 100 according to identification information of MPUs such as MPU1, MPU2, MPU3, ....

The cache device 350 monitoring this process (S107) checks whether the content server 200 has cached the MMT content delivered to the client device 100, and if the MMT content is not being cached, the A cache information message may be checked to cache the MMT content (S109). Then, it is determined whether the MMT content can be cached according to the cache policy (Cacheable) of the cache information message, and if the MMT content can be cached (S111), the MMT content is cached (S113). In this case, you can exit without caching the contents. At this time, the cache device 350 of the present invention may control the process of dividing and storing the MMT content in units of MPUs.

In addition, the cache information message of the present invention may include information on a caching policy for each MPU of MMT content. Through this, the cache device 350 of the present invention can control a more detailed caching process in units of MPUs. For example, the S111 determination process may be performed by checking the caching information message for each MPU, and if MPU1 and MPU2 are set to 'allow caching', the MPU1 and MPU2 cache, and if MPU3 is set to 'cannot cache', MPU3 can be controlled not to cache. Through this, when some scenes of MMT contents are to be provided only to paid subscribers, the cache device 350 of the present invention can cache only MMT contents that can be provided to all users without caching the corresponding scenes.

When the MMT content is cached through this process, the cache device 350 of the present invention can provide the MMT content to the client device 100 instead of the content server 200 .

Regarding this, referring to FIG. 6, as described above, the client device 100 of the present invention may request transmission of specific MMT content to the content server 200 in a state of being connected to the content server 200 (S201) ( S203).

In addition, the content server 200 of the present invention may stream the corresponding MMT content in MPU units and transmit it to the client device 100 (S205), and the cache device 350 monitoring this may transmit the MMT delivered in MPU units. It is determined whether the content is hit or not (S207 to S209).

At this time, the cache device 350 of the present invention may check the asset identification information in units of MPU. That is, since MPUs for the same asset have the same asset identification information, the cache device 350 of the present invention has an MPU corresponding to the same asset identification information as the MMT content delivered to the client device 100 stored in the storage unit If the MPU is hit more than a predetermined number of times, for example, 3 consecutive hits (S211), the cache device 350 of the present invention directly transfers the MMT content to the client device 100. In order to provide the MMT content delivered from the content server 200 to the client device 100, the transmission is blocked (S215).

In addition, the cache device 350 of the present invention may transmit cached MMT content to the client device 100 sequentially from the corresponding MPU after the MMT content finally delivered to the client device 100 in step S205 (S217). .

Meanwhile, when the content delivery system of the present invention includes the cache controller 340, the cache device 350 may transmit MMT content under the control of the cache controller 340.

At this time, the cache controller 340 of the present invention may store and manage cache lists cached by the plurality of cache devices 350 in advance, and through this, it is possible to identify and determine an optimal cache device for providing content. Also, the cache list may include identification information of the MPU for the MMT content, and the cache controller 340 may determine a cache hit process using the identification information of the MPU.

That is, as shown in FIG. 7 , the first cache device 350A and the second cache device 350B caching the MMT content store the cache list for the MMT content held by the cache controller 340 at regular intervals. ) can be transmitted. The cache list may include MPU identification information for MMT content held.

Upon receiving this, the cache controller 340 may store and manage the cache list according to the identification information of the cache device 350, and then, the client device 100 may be connected to the content server 200 by the MMT server ( 200) to request transmission of the MMT content (S405), and the content server 200 may stream and transmit it to the client device 100 (S407).

The cache controller 340, which is located between the client device 100 and the content server 200 and monitors information transmitted and received between the client device 100 and the content server 200 (S409), cache device 350 In addition, since the cache list includes MPU identification information, a cache hit is determined by comparing MPU identification information of MMT contents transmitted from the content server 200 to the client device 100. It can (S419).

And, if more than a certain number of consecutive hits occur (S415), the cache controller 340 blocks the transfer of the MMT content from the content server 200 to the client device 100 (S417), and the corresponding MMT content Content transmission may be requested to the first cache device 350A, which is confirmed to be caching (S419), and accordingly, the first cache device 350A transmits the content to the client device 100 instead of the content server 200. be able to transmit.

In addition, if the cache device 350 of the present invention does not cache the MMT content delivered from the content server 200, it may perform the process of caching the MMT content, but MMT content delivered from another cache device 350. A caching process for MMT may be determined and, if the corresponding MMT content is not being cached, a caching process may be performed.

In this regard, referring to FIG. 8 , in a situation where the client device 100 requests MMT content from the content server 200 (S501) and the MMT content is being delivered from the content server 200 to the terminal 100, the above The process may be monitored by the second cache device 350B (S505), and it is determined whether the corresponding MMT content is being cached. As a result of the determination, if the second cache device 350B is confirmed to be in a cache hit state (S509), the first cache device 350B is to provide MMT content to the client device 100 instead of the content server 200. The content transmitted from the content server 200 may be blocked (S511) and the MMT content stored therein may be sequentially delivered to the client device 100 in units of MPUs (S513).

At this time, the first cache device 350A, which is located between the client device 100 and the second cache device 350B and can monitor (S515) the client device 100 and the second cache device 350B, The cache information message of the MMT content delivered from the first cache device 350B is checked (S519), and the cache policy included in the cache information message is checked. And, if the cache policy is set to be cacheable (S521), the corresponding content can be cached (S523).

In addition, the cache information message checked in step S519 may be a cache information message transmitted by the origin server, and cache information newly set by the second cache device 350B, which is the MMT transmission entity in FIG. 8 . It can be a message.

As described above, according to the present invention, when an MMT sending entity that wants to transmit MMT contents transmits MMT contents to an MMT receiving entity that wants to receive MMT contents, a cache information message indicating a cache policy corresponding to the MMT contents is transmitted. By constructing and transmitting, the cache device 350 located on the path can cache the corresponding MMT content.

In addition, the present invention can determine whether or not to cache content in units of MPUs, so that a more detailed caching policy for MMT content can be established and managed.

In addition, in the present invention, when there is a transmission flow of MMT content delivered from the content server 200 to the client device 100, it is determined whether an entity located on the path is a cache hit in units of MPUs, and if it is in a cached state, Then, it can be transmitted to the client device 100 immediately from the MPU, so that more rapid content transmission may be possible.

In the above, the MMT content transmission method according to the embodiment of the present invention has been described.

The voice recognition service providing method of the present invention as described above may be provided in the form of a computer readable medium suitable for storing computer program instructions and data.

In particular, the computer program of the present invention provides an MMT content transmission method in a cache device capable of monitoring information between an MMT transmitting entity that wants to transmit MMT content and an MMT receiving entity that wants to receive MMT content. In the step of checking whether the cache device stores MMT (MPEG Media Transport) content requested by the MMT receiving subject in units of MPU (Media Processing Unit), and if it is determined that the MMT content is stored, Controlling the stored MMT content to be transmitted to the MMT receiving entity, or if it is determined that the MMT content is not stored, checking the cache information message of the MMT content delivered from the MMT transmitting entity and determining that it is cacheable If so, a step of copying and storing the MMT content transmitted from the MMT transmitting subject may be executed.

Such a computer-readable recording medium may include program commands, data files, data structures, etc. alone or in combination, and includes all types of recording devices storing data that can be read by a computer system. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs (Compact Disk Read Only Memory) and DVDs (Digital Video Disks). Optical media), magneto-optical media such as floptical disks, and program instructions such as ROM (Read Only Memory), RAM (RAM, Random Access Memory), flash memory, etc. and a hardware device specially configured to do so.

In addition, the computer-readable recording medium is distributed in computer systems connected through a network, so that computer-readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the technical field to which the present invention belongs.

Although the above has been described and illustrated in relation to preferred embodiments for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described in this way, without departing from the scope of the technical idea. It will be readily apparent to those skilled in the art that many changes and modifications can be made to the present invention. Accordingly, all such appropriate changes and modifications and equivalents should be regarded as falling within the scope of the present invention.

The present invention relates to a method for transmitting content, and more particularly, when the cache device is caching MMT content requested by a client device, the cache device may provide the MMT content to the client device instead of a content server. , MMT content transmission method in the cache device.

According to the present invention, the cache device constructs information on the MMT content it is caching in the form of a cache information message and transfers or shares the information to other cache devices, cache controllers, and content servers, thereby transmitting content that operates based on MMT. It can be applied to the system more easily, and through this, there is an advantage in that it is easy to change and apply the existing CDN service based on MMT. In addition, the present invention has industrial applicability because it is not only sufficiently commercially available or commercially viable, but also to the extent that it can be clearly implemented in practice.

100: client device 200: content server 300: network
310: internet network 320: core network 330: access network
340: cache controller 350: cache device 351: communication unit
352: control unit 353: storage unit
1000: content delivery system

Claims (11)

A cache device capable of monitoring information between an MMT sending entity that wants to transmit MMT content and an MMT receiving entity that wants to receive MMT content, comprising:
The cache device
A storage unit for storing MMT (MPEG Media Transport) content divided into MPU (Media Processing Unit) units; and
Whether or not the MMT content requested by the MMT receiving subject is stored in the storage is checked in units of the MPU, and if it is determined that the MMT content is stored, the MMT content stored in the storage is stored in the MMT receiving subject. Control unit for controlling to be transmitted to;
including,
The control unit
If the MMT content is not stored, a cache information message including information on a caching policy for each MPU of the MMT content delivered from the MMT sender is checked, and only cacheable MPUs are copied and stored in the storage unit. do,
The cache information message is
A cache device further comprising an asset ID, an expiration time (expire_time), and a maximum reference time (Max_age). According to claim 1,
The control unit
The cache device, characterized in that for determining that the MMT content is stored when the check is performed in units of the MPU and consecutive hits are generated more than a predetermined number of times. According to claim 2,
The control unit
Cache device, characterized in that for checking the asset ID through the hash value of the MPU, and determining that the MMT content is stored when the MPU including the same asset ID exists more than the predetermined number of times. According to claim 1,
The control unit
When it is determined that the MMT content is stored, the MMT content stored in the storage unit is controlled to be transmitted to the MMT receiving entity, and at the same time, transmission of the MMT content transmitted from the MMT transmitting entity is blocked. cache device. delete delete delete A method for transmitting MMT content in a cache device capable of monitoring information between an MMT transmitting entity that wants to transmit MMT content and an MMT receiving entity that wants to receive MMT content, the method comprising:
the cache device,
Checking whether MMT (MPEG Media Transport) content requested by the MMT receiving subject is stored in units of MPU (Media Processing Unit);
if it is determined that the MMT contents are stored, controlling the stored MMT contents to be transmitted to the MMT receiving subject; and
If the MMT content is not stored, check the cache information message including information on the caching policy for each MPU of the MMT content delivered from the MMT sender, copy only the cacheable MPU and control to store in the storage unit Step; including,
The cache information message is
The MMT content transmission method further comprising an asset ID, an expiration time (expire_time), and a maximum reference time (Max_age). delete A computer-readable recording medium recording a program for executing the method according to claim 8.
delete

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