JP2009251886A - Content transmission system, content transmission method, in-area terminal, and relay terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow acquiring of a content using an out-area terminal while reducing a load on a network, even if an in-area terminal that possesses the content cannot respond. <P>SOLUTION: Upon receiving an acquisition request for a predetermined content possessed by at least any one of in-area terminals (for example, DSC 20A, PC 20B, mobile phone 20C) in LAN 10 from an out-area terminal 50 through unicast communication, an address translator 30 issues the content acquisition request to respective in-area terminals. At least one of the requested contents, having been received from the in-area terminal, (for example, mobile phone 20C), is transmitted to the out-area terminal 50 that has requested acquisition of the content from the address translator 30. Thus, the content can be transmitted to the out-area terminal 50 even if the in-area terminal (for example, DSC 20A) that possess the content cannot respond. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a content transmission system and content in which a content unique identifier related to content in an area terminal is transmitted to a terminal outside the area via the relay terminal, and the terminal outside the area acquires the content via the relay terminal based on the content unique identifier The present invention relates to a transmission method, an in-area terminal, and a relay terminal.

  Conventionally, by using NAT (Network Address Translation) or NAPT (Network Address Port Translation) of a relay terminal, a content unique identifier related to content, such as a thumbnail image, is obtained from a terminal in an area existing in a LAN. The data is transmitted to an external terminal outside the area, and the external terminal can acquire the content from the internal terminal based on the content unique identifier.

  However, when the out-of-area terminal tries to acquire the content, if the in-area terminal that has transmitted the content unique identifier to the out-of-area terminal is turned off, the out-of-area terminal cannot access the in-area terminal, and the content Can not get. In addition, when the terminal in the area has moved outside the LAN, the address of the terminal in the area is different from the address when the terminal outside the area receives the content unique identifier. I can't get it.

Therefore, Patent Document 1 proposes an apparatus and method in which each server assigns a unique identifier to each content, and a client performs multicast content search for a plurality of servers based on the unique identifier. As a result, even if the power of one of the servers having the content to be searched is turned off, if the same content is copied to another server, the client can acquire the content from the other server. ing.
JP 2004-234158 A

  However, in the technique disclosed in Patent Document 1, when the client and the server belong to different LANs, the client has a server that can receive at a predetermined multicast address in addition to the LAN to which the target server belongs. Since the multicast is performed even for the LAN that is running, the load on the network increases.

  The present invention has been made in view of the above points, and reduces the load on the network even in a situation where the terminal in the area that originally owns the content cannot respond because the power is turned off or moved outside the LAN. It is an object of the present invention to provide a content transmission system, a content transmission method, an in-area terminal, and a relay terminal that enable content acquisition by an out-of-area terminal.

One aspect of the relay terminal according to the present invention is a relay terminal that transmits predetermined content received from an in-area terminal existing in a predetermined network area to an out-of-area terminal existing outside the predetermined network area. And
An acquisition request receiving means for receiving an acquisition request for a predetermined content held by any one or more of the in-area terminals from the out-of-area terminal by unicast communication;
An acquisition request transmitting means for making an acquisition request for the content to each terminal in the area based on the acquisition request for the content received by the acquisition request receiving means;
Content receiving means for receiving the content requested for acquisition from the terminal in the area;
Content transmitting means for transmitting at least one of the contents received by the content receiving means to the out-of-area terminal that has made an acquisition request for the content to the relay terminal;
It is characterized by comprising.
Further, according to one aspect of the content transmission system of the present invention, among at least one or more in-area terminals existing in a predetermined network area, at least one of the above-mentioned in-area terminals holds predetermined content. A content transmission system for transmitting to a terminal outside the area existing outside the predetermined network area via a relay terminal,
The terminal outside the area
First acquisition request transmission means for transmitting the acquisition request for the predetermined content to the relay terminal by unicast communication;
First content receiving means for receiving the content for which the acquisition request has been transmitted from the relay terminal;
Comprising
The relay terminal
Second acquisition request transmission means for making a content acquisition request to each of the in-area terminals based on the content acquisition request received from the out-of-area terminal;
First content transmitting means for transmitting content to the out-of-area terminal;
Comprising
Each of the above-mentioned terminals in the area
Second content transmitting means for transmitting the predetermined content in response to the content acquisition request received from the relay terminal to the relay terminal;
Comprising
The first content transmitting means of the relay terminal transmits at least one of the contents received from the in-area terminal to the out-of-area terminal that has requested the relay terminal to acquire the content. And
Further, according to one aspect of the content transmission method of the present invention, among at least one or more in-area terminals existing in a predetermined network area, at least one of the above-mentioned in-area terminals holds predetermined content. A content transmission method of a content transmission system for transmitting to a terminal outside the area existing outside the predetermined network area via a relay terminal,
A first content acquisition request step in which the acquisition request for the predetermined content is transmitted from the out-of-area terminal to the relay terminal by unicast communication;
Based on the acquisition request for the predetermined content transmitted in the first content acquisition request step, the content is transmitted from the relay terminal to each of the in-area terminals existing in the predetermined network area. A second content acquisition request step in which an acquisition request is transmitted;
The predetermined content in response to the content acquisition request in the second content acquisition request step sends an acquisition request for the predetermined content in the second content acquisition request step from the at least one in-area terminal. A first content providing step transmitted to the relay terminal that transmitted,
At least one of the predetermined contents transmitted in the first content providing step is transmitted from the relay terminal to the out-of-area terminal that has transmitted the acquisition request for the predetermined content in the first content acquisition request step. A second content providing step,
It is characterized by having.

Further, according to one aspect of the in-area terminal of the present invention, an area existing in the predetermined network area that transmits predetermined content to a terminal outside the area existing outside the predetermined network area via the relay terminal. An internal terminal,
Storage means for storing the predetermined content and information that the acquisition request destination of the predetermined content is the relay terminal;
Transmitting means for transmitting information to the relay terminal;
Receiving means for receiving information from the relay terminal;
Comprising
The transmitting means transmits information to the relay terminal that the predetermined content acquisition request destination is the relay terminal,
The receiving means receives the acquisition request for the predetermined content from the relay terminal that is the acquisition request destination of the predetermined content,
The transmission means transmits the predetermined content having the acquisition request to the relay terminal that has transmitted the acquisition request for the predetermined content to the terminal in the area.

  According to the present invention, when selecting content based on the content unique identifier received by the out-of-area terminal and acquiring content from the in-area terminal, the in-area terminal that originally owns the content is powered off or LAN To provide a content transmission system, a content transmission method, an in-area terminal, and a relay terminal that enable content acquisition by an out-of-area terminal while reducing the network load even in a situation where a response cannot be made due to movement to the outside Can do.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1A is a diagram showing a configuration of a content transmission system according to the first embodiment of the present invention.

  An in-area terminal (in the figure, a digital still camera (DSC) 20A, a personal computer (PC) 20B, a mobile phone 20C, a television receiver (TV) 20D) existing in a predetermined network area, for example, the LAN 10, is a relay terminal. It is possible to communicate with the out-of-area terminal 50 via the global network 40 such as the Internet outside the LAN 10 via the address translation device 30.

  The in-area terminals are not limited to the DSC 20A, PC 20B, mobile phone 20C, and TV 20D, but include personal digital assistants (PDAs), optical disc / HDD recorders, game machines, video cameras, printers, network connection storage ( There is no problem if it is a device capable of transmitting content such as NAS). Hereinafter, DSC 20A will be mainly described as an example of an in-area terminal.

  Examples of the out-of-area terminal 50 include contents such as a thumbnail image, a still image, and a hash value such as a PC, a mobile phone, a PDA, an optical disk / HDD recorder, a TV, a game machine, a video camera, a printer, a DSC, and a NAS. There is no problem as long as the device can acquire the unique identifier and make a content acquisition request.

  FIG. 1B is a diagram showing a configuration of a DSC 20A as an example of the in-area terminal. The DSC 20A includes a CPU 201, an input interface unit 202, a ROM 203, a RAM 204, a display unit 205, an external I / F 206, a file management unit 207, a recording unit 208, a compression / decompression engine 209, an imaging unit 210, and the like.

  The CPU 201 performs various controls using the RAM 204 according to a control program stored in the ROM 203. The CPU 201 is connected to the global network 40 via the external I / F 206 by a wired or wireless network protocol, and can communicate with the external terminal 50 outside the area. Data transmitted / received during communication with the external terminal 50 outside the area is stored in the RAM 204. The recording unit 208 is a non-volatile recording medium such as a semiconductor memory, a magnetic memory, a magnetic disk, an optical disk, a magneto-optical disk, or the like, or a non-volatile recording medium capable of recording information. A combination of media may be used. Furthermore, the recording unit 208 does not have to be composed of a single recording medium, and may be composed of a plurality of recording media. The input interface unit 202 is an operation input unit such as a switch, button, key, or dial for performing an operation input related to the DSC 20A. The input interface unit 202 may be a touch panel or the like superimposed on the display unit 205.

  In the DSC 20 </ b> A having such a configuration, at the time of shooting, the CPU 201 captures imaging data from the imaging unit 210 according to the input interface unit 202, displays it on the display unit 205, and stores it in the RAM 204. Then, a compression instruction is sent to the compression / decompression engine 209 to compress the image data stored in the RAM 204 into an image having a format designated by the CPU 201. The compressed image is recorded in the recording unit 208 through the file management unit 207 according to an instruction from the CPU 201.

  When the image recorded in the recording unit 208 is reproduced in this manner, first, the image in the recording unit 208 is opened through the file management unit 207 and decompressed according to the format recorded by the compression / decompression engine 209 according to an instruction from the CPU 201. The expanded image data is reproduced on the display unit 205.

  In addition, a setting screen for performing settings related to the DSC 20 </ b> A and image data at the time of imaging or reproduction can be displayed on the display unit 205, and the DSC 20 </ b> A can be set using the input interface 202. Furthermore, settings related to the DSC 20A and image data can be displayed on the display unit 205.

  FIG. 1C is a diagram illustrating a configuration of an address translation device 30 as an example of a relay terminal according to the first embodiment of the present invention. The address conversion device 30 includes a CPU 301, a ROM 302, a RAM 303, an address conversion unit 304, a WAN side I / F 305, and a LAN side I / F 306.

  The CPU 301 performs various controls using the RAM 303 according to a control program stored in the ROM 302. Further, the CPU 301 relays contents communicated via the WAN side I / F 305 and the LAN side I / F 306 by a wired or wireless network protocol. The WAN-side I / F 305 performs data transmission / reception with the global network 40, and the LAN-side I / F 306 performs data transmission / reception with each device in the LAN 10 connected thereto. The address conversion unit 304 creates an address conversion table 310 as shown in FIG. 1D in accordance with the connection status of the terminals in the area within the LAN 10, and addresses the data received via the LAN side I / F 306. According to the table 310, the source LAN side address and port number are converted into the WAN side address and port number, and transmitted to the destination address via the WAN side I / F 305. Further, the address conversion unit 304 converts the address and port number of the transmission destination into the LAN side address and port number according to the address conversion table 310 for the data received via the WAN side I / F 305 and converts the address and port number. Via the LAN side I / F 306.

  FIG. 1D shows an example of the address conversion table 310. For example, when the WAN-side I / F 305 of the address conversion device 30 receives data addressed to 111.2222.333 and port: 10001, the address conversion unit 304 sets the transmission destination according to the address conversion table 310. Address: 192.168.10.2. Port: Converts to 80. When the LAN side I / F 306 receives data from the address: 192.168.10.2 and the port: 80, the transmission source is the address: 1112.2223.44, the port according to the address conversion table 310. Is converted to 1: 0001.

  FIG. 1E is a diagram showing a configuration of the out-of-area terminal 50 such as a PC. The out-of-area terminal 50 includes a CPU 501, a ROM 502, a RAM 503, a compression / decompression engine 504, an external I / F 505, a file management unit 506, a recording unit 507, an input interface unit 508, a display unit 509, and the like.

  The CPU 501 performs various controls using the RAM 503 in accordance with control programs stored in the ROM 502 and the recording unit 507. The CPU 501 is connected to the global network 40 via the external I / F 505 by a wired or wireless network protocol, and can communicate with the DSC 20A and the like in the LAN 10. Data to be transmitted and received during communication with the DSC 20A is stored in the RAM 503. The received data is an image, and when this image is recorded, it is recorded in the recording unit 507.

  When the image recorded in the recording unit 507 is reproduced in this manner, first, the image in the recording unit 507 is opened through the file management unit 506 in accordance with an instruction from the CPU 501 and expanded according to the format recorded by the compression / decompression engine 504. The expanded image data is reproduced on the display unit 509.

  The input interface unit 508 is an operation input unit such as a switch, a button, a key, a dial, a keyboard, and a mouse for performing an operation input related to the out-of-area terminal 50. The input interface unit 508 may be a touch panel or the like superimposed on the display unit 509.

  Hereinafter, the operation of each unit constituting the content transmission system as described above will be described in detail with reference to the drawings.

  FIG. 2 is a diagram illustrating a flowchart for explaining an operation related to content transmission in the DSC 20A which is one of the in-area terminals.

  When the DSC 20A is turned on, the CPU 201 first determines whether or not a content unique ID, which is one of the content unique identifiers, has been associated with all the content recorded in the recording unit 208 ( In step S201), if there is content that has not yet been associated, the content unique ID is associated with the content that is not associated with the content unique ID (step S202). An example of the method for generating the content unique ID is a hash calculation based on the content data, and the generated content unique ID is stored in the recording unit 208. In this way, the content unique ID is associated with each content.

  Further, the CPU 201 determines whether or not content related information that is one of content unique identifiers exists for each content recorded in the recording unit 208 (step S203), and no content related information exists. If there is content, content-related information for the content is generated and recorded in the recording unit 208 (step S204). As examples of the content-related information, a thumbnail image can be used when the content is a still image, and a representative still image can be used when the content is a moving image. In this way, the content related information exists in the recording unit 208 for each content.

  Thereafter, the CPU 201 determines whether or not there is a content related information transmission command (step S205). This content-related information transmission command can be generated, for example, when a user gives an instruction using the input interface 202, or is automatically generated when the CPU 201 determines that the connection with the address translation device 30 has been completed. be able to. If there is a content related information transmission command, the content unique ID and content related information corresponding to the commanded content are read from the recording unit 208 and transmitted to the out-of-area terminal 50 (step S206). ).

  On the other hand, if there is no content-related information transmission command, it is determined whether or not a multicast content acquisition request has been received (step S207). If no multicast content acquisition request has been received, broadcast is further transmitted. It is determined whether or not a content acquisition request has been received (step S208). When a content acquisition request by multicast or broadcast is received, whether or not content associated with the same content unique ID as the acquired content unique ID included in the acquisition request exists in the recording unit 208, that is, It is determined whether or not the requested content is owned (step S209). Here, if there is content that matches the acquired content unique ID in the recording unit 208, the content is read out and returned as a content acquisition request response to the content acquisition request transmission source (step S210). On the other hand, if there is no content that matches the acquired content unique ID, the process returns to step S205.

  If it is determined in step S208 that a broadcast content acquisition request has not been received, it is further determined whether or not a unicast content acquisition request has been received (step S211). If no request has been received, the process returns to step S205. On the other hand, when a content acquisition request is received by unicast, the content associated with the same content unique ID as the acquired content unique ID included in the content acquisition request is recorded as in step S209. It is determined whether or not the content exists in the unit 208, that is, whether or not the requested content is owned (step S212). If there is content in the recording unit 208 that matches such an acquired content unique ID, the process proceeds to step S210, where the content is read out and sent back to the content acquisition request transmission source as a content acquisition request response. On the other hand, if it does not have the content that matches the acquired content unique ID, an unowned message indicating that it does not have the instructed content is transmitted as a content acquisition request response to the content acquisition request transmission source (step S213), the process returns to step S205.

  FIG. 3 is a flowchart for explaining operations related to content transmission / reception in the address translation device 30.

  When the power of the address conversion device 30 is turned on, as an initial operation, the CPU 301 first acquires a WAN address (step S301) and generates an address conversion table 310 (step S302).

  Thereafter, the presence / absence of reception from the LAN side I / F 306 is determined (step S303). If there is reception from the LAN side I / F 306, is it an address acquisition request from a terminal in the area in the LAN 10? It is determined whether or not (step S304). If the received content is an address acquisition request, the address of the terminal in the area within the LAN 10 is assigned (step S305), and the address conversion table 310 is updated (step S306).

  On the other hand, if the received content is not an address acquisition request, it is determined whether the received content is a response to the content acquisition request (step S307). If it is determined that a response to the content acquisition request has been received, an acquisition response process (to be described in detail later) is performed (step S308).

  On the other hand, when the received content is not a response to the content acquisition request, the source address of the received content is converted according to the address conversion table 310 (step S309), and this address is added to the converted content. Transmission is made to the destination address (step S310).

  When it is determined in step S303 that there is no reception from the LAN side I / F 306, or after the address translation table 310 is updated in step S306, or after the acquisition response process is performed in step S308. Alternatively, after transmitting to the destination address in step S310, the CPU 301 responds to the content acquisition request from the time when the content acquisition request is transmitted via the LAN side I / F 306 in step S315 described later. It is determined whether or not a predetermined time has passed (= timeout) with no error (step S311). Here, when a time-out occurs, an unowned message of content is transmitted as a content acquisition request response to the content acquisition request transmission source (step S312). In this transmission, the WAN address of the address translation device 30 (the port number uses the WAN side port number undefined in the address translation table 310) is set as the source address of the unowned message.

  When it is determined in step S311 that the time-out has not yet occurred, or after the content acquisition request response is transmitted to the content acquisition request transmission source in step S312, the CPU 301 determines whether or not there is reception from the WAN-side I / F 305. (Step S313), and if there is no reception, the process returns to step S303.

  On the other hand, if there is reception from the WAN side I / F 305, it is determined whether or not the received content is a content acquisition request (step S314). If the received content is a content acquisition request, a content acquisition request transfer process (to be described later in detail) is performed (step S315), and the process returns to step S303.

  On the other hand, if the received content is not a content acquisition request, the destination address of the received content is converted according to the address conversion table 310 (step S316), and the received content is transmitted to the terminal in the area of the converted destination address. (Step S317), the process returns to Step S303.

FIG. 4 is a flowchart of the acquisition response process in step 308 described above.
In this acquisition response process, the CPU 301 first determines whether or not the received response is the first content response to the same content acquisition request (step S308A). The original address is converted according to the address conversion table 310 (step S308B), the content is transmitted to the transmission destination address (step S308C), and the acquisition response process is terminated.

  On the other hand, if it is not the first content response, a content acquisition request to the LAN-side I / F 306 is made by unicasting in step S315, and is not yet received from terminals in all areas in the unicast LAN. It is determined whether or not a response is received by the retained message (step S308D). If so, as in step S312, the content acquisition request response is transmitted to the content acquisition request transmission source using the WAN address as the transmission source address and the content is not retained (step S308E). The acquisition response process is terminated.

  In step S308D, the content acquisition request to the LAN side I / F 306 is made by multicast, broadcast, or unicast, but a response by content is received from one or more terminals in the LAN. If it is determined that there is no response to an unowned message from a terminal in all areas, the acquisition response process is terminated without doing anything.

FIG. 5 is a diagram showing a flowchart of the content acquisition request transfer process in step S315.
In this content acquisition request transfer process, the CPU 301 converts the content received by the WAN-side I / F 305 into content corresponding to multicast (step S315A). An example of specific contents of conversion is conversion of a TCP packet into a UDP packet. Then, the converted received content is transmitted to a predetermined multicast address via the LAN side I / F 306 (step S315B), and the content acquisition request transfer process is terminated.

  FIG. 6 is a flowchart for explaining the operation related to content reception in the out-of-area terminal 50 according to the present embodiment.

  When the power of the out-of-area terminal 50 is turned on, the CPU 501 first determines whether or not there is reception (step S501). If there is any reception, it is determined whether or not the received content is a content unique ID and content related information including the source WAN side address (step S502). If it is such received content, the three pieces of information, that is, the content related information, the content unique ID, and the source WAN side address are associated and recorded in the recording unit 507 (step S503).

  On the other hand, when the received content does not include the above three pieces of information, processing corresponding to the received content is performed (step S504). For example, recording content, displaying content, transferring content, and the like.

  If it is determined that there is no reception in step S501, or after the processing in step S503 or step S504, it is determined whether or not there is a content acquisition request command (step S505). This content acquisition request command can be generated, for example, when the user gives an instruction using the input interface 508, or is automatically generated based on the determination of the CPU 501 that the recording has been completed in association with the above three pieces of information. Can do. If there is no content acquisition request command, the process returns to step S501.

  On the other hand, if there is a content acquisition request command, it is determined whether or not the acquisition request command is based on content-related information such as a thumbnail image (step S506). If it is based on the content related information, a content acquisition request is transmitted to the transmission source WAN side address recorded in the recording unit 507 in association with the content related information (step S507). At that time, the content unique ID recorded in association with the content related information is added to the content acquisition request as the acquired content unique ID.

  On the other hand, if the content acquisition request is not based on the content related information, the content acquisition request is transmitted to a predetermined transmission destination (step S508).

  After transmitting the content acquisition request in step S507 or step S508, the CPU 501 waits for reception from the content acquisition request transmission destination (step S509). Then, if there is a reception from the content acquisition request transmission destination, it is determined whether or not the received content is a content unowned message (step S510). Here, when the content non-holding message is received, the display unit 509 displays that the content could not be acquired (step S511), and returns to step S501.

  On the other hand, if the content received from the content acquisition request transmission destination is not a content unowned message, the content is recorded in the recording unit 507 (step S512), and the process returns to step S501.

  Hereinafter, based on a specific example, operation | movement of each part of the content transmission system which concerns on this embodiment is demonstrated.

  FIG. 7 is a diagram showing the content recording contents of the recording unit of the terminal in each area in the LAN 10. Here, it is assumed that DSC 20A, PC 20B, and mobile phone 20C exist in the LAN 10 as in-area terminals.

  For example, in the recording unit 208 of the DSC 20A, P810001. The content with the file name JPG is recorded in association with the content unique ID = 356A19B2... And the thumbnail image 60A1.

  In the recording unit 208B of the PC 20B, P8100022. The content with the file name JPG is associated with the content unique ID = 020D1743... And the thumbnail image 60B1, and P8100033. The content with the file name JPG is associated with the content unique ID = FB5E2C10... And the thumbnail image 60B2, and P8130004. The content with the file name JPG is recorded in association with the content unique ID = 680F452F... And the thumbnail image 60B3.

  In the recording unit 208C of the mobile phone 20C, P810001. The content with the file name JPG is associated with the content unique ID = 356A19B2... And the thumbnail image 60C1, and P8130002. The content with the file name JPG is recorded in association with the content unique ID = 020D1743... And the thumbnail image 60C2.

  The content unique ID is generated and recorded in step S202 described with reference to FIG. 2, and the thumbnail image is generated and recorded in step S204 described with reference to FIG.

  FIG. 8A shows the DSC 20A, the address translation device 30, and the out-of-area terminal 50 in a state where each content is recorded in association with the content unique ID in the recording unit of each in-area terminal. FIG. 7 is a diagram illustrating a sequence when the operation described with reference to FIGS. 2 to 6 is performed.

  If no event has occurred, the DSC 20A goes through the loop of steps S205 → S207 → S208 → S211 → S205 described above, and the address translation device 30 performs the steps S303 → S311 → S313 → S303 described above. The out-of-area terminal 50 goes around the loop of steps S501 → S505 → S501 described above.

  When the DSC 20A receives a content related information transmission command by means not specified here, the process proceeds from step S205 to step S206, and as a result, P810001. JPG thumbnail image 60A1 and content unique ID = 356A19B2... Are transmitted to the terminal 50 outside the area.

  In the address translation device 30 that has received it by the LAN side I / F 305, the process proceeds from step S303 → S304 → S307 → S309 → S310. As a result, the source address of the data received from the DSC 20A is converted into the address translation table. 310, and P81130001. JPG thumbnail image 60A1, content unique ID = 356A19B2,..., WAN side address 111.222.33.44 is transmitted via WAN side I / F 305 to out-of-area terminal 50 at the destination address.

  In the out-of-area terminal 50 that has received it, the process proceeds from step S501 to S502 to S503, and as a result, P810001. JPG thumbnail image 60A1, content unique ID = 356A19B2,..., WAN side address 111.222.33.44 are associated with each other and recorded in recording unit 507.

  Then, in the out-of-area terminal 50, P810001. When a content acquisition request command based on the JPG thumbnail image 60A1 is received, the process proceeds from step S505 to S1506 to S507, and as a result, P810001. A content acquisition request including the acquired content unique ID = 356A19B2... Is transmitted to the WAN address 111.222.33.44 associated with the JPG thumbnail image 60A1. That is, a content acquisition request is transmitted by unicast communication. After that, in step S509, reception of content from the transmission destination is awaited.

  In the address translation device 30 that has received the content acquisition request by unicast communication from the out-of-area terminal 50 at the WAN-side I / F 305, the process proceeds from step S313 → S314 → S315A → S315B. The content acquisition request received from the server is converted into content corresponding to multicast, and the converted content acquisition request including the acquired content unique ID = 356A19B2... Is transmitted to the multicast address 239.1.1.10 via the LAN side I / F 306. Send.

  In the DSC 20A in the LAN 10, the process proceeds from step S207 → S209 → S209 → S210, and as a result, the content having the content unique ID = 356A19B2... Matching the acquired content unique ID = 356A19B2. Since it has JPG, its P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  On the other hand, the PC 20B in the LAN also receives the content acquisition request, but there is no content having a content unique ID that matches the acquired content unique 1D = 356A19B2. Also do not send.

  Also, the mobile phone 20C in the LAN 10 owns the content having the content unique ID that matches the acquired content unique ID = 356A19B2..., But has not opened the multicast address 239.1.1.10. The acquisition request is not recognized, and therefore nothing is transmitted to the out-of-area terminal 50.

  Accordingly, in the address translation device 30, the process proceeds from step S303 → S304 → S307 → S308A → S308B → S308C. As a result, the content P8100011.P received from the DSC 20A is obtained. The JPG is converted from the transmission source address to 111.222.33.44 and port 10001 by the address conversion table 310 and transmitted to the out-of-area terminal 50 via the WAN I / F 305.

  The out-of-area terminal 50 that has received it proceeds from the above steps S506 → S510 → S512, and as a result, records P8100010001 in the recording unit 507.

  Here, suppose DSC 20A is P8100011. If the JPG is deleted from the recording unit 208 and no longer exists, the address translation device 30 waits for the time-out at step S311 and, at step S312, the content-unowned message as a content acquisition request response. It is transmitted to the content acquisition request transmission source.

  On the other hand, as shown in FIG. 8B, when the mobile phone 20C that owns the content having the content unique ID that matches the acquired content unique ID = 356A19B2... Has also opened the multicast address 239.1.1.10. In the P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  Content P810001.1 from the mobile phone 20C. In the address translation device 30 that has received the JPG, the process proceeds in the above steps S303 → S304 → S307 → S308A and receives the content P810001, but the DSC 20A has already received P810001. Since the response by JPG is received, it is not transmitted to the out-of-area terminal 50, and the process proceeds to step S308D. Here, since the content acquisition request is not made by unicast, it is determined as NO as a result, and the address translation device 30 does nothing.

  However, as shown in FIG. 8C, the DSC 20A responds to the content-related information transmission command in step S206 with P810001. When the JPG thumbnail image 60A1 and the content unique ID = 356A19B2... Are transmitted to the out-of-area terminal 50, the power is turned off, moved outside the LAN 10, or the content is deleted from the recording unit 208. In step S308A, the address translation device 30 sends the content P810001.1 from the mobile phone 20C. JPG is determined to be the first response due to the same content acquisition request. Therefore, in such a case, the process proceeds from step S308A → S308B → S308C, and as a result, the content P810001.01 received from the mobile phone 20C. The JPG is converted from the transmission source address to 111.222.33.44 and port 10001 by the address conversion table 310 and transmitted to the out-of-area terminal 50 via the WAN I / F 305.

  As described above, according to the first embodiment, the content acquisition request from the out-of-area terminal 50 is sent to each in-area terminal (for example, DSC 20A, PC 20B, mobile phone 20C) in the LAN 10 managed by the address translation device 30. ) To reduce the network load even when one or more of the terminals in the area that own the target content are in a power-off state or are not present in the LAN 10 and cannot respond. However, it is possible to acquire the target content with the out-of-area terminal 50.

  In the above description, the case where the content acquisition request is performed by multicast has been described as an example, but it is needless to say that the content acquisition request may be performed by broadcast or unicast. Hereinafter, each will be described as a modification of the first embodiment.

[Modification 1]
FIG. 9A is a flowchart of the content acquisition request transfer process in step S315 when a content acquisition request is made by broadcast.

  In the content acquisition request transfer process in this case, the CPU 301 converts the content received by the WAN side I / F 305 to the content corresponding to the broadcast (step S315C). An example of specific contents of conversion is conversion of a TCP packet into a UDP packet. Then, the converted received content is transmitted to a predetermined broadcast address via the LAN side I / F 306 (step S35D), and the content acquisition request transfer process is terminated.

  FIG. 10 is a diagram showing an operation sequence of the DSC 20A, the address translation device 30, and the out-of-area terminal 50 when a content acquisition request is made by broadcast. Hereinafter, only differences from FIG. 8A will be described.

  In this modification, in the address translation device 30 that has received the content acquisition request from the out-of-area terminal 50 at the WAN-side I / F 305, the process proceeds from step S313 → S314 → S315C → S315D. The content acquisition request received from 50 is converted into content corresponding to the broadcast, and the converted content acquisition request including the acquired content unique ID = 356A19B2... Is transmitted to the broadcast address 192.168.10.255 via the LAN side I / F 306. Send.

  In the DSC 20A in the LAN 10, the process proceeds from the above steps S207 → S208 → S209 → S209 → S210, and as a result, the content having the acquired content unique ID = 356A19B2..., That is, P810001. Since it has JPG, its P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  On the other hand, the PC 20B in the LAN also receives the content acquisition request, but there is no content having a content unique ID that matches the acquired content unique 1D = 356A19B2. Also do not send.

  Also, the mobile phone 20C in the LAN 10 receives the content acquisition request, and the content P8130001.P having a content unique ID that matches the acquired content unique ID = 356A19B2. Because I own JPG, P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  In the address translation device 30, the process proceeds from step S303 → S304 → S307 → S308A → S308B → S308C. As a result, the content P810001.1 received first from either the DSC 20A or the mobile phone 20C. JPG is converted into 111.2222.333.44, port 10001 (when the source is DSC20A) or port 10003 (when the source is mobile phone 20C) by the address conversion table 310, and the JPG is converted into WAN. To the terminal 50 outside the area via the side I / F 305.

  Next, even if the same content P8100011 is received from the other side of the DSC 20A or the mobile phone 20C, the process proceeds from step S308A to S308D, and as a result, NO is determined in step S308D. The content is not transmitted.

  Although not specifically shown, when the DSC 20A is turned off in the middle, moved out of the LAN 10, or the content is deleted from the recording unit 208, the address translation device 30 performs the above step S308A. Content P810001.P from the mobile phone 20C. Since the JPG determines that it is the first response due to the same content acquisition request, the content P810001.jpg received from the mobile phone 20C. The JPG can be transmitted to the out-of-area terminal 50 via the WAN I / F 305 by converting the transmission source address to 111.222.33.44 and port 10001 by the address conversion table 310.

[Modification 2]
FIG. 9B is a flowchart of the content acquisition request transfer process in step S315 when a content acquisition request is made by unicast.

  In the content acquisition request transfer process in this case, the CPU 301 converts the destination address of the content received by the WAN side I / F 305 into one of the LAN side address and port described in the address conversion table 310 ( In step S315E, the received content is transmitted to the converted transmission destination address (step S315F). Then, steps S315E and S315F are repeated until transmission to all addresses on the LAN side described in the address conversion table 310 is completed (step S315G).

  FIG. 11 is a diagram showing an operation sequence of the DSC 20A, the address translation device 30, and the out-of-area terminal 50 when a content acquisition request is made by unicast. Hereinafter, only differences from FIG. 8A will be described.

  In this modification, in the address translation device 30 that has received the content acquisition request from the out-of-area terminal 50 at the WAN-side I / F 305, the process proceeds from step S313 → S314 → S315E → S315F. 50, the transmission destination of the content acquisition request received from 50 is converted into one of the LAN side address and port number described in the address conversion table 310, that is, the LAN side address 192.168.10.2 and the port number 80. Then, a content acquisition request is transmitted to the address and port number via the LAN side I / F 306.

  In step S315G, since it is determined that the content acquisition request has not been transmitted for the remaining two addresses in the address conversion table 310, steps S315E and S315F are repeated. A content acquisition request is transmitted to 192.168.10.3, port number 80.

  Similarly, a content acquisition request is transmitted to address 192.168.10.4 and port number 80.

  Since the transmission to all the addresses described in the address conversion table 310 is completed (step S315G), the transmission of the content acquisition request is completed.

  In the DSC 20A in the LAN 10, the process proceeds from step S207 → S208 → S211 → S212, and as a result, the content having the content unique ID = 356A19B2... Matching the acquired content unique ID = 356A19B2. Since it has JPG, the process proceeds to step S210 and P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  On the other hand, similarly to the DSC 20A, the PC 20B in the LAN proceeds from step S207 → S208 → S211 → S212, and as a result, receives a content acquisition request, but the PC 20B matches the acquired content unique ID = 356A19B2. Since there is no content having the content unique ID, the process proceeds to step S213, and the content of the content for notifying that the content located at the acquired content unique ID = 356A19B2. Send an unheld message.

  Similarly to the DSC 20A, the mobile phone 20C in the LAN 10 has contents P810001... Having a content unique ID that matches the acquired content unique ID = 356A19B2. Because I own JPG, P810001. The JPG is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source.

  In the address translation device 30, the process proceeds from step S303, S304, S307, S308A, S308B, and S308C. As a result, the content P810001. JPG is converted into 111.2222.333.44, port 10001 (when the source is DSC20A) or port 10003 (when the source is mobile phone 20C) by the address conversion table 310, and the JPG is converted into WAN. To the terminal 50 outside the area via the side I / F 305.

  Further, the process proceeds from the above steps S303 → S304 → S307 → S308A → S308D, and as a result, even if a content non-holding message is received from the PC 20B, a content acquisition response from the DSC 20A or the other mobile phone 20C is still received. Therefore, NO is determined in step S308D, and the address translation device 30 does nothing.

  Next, when the same content P810001 is received from the other side of the DSC 20A or the mobile phone 20C, the process proceeds from step S308A to S308D. Since the response by JPG is received, it is not transmitted to the terminal 50 outside the area. Then, the process proceeds to step S308D, and as a result, it is determined that the content acquisition request to the LAN side is made by unicast. However, since the unowned message is received only from the PC 20B in the LAN 10, nothing is done here. do not do.

  Here, it is assumed that the DSC 20A and the mobile phone 20C are P810001. If there is no JPG, since all the intra-area terminals in the LAN 10 of the DSC 20A, the PC 20B, and the mobile phone 20C transmit a content non-holding message as a result of the step S213, the address translation device 30 As a result of S308D and S308E, a content-unowned message as a content acquisition request response is transmitted to the out-of-area terminal 50 that is the content acquisition request transmission source with a transmission source address of 111.222.33.44.

  Although not specifically shown, when the DSC 20A is turned off in the middle, moved out of the LAN 10, or the content is deleted from the recording unit 208, the address translation device 30 performs the above step S308A. Content P810001.P from the mobile phone 20C. Since the JPG determines that it is the first response due to the same content acquisition request, the content P810001.jpg received from the mobile phone 20C. The JPG can be transmitted to the out-of-area terminal 50 via the WAN I / F 305 by converting the transmission source address to 111.222.33.44 and port 10001 by the address conversion table 310.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  Since the configuration of the content transmission system according to the present embodiment and the in-area terminal, the address translation device 30 and the out-of-area terminal 50 in the system are the same as those in the first embodiment, description thereof is omitted.

  FIG. 12 is a flowchart illustrating an operation related to content transmission in the DSC 20A as an example of an in-area terminal according to the second embodiment. Here, processes similar to those in the first embodiment are denoted by the same reference numerals as those in FIG. Therefore, hereinafter, the description will focus on the differences from the first embodiment.

  Steps S201 to S204 are as described in the first embodiment.

  In the present embodiment, the CPU 201 of the DSC 20A determines that content-related information exists for each content recorded in the recording unit 208 in step S203, or if the content-related information is determined in step S204. After content-related information for non-existing content is generated and recorded in the recording unit 208, a WAN-side address acquisition request is made to the address translation device 30 to acquire the WAN-side address (step S221). The acquired WAN address is recorded in the RAM 204 or the recording unit 208.

  Then, for example, there is a content related information transmission command that is generated when the user gives an instruction using the input interface 202 or when the CPU 201 determines that the WAN address has been acquired from the address translation device 30. In the case (step S205), the content unique ID, the content related information, and the acquired WAN address corresponding to the requested content are transmitted to the out-of-area terminal 50 (step S222).

  Subsequent steps S207 to S213 are as described in the first embodiment.

  FIG. 13 is a diagram illustrating a flowchart for explaining operations related to content transmission / reception in the address translation device 30 according to the second embodiment. Here, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG. Therefore, hereinafter, the description will focus on the differences from the first embodiment.

  Steps S301 to S308 are as described in the first embodiment.

  In the present embodiment, if the CPU 301 of the address translation device 30 determines in step S307 that the received content from the LAN side I / F 306 is neither an address acquisition request nor a response to the content acquisition request, the received content is further changed. It is determined whether or not it is a WAN side address acquisition request (step S321). If the received content is a WAN address acquisition request, the WAN address is acquired from the address conversion table 310 and transmitted to the WAN address request source via the LAN I / F 306 (step S322). ), The process proceeds to step S311.

  If the received content is not a WAN address acquisition request, the received content is transmitted to the destination address (step S323), and the process proceeds to step S311.

  Subsequent steps S311 to S317 are as described in the first embodiment.

  FIG. 14 is a diagram showing an operation sequence of the DSC 20A, the address translation device 30, and the out-of-area terminal 50 in the present embodiment. Here, a case where a content acquisition request is made by multicast will be described, but it goes without saying that a content acquisition request can also be made by broadcast or unicast as described in the modification of the first embodiment. It is.

Hereinafter, only differences from FIG. 8A will be described.
When the power of the DSC 20A in the LAN 10 is turned on, the DSC 20A obtains the WAN address 111.222.33.34 from the address translator 30 as a result of the step S221 and the step S322 in the address translator 30.

  When the DSC 20A receives a content-related information transmission command by means not specified here, the process proceeds from step S205 to step S222, and as a result, P810001. The JPG thumbnail image 60A1, the content unique ID = 356A19B2,..., And the acquired WAN address 111.2222.333.44 are transmitted to the out-of-area terminal 50.

  In the address translation device 30 that has received it at the LAN side I / F 305, the process proceeds from step S303 → S304 → S307 → S321 → S323, and as a result, the P810001. JPG thumbnail image 60A1, content unique ID = 356A19B2,..., WAN side address 111.222.33.44 is transmitted via WAN side I / F 305 to out-of-area terminal 50 at the destination address.

  The subsequent sequence is as described in the first embodiment.

  As described above, also in the second embodiment, as in the first embodiment, a content acquisition request from the out-of-area terminal 50 is sent to each in-area terminal (for example, in the LAN 10 managed by the address translation device 30 (for example, DSC 20A, PC 20B, mobile phone 20C), so that at least one of the terminals in the area that owns the target content is in a power-off state, or does not exist in LAN 10 and cannot respond The target content can be acquired by the out-of-area terminal 50 while reducing the network load.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

(Appendix)
The invention having the following configuration can be extracted from the specific embodiment.

(1) A relay terminal for transmitting predetermined content received from an in-area terminal existing in a predetermined network area to an out-of-area terminal existing outside the predetermined network area,
An acquisition request receiving means for receiving an acquisition request for a predetermined content held by any one or more of the in-area terminals from the out-of-area terminal by unicast communication;
An acquisition request transmitting means for making an acquisition request for the content to each terminal in the area based on the acquisition request for the content received by the acquisition request receiving means;
Content receiving means for receiving the content requested for acquisition from the terminal in the area;
Content transmitting means for transmitting at least one of the contents received by the content receiving means to the out-of-area terminal that has made an acquisition request for the content to the relay terminal;
A relay terminal comprising:

(Corresponding embodiment)
The first and second embodiments correspond to the embodiment related to the relay terminal described in (1). In these embodiments, the LAN 10 is in the predetermined network area, the DSC 20A, the PC 20B, the mobile phone 20C, and the TV 20D are in the area terminal, the out-of-area terminal 50 is in the out-of-area terminal, and the address translation device 30 is in the relay. In the terminal, the CPU 301 and the WAN I / F unit 305 correspond to the acquisition request reception unit and the content transmission unit, and the CPU 301 and the LAN side I / F unit 306 correspond to the acquisition request transmission unit and the content reception unit, respectively.

(Function and effect)
According to the relay terminal described in (1), since the relay terminal transmits the content acquisition request to each intra-area terminal in the network area managed by the relay terminal, the intra-area terminal that originally owns the content Even in a situation where a response cannot be made because the power is turned off or moved outside the LAN, the out-of-area terminal can acquire the content while reducing the load on the network.

(2) Prior to receiving the acquisition request for the predetermined content from the terminal outside the area, the unique identifier of the predetermined content corresponding to the predetermined content is received from any one or more of the terminals within the area. Content identifier receiving means;
Content acquisition related information transmitting means for transmitting, to the out-of-area terminal, a unique identifier of the predetermined content and information regarding the relay terminal as an acquisition request destination of the predetermined content;
The relay terminal according to (1), further comprising:

(Corresponding embodiment)
The embodiment relating to the relay terminal described in (2) corresponds to the first and second embodiments. In these embodiments, the CPU 301 and the LAN side I / F unit 306 are used as the content identifier receiving means, and the WAN side address is used as the information that the relay terminal is used as the predetermined content acquisition request destination. The / F unit 305 corresponds to the content acquisition related information transmission unit.

(Function and effect)
According to the relay terminal described in (2), unicast communication from an out-of-area terminal is possible by transmitting information with the relay terminal as a content acquisition request destination, and the network load is reduced. Can do.
The unique identifier of the content is the same even when one or more of the terminals in the area that owns the target content is in a power-off state or is not in the network area and cannot respond. Since the content can be received from the terminal in the area having the content, the target content can be acquired while reducing the network load.

  (3) The specific identifier of the predetermined content is at least one of a thumbnail image of the predetermined content, a still image of the predetermined content, and a hash value obtained by hash calculation of electronic data of the predetermined content (2) The relay terminal according to (2).

(Corresponding embodiment)
The embodiment relating to the relay terminal described in (3) corresponds to the first and second embodiments.

(Function and effect)
According to the relay terminal described in (3), it is possible to transmit information for specifying content without increasing the traffic.

  (4) When the content receiving means receives a plurality of contents requested for acquisition, the content transmitting means transmits only one of the received contents to the out-of-area terminal ( The relay terminal described in 1).

(Corresponding embodiment)
The embodiment relating to the relay terminal described in (4) corresponds to the first and second embodiments.

(Function and effect)
According to the relay terminal described in (4), since the same content is not transmitted from the relay terminal to the out-of-area terminal a plurality of times, one or more of the in-area terminals that own the target content Even if the device is in a power-off state or does not exist in the network area and cannot respond, the target content can be acquired while reducing the network load.

  (5) The relay terminal according to (1), wherein the acquisition request transmission unit makes the acquisition request for the content by multicast, broadcast, or unicast.

(Corresponding embodiment)
The embodiment related to the relay terminal described in (5) corresponds to the first and second embodiments.

(Function and effect)
According to the relay terminal described in (5), the communication method in the predetermined network area is not limited, and any network design can be supported.

(6) There is an open network between the relay terminal and the terminal outside the area,
The relay terminal according to (1), wherein the acquisition request receiving unit receives the content acquisition request via the open network.

(Corresponding embodiment)
The embodiment relating to the relay terminal described in (6) corresponds to the first and second embodiments. In these embodiments, a global network 40 such as the Internet corresponds to the open network.

(Function and effect)
According to the relay terminal described in (6), it is possible to acquire content at a terminal outside the area connected to the open network while reducing the network load of the open network.

(7) Out of at least one in-area terminal existing in a predetermined network area, at least one in-area terminal holds predetermined content held by the predetermined network via a relay terminal A content transmission system that transmits to a terminal outside the area that exists outside the area,
The terminal outside the area
First acquisition request transmission means for transmitting the acquisition request for the predetermined content to the relay terminal by unicast communication;
First content receiving means for receiving the content for which the acquisition request has been transmitted from the relay terminal;
Comprising
The relay terminal
Second acquisition request transmission means for making a content acquisition request to each of the in-area terminals based on the content acquisition request received from the out-of-area terminal;
First content transmitting means for transmitting content to the out-of-area terminal;
Comprising
Each of the above-mentioned terminals in the area
Second content transmitting means for transmitting the predetermined content in response to the content acquisition request received from the relay terminal to the relay terminal;
Comprising
The first content transmitting means of the relay terminal transmits at least one of the contents received from the in-area terminal to the out-of-area terminal that has requested the relay terminal to acquire the content. Content transmission system.

(Corresponding embodiment)
The embodiment relating to the content transmission system described in (7) corresponds to the first and second embodiments. In these embodiments, the LAN 10 is in the predetermined network area, the DSC 20A, the PC 20B, the mobile phone 20C, and the TV 20D are in the area terminal, the address translation device 30 is in the relay terminal, and the out-of-area terminal 50 is outside the area. In the terminal, the CPU 501 and the external I / F 505 are the first acquisition request transmission unit and the first content reception unit, the CPU 301 and the LAN side I / F unit 306 are the second acquisition request transmission unit, the CPU 301 and The WAN I / F unit 305 corresponds to the first content transmission unit, and the CPU 201 and the external I / F 206 correspond to the second content transmission unit.

(Function and effect)
According to the content transmission system described in (7), a content acquisition request is transmitted from an out-of-area terminal to a relay terminal by unicast communication, and the relay terminal that receives the content acquisition request manages the content acquisition request by itself. Even if the terminal in the area that originally owns the content cannot be responded because it is turned off or moved outside the LAN, the network load is reduced while transmitting to each terminal in the area. The external terminal can acquire the content.

(8) The relay terminal
Content identifier reception for receiving a unique identifier of the predetermined content corresponding to the predetermined content from any one or more of the in-area terminals prior to receiving the acquisition request for the predetermined content from the terminal outside the area Means,
Content acquisition related information transmitting means for transmitting, to the out-of-area terminal, a unique identifier of the predetermined content and information regarding the relay terminal as an acquisition request destination of the predetermined content;
The content transmission system according to (7), further comprising:

(Corresponding embodiment)
The embodiment relating to the content transmission system described in (8) corresponds to the first and second embodiments. In these embodiments, the CPU 301 and the LAN side I / F unit 306 are used as the content identifier receiving means, and the WAN side address is used as the information that the relay terminal is used as the predetermined content acquisition request destination. The / F unit 305 corresponds to the content acquisition related information transmission unit.

(Function and effect)
According to the content transmission system described in (8), unicast communication from an out-of-area terminal is possible by transmitting information with the relay terminal as a content acquisition request destination, and the network load is reduced. be able to.
The unique identifier of the content is the same even when one or more of the terminals in the area that owns the target content is in a power-off state or is not in the network area and cannot respond. Since the content can be transmitted from the terminal in the area having the content, the target content can be acquired while reducing the network load.

(9) Of the at least one in-area terminal existing in the predetermined network area, the predetermined content held by at least one in-area terminal is transferred to the predetermined network via the relay terminal. A content transmission method of a content transmission system for transmitting to a terminal outside the area existing outside the area,
A first content acquisition request step in which the acquisition request for the predetermined content is transmitted from the out-of-area terminal to the relay terminal by unicast communication;
Based on the acquisition request for the predetermined content transmitted in the first content acquisition request step, the content is transmitted from the relay terminal to each of the in-area terminals existing in the predetermined network area. A second content acquisition request step in which an acquisition request is transmitted;
The predetermined content in response to the content acquisition request in the second content acquisition request step sends an acquisition request for the predetermined content in the second content acquisition request step from the at least one in-area terminal. A first content providing step transmitted to the relay terminal that transmitted,
At least one of the predetermined contents transmitted in the first content providing step is transmitted from the relay terminal to the out-of-area terminal that has transmitted the acquisition request for the predetermined content in the first content acquisition request step. A second content providing step,
The content transmission method characterized by having.

(Corresponding embodiment)
The first and second embodiments correspond to the content transmission method described in (9). In these embodiments, the LAN 10 is in the predetermined network area, the DSC 20A, the PC 20B, the mobile phone 20C, and the TV 20D are in the area terminal, the address translation device 30 is in the relay terminal, and the out-of-area terminal 50 is outside the area. It corresponds to each terminal.

(Function and effect)
According to the content transmission method described in (9), a content acquisition request is transmitted from an out-of-area terminal to a relay terminal by unicast communication, and the relay terminal that receives the content acquisition request manages the content acquisition request by itself. Even if the terminal in the area that originally owns the content cannot be responded because it is turned off or moved outside the LAN, the network load is reduced while transmitting to each terminal in the area. The external terminal can acquire the content.

(10) a first content identifier providing step in which a unique identifier of the predetermined content corresponding to the predetermined content is transmitted from the in-area terminal to the relay terminal;
The unique identifier of the predetermined content transmitted in the first content identifier providing step and the information regarding the relay terminal as the acquisition request destination of the predetermined content are transmitted from the relay device to the out-of-area terminal. A second content identifier providing step,
Further comprising
In the first content acquisition request step, the predetermined content acquisition request corresponding to the unique identifier of the predetermined content transmitted in the second content identifier providing step is sent from the out-of-area terminal to the predetermined content. The content transmission method according to (9), wherein the content transmission method is transmitted to the relay terminal that is the content acquisition request destination.

(Corresponding embodiment)
The embodiment related to the content transmission method described in (10) corresponds to the first and second embodiments.

(Function and effect)
According to the content transmission method described in (10), unicast communication from an out-of-area terminal is possible by transmitting information that uses a relay terminal as a content acquisition request destination, thereby reducing the network load. be able to.
The unique identifier of the content is the same even when one or more of the terminals in the area that owns the target content is in a power-off state or is not in the network area and cannot respond. Since the content can be transmitted from the terminal in the area having the content, the target content can be acquired while reducing the network load.

(11) An in-area terminal existing in the predetermined network area that transmits predetermined content to a terminal outside the area existing outside the predetermined network area via a relay terminal,
Storage means for storing the predetermined content and information that the acquisition request destination of the predetermined content is the relay terminal;
Transmitting means for transmitting information to the relay terminal;
Receiving means for receiving information from the relay terminal;
Comprising
The transmitting means transmits information to the relay terminal that the predetermined content acquisition request destination is the relay terminal,
The receiving means receives the acquisition request for the predetermined content from the relay terminal that is the acquisition request destination of the predetermined content,
The in-area terminal characterized in that the transmitting means transmits the predetermined content requested for the acquisition to the relay terminal that has transmitted the acquisition request for the predetermined content to the terminal in the area.

(Corresponding embodiment)
The embodiment related to the in-area terminal described in (11) corresponds to the second embodiment. In the embodiment, the address translation device 30 is the relay terminal, the LAN 10 is the predetermined network area, the out-of-area terminal 50 is the out-of-area terminal, the DSC 20A, the PC 20B, the mobile phone 20C, and the TV 20D are the in-area terminal. In addition, the recording unit 208 and the RAM 204 are in the storage unit, the CPU 201 and the external I / F 206 are in the transmission unit and the reception unit, and the WAN side address is the information that the acquisition request destination of the predetermined content is the relay terminal. Correspond.

(Function and effect)
According to the in-area terminal described in (11), unicast communication from an out-of-area terminal to the relay terminal becomes possible by transmitting information that uses the relay terminal as a content acquisition request destination, In response to a content acquisition request from a relay terminal that has received a content acquisition request via unicast communication from an external terminal, the content requested by the relay terminal is transmitted. Is possible.
In addition, even when the information acquisition request destination of the predetermined content is not transmitted to the relay terminal as the relay terminal, the relay that has received the content acquisition request by the unicast communication from the terminal outside the area In response to a content acquisition request from the terminal, if there is content for which the acquisition request has been made, it is transmitted, so a response is made because the terminal in the area that originally owns the content is powered off or moved outside the LAN Even in a situation where this is not possible, the out-of-area terminal can acquire content while reducing the load on the network.

(12) The storage means stores a unique identifier of the predetermined content corresponding to the predetermined content,
The transmission means transmits the unique identifier of the predetermined content to the relay terminal together with information indicating that the acquisition request destination of the predetermined content is the relay terminal,
The reception means receives the acquisition request for the predetermined content based on the unique identifier of the predetermined content from the relay terminal that is the acquisition request destination of the predetermined content,
The transmission means transmits the predetermined content requested for the acquisition based on a unique identifier of the predetermined content to the relay terminal that has transmitted the acquisition request for the predetermined content to the terminal in the area. The terminal in the area according to (11).

(Corresponding embodiment)
The embodiment relating to the in-area terminal described in (12) corresponds to the second embodiment.

(Function and effect)
According to the in-area terminal described in (12), one or more of the in-area terminals possessing the target content are in a power-off state or are not present in the network area and respond. Even in a situation where it is not possible to transmit content from an in-area terminal having the same content unique identifier, it is possible to obtain the desired content while reducing the network load.

  (13) Prior to transmitting the information that the acquisition request destination of the predetermined content is the relay terminal to the relay terminal, the reception request destination is the information that the acquisition request destination of the predetermined content is the relay terminal. The in-area terminal according to (11), which is received from the relay terminal and stored in the storage unit.

(Corresponding embodiment)
The embodiment related to the in-area terminal described in (13) corresponds to the second embodiment.

(Function and effect)
According to the in-area terminal described in (13), since the information that the destination of the content acquisition request is the relay terminal is acquired in advance from the relay terminal, the in-area terminal is placed in another network area. It becomes possible to move.

1A is a diagram showing a configuration of a content transmission system according to the first embodiment of the present invention, and FIG. 1B is a diagram showing a configuration of a DSC as an example of an in-area terminal, FIG. 1C is a diagram illustrating a configuration of an address translation device as an example of a relay terminal according to the first embodiment of the present invention, and FIG. 1D is a diagram illustrating an example of an address translation table. FIG. 1E is a diagram showing a configuration of an out-of-area terminal. FIG. 2 is a flowchart for explaining an operation related to content transmission in the DSC. FIG. 3 is a diagram illustrating a flowchart for explaining operations related to content transmission / reception in the address translation device. FIG. 4 is a diagram illustrating a flowchart of the acquisition response process. FIG. 5 is a flowchart of the content acquisition request transfer process. FIG. 6 is a flowchart for explaining the operation related to content reception in the out-of-area terminal. FIG. 7 is a diagram showing the content recording contents of the recording unit of each area terminal. FIG. 8A is a diagram illustrating an operation sequence of the DSC, the address translation device, and the out-of-area terminal. FIG. 8B is a diagram showing an operation sequence when the mobile phone also opens a multicast address. FIG. 8C is a diagram illustrating an operation sequence when the DSC is no longer present in the LAN. FIG. 9A is a diagram showing a flowchart of content acquisition request transfer processing in a case where a content acquisition request is made by broadcast as Modification 1 of the first embodiment, and FIG. It is a figure which shows the flowchart of a content acquisition request transfer process in the case of performing the acquisition request of a content by unicast as the modification 2 of embodiment. FIG. 10 is a diagram illustrating an operation sequence of the DSC, the address translation device, and the out-of-area terminal in the first modification. FIG. 11 is a diagram illustrating an operation sequence of the DSC, the address translation device, and the out-of-area terminal in the second modification. FIG. 12 is a flowchart for explaining an operation related to content transmission in the DSC as an example of the in-area terminal according to the second embodiment of the present invention. FIG. 13 is a diagram illustrating a flowchart for explaining operations related to content transmission / reception in the address translation device according to the second embodiment. FIG. 14 is a diagram illustrating an operation sequence of the DSC, the address translation device, and the out-of-area terminal in the second embodiment.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... LAN, 20A ... Digital still camera (DSC), 20B ... Personal computer (PC), 20C ... Mobile phone, 20D ... Television receiver (TV), 30 ... Address conversion device, 40 ... Global network, 50 ... Area Outer terminal, 60A1, 60B1 to 60B3, 60C1, 60C2 ... Thumbnail image, 201, 301, 501 ... CPU, 202, 508 ... Input interface unit, 203, 302, 502 ... ROM, 204, 303, 503 ... RAM, 205, 509 ... Display unit, 206,505 ... External I / F, 207,506 ... File management unit, 208, 208B, 208C, 507 ... Recording unit, 209,504 ... Compression / decompression engine, 210 ... Imaging unit, 304 ... Address conversion Part, 305 ... WAN Side I / F unit, 306... LAN side I / F unit, 310... Address conversion table.

Claims (13)

A relay terminal for transmitting predetermined content received from an in-area terminal existing in a predetermined network area to an out-of-area terminal existing outside the predetermined network area,
An acquisition request receiving means for receiving an acquisition request for a predetermined content held by any one or more of the in-area terminals from the out-of-area terminal by unicast communication;
An acquisition request transmitting means for making an acquisition request for the content to each terminal in the area based on the acquisition request for the content received by the acquisition request receiving means;
Content receiving means for receiving the content requested for acquisition from the terminal in the area;
Content transmitting means for transmitting at least one of the contents received by the content receiving means to the out-of-area terminal that has made an acquisition request for the content to the relay terminal;
A relay terminal comprising: Content identifier reception for receiving a unique identifier of the predetermined content corresponding to the predetermined content from any one or more of the in-area terminals prior to receiving the acquisition request for the predetermined content from the terminal outside the area Means,
Content acquisition related information transmitting means for transmitting, to the out-of-area terminal, a unique identifier of the predetermined content and information regarding the relay terminal as an acquisition request destination of the predetermined content;
The relay terminal according to claim 1, further comprising:   The unique identifier of the predetermined content includes at least one of a thumbnail image of the predetermined content, a still image of the predetermined content, and a hash value obtained by hash calculation of electronic data of the predetermined content. The relay terminal according to claim 2.   2. The content transmitting unit according to claim 1, wherein when the content receiving unit receives a plurality of contents requested to be acquired, the content transmitting unit transmits only one of the received contents to the terminal outside the area. The relay terminal described.   The relay terminal according to claim 1, wherein the acquisition request transmission unit makes the acquisition request for the content by multicast, broadcast, or unicast. There is an open network between the relay terminal and the terminal outside the area,
The relay terminal according to claim 1, wherein the acquisition request receiving unit receives the content acquisition request via the open network. Out of the predetermined network area, the predetermined content held by at least one of the in-area terminals among the at least one in-area terminal existing in the predetermined network area is transmitted via the relay terminal. A content transmission system for transmitting to an out-of-area terminal existing in
The terminal outside the area
First acquisition request transmission means for transmitting the acquisition request for the predetermined content to the relay terminal by unicast communication;
First content receiving means for receiving the content for which the acquisition request has been transmitted from the relay terminal;
Comprising
The relay terminal
Second acquisition request transmission means for making a content acquisition request to each of the in-area terminals based on the content acquisition request received from the out-of-area terminal;
First content transmitting means for transmitting content to the out-of-area terminal;
Comprising
Each of the above-mentioned terminals in the area
Second content transmitting means for transmitting the predetermined content in response to the content acquisition request received from the relay terminal to the relay terminal;
Comprising
The first content transmitting means of the relay terminal transmits at least one of the contents received from the in-area terminal to the out-of-area terminal that has requested the relay terminal to acquire the content. Content transmission system. The relay terminal
Content identifier reception for receiving a unique identifier of the predetermined content corresponding to the predetermined content from any one or more of the in-area terminals prior to receiving the acquisition request for the predetermined content from the terminal outside the area Means,
Content acquisition related information transmitting means for transmitting, to the out-of-area terminal, a unique identifier of the predetermined content and information regarding the relay terminal as an acquisition request destination of the predetermined content;
The content transmission system according to claim 7, further comprising: Out of the predetermined network area, the predetermined content held by at least one of the in-area terminals among the at least one in-area terminal existing in the predetermined network area is transmitted via the relay terminal. A content transmission method of a content transmission system for transmitting to an out-of-area terminal existing in
A first content acquisition request step in which the acquisition request for the predetermined content is transmitted from the out-of-area terminal to the relay terminal by unicast communication;
Based on the acquisition request for the predetermined content transmitted in the first content acquisition request step, the content is transmitted from the relay terminal to each of the in-area terminals existing in the predetermined network area. A second content acquisition request step in which an acquisition request is transmitted;
The predetermined content in response to the content acquisition request in the second content acquisition request step sends an acquisition request for the predetermined content in the second content acquisition request step from the at least one in-area terminal. A first content providing step transmitted to the relay terminal that transmitted,
At least one of the predetermined contents transmitted in the first content providing step is transmitted from the relay terminal to the out-of-area terminal that has transmitted the acquisition request for the predetermined content in the first content acquisition request step. A second content providing step,
The content transmission method characterized by having. A first content identifier providing step in which a unique identifier of the predetermined content corresponding to the predetermined content is transmitted from the in-area terminal to the relay terminal;
The unique identifier of the predetermined content transmitted in the first content identifier providing step and the information regarding the relay terminal as the acquisition request destination of the predetermined content are transmitted from the relay device to the out-of-area terminal. A second content identifier providing step,
Further comprising
In the first content acquisition request step, the predetermined content acquisition request corresponding to the unique identifier of the predetermined content transmitted in the second content identifier providing step is sent from the out-of-area terminal to the predetermined content. The content transmission method according to claim 9, wherein the content transmission method is transmitted to the relay terminal which is a content acquisition request destination. An in-area terminal existing in the predetermined network area that transmits predetermined content to a terminal outside the area existing outside the predetermined network area via a relay terminal,
Storage means for storing the predetermined content and information that the acquisition request destination of the predetermined content is the relay terminal;
Transmitting means for transmitting information to the relay terminal;
Receiving means for receiving information from the relay terminal;
Comprising
The transmitting means transmits information to the relay terminal that the predetermined content acquisition request destination is the relay terminal,
The receiving means receives the acquisition request for the predetermined content from the relay terminal that is the acquisition request destination of the predetermined content,
The in-area terminal characterized in that the transmitting means transmits the predetermined content requested for the acquisition to the relay terminal that has transmitted the acquisition request for the predetermined content to the terminal in the area. The storage means stores a unique identifier of the predetermined content corresponding to the predetermined content;
The transmission means transmits the unique identifier of the predetermined content to the relay terminal together with information indicating that the acquisition request destination of the predetermined content is the relay terminal,
The reception means receives the acquisition request for the predetermined content based on the unique identifier of the predetermined content from the relay terminal that is the acquisition request destination of the predetermined content,
The transmission means transmits the predetermined content requested for the acquisition based on a unique identifier of the predetermined content to the relay terminal that has transmitted the acquisition request for the predetermined content to the terminal in the area. The in-area terminal according to claim 11.   The receiving means sends information to the relay terminal that the predetermined content acquisition request destination is the relay terminal, and the predetermined content acquisition request destination is the relay terminal. 12. The in-area terminal according to claim 11, wherein the in-area terminal is received from a terminal and stored in the storage unit.

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