JP5940931B2 - Server device, communication device, and program - Google Patents

Description

  The present invention relates to a content caching technique.

  In the Internet, a so-called proxy server is provided. When the proxy server caches the transferred web content, that is, temporarily stores it and receives a message addressed to a web site that requests the web content, the proxy server caches the web content requested by the message. If so, the cached web content is transmitted to the requesting client device without transferring the message to the web site. On the other hand, when the web content requested by the message is not cached, the message is transferred as it is to the web site. By providing a proxy server, the client device can quickly receive the requested web content, and the web site can reduce its load.

  In recent years, content distribution techniques called ICN (Information Centric Networking) and NDN (Named Data Networking) have attracted attention (see Non-Patent Documents 1 and 2). ICN and NDN are for distributing content to client devices based on the name of the content, not the IP address. In these ICNs and the like, routers in the middle of content distribution cache the transferred content.

Jacobson, V .; Setters, D .; K. Thornton, J .; D. Plus, M .; F. Briggs, N .; Brainnard, R .; , "Networking named content," Proceedings of the 5th ACM International Conference on Emergence Networking Experiences and Technologies (CoNEXT 9 December, 2009) http://www.sail-project.eu/about-sail/

  In recent years, with the spread of so-called smartphones, many people have accessed websites in places where a lot of people spend a certain amount of time, such as in airports, station buildings, buses and trains. I am browsing news. At this time, even if a plurality of people in a certain area are accessing the same content, they each occupy a network line such as a cellular phone network as an independent process. Therefore, by storing and sharing the same content accessed by a plurality of people in a certain area by some method, traffic to the network can be reduced.

  The present invention provides a server device that can distribute content acquired and stored by a certain range of communication devices to other communication devices, a communication device that provides the stored content to the server device, and a program. .

According to one aspect of the present invention, a communication device that acquires content via a first network and a server device that communicates wirelessly via a second network different from the first network communicate the presence of the server device. When the advertising means for repeatedly transmitting the advertisement signal for notifying the apparatus and the identification information of the content stored by the communication apparatus are received from the communication apparatus, the identification information is stored in the storage means in association with the communication apparatus. Management means for determining, and upon receiving an inquiry message including content identification information from the communication device, a determination means for determining whether the storage means stores identification information included in the inquiry message, and When the storage means stores the identification information included in the inquiry message, the management means The content corresponding to the identification information is acquired from the communication device corresponding to the identification information stored by the storage means, and the acquired content is transmitted to the communication device that is the transmission source of the inquiry message. To do.

According to one aspect of the present invention, to retrieve the content via a first network, a communication apparatus for communicating by a server apparatus by radio via a different second network from the first network, from the server apparatus, said server Receiving means for receiving an advertisement signal for advertising the presence of the apparatus; transmitting means for transmitting an inquiry message including identification information of the content to the server apparatus when acquiring the content; and identification included in the inquiry message If the content corresponding to the information cannot be acquired from the server device, the content is acquired from the device holding the content, and when the acquired content is stored, the server device identifies the stored content. And a management means for transmitting information.

  The server device can distribute content acquired and stored by a certain range of communication devices to other communication devices. With this configuration, traffic to the network can be reduced.

1 is a schematic configuration diagram of a system according to an embodiment. FIG. The sequence diagram in case the server apparatus is not caching the content by one Embodiment. The sequence diagram in case the server apparatus is caching the content by one Embodiment. The schematic block diagram of the server apparatus by one Embodiment. 1 is a schematic configuration diagram of a communication device according to an embodiment. FIG.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the following drawings, components that are not necessary for the description of the embodiments are omitted from the drawings.

  FIG. 1 is a schematic configuration diagram of a system according to an embodiment. In the present embodiment, the communication device 2 is, for example, a mobile phone terminal, and can connect to the network 3 and access the web server 4 on the network 3 by, for example, a radio signal conforming to the 3GPP standard. The network 3 expresses a mobile communication network and the Internet collectively. Further, in FIG. 1, only one web server 4 is shown, but the number is an example. Note that the access method to the network 3 is not limited to a method using a radio signal conforming to the 3GPP standard, and a signal based on an arbitrary radio standard can be used.

  The communication device 2 has a wireless LAN interface, for example, and is configured to communicate with the server device 1 by transmitting and receiving wireless signals. Although FIG. 1 shows three communication devices 2 of communication devices # 1 to # 3, the number is an example. In the present embodiment, the server device 1 and the communication device 2 communicate according to the wireless LAN standard, but any wireless standard can be used.

  Hereinafter, operations of the server device 1 and the communication device 2 will be described with reference to FIGS. 2 and 3. First, as shown in S21, the server apparatus 1 broadcasts an advertisement signal in S21 and notifies the communication apparatus 2 of its own existence. The advertisement signal includes information necessary for the communication device 2 to communicate with the server device 1. Note that the transmission of the advertisement signal by the server device 1 is repeatedly performed. Subsequently, when the user of the communication device # 1 controls the communication device # 1 to acquire a certain content (target content), the communication device # 1 sends the target content to the web server 4 that holds the target content. First, an inquiry is made as to whether or not the target content can be distributed to the server device 1 using an inquiry message including identification information of the target content, for example, a URI (S22). Here, it is assumed that the server apparatus 1 has not yet cached, that is, stored any content. Therefore, the server apparatus 1 transmits a negative response indicating that the content cannot be distributed to the communication apparatus # 1 in S23.

  If a negative response is received, the communication device # 1 requests the target content from the web server 4 (S24). When the requested target content is received in S25, the communication apparatus # 1 determines whether to cache the content received in S26. . For example, if the target content is content that does not permit caching, the communication device # 1 selects not to cache. Further, even if the content can be cached, it can be selected that the user of the communication device # 1 does not cache based on the criteria set in advance in the communication device # 1, for example, the domain name. Moreover, it can also be set as the structure which communication apparatus # 1 displays and selects a user each time whether it caches.

  If the cache is selected in S26, the communication device # 1 caches the target content. At this time, the communication device # 1 can set a cache expiration date. When the target content indicates the cache expiration date, the cache expiration date can be set as the expiration date, or an arbitrary time limit earlier than the expiration date can be set. If the target content does not indicate the cache expiration date, an arbitrary expiration date can be set. Thereafter, in S27, the communication device # 1 notifies the server device 1 of the identification information of the target content to be cached, for example, the URI and the expiration date of the cache. The time limit is stored in association with communication device # 1. If not cached, the processing of S26 and S27 is not performed.

  Next, FIG. 3 shows a sequence when the user of the communication device # 2 performs an operation on the communication device # 2 to acquire the same target content that the communication device # 1 has acquired in S25. In S31, the communication device # 2 inquires of the server device 1 whether the target content can be distributed. Since the server apparatus 1 stores the content identification information included in the inquiry message from the communication apparatus # 2 in the process of S28, the server apparatus 1 transmits an affirmative response to the communication apparatus # 2 in S32. If the expiration date of the target content cache has expired, a negative response is transmitted. In S33, a request message for requesting the target content is transmitted to the communication device # 1, and when the target content is received in S34, the target content is transmitted to the communication device # 2 in S35, and the target content is stored in S36. . For example, when the communication device # 1 is outside the communication range with the server device 1 at the time of transmitting the content request in S33, the server device 1 cannot receive the content. Therefore, if the server apparatus 1 does not receive content from the communication apparatus # 1 even after a predetermined time, the server apparatus 1 transmits a negative response to the communication apparatus # 2.

  Accordingly, the communication device # 2 can acquire the target content through local communication without requesting the target content from the web server 4. Since the server device stores the target content in S36, for example, when the communication device # 3 acquires the same target content, the processing in S33 and S34 is not necessary, and the content inquiry is received in S31. Then, the server device 1 can transmit the target content for which an inquiry is received together with an affirmative response. In the sequence of FIG. 3, the affirmative response in S32 can be omitted, and the target content can be transmitted together with the affirmative response in S35. Further, the storage of the target content in S36 may be performed before S35. Although the expiration date can be set for the content stored in S36, the expiration date set by the communication device # 1 can be used, or the server device 1 can newly set the expiration date. However, if a cache expiration date is set for the content itself, the expiration date is earlier than the expiration date.

  2 and 3, one content is inquired and only one content is transmitted, but for example, a plurality of contents can be inquired collectively. In this case, the inquiry message includes the number of requested contents and identification information of each content. When a plurality of contents are transmitted, the number of contents to be transmitted and each content are included.

  FIG. 4 shows a schematic configuration of the server apparatus 1 according to the present embodiment. The communication unit 11 communicates with the communication device 2 via a wireless LAN, for example. The advertisement unit 12 repeatedly transmits the advertisement signal indicated by S21 in FIG. 2 to notify the communication device 2 of the presence of the server device 1. When the content management unit 13 receives a content inquiry from the communication device 2, the storage unit 14 does not hold the content, and the storage unit 14 holds the correspondence between the identification information of the content and the communication device 2. If not, a negative response is transmitted to the inquiring communication device 2. On the other hand, when the storage unit 14 holds the content, the content is transmitted to the communication device 2 that has inquired. Further, when the storage unit 14 holds information on the communication device 2 that holds the content but does not hold the content, the content is received from the communication device 2 that stores the content. The acquired content is transmitted to the communication device 2 that has acquired and inquired. In addition, when the content management unit 13 acquires content from the communication device 2, the content management unit 13 stores the content in the storage unit 14. At that time, a storage expiration date can also be set. Further, upon receiving the content identification information and the expiration date notification from the communication device 2, the content management unit 13 associates the communication device 2 with the content identification information and the expiration date and stores them in the storage unit 14. When the expiration date is set, the content management unit 13 transmits a negative response to the communication device 2 when the expiration date of the content inquired from the communication device 2 has passed.

  FIG. 5 shows a schematic configuration of the communication apparatus 2 according to the present embodiment. The communication unit 21 communicates with the server device 1 via, for example, a wireless LAN, and the communication unit 22 communicates with the network 3 wirelessly. The control unit 23 includes an input / output unit that receives input from the user and displays content to the user, and controls the entire communication device 2. When the control unit 23 receives an instruction to acquire content from the user, the content management unit 24 determines whether the content is cached, that is, stored in the storage unit 25. If the content is cached, the content management unit 24 selects the cached content. Output to the control unit 23. On the other hand, when the requested content is not cached, the content management unit 24 inquires of the server device 1 about the content via the communication unit 21, and when receiving the content from the server device 1, outputs the received content to the control unit 23. And display. Further, when the requested content is not cached and the content cannot be acquired from the server device 1, the content management unit 24 acquires the content from the web server 4 via the communication unit 22. In any case, when the content is acquired, the control unit 23 determines whether or not to cache the acquired content, and notifies the content management unit 24 when it is cached. At this time, the control unit 23 can determine the expiration date of the cache. When the content management unit 24 receives a notification of caching from the control unit 23, the content management unit 24 caches it in the storage unit 25 and notifies the server device 1 of the identification information and expiration date of the content cached by the communication unit 21.

  In the above-described embodiment, the content already cached when the communication device 2 enters the range in which the communication with the server device 1 can be communicated is not notified to the server device 2. Can be configured to notify the server device 1 of the already cached content. In the above embodiment, the communication device 1 notifies the server device of all the contents to be cached. However, not all of the contents to be cached conforms to a predetermined standard, or is permitted by the user. The configuration may be such that only the content is notified to the server device 1. Further, the server device 1 stores the expiration date notified when the cached content is received from the communication device 2, but the server device 1 newly sets an expiration date earlier than the notified expiration date. It may be stored, and a configuration in which the expiration date is not managed may be employed. When the expiration date is not managed, when the server device 1 requests the content from the communication device 2 that caches the content, the communication device 2 may already discard the content. In this case, the communication device 2 transmits a negative response to the server device 1 to notify the server device 1 that the content is not cached.

  As described above, according to the present embodiment, the server device 1 does not need to be connected to the network 3, and the server device 1 can be easily installed on a vehicle or the like. In addition, the communication device 2 in the range capable of communicating with the server device 1 does not need to request duplicate content from the network 3 and can acquire the content with low delay. The server device 1 is not limited to being installed on a vehicle or the like. For example, since the server apparatus 1 does not need to be connected to the network 3, it is possible to obtain an effect of suppressing traffic to the network 3 by installing the server apparatus 1 in a place where people gather such as an airport or a station. Note that the reason why only the content identification information is received instead of the content in S27 of FIG. 2 is to suppress the transmission / reception of the content that the other communication device 2 does not request and the cache by the server device 1. The content itself can be acquired in S27.

  The server device 1 and the communication device 2 according to the present invention can be realized by a program that causes a computer to operate as the server device 1 or the communication device 2. These computer programs can be stored in a computer-readable storage medium or distributed via a network. Furthermore, the server device 1 of the present invention is not limited to the one arranged at a certain position, and can be constituted by a plurality of devices arranged at distributed positions. In this case, each device communicates with each other by wire or wirelessly. At this time, the communication unit 11 of the server device 1 may be a plurality of communication units 11 installed at a plurality of geographically dispersed positions instead of one. With this configuration, it is possible to collect content from a large number of communication devices 2 existing in a range that cannot be covered by one communication unit 11, such as an airport or an underground shopping center, and further reduce the acquisition of duplicate content from the network 3 side. Can be made.

Claims (13)

A communication device that acquires content via a first network, and a server device that communicates wirelessly via a second network different from the first network ,
Advertising means for repeatedly transmitting an advertising signal for notifying the communication device of the presence of the server device;
When receiving the identification information of the content stored by the communication device from the communication device, a management unit that stores the identification information in the storage unit in association with the communication device;
When receiving an inquiry message including content identification information from the communication device, the determination unit determines whether the storage unit stores the identification information included in the inquiry message;
With
When the storage unit stores the identification information included in the inquiry message, the management unit acquires the content corresponding to the identification information from the communication device corresponding to the identification information stored by the storage unit. Transmitting the acquired content to a communication device that is a transmission source of the inquiry message;
The server apparatus characterized by the above-mentioned. The management means, when receiving the expiration date of storage together with the identification information of the content stored by the communication device from the communication device, stores the identification information and the expiration date in the storage device in association with the communication device,
The determination unit determines that the storage unit has not stored the identification information when the expiration date of storage of the content corresponding to the identification information included in the inquiry message has passed.
The server apparatus according to claim 1. When the management unit acquires content corresponding to the identification information from the communication device corresponding to the identification information stored by the storage unit, the management unit stores the acquired content in the storage unit.
The server apparatus according to claim 1 or 2, wherein When the determination unit receives the inquiry message from the communication device, the determination unit determines whether the storage unit stores the content corresponding to the identification information included in the inquiry message, and the content corresponding to the identification information is If the storage means is not stored, determine whether the storage means stores the identification information,
When the storage unit stores the content corresponding to the identification information included in the inquiry message, the management unit stores the content stored in the storage unit as the transmission source of the inquiry message. Send to
The server device according to claim 3. If the storage unit does not store the identification information included in the inquiry message and the content corresponding to the identification information is not stored, the determination unit is a communication device that is a transmission source of the inquiry message Send a negative response to
The server device according to claim 4, wherein: A communication device that acquires content via a first network and communicates wirelessly with a server device via a second network different from the first network ,
From the server device, receiving means for receiving an advertisement signal for advertising the presence of the server device,
Transmitting means for transmitting an inquiry message including identification information of the content to the server device when acquiring the content;
If the content corresponding to the identification information included in the inquiry message cannot be acquired from the server device, the content is acquired from the device holding the content, and the acquired content is stored. A management means for transmitting the stored content identification information;
A communication apparatus comprising: When the management unit receives a request message including identification information of the stored content from the server device, the management unit transmits the content to the server device.
The communication apparatus according to claim 6. The management unit sets an expiration date of the stored content, and if the expiration date of the content corresponding to the identification information included in the request message received from the server device has passed, a negative response is sent to the server device Send,
The communication apparatus according to claim 7. The management means transmits a storage expiration date together with identification information of the stored content.
The communication apparatus according to claim 6, wherein the communication apparatus is configured as described above. The management means selects a content to be stored based on a predetermined criterion or an input from a user.
The communication device according to any one of claims 6 to 9, wherein The management means transmits, to the server device, identification information of a content selected based on a predetermined reference or input from a user among the stored content.
The communication apparatus according to any one of claims 6 to 10, wherein   A program that causes a computer to function as the server device according to claim 1.   A program that causes a computer to function as the communication device according to any one of claims 6 to 11.

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