KR102004311B1 - Method for detection of hand-over for mobile network, and apparatus for the same - Google Patents

Abstract

The present invention relates to a handover detection method, a cache apparatus and a cache control apparatus for the same, and more particularly, The mobile terminal manages the terminal connection information including the identification information and determines that the user terminal is handed over when a content retransmission request message of the user terminal is detected by another cache apparatus, .

Description

TECHNICAL FIELD [0001] The present invention relates to a handover detection method, a cache apparatus and a cache control apparatus for the same,

The present invention relates to a handover detection method, and more particularly, to a handover detection method using a retransmission message for a content request received from a user terminal, a cache apparatus for the same, and a cache control apparatus .

2. Description of the Related Art [0002] In recent years, with the improvement of performance of a user terminal such as a smart phone and development of a mobile communication technology, a user can access a web server provided by a contents provider (CP) , Video, audio, and applications. In addition, the frequency of using contents through a mobile network (e.g., mobile communication network) in which the mobility of users is guaranteed is also continuously increasing.

However, while the number of Web servers provided by a content provider (CP) is limited, the number of users wishing to access the web server is rapidly increasing. As a result, various problems such as data loss, bottleneck, transmission delay, .

The CDN (Contents Delivery Network) is one that has emerged to solve this problem.

CDN is a service for reliably delivering various kinds of contents such as photographs, movies, music videos, etc. to user terminals. More specifically, the CDN may be configured to transmit various contents such as image, video, audio, etc., which are located in a web server of a content provider (CP) remote from the user terminal, In the cache apparatus in a distributed manner. Thereafter, when a content request message is received from the user terminal, the cache device located closest to the user terminal transmits the content from the cache device to the user terminal in response. As a result, the CDN improves the content access speed and can provide contents more stably.

The CDN service with various advantages has been introduced mainly in the wired network, and technologies for application to the mobile network are emerging. However, in the CDN service, there is no method that can effectively detect the handover of the user terminal that occurs during the content transmission in the wireless network.

For example, in the LTE (Long Term Evolution), which is currently being commercialized, when only the eNodeB is changed according to the movement of the UE, when the eNodeB and the MME (Mobility Management Entity) are changed, the eNodeB and the S- (Vertical handover) when the eNodeB, the MME, and the S-GW (Serving Gateway) are changed, the 3G network changes from the LTE network or the LTE network to the 3G network (vertical handover) There is a problem that the cache apparatus must be designed considering the structure and characteristics of each network in advance.

Therefore, it is necessary to develop a technology capable of detecting a handover of a user terminal, which occurs during content transmission in a mobile network to which the CDN service is applied, even when the structure and characteristics of the network are not recognized in advance.

Korean Registered Patent No. 10-1070982, Sep. 29, 2011 Registered (name: method for providing contents to portable terminal using a plurality of CDN servers and control device for the method)

Disclosure of Invention Technical Problem [8] The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a handover detection method capable of more effectively detecting a handover of a user terminal occurring during a CDN service in a mobile network, And to provide a control device.

It is another object of the present invention to provide a handover detection method capable of detecting a handover of a user terminal more easily without considering the structure and characteristics of the network, and a cache apparatus and a cache control apparatus therefor.

In particular, the present invention relates to a handover detection method for detecting a handover of a user terminal by monitoring a content retransmission request message generated from a user terminal that has not received content through a handover while receiving content through a specific radio access network And a cache apparatus and a cache control apparatus therefor.

More specifically, the present invention stores terminal access information for a user terminal that is providing content for each cache device, stores the terminal access information for a user terminal that is not receiving content by handover while receiving content through a specific radio access network A handover detection method for determining that the user terminal is handed over when the terminal access information for the user terminal that transmitted the content retransmission request message is stored, Cache control device.

According to an aspect of the present invention, a cache apparatus includes a storage unit and a control unit. The storage unit stores at least one content and terminal access information received from another cache apparatus. The controller monitors a message transmitted from at least one user terminal and detects a content retransmission request message. When the content retransmission request message is detected, the controller extracts the terminal address information of the user terminal from the content retransmission request message. If the extracted terminal address information is included in the pre-stored terminal connection information, the control unit notifies the handover of the user terminal to another cache apparatus that has transmitted the terminal connection information.

In the cache apparatus according to an embodiment of the present invention, the controller extracts content requested from the user terminal and provides the extracted content to the user terminal.

Here, the terminal connection information may include identification information of the corresponding cache apparatus and terminal address information extracted from the content request message.

In the cache apparatus according to an embodiment of the present invention, after the control unit notifies the other cache apparatus of the handover of the user terminal, the content identification information and the other cache apparatus are transmitted from the other cache apparatus to the user terminal And may provide the user terminal with data after the content stop point in the content corresponding to the content identification information.

In the cache apparatus according to an embodiment of the present invention, the controller may generate terminal connection information for a user terminal providing content and transmit the terminal connection information to at least one other cache apparatus.

In addition, as another solution means of the above-mentioned problem of the present invention, there is provided a cache control apparatus including a communication unit, a storage unit, and a control unit. The communication unit of the cache control unit is for transmitting and receiving data to and from a plurality of cache devices distributed on the network. The storage unit stores, for each of the plurality of cache apparatuses, terminal access information including terminal address information for a user terminal receiving content in an area of each cache apparatus and identification information of the corresponding cache apparatus. The control unit, when receiving the terminal connection information for the specific user terminal receiving the content from the specific cache apparatus through the communication unit, compares the terminal connection information stored previously for each of the plurality of cache apparatuses in the storage unit , It is determined whether or not the specific user terminal is handed over.

Here, the terminal connection information is transmitted from the specific cache apparatus to the cache control apparatus when the specific cache apparatus detects the content request message or the content re-request message transmitted from the specific user terminal.

The control unit compares the received terminal access information with the received terminal access information so that if the terminal address information matches but the identification information of the cache apparatus and the terminal access information are stored in the storage unit, It can be judged that it is over.

In addition, in the cache control apparatus, when it is determined that the specific user terminal has been handed over, the control unit refers to the identification information of the cache apparatus included in the terminal connection information stored in the storage unit, And notifies the handover of the specific user terminal to the previous cache apparatus that was connected before being overlaid.

The control unit of the cache control unit may transmit the content transmission information on the content data transmitted from the previous cache apparatus connected to the specific user terminal before handover to the specific user terminal, To a cache device.

At this time, the control unit of the cache control apparatus can receive the content transmission information on the content data transmitted from the previous cache apparatus which notified the handover of the specific user terminal to the specific user terminal.

The control unit of the cache control unit may further store the received terminal connection information in the storage unit if it is determined that the specific user terminal has not been handed over and if the specific user terminal is determined to be handed over, The identification information of the cache apparatus included in the terminal connection information stored in the storage unit is changed to the identification information of the cache apparatus included in the received terminal connection information.

In addition, the present invention provides, as a further task solution, a method, comprising the steps of: monitoring a message sent by a cache device from a user terminal; Detecting the content retransmission request message by the cache apparatus through the monitoring; Extracting the terminal address information of the user terminal from the content retransmission request message, if the content retransmission request message is detected; Checking whether the extracted terminal address information is included in the pre-stored terminal access information by referring to the terminal access information of the user terminal providing the content by the previously stored other cache apparatus; And if the terminal address information is included in the pre-stored terminal connection information, the user terminal confirms another cache device that the user terminal was receiving content through the terminal connection information, And notifying the handover of the handover.

The method of detecting a handover in a cache apparatus according to claim 1, further comprising: before the step of checking whether the terminal address information is included in the terminal connection information, Receiving; And storing the terminal connection information received by the cache apparatus.

The method of detecting a handover in the cache apparatus is characterized in that after notifying the handover of the user terminal, the cache apparatus receives content information including information on content identification information and content abortion time from the other cache apparatus step; And providing the data after the content suspension time point to the user terminal among the contents corresponding to the content identification information.

The method of detecting a handover in the cache apparatus may further include generating terminal access information including the identification information of the cache apparatus and terminal address information of the user terminal providing the content, And transmitting the terminal connection information to at least one other cache apparatus located in the vicinity of the cache apparatus.

In addition, the present invention provides, as still another solution to the above-mentioned problem, a method comprising: receiving a content request message transmitted from a user terminal; Providing the content corresponding to the content request message to the user terminal; Extracting terminal address information of the user terminal from the content request message, and generating terminal access information including the terminal identification information and the terminal address information; And transmitting the terminal connection information to at least one other cache apparatus located in the vicinity of the cache apparatus.

The method of detecting a handover in a cache apparatus includes the steps of: the cache apparatus receiving a handover notification of the user terminal from another cache apparatus; Checking whether the content is being transmitted to the user terminal by the cache device; Stopping the transmission of the content to the user terminal if there is content being transmitted to the user terminal; Generating content information including content identification information on content for which the cache device has been suspended and information on a content stop time; And transmitting, by the cache apparatus, the content information to another cache apparatus notified of the handover.

In addition, according to another aspect of the present invention, there is provided a cache apparatus including: a plurality of cache apparatuses distributed on a network; terminal address information of a user terminal receiving content in an area of each cache apparatus; Storing terminal connection information including the terminal connection information; Receiving terminal access information for a specific user terminal receiving current contents from a specific cache apparatus in an area of the specific cache apparatus; And comparing the received terminal connection information with pre-stored terminal connection information to determine whether the specific user terminal is handed over.

The terminal access information is transmitted from the specific cache apparatus to the cache control apparatus when the specific cache apparatus detects the content request message or the content re-request message transmitted from the specific user terminal, .

In addition, in the method for detecting a handover of the cache control device, the step of determining whether to perform the handover may include comparing the terminal access information with the received terminal access information, It is possible to determine that the specific user terminal has been handed over.

The handover detection method in the cache control apparatus may further include the step of, when it is determined that the specific user terminal is handed over, referring to the identification information of the cache apparatus mapped with the same terminal address information, And notifying the handover of the user terminal to a previous cache device connected before the specific user terminal is handed over.

The method of detecting a handover of a cache control apparatus according to the present invention is characterized in that when the specific user terminal is judged to have been handed over, a previous cache apparatus connected before handover transmits content transmission information on content data transmitted to the user terminal To the specific cache apparatus.

The method of detecting a handover of the cache control apparatus may further include receiving content transmission information on content data transmitted from the cache apparatus that has notified handover of the specific user terminal to the specific user terminal.

The method further comprises storing the received terminal connection information in the storage unit when the specific user terminal is determined as not being handed over, And changing the identification information of the cache apparatus included in the terminal connection information stored in the storage unit to the identification information of the cache apparatus included in the received terminal connection information.

According to the present invention, there is an advantage that handover detection can be performed by applying an existing CDN service based on a wired network to a mobile network without a large design change.

Particularly, according to the present invention, it is possible to more easily detect handover of a user terminal occurring during content transmission in a mobile network to which a CDN service is applied.

Particularly, according to the present invention, it is possible to detect handover of a user terminal independently of a mobile network, thereby facilitating system implementation.

1 is a schematic configuration diagram of a general content providing system.
2 illustrates a structure of a content providing system operating in a mobile network according to an embodiment of the present invention.
3 is a view for explaining a principle of handover detection in a content providing system according to an embodiment of the present invention.
4 is a block diagram illustrating a main configuration of a cache apparatus according to an embodiment of the present invention.
5 is a schematic flowchart of a handover detection method in a content providing system operating in a mobile network according to an embodiment of the present invention.
6 is a flowchart illustrating a method of detecting a handover in a content providing system operating in a mobile network according to an exemplary embodiment of the present invention.
7 is a flowchart illustrating a process of generating and transmitting UE connection information in a handover detection method according to an embodiment of the present invention.
8 is a flowchart of a content providing system to which a handover detection method according to an embodiment of the present invention is applied.
9 is a block diagram illustrating the structure of a content providing system according to another embodiment of the present invention.
10 is a block diagram illustrating a main configuration of a cache control apparatus according to another embodiment of the present invention.
11 is a flowchart illustrating a handover detection process in a content providing system according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention. This is to omit the unnecessary description so as to convey the key of the present invention more clearly without fading. Also, the terms first, second, etc. are used for describing various components and are used only for the purpose of distinguishing one component from another component, and are not used to define the components.

The same reference numerals are used for portions having similar functions and functions throughout the drawings.

Hereinafter, a method of detecting a handover in a mobile network to which a CDN service is applied according to an embodiment of the present invention will be described with reference to FIG.

1 is a diagram for explaining a basic concept of a content providing system.

Referring to FIG. 1, a content providing system 1000 may include a user terminal 100, a content providing apparatus 200, and a plurality of cache apparatuses 330 distributed on a network 300.

The user terminal 100 confirms a request for a specific content from a user to a terminal that intends to use the content served by the content providing apparatus 200 according to a user request. The request for the specific content can be made by selecting a specific content from a plurality of contents displayed in the service page. Accordingly, the user terminal 100 confirms the URL (Uniform Resource Locator) of the content requested by the user, and transmits the address information (IP address) of the content providing apparatus 200 corresponding to the URL through a DNS (Domain Name System) ). Then, the user terminal 100 requests content from the content providing apparatus 200 corresponding to the address information, and then receives the content from the content providing apparatus 200.

The content providing apparatus 200 provides various contents such as photographs, video, audio, applications, etc. to the user terminal 100 and provides at least one content from a contents provider (CP) And provides the content to a plurality of user terminals 100 through the network 300.

A plurality of cache devices 330 are distributed on the network 300 and store a part or all of a plurality of contents to be served to the user terminal 100 by the content providing device 200, And transmits it to the user terminal 100 instead of the device 200.

For example, the content providing apparatus 200 may generate a copy of the content to a plurality of cache devices 330 distributed on the network 300 according to a predetermined content distribution policy, do. Here, the content distribution policy may be set differently according to a CDN (Contents Delivery Network) provider. As another example, according to a transparent cache technique, a plurality of cache devices 331, 332, and 370 may transmit traffic transmitted from the content providing apparatus 200 to the user terminal 100 through a mirroring technique The content may be received and stored from the content providing apparatus 200 through a mirroring method of copying and storing the content or a caching method of storing the content requested by the user terminal 100 according to a preset cache policy.

The content providing system may be configured to select a cache device to provide content to the user terminal 100 in an environment in which a predetermined content is stored in a plurality of cache devices 330 as described above, ) Device (not shown).

More specifically, the user terminal 100 generates a content request message (for example, an HTTP GET message) including URL information about specific content requested by the user at the request of the user. The user terminal 100 obtains the address information of the content providing apparatus 200 through the DNS (not shown), and then transmits the content request message to the content providing apparatus 200. A GLB device (not shown) connected to the network 300 together with the content providing device 200 monitors the GLB device to determine an optimal one of the plurality of cache devices 331, 332, and 370 distributed on the network 300 Selects the cache device, and returns the address information of the selected cache device 330 to the user terminal 100.

For example, the optimal cache apparatus may be selected in consideration of the load state of the cache apparatus or the type of contents stored in the cache apparatus, and the cache apparatus closest to the user terminal 100 may be selected.

Thereafter, when the address information for the specific cache apparatus 330 is returned from the GLB apparatus (not shown), the user terminal 100 transmits a content request message to the cache apparatus 330, And provide the contents corresponding to the message to the user terminal 100. [

A network 300 in which a plurality of cache devices 330 are distributed at key points means a communication network for transmitting and receiving information between the user terminal 100 and the content providing apparatus 200. In particular, it may be a mixed form of one or more communication networks implemented using various types of wired / wireless communication technologies such as an internet network, an intranet network, a mobile communication network, and a satellite communication network as well as a single type communication network. A network 300 according to an embodiment of the present invention includes a mobile network that communicates with a user terminal 100 in a wireless manner.

In addition, the network 300 of the present invention may include a cloud computing system capable of storing computing resources such as hardware, software, etc., coupled with a cache device, and providing the computing resources required by the client to the terminal. Here, cloud computing means a computer environment in which all information of a user is stored in a server on the Internet and the information can be used anytime and anywhere through various IT devices.

The network 300 may be a closed network such as a LAN (Local Area Network) or a WAN (Wide Area Network), an open network such as the Internet, a CDMA (Code Division Multiple Access), a WCDMA Multiple Access), Global System for Mobile Communications (GSM), Long Term Evolution (LTE), and the like.

The present invention is for detecting a handover of a user terminal 100 receiving content in a content providing system 1000 in which a plurality of cache devices 330 exist, The handover of the user terminal 100 occurring during the provision of the content is detected.

Hereinafter, a method of detecting a handover in a content providing system operating in a mobile network according to an embodiment of the present invention will be described with reference to FIG.

2 illustrates a structure of a content providing system including a mobile network according to an embodiment of the present invention.

Referring to FIG. 2, a network 300 of a content providing system 1000 according to an exemplary embodiment of the present invention includes a mobile network 310 to which a user terminal 100 accesses in a wireless manner. In addition, the mobile network 310 may be connected to an IP network including the Internet network 320. Accordingly, the user terminal 100 can communicate with the content providing apparatus 200 through the mobile network 310 and the Internet network 320. [

The mobile network 310 includes a plurality of radio access networks 311 and 312 and a core network 313. Here, the plurality of radio access networks 311 and 312 are divided into a first radio access network 311 and a second radio access network 312 for convenience of explanation.

As described above, the user terminal 100 may be connected to the mobile network 310 as a terminal of a user who uses content provided from the content providing apparatus 200 according to a user request. At this time, the user terminal 100 can be handed over between the plurality of radio access networks 311 and 313 included in the mobile network 310 according to the movement of the user.

For example, when the user terminal 100 is located in the coverage area of the first radio access network 311 and is connected to the first radio access network 311 and a content request is generated, the user terminal 100 transmits a local DNS (not shown) And transmits the content request message to the content providing apparatus 200 corresponding to the acquired address information. Thereafter, content is received from the content providing apparatus 200 or received through the cache apparatus to be described later.

The first and second radio access networks 311 and 312 that constitute the mobile network 310 are access networks for performing radio communication with the user terminal 100. The first and second radio access networks 311 and 312 may be a base station, A Node B, an eNodeB, and the like, and a base station controller such as a base station controller (BSC) and a radio network controller (RNC).

Alternatively, the digital signal processing unit and the radio signal processing unit integrally implemented in the base station may be divided into a digital unit (hereinafter referred to as DU) and a radio unit (hereinafter referred to as RU) A plurality of RUs (not shown) may be provided in each of the regions, and a plurality of RUs (not shown) may be connected to a centralized DU (not shown).

The core network 313 configuring the mobile network 310 together with the first and second radio access networks 311 and 312 includes first and second radio access networks 311 and 312 and an external network 320, ).

The core network 313 is a control system that performs main functions for mobile communication services such as call processing, mobility control and switching between a plurality of radio access networks 311 and 312, And various functional elements such as a packet core device (not shown) and a router (not shown) serving to perform interworking between the mobile network 310 and an external network such as the Internet network 320 Lt; / RTI > Since the elements constituting the core network 313 are well-known structures, a detailed description thereof will be omitted in the embodiment of the present invention.

The Internet network 320 is a conventional public communication network in which information is exchanged according to the TCP / IP protocol. The Internet network 320 is connected to the content providing apparatus 200 and transmits content provided from the content providing apparatus 200 to the core network 313 and the first and second radio access networks 311 and 312 to the user terminal 100 or to a plurality of cache devices 331 and 332 according to a predetermined distribution policy.

A GLB device (not shown) that plays a role of distributing a load for providing contents is connected to the Internet network 320 or the mobile network 310 and more specifically to the core network 313, 331, and 332, or may perform various controls on the cache apparatus. The plurality of cache devices 331 and 332 are divided into a first cache device 331 and a second cache device 332 for convenience of explanation.

For example, when the user terminal 100 accesses the first radio access network 311 at the request of the user and the URL information of the specific content desired by the user is input, the user terminal 100 transmits a content request message And acquires address information in the content providing apparatus 200 through a local DNS (not shown). After the GLB device (not shown) confirms the content request message to the content providing apparatus 200, the GLB device (not shown) transmits a content request message to the content providing device 200 through a plurality of caches The first cache device 331 closest to the first radio access network 311 is selected and the address information on the first cache device 331 is returned to the user terminal 100 . The delivery of the address information (IP address) at this time can be implemented by various known methods such as, for example, HTTP redirecting. Thereafter, the user terminal 100 transmits a content request message to the first cache apparatus 331, and when the content corresponding to the content request message received from the user terminal 100 exists in the first cache apparatus 331, The content providing apparatus 200 may provide the content to the user terminal 100 or may request and receive the corresponding content from the content providing apparatus 200 and may mirror the received content and provide the content to the user terminal 100.

The content request message transmitted from the user terminal 100 to the content providing apparatus 200 through the mobile network 310 and the Internet network 320 may be distributed to the mobile network 310, For example, the first cache device 331 is verified through a mirroring technique. If the first cache apparatus 331 is caching the content requested by the content request message, the first cache apparatus 331 may transmit the content stored in the first cache apparatus 331 to the first radio access network 311 instead of the content providing apparatus 200. [ To the user terminal 100 directly. On the other hand, if the requested content is not being cached, the content request message transmitted from the user terminal 100 is transmitted to the content providing apparatus 200 and transmitted from the content providing apparatus 200 to the user terminal 100 The first cache device 331 copies and stores the content.

Here, the first and second cache devices 331 and 332 according to an embodiment of the present invention will be described in more detail. The first and second cache devices 331 and 332 of the present invention are mobile devices The content providing server 310 may distribute content to the user terminal 100 and may be distributed to the edge of the core network 313 connected to the first and second radio access networks 311 and 312. For example, May be connected between the first and second radio access networks 311 and 312 and a packet core apparatus (EPC) (not shown) of the core network 313 using a router (not shown).

The cache devices 331 and 332 may be disposed on the basis of the radio access networks 311 and 312 and store a part or all of the content provided from the content providing apparatus 200 and transmit the content providing apparatus 200 Instead, the user terminal 100 connected to the radio access networks 311 and 312 performs content provision.

For reference, the mobile packet transmitted and received on the mobile network 310 is transmitted through a GTP (GPRS Tunneling Protocol) tunnel unlike the Internet network 320. For example, when the user terminal 100 transmits a content request message requesting content provided by the content providing apparatus 200, the source address information of the user terminal 100 (the IP address of the user terminal 100) (ENodeB) of the first radio access network 311 transmits the IP packet including the destination address information (IP information of the content providing apparatus 200) to the first radio access network 311, Converts the GTP header, the UDP header, and the IP header for GTP tunneling into a mobile packet, and transmits the mobile packet to the core network 313. At this time, the GTP header may include tunneling end point ID (TEID) assigned to the user terminal 100. The core network 313 removes the GTP header, the UDP header, and the IP header for GTP tunneling, and transmits the original IP packet transmitted from the user terminal 100 to the content providing apparatus 200 through the Internet- .

At this time, the first cache unit 331 monitors the mobile packet transmitted from the first radio access network 311 by using the mirroring technique or the like, checks the content request message of the user terminal 100, And transmits the stored contents to the user terminal 100 through the first radio access network 311. [

To this end, the first cache unit 331 converts the data of the content into a mobile packet including a GTP header, a UDP header and an IP header for GTP tunneling, and transmits the mobile packet to the first radio access network 311, The radio access network 311 may remove the GTP header, the UDP header, and the IP header for GTP tunneling in the received mobile packet, and may transmit the removed GTP header, the UDP header, and the IP header for GTP tunneling to the user terminal 100 through the radio interval.

At this time, the first and second cache devices 331 and 332 according to the embodiment of the present invention detect whether a handover occurs in the user terminal 100 while providing the content to the user terminal 100 .

In the following description, for convenience of explanation, it is assumed that each cache device 331 and 332 copies a mobile packet transmitted through the mobile network 310 without affecting traffic, and then copies the mobile packet to the user terminal 100 The present invention is not limited thereto. The content may be transmitted to the user terminal 100 through the caching method.

Referring to FIG. 2, the user terminal 100 may move to the second radio access network 312 while receiving content from the first cache device 331 while being connected to the first radio access network 311. The first cache device 331 generates the terminal access information indicating that content is being provided to the user terminal 100 in the area currently supported by the first cache device 331 when providing the content to the user terminal 100, To the other cache devices in the vicinity, for example, the second cache device 332. Herein, the terminal access information includes the source address information of the user terminal 100 extracted from the content request message, more precisely the terminal address information of the user terminal 100 and the identification information of the cache apparatus, And is identification information.

When the user terminal 100 moves to the area of the second radio access network 312 in the above state, the user terminal 100, which has received the content from the first cache device 331 through the first radio access network 311, The content retransmission request message is transmitted to the content providing apparatus 200. Since the user terminal 200 transmits the content retransmission request message to the content providing apparatus 200, .

In step S1, the user terminal 100 transmits a content request message (for example, an HTTP GET message) to the content providing apparatus 200 to establish a communication path.

Here, since the process up to the session connection is a known technique, a detailed description will be omitted.

In step S2, the first cache device 331 mirrors the content received from the content providing apparatus 200 and provides the mirrored content to the user terminal 100. [ The first cache device 331 transmits a message exchanged between the user terminal 100 and the content providing apparatus 200. The first cache apparatus 331 receives the content from the content providing apparatus 200, And provides the content received from the content providing apparatus 200 to the user terminal 100 in a mirrored manner.

Then, when the content corresponding to the content request message is normally received, the user terminal 100 transmits a response message (e.g., an ACK message) indicating that the content has been normally received. At this time, the ACK message provided by the user terminal 100 to the content providing apparatus 200 is transmitted together with the serial number. For example, if a data packet from 0 to 3,000 of the contents data packet is normally received The user terminal 100 has successfully received the data packet of up to 3000 times and then transmits an ACK message to the contents providing apparatus 200 to transmit the data packet 3001 (S3).

Here, if it is a normal process, the user terminal 100 must receive the data packet 3001 from the content providing apparatus 200. If the user terminal 100 moves out of the area of the first radio access network 311 as shown in FIG. 2 When moving to the second radio access network 312, the user terminal 100 will not receive any further mirrored content from the content providing apparatus 200, or more precisely, from the first cache apparatus 331.

Since the user terminal 100 has not normally received the content, it transmits a content retransmission request message to the content providing apparatus 200. Here, the content retransmission request message can be determined by checking the sequence number assigned to the message. That is, when the content is not normally received from the content providing apparatus 200, the user terminal 100 transmits the message transmitted to the content providing apparatus 200 last, as in the case of A including steps S4 through S6 of FIG. (E.g., ACK 3001) having the same serial number as the serial number is continuously transmitted to the content providing apparatus 200. Accordingly, when the content retransmission request message including the same serial number is repeatedly monitored, the second cache device 332 connected to the second radio access network 312, to which the user terminal 100 has moved, It is determined that the handover has occurred.

More specifically, when the content retransmission request message is received from the user terminal 100, the second cache apparatus 332 extracts the source address information, i.e., the terminal address information of the user terminal 100, from the content retransmission request message, It is determined whether the terminal address information is included in the terminal connection information received from the peripheral cache apparatus including the first cache apparatus 331. [ When the user terminal 100 receives the terminal access information received from the neighboring cache apparatus from the coverage area of the first radio access network 311, that is, the area supported by the first cache apparatus 331, 312) to the coverage area. Accordingly, when a content retransmission request message containing source address information found in another cache apparatus is detected as the source address information, the second cache apparatus 332 determines that the handover is performed.

As described above, by monitoring the messages transmitted and received from the user terminal 100 and using the content retransmission request message, it is possible to more easily detect the handover of the user terminal 100 without any design change .

In addition, by detecting a handover using a message transmitted and received by the user terminal 100, it is possible to more easily detect a handover without considering the structure and characteristics of various networks in advance, .

The method for detecting handover of the user terminal 100 in the content providing system operating in the mobile network according to an embodiment of the present invention has been schematically described above.

The mobile network 310 may include a configuration for performing various functions in addition to the configuration described above. However, only the configuration necessary for explaining the mobile content providing process has been described in the embodiment of the present invention.

For convenience of explanation, the TCP / IP protocol will be described as an example, but the present invention is not limited thereto.

Hereinafter, a main configuration and an operation method of the cache apparatus according to an embodiment of the present invention will be described in more detail.

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

For reference, the plurality of cache devices 330, 331, and 332 shown in FIGS. 1 and 2 differ only in the area for providing contents, and their configurations and operations are substantially the same.

2 and 4, the cache apparatus 330 of the present invention includes a storage unit 330a, a control unit 330b, and an interface unit 330c.

The storage unit 330a stores a part or all of one or more contents provided from the contents providing apparatus 200. [ In particular, the storage unit 330a may store a part or all of one or more contents selected according to a predetermined distribution policy or a caching policy.

In particular, the storage unit 330a of the present invention can store terminal connection information for content provisioning transmitted from at least one other cache apparatus by a control unit 330b, which will be described later.

In addition, the storage unit 330a stores the unique identification information of the cache apparatus 330 itself, which is necessary for generating the terminal connection information indicating that content is being provided to the user terminal 100 located in the area currently supported by the user, Location information of other cache devices in the vicinity, or identification information of other cache devices.

To this end, the storage unit 330a of the present invention includes a cache information storage module 330aa for storing identification information of the cache apparatus itself, location information or identification information of other cache apparatuses, and storing terminal access information generated or received, And a content storage module 361b for storing the content.

The control unit 330b may control the contents stored in the storage unit 330a according to a preset policy as a means for controlling the entire content delivery process in the cache apparatus 330. [ Here, the content may be received from the content providing apparatus 200 in a caching scheme or a mirroring scheme and stored.

In addition, the control unit 330b monitors a transmission / reception message of the user terminal 100 transmitted through the assigned radio access network 311 or 312, and when the monitoring result indicates that the user terminal 100 requests content, The content providing apparatus 200 is controlled so that the content is transmitted to the user terminal 100. In this case,

At this time, the control unit 330b may emulate the content to be transmitted to the user terminal 100 as a mobile packet and transmit the same. Here, the emulation means that the content data is composed of mobile packets transmitted from the core network 313 to the first radio access network 311. For example, when the user terminal 100 is the destination and the first A UDP header, a GTP header including the tunneling identification information, and an IP header for GTP tunneling to the IP packet from which the cache apparatus 331 originates. After generating such a mobile packet, it is provided to the user terminal 100.

If the content corresponding to the content request message does not exist in the storage unit 330a, the control unit 330a requests the corresponding content to the source server connected to the Internet 320, i.e., the content providing apparatus 200 And provide the received content to the user terminal 100 through the mirroring technology. At this time, by caching the content received from the content providing apparatus 200, the content may be provided to the user terminal 100 at a later time when the user terminal 100 requests the content.

Particularly, while the contents are being provided to the user terminal 100, the control unit 330b may notify the other cache apparatuses that the contents are being provided to the user terminal 100 located in the area currently supported by the user Terminal access information is generated and transmitted. Also, when terminal connection information of another cache apparatus is received, the received terminal connection information is stored in the storage unit 330a.

In addition, the controller 330b of the present invention monitors a message transmitted from the user terminal 100 and detects a handover of the user terminal 100 through the monitoring. 2 and 3, the controller 330b monitors a message transmitted through the mobile network 310, that is, a mobile packet, through the interface 330c, which will be described later, When a repetitive transmission of a content retransmission request message, that is, an ACK message including the same sequence number, is monitored from the user terminal 100, it is detected as a content retransmission request message, and the source address information, i.e., The terminal address information of the terminal 100 is extracted. If the extracted terminal address information is included in the terminal connection information previously stored in the storage unit 330a, the terminal determines that the user terminal 100 is a handed-over terminal.

Then, the control unit 330b confirms the past cache apparatus before the handover of the user terminal 100 through the terminal connection information, and transmits a handover notification message (e.g., Handover request, Handover required, Handover command) to the past cache apparatus And handover is notified.

In addition, when the handover notification message is received from another cache apparatus, the controller 330b extracts the terminal address information of the user terminal 100 from the handover notification message, and then checks the content provided by the corresponding terminal address information Abort the content transmission.

Thereafter, the control unit 330b generates content information including content identification information and content discontinuation time information, and transmits the content information to another cache apparatus that has transmitted the handover notification message.

To this end, the control unit 330b of the present invention generates a cache management module 330ba that stores or manages the content provided from the content providing apparatus 200 in the storage unit 330a according to a preset method, A handover detection module 330bb for monitoring a content request message and a content retransmission request message through a message transmitted and received through the mobile network 310 and detecting a handover through a content retransmission request message, And a content providing module 330bc for providing content according to a predetermined method.

In addition, the cache apparatus 330 of the present invention includes an interface unit 330c.

The interface unit 330c is a configuration for monitoring a message transmitted through the mobile network 310, that is, a mobile packet, and for transmitting the mobile packet generated by the control unit 330b to the mobile network 310. [ The interface unit 330c includes a mirroring module 330ca for copying a mobile packet transmitted through the mobile network 310 and providing the mobile packet to the controller 330b and a mobile packet generated by the controller 330b to the mobile network 310 And an injection module 330cb for transmitting the injection module 330cb to the user terminal 100 via the network.

The main configuration and the operation method of the cache apparatus according to the embodiment of the present invention have been described with reference to FIG. However, not all of the components shown in FIG. 4 are essential components, and a cache device may be implemented by more components than shown, or a cache device may be implemented by fewer components .

As described above, the cache apparatus according to an embodiment of the present invention has an advantage of being able to detect handover more easily by checking the content retransmission request message received from the user terminal 100, and is easy to implement the system.

A method for detecting a user terminal handover in a content providing system operating in a mobile network according to an embodiment of the present invention will be described in more detail with reference to FIGs. 5 to 8. FIG.

5 is a schematic flowchart of a handover detection method in a content providing system according to an embodiment of the present invention.

The first cache apparatus 331 is a cache apparatus connected to the radio access network before the user terminal 100 handover, i.e., the first radio access network 311, and the second cache apparatus 332 The operation of the first cache device 331 is not limited to the operation of the second cache device 332. That is, And the operation in the second cache device 332 may also be performed in the first cache device 331 as it is.

Referring to FIGS. 2 to 5, each of the cache devices 331 and 332 monitors a message transmitted from the user terminal 100 to check if a content retransmission request message is generated (S101). For example, when the user terminal 100 moves from the first radio access network 311 to the second radio access network 312 while receiving content in the coverage area of the first radio access network 311, the user terminal 100 ) Can not normally receive the content. Accordingly, the user terminal 100 transmits a content retransmission request message to the content providing apparatus 200 through the second radio access network 312. Accordingly, the second cache apparatus 332 monitors a message transmitted from the user terminal 100 and detects a content retransmission request message transmitted from the handed-over user terminal 100.

When the content retransmission request message is confirmed, the second cache apparatus 332 extracts the terminal address information from the content retransmission request message (S103), compares it with the terminal connection information of other previously stored cache apparatus (S105) (S107), the user terminal 100 that has transmitted the content retransmission request message receives the content from another cache device, i.e., the other wireless access network, i.e., the second wireless access network 312 ). ≪ / RTI >

Since the change of the radio access network means handover, the second cache apparatus 332 detects that the user terminal 100 is handed over to another cache apparatus 332 that provides the terminal access information to the user terminal 100, The first cache apparatus 331 (step S109).

Hereinafter, a handover detection method according to an embodiment of the present invention will be described in more detail with reference to FIG.

FIG. 6 is a flowchart illustrating a handover detection method in a content providing system operating in a mobile network according to an exemplary embodiment of the present invention. Referring to FIG.

2 to 6, the second cache apparatus 332 monitors a message (i.e., a mobile packet) transmitted from a user terminal (S201) and transmits a content retransmission request message, i.e., a TCP ACK message repeatedly (S203).

In other words, when the user terminal 100 receiving the content from the first cache device 331 moves to the area of the second radio access network 312 out of the area supported by the first cache device 331, The content providing apparatus 100 does not receive any further content from the first cache apparatus 331 and therefore does not receive a content retransmission request message, that is, a TCP having the same serial number as the serial number of the message last transmitted to the content providing apparatus 200 And repeatedly transmits an ACK message until a packet corresponding to the corresponding serial number is received. When the repetitive TCP ACK message is monitored, the second cache device 332 determines the monitored ACK message as a content retransmission request message. At this time, because the user terminal 100 can not normally receive the content due to a communication status failure or the like, in order to distinguish this situation from the situation, a threshold value is set and a predetermined threshold value, for example, TCP ACK Message is generated (S205).

If a TCP ACK message (content retransmission request message) is generated repeatedly over a threshold value, the second cache device 332 extracts the terminal address information from the content retransmission request message (S209). Then, the terminal access information is compared with the terminal address information extracted from the content retransmission request message with the terminal access information previously received from another cache device, for example, the first cache device 331 (S211), and the terminal access information is compared with the extracted terminal address information It is confirmed whether the terminal address information exists (S213).

If it is determined that there is information matching the extracted terminal address information in the terminal connection information received from another cache apparatus, the second cache apparatus 332 determines that the user terminal 100 is handed over (S215) The user terminal 100 generates and transmits a handover notification message to the past cache device used before the handover of the user terminal 100, that is, the first cache device 331 (S217).

As described with reference to FIGS. 5 and 6, in order to determine the handover of the user terminal 100 by comparing the terminal access information received from other cache devices with the terminal address information extracted through the content retransmission request message, It is preferable to receive and store the terminal connection information for the terminals connected to the cache apparatus from the first cache apparatus 331, for example.

To this end, the cache devices 331 and 332 further perform the process of FIG.

7 is a flowchart illustrating a process of generating terminal connection information according to an embodiment of the present invention.

Referring to FIGS. 2 to 7, the cache devices, for example, the first cache device 331, monitor a message transmitted from the user terminal 100 to check a content request message (S301). That is, the user terminal 100 extracts a content request message to be transmitted to the content providing apparatus 200 in order to request the content. The content request message may be, for example, an HTTP REQUEST message.

When the monitoring result content request message is confirmed, the first cache device 331 extracts the source address information, i.e., the terminal address information, from the content request message (S303), and then the user terminal 100 And generates terminal connection information indicating that the terminal is providing the content (S305). The terminal access information includes the terminal address information extracted from the content request message and the identification information of the first cache apparatus 331.

Then, the first cache apparatus 331 transmits the generated terminal connection information to at least one other cache apparatus around the first cache apparatus 331, for example, the second cache apparatus 332 (S307). The second cache apparatus 332 can know that the user terminal corresponding to the terminal address information is receiving the content through the first cache apparatus 331,

Concurrently with the above-described process, the content requested in the content request message is provided from the second cache device 332 or the content providing device 200 to the corresponding user terminal. More specifically, if the second cache apparatus 332 is caching the content requested in the content request message, the second cache apparatus 332 directly provides the content to the user terminal. If the content requested by the second cache device 332 is not cached, the content is transmitted from the content providing device 200 to the corresponding user terminal. At this time, the second cache device 332 transmits the content Can be copied and cached through a mirroring technique.

The operation procedure between the first cache apparatus 331 and the second cache apparatus 332 will be described in more detail with reference to FIG.

8 is a data flow diagram of a handover detection method in a content providing system operating in a mobile network according to an embodiment of the present invention.

Referring to FIGS. 2 to 8, each of the cache devices 331 and 332 monitors a message (i.e., a packet) transmitted from the user terminal 100 to the content providing apparatus 200 and checks whether a content request message exists. In the following embodiment, it is assumed that the first cache apparatus 331 confirms the content request message transmitted from the user terminal 100. [ Therefore, if the content request message of the user terminal 100 is confirmed through monitoring (S403), the first cache apparatus 331 checks whether the content corresponding to the content request message exists (S405) And provides it to the user terminal 100 (S407). If the content corresponding to the content request message does not exist, the content providing apparatus 200 requests and receives the corresponding content and provides the corresponding content to the user terminal 100, (S439).

At this time, the first cache device 331 extracts the source address information, i.e., the terminal address information of the user terminal 100, from the content request message (S409). The first cache device 331 generates terminal connection information including the extracted terminal address information and the identification information of the first cache device 331 in step S411 and transmits the generated connection information to the other neighboring cache devices, And transmits the generated terminal connection information (step S413).

The second cache device 332 stores the terminal connection information received from the first cache device 331.

When the user terminal 100 moves from the first radio access network 311 to the second radio access network 312 and the handover is performed at step S415, the user terminal 100 is no longer connected to the first radio access network 311 The content providing apparatus 200 transmits the content retransmission request message to the content providing apparatus 200. [

The second cache apparatus 332 monitors whether there is a content retransmission request message among the messages transmitted / received between the user terminal 100 and the content providing apparatus 200 (S417). If the content retransmission request message is confirmed The terminal address information extracted from the first cache device 331 is compared with the previously stored terminal connection information, and the terminal address information extracted in step S421 is stored in advance (step S421) And judges whether or not it matches the terminal connection information (S423).

If it is determined that the extracted terminal address information matches the previously stored terminal access information, the user terminal 100 determines that the first cache access request is received from the first cache access unit 311 in the area supported by the first cache unit 331, The second cache device 332 determines that the user terminal 100 has been handed over and generates a handover notification message because the second cache access device 332 has moved to the area supported by the device 332, (S425). The second cache apparatus 332 confirms the identification information of the first cache apparatus 331 from the previously stored terminal connection information (S427), and then transmits the handover notification message to the first cache apparatus 331 (S429 ).

The first cache device 331 receives the content and confirms that the user terminal 100 is not connected to the first radio access network 311, And stops providing the contents so that no more contents are provided to the user terminal 100 (S431).

The first cache device 331 generates content information including content identification information and content discontinuation time information at step S433 and transmits the generated content information to the second cache device corresponding to the area where the user terminal 100 is handed over 332 (S435).

Thereafter, the second cache apparatus 332 confirms the content information provided from the first cache apparatus 331, and provides the content to the user terminal 100 from a point of time when the content provision is stopped (S437).

As described above, the handover detection method in the mobile network according to an embodiment of the present invention detects the handover of the user terminal 100 through the message related to the content request / retransmission request transmitted from the user terminal 100 , Handover can be easily detected without a large design change, and it can be applied independently regardless of the structure and characteristics of the network.

In the above embodiment, the case where the cache apparatus 330, 331, 332 detects the handover of the user terminal 100 has been described. However, the present invention is not limited to this, 330, 331, and 332. The handover of the user terminal 100 can be detected through a separate device for managing the handover of the user terminal 100,

FIG. 9 is a network structure diagram illustrating a content providing system according to another embodiment of the present invention.

In the following description, description of the same configuration as that of the embodiment of the present invention described with reference to Fig. 1 and Fig. 2 will be omitted. For example, in FIG. 9, the structure of the network 300 to which the content providing system is applied may be applied in the same manner as in the embodiments of FIGS. 1 and 2. FIG. The user terminal 100 is assumed to be handed over from the first radio access network 311 to the second radio access network 312 as in the above-described embodiments.

9, a content providing system according to another embodiment of the present invention includes a cache control device 340 together with a plurality of cache devices 331 'and 332' distributed in a mobile network 310 Lt; / RTI > The plurality of cache devices 331 'and 332' will be described as a first cache device 331 'and a second cache device 332' for convenience of explanation.

The first and second cache devices 331 'and 332' are respectively connected to different radio access networks of the mobile network 320, for example, the first and second radio access networks 311 and 312, Monitors the messages of the user terminal 100 transmitted through the terminals 311 and 312.

To this end, the first and second cache devices 331 'and 332' transmit a message transmitted from the user terminal 100 to the content providing apparatus 200 through the first and second radio access networks 311 and 312 through the mirroring technique Can be copied and analyzed.

When the content request message transmitted from the user terminal 100 is detected as a result of the monitoring, the first and second cache devices 331 'and 332' determine whether the content requested by the user terminal 100 is cached by the user terminal 100 And transmits the requested content to the user terminal 100 if it is cached. On the contrary, if the requested content is not cached, the content transmitted from the content providing apparatus 200 to the user terminal 100 is mirrored while supporting the content to be transmitted from the content providing apparatus 200 to the user terminal 100 Copy and cache through technology.

When the content request message is detected, the first and second cache devices 331 'and 332' according to the present invention extract the terminal address information of the user terminal 100 that has transmitted the content request message, And generates terminal access information including information and its own identification information. The first and second cache devices 331 'and 332' transmit the generated terminal connection information to the cache controller 340.

Also, the first and second cache devices 331 'and 332' may detect a content retransmission request message transmitted from the user terminal 100 while monitoring the transmission / reception messages of the user terminal 100. The content retransmission request message may be, for example, a TCP ACK message repeatedly transmitted including the same sequence number. That is, the first and second cache devices 331 'and 332' may determine that a content retransmission request message is detected when a TCP ACK message including the same serial number is repeatedly transmitted over a threshold value. The entire contents retransmission request message may be generated when the handed-over user terminal 100 fails to receive the packet of the content in the handover process.

When the content retransmission request message is detected, the first and second cache devices 331 'and 332' extract the terminal address information of the user terminal 100 from the content retransmission request message. The first and second cache devices 331 'and 332' generate terminal connection information including extracted terminal address information and identification information of the terminal. The first and second cache devices 331 'and 332' transmit the generated terminal connection information to the cache controller 340.

The first and second cache apparatuses 331 'and 332' according to another embodiment of the present invention may transmit terminal access information to the cache control apparatus 340 when a content request message or a content retransmission request message is detected, And may operate in the same manner as the first and second cache devices 331 and 332 according to an embodiment of the present invention.

The cache control unit 340 determines the handover between the plurality of cache devices, that is, the first and second cache devices 331 'and 332' in the content transmission system according to the present invention, Transmission. In addition, the cache controller 340 may control content caching and content transmission of the first and second cache devices 331 'and 332'.

This cache control device 340 may be arranged to communicate with the first and second cache devices 331 ', 332' in the core network 313 of the mobile network 310. The cache control apparatus 340 is disposed between the content providing apparatus 200 and the user terminal 100 in the core network 313 with the Internet network 320 to which the content providing apparatus 200 is connected, You can monitor or control the messages that are sent. For example, when content is being provided from the first and second cache devices 331 'and 332' to the user terminal 100, the cache control device 340 may transmit the content, It is possible to prevent the user from entering the user terminal 310.

Particularly, in the present invention, the cache control device 340 controls the number of cache devices, that is, the first and second cache devices 331 'and 332' distributed on the network 300, Receives the terminal access information transmitted upon detection of the content request message or the content retransmission request message, and stores the terminal access information for each cache device. The terminal access information stored in the cache controller 340 is connected to the first and second radio access networks 311 and 312 corresponding to the first and second cache devices 331 'and 332' ).

In addition, when the cache control apparatus 340 receives the terminal connection information for the user terminal 100 receiving the current contents from the first and second cache apparatuses 331 'and 332' in the area of the corresponding cache apparatus, And judges whether or not the user terminal 100 is handed over by comparing the terminal access information with the terminal access information for each of the plurality of cache apparatuses previously stored. For example, after the cache control apparatus 340 receives and stores the terminal connection information from the first cache apparatus 331 ', the cache control apparatus 340 receives the terminal connection information from the second cache apparatus 332' The user terminal 100 compares the received terminal access information with previously stored terminal access information and if the identification information of the cache apparatus is different while the terminal address information is identical to the received terminal access information, It is determined that the area of the first cache device 331 'is handed over to the area of the second cache device 332'.

If it is determined that the user terminal 100 has been handed over, the cache control device 340 determines a cache device mapped with the same terminal access information among the terminal access information for each of the plurality of cache devices previously stored, for example, And notifies the handover of the user terminal 100 to the cache apparatus 331 '.

If the cache controller 340 determines that the user terminal 100 has been handed over, the cache controller 340 determines whether the previous cache device, i.e., the first cache device 331 ' 100 to the handed-over cache device, that is, the second cache device 332 '. The second cache device 332 'can transmit content seamlessly to the user terminal 100 by referring to the information on the content data.

At this time, the cache control device 340 determines whether the content data transmitted from the cache device that has notified the handover of the user terminal 100, that is, the first cache device 331 ' Can be received.

If it is determined that the user terminal 100 has not been handed over, the cache control apparatus 340 additionally stores the received terminal access information, and if it is determined that the user terminal is handed over, The identification information of the cache apparatus included in the connection information is changed to the identification information of the cache apparatus included in the received terminal connection information.

10 is a block diagram showing a configuration of a cache control apparatus of a content transmission system according to another embodiment of the present invention.

10, the cache controller 340 according to another embodiment of the present invention may include a communication unit 341, a storage unit 342, and a control unit 343.

The communication unit 341 is a means for performing data transmission / reception with a plurality of cache devices 331 'and 332' and / or the mobile network 310. In another embodiment of the present invention, the cache controller 340 may be connected to a plurality of cache devices 331 'and 332' via a dedicated line or an Internet network, and may be connected through a mobile network 310 It is possible.

The storage unit 342 is a configuration for storing data and programs necessary for the operation of the cache control unit 340. [ In another embodiment of the present invention, the storage unit 342 may store the terminal access information for the user terminal 100, which receives contents in the area of each cache apparatus, for each of the plurality of cache apparatuses 331 'and 332' (342a). The terminal connection information 342a is stored for each of the cache devices 331 'and 332' distributed and arranged in the network 300. [

The control unit 343 receives the terminal connection information for the user terminal 100 receiving the content from the specific cache apparatus, for example, the second cache apparatus 332 'in the area of the corresponding cache apparatus, through the communication unit 341 The mobile terminal 100 compares the terminal access information previously stored for each of a plurality of cache devices in the storage unit 342 to determine whether the user terminal 100 is handed over. More specifically, the cache control apparatus 340 compares the received terminal connection information with the terminal connection information stored in the storage unit 342, and notifies the cache control apparatus 340 that the terminal address information matches the identification information of the cache apparatus If the access information exists, it is determined that the user terminal 100 corresponding to the corresponding terminal address information is handed over.

When the first and second cache devices 331 'and 332' detect a content request message or a content re-request message transmitted from the user terminal 100, the terminal access information is transmitted to the first and second cache devices 331 'and 332' ', 332' to the cache controller 340.

The control unit 343 refers to the cache apparatus identification information of the corresponding terminal connection information stored in the storage unit 342 to determine whether the user terminal 100 is handed over, And controls the communication unit 341 to notify the handover of the user terminal 100 to the first cache apparatus 331 'that has been connected before being overridden.

In addition, the control unit 343 receives the content transmission information on the content data transmitted from the first cache apparatus 331 ', which notified the handover of the user terminal 100 to the user terminal 100, To the handed-over cache device, i.e., the second cache device 332 '.

If it is determined that the user terminal 100 has not been handed over, the control unit 343 additionally stores the received terminal connection information in the storage unit 342, and determines that the user terminal is handed over The identification information of the cache apparatus included in the terminal connection information stored in the storage unit 342 is changed to the identification information of the cache apparatus included in the received terminal connection information.

A handover detection method according to another embodiment of the present invention using the cache control device 340 configured as described above will be described with reference to FIG.

11 is a message flow diagram illustrating a handover detection process of a content transmission system according to another embodiment of the present invention.

In the following description, it is assumed that the user terminal 100 is handed over to the second radio access network 312 while being connected to the first radio access network 311 and receiving content through the first cache apparatus 331 ' .

11, when the user terminal 100 connected to the first radio access network 311 receives content through the first cache device 331 '(S501), the first cache device 331' And extracts the terminal address information of the terminal 100 (S503). Then, the first cache apparatus 331 'generates terminal connection information including the extracted terminal address information and its identification information, and transmits the terminal connection information to the cache control apparatus 340 (S505). The steps S503 and S505 may be performed when the first cache device 331 'detects a content request message of the user terminal 100.

When the cache control apparatus 340 receives the terminal access information transmitted by the detection of the content request message from the plurality of cache apparatuses 331 'and 332' distributed on the network 300 as in step S505, The terminal access information having the terminal address information is received first, and thus the received terminal access information is stored. At this time, the terminal connection information is stored for each cache device.

In this state, when the user terminal 100 moves to the coverage area of the second radio access network 312 and handover occurs (S509), the content transmitted to the user terminal 100 through the first radio access network 312 And no packet is received at the user terminal 100 side.

Accordingly, the user terminal 100 transmits a content retransmission request message for an unreceived packet, which is transmitted through the second radio access network 312 handed over.

Accordingly, the second cache device 332 'connected to the second radio access network 312 detects the content retransmission request message of the user terminal 100 during the monitoring of the message transmitted through the second radio access network 312 (S513).

In this manner, the second cache device 332 ', which detects the content retransmission request message, extracts the terminal address information of the user terminal 100 from the content retransmission request message at step S515. The second cache apparatus 332 'generates terminal connection information including the extracted terminal address information and its own cache apparatus identification information, and transmits the generated terminal connection information to the cache control apparatus 340 (S517).

In this manner, the cache control device 340, which receives the terminal connection information transmitted by detecting the content retransmission request message from the second cache device 332 ', compares the received terminal connection information with the previously stored terminal connection information (S519).

At this time, since the terminal access information transmitted from the first cache apparatus 331 'is stored, the terminal access information is compared with the received terminal access information, but the terminal access information having the same identification information of the cache apparatus is stored In this case, it can be determined that the user terminal 100 corresponding to the corresponding terminal address information is handed over.

Therefore, the cache control device 340 judging the handover according to the comparison result of step S519 refers to the identification information of the cache device mapped to the stored terminal connection information, and accesses the user terminal 100 before handover of the user terminal 100 The first cache apparatus 331 'notifies whether the user terminal 100 is handed over (S521).

Since the first cache apparatus 331 'can not receive any more content through the first radio access network 311, the first cache apparatus 331' is provided to the user terminal 100 through the first radio access network 311 (S523). ≪ / RTI >

Then, the first cache device 331 'transmits content transmission information including information indicating the time point at which the content is stopped, that is, the content to the user terminal 100, to the cache control device 340 (S525).

The cache control apparatus 340 transmits the content transmission information to the second cache apparatus 332 'to which the user terminal 100 has been handed over (S527), and the second cache apparatus 332' To the user terminal 100 without interruption (S529).

In addition, in step S505, the cache control device 340 receiving the terminal connection information does not store the terminal connection information having the same terminal address information, i.e., before the user terminal 100 is handed over, And further stores the received terminal connection information in the storage unit 342. [ On the other hand, the cache control device 340 receiving the terminal connection information in step S517 stores terminal connection information having the same terminal address information as the received terminal connection information, that is, The terminal access information for each cache apparatus can be updated by changing the identification information of the cache apparatus included in the previously stored terminal access information to the identification information of the cache apparatus included in the received terminal access information.

In the foregoing, a handover detection method in a content providing system operating in a mobile network according to various embodiments of the present invention has been described.

The method of detecting a handover in a content providing system operating in a mobile network according to an embodiment of the present invention can be implemented as computer readable code on a computer readable recording medium. The computer readable recording medium may include program instructions, data files, data structures, and the like, alone or in combination, and includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include 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), and a digital video disk (ROM), random access memory (RAM), flash memory, and the like, such as a magneto-optical medium such as a magneto-optical medium and a floppy disk, And hardware devices that are specifically configured to perform the functions described herein.

In addition, the computer-readable recording medium may be distributed over network-connected computer systems 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 of the technical field to which the present invention belongs.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be appreciated by those skilled in the art that numerous changes and modifications can be made to the invention. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

The present invention relates to a handover detection method, and more particularly, to a handover detection method in a cache apparatus using a retransmission request message for a content request generated from a handed-over user terminal, ≪ / RTI >

According to the present invention, it is possible to detect handover of a user terminal through a content retransmission request message generated from a user terminal, thereby enabling easy handover detection without a large design change, It is possible to reduce the service implementation cost, thereby contributing to the development of the mobile industry.

100: user terminal 200: content providing apparatus 300: network
311: first radio access network 312: second radio access network 313: core network
320: Internet network 330: cache device 331: first cache device
332: second cache device 370: third cache device
1000: Content providing system

Claims (25)

A storage unit for storing at least one content and terminal connection information received from another cache apparatus; And
The method comprising the steps of: monitoring a message transmitted from at least one user terminal, extracting terminal address information of the user terminal from the content retransmission request message when a content retransmission request message is detected, A control unit for notifying handover of the user terminal to another cache apparatus that has transmitted the terminal connection information;
And a cache memory. The method according to claim 1,
The control unit
And extracts the content requested from the user terminal from the storage unit and provides the extracted content to the user terminal. The method according to claim 1,
The terminal connection information
The identification information of the corresponding cache apparatus and the terminal address information extracted from the content request message of the user terminal providing the content by the corresponding cache apparatus. 3. The method of claim 2,
The control unit
Receiving content information including content identification information from the other cache device and information on content data transmitted from the other cache device to the user terminal after notifying the other cache device of the handover of the user terminal, And provides data to the user terminal after the content interruption time in the content corresponding to the content identification information. 3. The method of claim 2,
The control unit
The terminal access information for the user terminal providing the content is generated and transmitted to at least one other cache apparatus. A communication unit for transmitting and receiving data to and from a plurality of cache devices distributed on a network;
A storage unit for storing terminal access information including terminal address information for a user terminal receiving content in an area of each cache apparatus and identification information of the corresponding cache apparatus for each of the plurality of cache apparatuses; And
When receiving terminal connection information for a specific user terminal that is receiving content from a specific cache apparatus via the communication unit, comparing the terminal connection information previously stored for each of the plurality of cache apparatuses to the storage unit, And a controller for determining whether or not the user terminal is handed over. The method according to claim 6,
Wherein the terminal access information is transmitted from the specific cache apparatus to the cache control apparatus when the specific cache apparatus detects the content request message or the content re-request message transmitted from the specific user terminal. 7. The apparatus of claim 6, wherein the control unit
Comparing the received terminal access information with the received terminal access information to determine that the specific user terminal is handed over if the terminal address information matches but the identification information of the cache apparatus and the terminal connection information are stored in the storage unit. controller. 7. The apparatus of claim 6, wherein the control unit
If it is determined that the specific user terminal has been handed over, referring to the identification information of the cache apparatus included in the terminal connection information stored in the storage unit, And notifies the handover of the user terminal. 10. The apparatus of claim 9, wherein the control unit
And transmits the content transmission information on the content data transmitted from the previous cache device connected to the specific user terminal before the handover to the specific cache device when it is determined that the specific user terminal has been handed over. controller. 10. The apparatus of claim 9, wherein the control unit
Wherein the cache control unit receives the content transmission information for the content data transmitted from the previous cache apparatus that has notified the handover of the specific user terminal to the specific user terminal. 7. The apparatus of claim 6, wherein the control unit
If the specific user terminal is judged as not being handed over, the received terminal connection information is additionally stored in the storage unit. If it is determined that the specific user terminal is handed over, the terminal access information is included in the terminal connection information stored in the storage unit And changes the identification information of the cache apparatus to the identification information of the cache apparatus included in the received terminal connection information. The cache device monitoring a message sent from a user terminal;
Detecting the content retransmission request message by the cache apparatus through the monitoring;
Extracting the terminal address information of the user terminal from the content retransmission request message, if the content retransmission request message is detected;
Checking whether the extracted terminal address information is included in the pre-stored terminal access information by referring to the terminal access information of the user terminal providing the content by the previously stored other cache apparatus; And
If the terminal address information is included in the pre-stored terminal connection information, the user terminal confirms another cache device that the user terminal was receiving content through the terminal connection information, Notifying over;
And determining whether the handover is successful. 14. The method of claim 13,
Before confirming whether the terminal address information is included in the terminal connection information,
Receiving, by the cache apparatus, terminal access information for the terminal being provided by the content from the another cache apparatus; And
Storing the terminal connection information received by the cache apparatus;
The method comprising the steps of: detecting a handover in a cache apparatus; 14. The method of claim 13,
After notifying the handover of the user terminal,
Receiving, by the cache apparatus, content information including content identification information and information on a content stop time from the other cache apparatus; And
Providing the cache apparatus with data after the contents abortion time from the contents corresponding to the contents identification information to the user terminal;
The method comprising the steps of: detecting a handover in a cache apparatus; 14. The method of claim 13,
Generating the terminal connection information including the identification information of the cache apparatus and the terminal address information of the user terminal providing the content; And
Transmitting the terminal connection information to at least one other cache apparatus located in the vicinity of the cache apparatus
The method comprising the steps of: detecting a handover in a cache apparatus; Receiving a content request message sent from a user terminal;
Providing the content corresponding to the content request message to the user terminal;
Extracting terminal address information of the user terminal from the content request message, and generating terminal access information including the terminal identification information and the terminal address information; And
Transmitting the terminal connection information to at least one other cache device located in the vicinity of the cache device;
And determining whether the handover is successful. 18. The method of claim 17,
The cache device receiving a handover notification of the user terminal from another cache device;
Checking whether the content is being transmitted to the user terminal by the cache device;
Stopping the transmission of the content to the user terminal if there is content being transmitted to the user terminal;
Generating content information including content identification information on content for which the cache device has been suspended and information on a content stop time; And
The cache device transmitting the content information to another cache device notified of the handover;
The method comprising the steps of: detecting a handover in a cache apparatus; Storing terminal access information including terminal address information of a user terminal and identification information of a corresponding cache apparatus, the content of which is provided in a region of each cache apparatus, for each of a plurality of cache apparatuses distributed on a network;
Receiving terminal access information for a specific user terminal receiving current contents from a specific cache apparatus in an area of the specific cache apparatus; And
Comparing the received terminal connection information with pre-stored terminal connection information to determine whether the specific user terminal is handed over
Wherein the cache control apparatus comprises: 20. The method according to claim 19, wherein in the step of receiving the terminal connection information,
Wherein the terminal access information is transmitted from the specific cache apparatus to the cache control apparatus when the specific cache apparatus detects the content request message or the content re-request message transmitted from the specific user terminal. Way. 20. The method of claim 19,
The step of determining whether or not the handover is performed includes:
If there is terminal access information that matches the terminal access information but does not match the identification information of the cache apparatus among the pre-stored terminal access information, it is determined that the specific user terminal is handed over The cache control apparatus comprising: 20. The method of claim 19,
If it is determined that the specific user terminal has been handed over, referring to the identification information of the cache apparatus mapped with the same terminal address information from the stored terminal access information, Further comprising the step of notifying the handover of the user terminal to the handover detection unit. 20. The method of claim 19,
If it is determined that the specific user terminal has been handed over, transmitting the content transmission information on the content data transmitted from the previous cache device connected to the user terminal before handover to the specific cache device Wherein the cache control device is a handover detecting device. 24. The method of claim 23,
Further comprising the step of receiving content transmission information for content data transmitted from the cache apparatus that has notified the handover of the specific user terminal to the specific user terminal. 20. The method of claim 19,
Wherein the control unit further stores the received terminal connection information if it is determined that the specific user terminal has not been handed over and stores identification information of the cache apparatus included in the stored terminal connection information, To the identification information of the cache apparatus included in the received terminal connection information.

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