JP2015065493A - Content distribution system, content distribution device, content distribution method, and content distribution program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To distribute a content of an appropriate bit rate according to the status of a network band.SOLUTION: A content distribution system includes: a distribution server 20 that caches a content and distributes it; and a management server that controls distribution of the content according to presence or absence of a cache. The management server includes control means that, if the caches of the target content which is requested from a communication terminal 10 does not exist in the distribution server 20, transfers the target content to the distribution server 20 while relaying a response from a content server to the communication terminal 10. The distribution server 20 includes: cache means that accumulates the target content, which is transferred from the management server, in a cache DB 21; and conversion means that, after the data distribution of the content from the content server is finished and the accumulation of the target content is complete, converts the target content, which is accumulated in the cache DB 21, into a media segment file, and notifies the management server of it.

Description

  The present invention relates to a content distribution technique, and more particularly, to a content distribution technique that distributes content having an appropriate bit rate in accordance with network bandwidth conditions.

  In recent years, multifunctional mobile terminals called smartphones have become widespread, and opportunities for viewing content such as moving images on mobile terminals are increasing. On the other hand, data communication traffic by smartphones is increasing more than the penetration rate of smartphones, and reduction of data communication traffic has become an issue for each mobile communication company. Most of the data communication traffic is HTTP (Hypertext Transfer Protocol) traffic, and more than half of the HTTP traffic is said to be moving image data.

  As a scene to watch a video on a smartphone, there are many cases of watching while moving, such as on a train or bus. However, when a mobile terminal is moving at high speed and viewing the video by accessing the web, the fluctuation of the band is so large that buffering cannot catch up with the video playback speed, and the video playback is frequently interrupted. is there. For this reason, there is a problem that the user experience is greatly reduced.

  For example, in the case of general video distribution, even if the NW is congested and the bandwidth is being compressed, high bit rate data may be transmitted in the narrow bandwidth (for example, only 200 kbps is available) However, the video content of 500 kbps may be distributed). For this reason, the data distribution is delayed and the playback of the moving image does not start easily. Even if it starts, the buffer is lost and the viewing is interrupted, so that the viewer's QoE (quality of experience) is significantly reduced. This is likely to become even more prominent in the future when smartphone traffic is expected to increase rapidly.

  In order to solve such a problem, HLS (HTTP Live Streaming) can be cited as a distribution technique that dynamically changes the viewing bit rate of a moving image in accordance with bandwidth fluctuations. HLS can be streamed in HLS format on most smartphones, iPhone, iPod touch with iOS 3.0 or higher, iPad with iOS 3.2 or higher, and Android 3.0 or higher.

  On the other hand, in content distribution using a mobile terminal as a distribution destination, it is necessary to consider the reception capability and display capability on the mobile terminal side. For example, in Patent Document 1 and Patent Document 2, it is possible to distribute the same content to various terminals by converting and distributing the content according to the model of the mobile terminal. In addition, by caching the converted content, it is possible to distribute the converted content without performing conversion processing every time it is accessed, and it is possible to perform distribution that ensures QoS (Quality of Service).

Re-specialized WO2011 / 049193 Re-specialized WO2011 / 049179

  In the HLS, there is a problem that the content server side must prepare a large number of files due to its characteristics. Also, there is a problem that it is troublesome for the user to upload an HLS compatible video. Therefore, HLS has not yet been widely spread. In addition, since HLS has started to spread recently, most of the general moving image content does not support HLS. For this reason, mobile carriers need to take some measures to maintain / improve QoE and reduce bandwidth based on the fact that future HTTP traffic will increase rapidly and that more than half of them are video content. Conceivable.

  The technologies disclosed in Patent Document 1 and Patent Document 2 determine which stored cache content is to be used by the first access from the user. Once the cache content is determined, the content is distributed to the end. I do. However, the mobile NW band fluctuation is so severe that while watching the video for many minutes, the NW band that can watch the video of the first determined bit rate is rarely maintained during viewing. There is a problem that viewing interruption occurs due to the above.

(Object of invention)
An object of the present invention is to provide a content distribution system, a content distribution device, a content distribution method, and a content distribution program that solve the above-described problems and distribute content having an appropriate bit rate according to the state of the network bandwidth. is there.

  The first content distribution system of the present invention includes a distribution server that caches and distributes content, and a management server that controls distribution of content according to the presence or absence of the cache, and the management server is requested from a communication terminal. A cache determination unit that determines whether or not the target content is cached in the distribution server, and if the distribution server does not have a cache of the target content requested from the communication terminal, the response from the content server is relayed to the communication terminal. However, the control means for transferring the target content to the distribution server, the distribution server stores the target content transferred from the management server in the cache DB, and the data distribution of the content from the content server is terminated. After the target content has been accumulated, It converts the target content accumulated in the Interview DB to the media segment file, and a conversion means for notifying the management server.

  A first content distribution method according to the present invention is a content distribution method by a content distribution system including a distribution server that caches and distributes content, and a management server that controls distribution of the content according to the presence or absence of the cache, A cache determination step in which the management server determines whether or not the target content requested from the communication terminal is cached in the distribution server; and if the distribution server does not have a cache of the target content requested from the communication terminal A control step of transferring the target content to the distribution server while relaying a response from the server to the communication terminal, and the distribution server storing the target content transferred from the management server in the cache DB; Content from the server Over data distribution has been completed, and, after the target content storage is completed, converts the target content stored in the cache DB to the media segment file, it executes an exchange step of notifying the management server.

  A first content distribution program according to the present invention operates on a computer constituting a content distribution system including a distribution server that caches and distributes content, and a management server that controls distribution of the content according to the presence or absence of the cache. A content distribution program, comprising: a computer that constitutes the management server; a cache determination unit that determines whether target content requested from a communication terminal is cached in the distribution server; and a target content requested from the communication terminal When the cache does not exist in the distribution server, it relays the response from the content server to the communication terminal, functions as a control means for transferring the target content to the distribution server, and the computer constituting the distribution server is transferred from the management server. Target content After the data distribution of the content from the cache means and the content server is completed and the accumulation of the target content is completed, the target content stored in the cache DB is converted into a media segment file and managed. It functions as a conversion means for notifying the server of that fact.

  According to the present invention, it is possible to distribute content having an appropriate bit rate according to the state of the network bandwidth.

It is a block diagram which shows the structure of the content delivery system by the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the content delivery system by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the content delivery system by the 2nd Embodiment of this invention. It is a figure which shows the structural example of the master index file by the 2nd Embodiment of this invention, and an alternative index file. It is a figure which shows the structural example of management information DB by the 2nd Embodiment of this invention. It is a figure which shows the structural example at the time of introducing the delivery server and management server by the 2nd Embodiment of this invention in a commercial network. It is a sequence diagram which shows operation | movement of the content delivery system by the 2nd Embodiment of this invention. It is a sequence diagram which shows operation | movement of the content delivery system by the 2nd Embodiment of this invention. It is a figure which shows the structural example of the master index file by the 2nd Embodiment of this invention. It is a figure which shows the structural example of the alternative index file by the 2nd Embodiment of this invention. It is a figure which shows the structural example of the master index file by the 2nd Embodiment of this invention. It is a sequence diagram which shows operation | movement of the content delivery system by the 2nd Embodiment of this invention. It is a block diagram which shows the hardware structural example of the management server of this invention.

  In order to clarify the above and other objects, features and advantages of the present invention, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In addition to the above-described object of the present invention, other technical problems, means for solving the technical problems, and operational effects thereof will become apparent from the disclosure of the following embodiments. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a content distribution system 100 according to the first embodiment of the present invention.

  Referring to FIG. 1, a content distribution system 100 according to the present embodiment includes a distribution server 20 that caches and distributes content, a management server 30 that controls distribution of content according to the presence or absence of a cache, and a management server 30. And a communication terminal 10 that transmits a content request and receives content from the content server 90 via the distribution server 20 or the management server 30.

  The management server 30 includes a cache determination unit 31 that determines whether or not the target content requested from the communication terminal 10 is cached in the distribution server 20, and if the distribution server 20 does not have a cache of the target content, Control means 33 for transferring the target content to the distribution server 20 while relaying a response from the server 90 to the communication terminal 10.

  The distribution server 20 stores the target content transferred from the management server 30 in the cache DB 21, and after the data distribution of the content from the content server 90 is completed and the storage of the target content is completed, Conversion means 23 for converting the target content stored in the DB 21 into a media segment file and notifying the management server 30 of the content.

(Description of the operation of the first embodiment)
Next, the operation of the content distribution system 100 according to the present embodiment will be described in detail with reference to the flowchart of FIG.

  First, the communication terminal 10 transmits a content distribution request to the management server 30 (step S201).

  When the management server 30 receives the request, the cache determination unit 31 determines whether the requested content is cached in the distribution server 20 (step S202).

  When the cache of the target content does not exist in the distribution server 20 (step S203 “NO”), the control unit 33 of the management server 30 distributes the target content while relaying the response from the content server 90 to the communication terminal 10. Transfer to the server 20 (step S204). If the target content cache exists in the distribution server 20, the distribution server 20 distributes the cache (step S205).

  When the transfer of the target content is received from the management server 30, the cache unit 22 of the distribution server 20 stores the target content in the cache DB 21 (step S206).

  After the data distribution of the content from the content server 90 is completed and the accumulation of the target content is completed, the conversion unit 23 of the distribution server 20 converts the target content stored in the cache DB 21 into a media segment file, This is notified to the management server 30 (step S207).

(Effects of the first embodiment)
According to this embodiment, even when the target content is not cached, the content can be smoothly distributed. In Patent Document 1, when the target content is not cached, the content is converted to an optimal content, and the converted content is cached and distributed at the same time. However, as in Patent Document 1, the content is converted in real time. In the method of distributing the converted content after caching, there is a high possibility of causing a QoE reduction based on server delay. On the other hand, according to the present embodiment, since the original content, not the converted content, is distributed and the cache / conversion process is performed in another process, the QoE can be improved. In addition, since the original content is not re-encoded and the file format is not converted, there is an advantage that there is little impossibility to the server.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  The configuration of the content distribution system 100 according to this embodiment is shown in FIG.

  The content distribution system 100 according to the present embodiment includes a communication terminal 10, a distribution server 20, and a management server 30.

  The distribution server 20 includes a cache unit 22 that caches content in the cache DB 21, a conversion unit 23 that converts the content for HLS distribution, and a distribution unit 24 that performs HLS distribution of the converted content to the communication terminal 10.

  The management server 30 includes a cache determination unit 31 that determines whether the target content is cached, a file generation unit 32 that generates a master index file and an alternative index file, a control unit 33 that controls the distribution server 20 and the own server, Management information DB 35 for storing NW bandwidth status and information specific to each terminal (communication terminal 10 resource information, contract information, data communication usage status, location information, etc.) and management information DB 35 are scattered. Determining means 34 for determining an appropriate bit rate of the content to be distributed.

  Here, FIG. 4 shows a configuration example of the master index file and the alternative index file generated by the file generating means 32.

  A configuration example of the management information DB 35 is shown in FIG. The management information DB 35 stores common information, user specific information, moving image specific information, and maintenance person registration control information.

  The shared information includes an NW band and cache holding information. The cache holding information is information indicating whether each content exists in the cache.

  The user fixed information includes position information of the communication terminal 10 unique to each user, contract details, and data communication usage status.

  The moving image unique information is composed of a master index file and an alternative index file.

  The maintenance person registration control information includes uniform bandwidth control information, time zone bandwidth control information, regional bandwidth control information, and specific URL bandwidth control information.

  The maintenance person registration control information may be directly registered by the maintenance person on the management server 30, or the management server 30 is connected to the maintenance management network of the maintenance person, and information is added to or deleted from the management information DB 35 by a command. It may be done. Each information stored in the management information DB 35 is not limited to the above, and can be arbitrarily set by a maintenance person.

  Here, FIG. 6 shows an example in which the distribution server 20 and the management server 30 of the present embodiment are installed in a mobile data communication network or ISP provider network. Since ENB40, S-GW50, P-GW60, and L3SW70 are not essential parts of the present invention, detailed description thereof will be omitted. The management server 30 is connected to the maintenance management network of the maintenance person, and the maintenance person can add / delete information to / from the management information DB 35 by a command.

  The management server 30 according to the present embodiment does not obtain information from the nodes existing in the packet network, but monitors and predicts the fluctuation of the NW band by itself, and when it is actually introduced into the commercial network, the NW configuration And technical difficulty of introduction can be significantly reduced. In addition, it can be introduced simply by adding in to an NW device in an existing network, and it is not necessary to cooperate with other nodes, so that the introduction is easy.

(Description of operation of second embodiment)
Next, the operation of the content distribution system 100 according to the present embodiment will be described in detail with reference to the drawings.

  First, the operation when the content to be distributed does not exist in the cache will be described using the sequence diagram of FIG.

  First, when an http request is transmitted from the communication terminal 10 to the management server 30, the management server 30 transmits the request to the corresponding content server 90 and receives the response. Next, the cache determination unit 31 of the management server 30 refers to the “cache possession information” in the management information DB 35 and determines whether or not the target content cache exists.

  If it is determined that the target content cache does not exist, the control unit 33 relays the response from the content server 90 to the communication terminal 10 and transfers the “cache accumulation request” and the cache target content to the distribution server 20. . The content is stored in the cache DB 21 by the cache means 22 of the distribution server 20.

  After the distribution of the content data from the content server 90 is completed and the storage of the content cache is completed, the conversion unit 23 of the distribution server 20 converts the content stored in the cache DB 21 into an HLS distribution file (media segment). (The number of media segment files can be changed by setting). After the conversion is completed, the conversion unit 23 transmits a “cache accumulation completion notification” to the management server 30, and the control unit 33 of the management server 30 updates the “cache holding information” in the management information DB 35 upon receiving the notification.

  Next, an operation when there is a cache of content to be distributed will be described using the sequence diagram of FIG. Assume that the cache DB 21 stores media segment files of three types of bit rates: High, mid, and low.

  First, when an http request is transmitted from the communication terminal 10 to the management server 30, the management server 30 transmits the request to the corresponding content server 90 and receives the response. Next, the cache determination unit 31 of the management server 30 refers to the “cache possession information” in the management information DB 35 and determines whether or not the target content cache exists.

  If it is determined that the target content cache exists, the file generation unit 32 queries the management information DB for “user-specific information” and “maintenance person registration control information”, and based on the result, determines the master index file and the alternative index file. Generate.

  Examples of the master index file and the alternative index file generated by the file generating unit 32 at this time are shown in FIGS. Here, since there is no restriction by the maintenance person in particular, a URI (Uniform Resource Identifier) indicating media segment files of three types of high, mid, and low is described in the master index file. After completion of the description, the file generation unit 32 rewrites the response from the content server 90 and returns a response in which the URI of the master index file is described to the communication terminal 10. Thereby, switching to HLS distribution is performed. Another example of the master index file is shown in FIG.

  Upon receiving the response, the communication terminal 10 selects an appropriate bit rate described in the master index file and transmits a Get request for the alternative index file to the management server 30. Here, it is assumed that the communication terminal 10 has selected an alternative index file of “BANDWIDTH = 500000” (low).

  When the management server 30 receives the substitute index file acquisition request, the determination unit 34 refers to the management information DB 35 to refer to the NW band and checks whether a file having the requested bit rate can be transmitted. It is assumed that the status and fluctuation of the NW band are constantly monitored and predicted by the management server 30.

  If the determination unit 34 determines that the file can be transmitted, the determination unit 34 returns the information of the alternative index file to the communication terminal 10 as a response. Even if the bandwidth check is NG, the determination unit 34 transmits the lowest bit rate described in the master index file.

  Next, the communication terminal 10 transmits a media segment file acquisition request to the distribution server 20 based on the URI described in the alternative index file, and the distribution unit 24 of the distribution server 20 selects the target content in response to the request. To deliver.

  On the other hand, when the communication terminal 10 selects an alternative index file of “BANDWIDTH = 1000000” (mid) and the determination unit 34 of the management server 30 determines that the distribution of the mid file is impossible as a result of checking the NW band, the determination is made. The means 34 transmits the media index file of the low file to the communication terminal 10 as a response regardless of the request of the communication terminal 10.

  Next, with reference to the sequence diagram of FIG. 12, an operation in the case where bandwidth control information is added to the management information DB 35 by the maintainer and the NW bandwidth is limited to “BANDWIDTH = 500000” will be described.

  First, when an http request is transmitted from the communication terminal 10 to the management server 30, the management server 30 transmits the request to the corresponding content server 90 and receives the response. Next, the cache determination unit 31 of the management server 30 refers to the “cache possession information” in the management information DB 35 and determines whether or not the target content cache exists.

  When it is determined that the target content cache exists, the file generation unit 32 refers to the “user-specific information” and the “maintenance person registration control information” in the management information DB 35, and based on the result, the master index file and the alternative index file Is generated. Here, since there is a restriction “BANDWIDTH = 500000” in the maintenance person registration control information, the file generation unit 32 creates a master index file in which only the low alternative index file is described. The subsequent operation is the same as the basic operation described above.

(Effects of the second embodiment)
According to the present embodiment, by dynamically generating an index file, even general content distribution that does not support HLS (HTTP Live Streaming) can be converted to HLS distribution, QoE can be improved and NW bandwidth can be reduced. In other words, according to the present embodiment, the cached video is converted into a media segment file corresponding to a plurality of bit rates for a single video in the same way as normal HLS distribution, so that the HTTP transmitted from the client is converted. If the request is content already cached in the distribution server 20, the management server 30 creates a master / alternate index file based on the control conditions, rewrites the URI of the HTTP header with the URI of the master index file, and It is possible to switch to HLS distribution by returning a response to.

  Further, according to the present embodiment, it is possible to reduce congestion of the NW band and improve the user's QoE. A typical communication terminal observes the effective bandwidth during playback of a stream, and if the bandwidth is deemed to be compatible with the stream, an alternative index is selected from the list described in the master index file. A high-quality stream can be used by specifying a file and switching to a higher-quality stream. Also, if a low quality stream is available and the current bandwidth is deemed incompatible with the current stream, the client will similarly switch to a lower quality stream. In this regard, in the present embodiment, in the present invention, the management server 30 also grasps the NW bandwidth status, selects the optimum bit rate regardless of the request from the client, and considers the control conditions from the maintenance person. Thus, by determining the bit rate of the content to be distributed to the client side, it is possible to reduce congestion of the NW band and improve the user's QoE.

  Moreover, according to this Embodiment, according to the request | requirement from a maintenance person, the bit rate of the moving image to deliver can be controlled with control conditions, such as a time slot | zone and a specific area. That is, the bit rate that can be selected by the user at the time of creating the index file can be dynamically changed according to the request of the maintenance person. This makes it possible for maintenance personnel to deliver content only at the lowest bit rate to the NW during peak periods, areas where congestion is likely to occur, or heavy users, enabling bandwidth control and traffic reduction. It becomes. In addition, when a disaster occurs, control is performed so that only delivery at the lowest bit rate is performed, and it is possible to reduce the NW congestion state and reduce the bandwidth.

  Further, according to the present embodiment, even if the user request is normal content distribution, it is possible to switch to HLS distribution, so that it is possible to distribute at an adaptive bit rate, and to reduce the user's opportunity to interrupt viewing. The user experience can be improved.

  Further, according to the present embodiment, it is very easy to introduce a content distribution system. First, the cooperation of the EPC device as in Patent Document 1 is not required. Further, in the method of obtaining information from a node existing in the packet network as in Patent Document 2, it is necessary to cooperate with other nodes. However, in this embodiment, the management server 30 monitors and predicts the fluctuation of the NW band by itself. Therefore, it can be introduced simply by adding in to the network device of the existing network and setting the HTTP traffic to be distributed to the carrier side network device to be added in, and does not require cooperation with other nodes.

  Further, according to the present embodiment, since the distribution using HLS is performed, it is possible to distribute the content without interrupting viewing. In the present embodiment, the cache content is segmented on the time axis, and the same content has a plurality of bit rates. Rather than simply selecting the accumulated content, it is possible to prevent viewing interruption by monitoring the fluctuation of the NW bandwidth of the user and changing the bit rate of the content to be distributed while viewing the content (video). it can.

  Next, a hardware configuration example of the management server 30 of the present invention will be described with reference to FIG.

  Referring to FIG. 13, the management server 30 of the present invention has a hardware configuration similar to that of a general computer device, and includes data such as a CPU (Central Processing Unit) 1001 and a RAM (Random Access Memory). A main storage unit 1002 used for a work area and a temporary data saving area, a communication unit 1003 that transmits and receives data via a network, an input device 1005 and an output device 1006, and an input device that transmits and receives data. An output interface unit 1004 and a system bus 1008 for interconnecting the above-described components are provided. The storage device 1007 is realized by, for example, a hard disk device including a non-volatile memory such as a ROM (Read Only Memory), a magnetic disk, and a semiconductor memory.

  Each function of the management server 30 according to the present invention is realized by mounting circuit components, which are hardware components such as LSI (Large Scale Integration), incorporating a program, so that the operation is realized in hardware. The program that provides the function can be realized in software by storing the program in the storage device 1007, loading the program into the main storage unit 1002, and executing it by the CPU 1001.

  The distribution server 20 of the present invention also has the hardware configuration as described above, and realizes each function in hardware or software.

  The present invention has been described above with reference to preferred embodiments. However, the present invention is not necessarily limited to the above embodiments, and various modifications can be made within the scope of the technical idea. it can.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single component is formed of a plurality of members. It may be that a certain component is a part of another component, a part of a certain component overlaps with a part of another component, or the like.

  Moreover, although the several procedure is described in order in the method and computer program of this invention, the order of the description does not limit the order which performs a several procedure. For this reason, when implementing the method and computer program of this invention, the order of the several procedure can be changed in the range which does not interfere in content.

  The plurality of procedures of the method and the computer program of the present invention are not limited to being executed at different timings. For this reason, another procedure may occur during the execution of a certain procedure, or some or all of the execution timing of a certain procedure and the execution timing of another procedure may overlap.

  Further, a part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
A distribution server that caches and distributes content;
A management server that controls distribution of content according to the presence or absence of the cache,
The management server is
Cache determination means for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
Control means for transferring the target content to the distribution server while relaying a response from the content server to the communication terminal when a cache of the target content requested from the communication terminal does not exist in the distribution server;
The distribution server is
Cache means for storing the target content transferred from the management server in a cache DB;
After data distribution of content from the content server is completed and accumulation of the target content is completed, the target content stored in the cache DB is converted into a media segment file, and the management server is notified accordingly A content distribution system comprising: a converting means for performing the processing.

(Appendix 2)
The management server is
When there is a cache of the target content, provided with file generation means for generating a master index file and an alternative index file based on preset control information and information unique to the communication terminal,
The file generation means includes
The content distribution system according to appendix 1, wherein a URI of the master index file is described in a response from the content server, and the response is transmitted to the communication terminal.

(Appendix 3)
The management server is
The communication terminal checks the NW bandwidth in response to the Get request of the alternative index file selected and transmitted from the appropriate bit rate described in the master index file, and the file of the requested bit rate is A determination means for determining whether transmission is possible,
The determining means includes
When it is determined that the requested bit rate file can be transmitted, the information of the alternative index file is transmitted to the communication terminal,
The content according to appendix 2, wherein a media index file of a low file is transmitted to the communication terminal regardless of the request from the communication terminal when it is determined that the requested bit rate file cannot be transmitted. Distribution system.

(Appendix 4)
The management server is
Content information cached in the distribution server;
The control information;
Information specific to the communication terminal;
The content distribution system according to appendix 3, further comprising a management information DB that stores the status of the NW band.

(Appendix 5)
The control information is
The content distribution system according to appendix 3 or appendix 4, characterized by including at least one of uniform bandwidth control information, time zone bandwidth control information, regional bandwidth control information, and specific URL bandwidth control information.

(Appendix 6)
The master index file is
6. Any one of URIs of media segment files of at least three types of bit rates of High, mid, and low are described based on the control information. Content distribution system.

(Appendix 7)
The cache DB is
7. The content distribution system according to any one of appendix 1 to appendix 6, wherein media segment files having three types of bit rates of High, mid, and low are stored.

(Appendix 8)
8. The content distribution system according to any one of appendix 1 to appendix 7, wherein the content request from the communication terminal is an HTTP request.

(Appendix 9)
A content distribution method by a content distribution system comprising: a distribution server that caches and distributes content; and a management server that controls distribution of the content according to the presence or absence of the cache,
The management server is
A cache determination step for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
Executing a control step of transferring the target content to the distribution server while relaying a response from the content server to the communication terminal when a cache of the target content requested from the communication terminal does not exist in the distribution server. ,
The distribution server is
A cache step of storing the target content transferred from the management server in a cache DB;
The exchange step of converting the target content stored in the cache DB into a media segment file and notifying the management server after data distribution of the content from the content server is completed and the storage of the target content is completed The content distribution method characterized by performing these.

(Appendix 10)
The management server is
When the target content cache exists, based on control information set in advance and information unique to the communication terminal, execute a file generation step of generating a master index file and an alternative index file,
In the file generation step,
The content distribution method according to appendix 9, wherein the URI of the master index file is described in a response from the content server, and the response is transmitted to the communication terminal.

(Appendix 11)
The management server is
The communication terminal checks the NW bandwidth in response to the Get request of the alternative index file selected and transmitted from the appropriate bit rate described in the master index file, and the file of the requested bit rate is Perform a decision step to determine if transmission is possible,
In the determining step,
When it is determined that the requested bit rate file can be transmitted, the information of the alternative index file is transmitted to the communication terminal,
11. The content according to appendix 10, wherein when it is determined that the requested bit rate file cannot be transmitted, the media index file of the low file is transmitted to the communication terminal regardless of the request of the communication terminal. Delivery method.

(Appendix 12)
The management information DB provided in the management server is
Content information cached in the distribution server;
The control information;
Information specific to the communication terminal;
The content distribution method according to appendix 11, wherein the NW band status is stored.

(Appendix 13)
The control information is
The content distribution method according to appendix 11 or appendix 12, characterized in that it includes at least one of uniform bandwidth control information, time zone bandwidth control information, regional bandwidth control information, and specific URL bandwidth control information.

(Appendix 14)
The master index file is
Any one of URIs of media segment files of at least three types of bit rates of High, mid, and low is described based on the control information. Content distribution method.

(Appendix 15)
The cache DB is
15. The content distribution method according to any one of appendix 9 to appendix 14, wherein media segment files having three types of bit rates of High, mid, and low are stored.

(Appendix 16)
The content distribution method according to any one of appendix 9 to appendix 15, wherein the content request from the communication terminal is an HTTP request.

(Appendix 17)
A content distribution program that operates on a computer that constitutes a content distribution system including a distribution server that caches and distributes content, and a management server that controls distribution of content according to the presence or absence of the cache,
A computer constituting the management server;
Cache determination means for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
When the cache of the target content requested from the communication terminal does not exist in the distribution server, while functioning as a control means for transferring the target content to the distribution server while relaying the response from the content server to the communication terminal,
A computer constituting the distribution server;
Cache means for storing the target content transferred from the management server in a cache DB;
After data distribution of content from the content server is completed and accumulation of the target content is completed, the target content stored in the cache DB is converted into a media segment file, and the management server is notified accordingly A content distribution program that functions as a conversion means.

(Appendix 18)
A computer constituting the management server;
When there is a cache of the target content, based on control information set in advance and information unique to the communication terminal, function as a file generation unit that generates a master index file and an alternative index file,
The file generation means includes
The content distribution program according to appendix 17, wherein the URI of the master index file is described in a response from the content server, and the response is transmitted to the communication terminal.

(Appendix 19)
A computer constituting the management server;
The communication terminal checks the NW bandwidth in response to the Get request of the alternative index file selected and transmitted from the appropriate bit rate described in the master index file, and the file of the requested bit rate is Function as a decision means to determine whether or not transmission is possible,
The determining means includes
When it is determined that the requested bit rate file can be transmitted, the information of the alternative index file is transmitted to the communication terminal,
19. The content according to appendix 18, wherein when it is determined that the requested bit rate file cannot be transmitted, the media index file of the low file is transmitted to the communication terminal regardless of the request of the communication terminal. Delivery program.

(Appendix 20)
The management information DB provided in the management server is
Content information cached in the distribution server;
The control information;
Information specific to the communication terminal;
The content distribution program according to appendix 19, wherein the NW band status is stored.

(Appendix 21)
The control information is
The content distribution program according to appendix 19 or appendix 20, characterized in that it includes at least one of uniform bandwidth control information, time zone bandwidth control information, regional bandwidth control information, and specific URL bandwidth control information.

(Appendix 22)
The master index file is
Any one of URIs of media segment files having at least three types of bit rates of High, mid, and low is described based on the control information. Content distribution program.

(Appendix 23)
The cache DB is
23. The content distribution method according to any one of appendix 17 to appendix 22, wherein media segment files having three types of bit rates of High, mid, and low are stored.

(Appendix 24)
The content distribution program according to any one of appendix 17 to appendix 23, wherein the content request from the communication terminal is an HTTP request.

10: Communication terminal 20: Distribution server 21: Cache DB
22: Cache means 23: Conversion means 24: Distribution means 30: Management server 31 Cache determination means 32: File generation means 33: Control means 34: Determination means 35: Management information DB
40: eNB
50: S-GW
60: P-GW
70: L3SW
80: Monitoring server 90: Content server 100: Content distribution system 1001: CPU
1002: Main storage unit 1003: Communication unit 1004: Input / output interface unit 1005: Input device 1006: Output device 1007: Storage device 1008: System bus

Claims (10)

A distribution server that caches and distributes content;
A management server that controls distribution of content according to the presence or absence of the cache,
The management server is
Cache determination means for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
Control means for transferring the target content to the distribution server while relaying a response from the content server to the communication terminal when a cache of the target content requested from the communication terminal does not exist in the distribution server;
The distribution server is
Cache means for storing the target content transferred from the management server in a cache DB;
After data distribution of content from the content server is completed and accumulation of the target content is completed, the target content stored in the cache DB is converted into a media segment file, and the management server is notified accordingly A content distribution system comprising: a converting means for performing the processing. The management server is
When there is a cache of the target content, provided with file generation means for generating a master index file and an alternative index file based on preset control information and information unique to the communication terminal,
The file generation means includes
The content distribution system according to claim 1, wherein a URI of the master index file is described in a response from the content server, and the response is transmitted to the communication terminal. The management server is
The communication terminal checks the NW bandwidth in response to the Get request of the alternative index file selected and transmitted from the appropriate bit rate described in the master index file, and the file of the requested bit rate is A determination means for determining whether transmission is possible,
The determining means includes
When it is determined that the requested bit rate file can be transmitted, the information of the alternative index file is transmitted to the communication terminal,
The media index file of a low file is transmitted to the communication terminal regardless of the request from the communication terminal when it is determined that the requested bit rate file cannot be transmitted. Content distribution system. The management server is
Content information cached in the distribution server;
The control information;
Information specific to the communication terminal;
The content distribution system according to claim 3, further comprising a management information DB that stores the status of the NW band. The control information is
5. The content distribution system according to claim 3, comprising at least one of uniform bandwidth control information, time zone bandwidth control information, regional bandwidth control information, and specific URL bandwidth control information. The master index file is
Any one of URIs of media segment files having at least three types of bit rates of High, mid, and low is described based on the control information. The content distribution system described. The cache DB is
The content distribution system according to any one of claims 1 to 6, wherein media segment files of three types of bit rates of High, mid, and low are stored.   The content distribution system according to any one of claims 1 to 7, wherein the content request from the communication terminal is an HTTP request. A content distribution method by a content distribution system comprising: a distribution server that caches and distributes content; and a management server that controls distribution of the content according to the presence or absence of the cache,
The management server is
A cache determination step for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
Executing a control step of transferring the target content to the distribution server while relaying a response from the content server to the communication terminal when a cache of the target content requested from the communication terminal does not exist in the distribution server. ,
The distribution server is
A cache step of storing the target content transferred from the management server in a cache DB;
The exchange step of converting the target content stored in the cache DB into a media segment file and notifying the management server after data distribution of the content from the content server is completed and the storage of the target content is completed The content distribution method characterized by performing these. A content distribution program that operates on a computer that constitutes a content distribution system including a distribution server that caches and distributes content, and a management server that controls distribution of content according to the presence or absence of the cache,
A computer constituting the management server;
Cache determination means for determining whether or not the target content requested from the communication terminal is cached in the distribution server;
When the cache of the target content requested from the communication terminal does not exist in the distribution server, while functioning as a control means for transferring the target content to the distribution server while relaying the response from the content server to the communication terminal,
A computer constituting the distribution server;
Cache means for storing the target content transferred from the management server in a cache DB;
After data distribution of content from the content server is completed and accumulation of the target content is completed, the target content stored in the cache DB is converted into a media segment file, and the management server is notified accordingly A content distribution program that functions as a conversion means.

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