JP2011182262A - Communication method, content transmitting apparatus and content download device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To complete download of a large-capacity content even if interruption is repeated, while easily resuming the download after the interruption. <P>SOLUTION: A content transmitting server (110) transmits a reconnection address (RBD) to a content download terminal (230). In resuming the download of the content information after the interruption, the terminal (230) designates the server (110) using the reconnection address and transmits progress information. In the server (110), authentication is performed using the progress information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication method, a content transmission device, and a content download device, and more particularly, to a communication method, a content transmission device, and a content download device that are suitable when content information download is interrupted.

  When a communication terminal and a data server are communicating via a network such as a wireless LAN (Local Area Network), a cellular phone network, or a wired LAN, the communication line constituting the network is temporarily disconnected for some reason. Then, normally, if the communication line is connected again within the time-out period, these can continue communication. However, if the communication line is still disconnected even after the timeout time is exceeded, the communication terminal and the data server forcibly terminate communication as a communication error.

When the communication terminal resumes communication with the data server after the communication between the communication terminal and the data server is forcibly terminated, the communication terminal and the data server start a new communication. Therefore, network authentication and data transfer must be performed from the beginning.
In particular, when the communication terminal is a mobile terminal, the connection and disconnection of the communication line are repeated as the communication terminal moves. When such a communication terminal downloads content information of a large data size such as music or video from a data server, it is difficult to complete the download because network authentication and data transfer restart are repeated. there were. In addition, in the case where the communication terminal downloads the content information of the paid content from the data server, if the communication between the communication terminal and the data server is terminated halfway, the communication terminal and the data server communicate with each other. When resuming downloads, user authentication processing, content selection processing, billing processing for confirming whether or not the user accepts billing must be performed from the beginning, and it takes a long time to resume download .

  For this reason, for example, in the invention described in Patent Document 1, the suspension / resumption timer value at the time of data download is made variable, and the suspension / resumption timer value (timeout time) is set using the average throughput during the data download as a parameter. By controlling, even if a communication line failure occurs temporarily, a timeout is prevented from occurring as much as possible.

Japanese Patent Laying-Open No. 2002-32284 (paragraphs 0017 to 0029, FIG. 1)

However, when the communication terminal is a vehicle-mounted terminal, it may take a longer time than the suspension / resumption timer value until the communication terminal can connect to the communication line after disconnecting the line. Will end communication. In such a case, the communication terminal has to download the content information whose download has been interrupted from the beginning, which is wasteful of communication.
Therefore, an object of the present invention is to provide a technology that can easily download a continuation of information for which download has been interrupted.

The present invention
A communication method performed by a content communication system having a content transmission device and a content download device that downloads content information from the content transmission device via a network,
A content transmission processing step of dividing the content information into a plurality of transmission packets and transmitting the content information to the content download device for downloading by the content download device;
An address notification step in which the content transmission device notifies the content download device of a reconnection address used for designating the content transmission device when restarting after the download is interrupted;
A transmission side progress information storage step in which the content transmission device stores progress information indicating the degree of progress of the download in a user management information storage unit;
After the download is interrupted, the content download device is connected to the content transmission device using the reconnection address, and progress information indicating the degree of download progress generated by the content download device is transmitted to the content transmission device. A reconnect step to notify,
The content transmission apparatus compares the progress information stored in the user management information storage unit with the progress information notified from the content download apparatus, and whether or not the comparison result satisfies a predetermined condition A re-authentication step to determine
In the resuming authentication step, on the condition that the result of the comparison is determined to satisfy the predetermined condition, the content transmission device transmits the continuation of the content information on which the download has been interrupted to the content download device. And a transmission resumption processing step for transmitting.

  According to the present invention, it is possible to easily download a continuation of information for which downloading has been interrupted.

1 is a schematic configuration diagram of a content communication system according to Embodiment 1. FIG. 3 is a block diagram illustrating a configuration example of a server used as a content transmission device according to Embodiment 1. FIG. 3 is a block diagram illustrating a configuration example of a terminal used as a content download device in Embodiment 1. FIG. FIG. 2 is a schematic configuration diagram showing functional blocks of a server and a terminal in the first embodiment. 5 is a flowchart illustrating a transmission process in which a server transmits content information in the first embodiment. 4 is a flowchart illustrating a download process in which a terminal downloads content information in the first embodiment. In Embodiment 1, it is a sequence diagram which shows the process at the time of a terminal downloading content information from a server. 5 is a flowchart illustrating reconnection transmission processing in which the server continues transmission of content information after reconnection in the first embodiment. 5 is a flowchart illustrating a reconnection download process in which the terminal continues to download content information after reconnection in the first embodiment. In Embodiment 1, it is a sequence diagram which shows the process in which a terminal continues downloading of content information from a server after reconnection. 3 is a schematic diagram of a TCP packet according to Embodiment 1. FIG. 6 is a schematic diagram illustrating an example of a reconnection address when using CGI in Embodiment 1. FIG.

Embodiment 1 FIG.
FIG. 1 shows a content communication system 100 according to Embodiment 1 of the present invention. The illustrated content communication system 100 includes a server 110 used as a content transmission device and a terminal 230 used as a content download device. The terminal 230 is a mobile terminal used in an in-vehicle multimedia system, for example. The server 110 and the terminal 230 can transmit and receive information to and from each other via the network 150. Terminal 230 is connected to network 150 via wireless network access points 151A, 151B,.

  In the following description and drawings, the wireless network access point is abbreviated as AP, and each AP 151A, 151B,.

When there is a content download request from the terminal 230, the server 110 transmits content information after executing a user authentication process or the like.
It is assumed that there are a plurality of APs 151, and the installation locations of the plurality of APs 151 are separated from the installation locations of other APs 151, and there are locations where communication areas are not continuous.
For example, the communication area of one AP 151A and another AP 151B is not continuous. In this case, when the terminal 230 moves from the communication area of the AP 151A to the communication area of the AP 151B, the terminal 230 is disconnected from the AP 151A. As a result, it becomes impossible to connect to any AP 151. By entering the communication area of the AP 151B, it becomes possible to connect to the AP 151B.

  FIG. 2 shows a configuration example of the server 110. The illustrated server 110 includes a CPU 111, a ROM 112, a RAM 113, a NIM (Network Interface Module) 114, a writing / reading unit 115, a command input unit 116, a content information recording disk 117, and a user management information recording disk 118.

The CPU 111 executes or controls processing performed by the server 110. The CPU 111 executes or controls various processes by loading the program into the RAM 113 and executing the loaded program.
The ROM 112 stores a program for executing or controlling processing performed by the server 110 and settings that are necessary for starting the server 110 and that do not need to be changed.
The RAM 113 temporarily holds programs and data executed by the CPU 111.
The NIM 114 is an interface for connecting to the network 150.
The content information recording disk 117 records content information CD such as moving images and music.

The user management information recording disk 118 records authentication information VR and resumption information SD.
The writing / reading unit 115 writes information to the content information recording disk 117 or the user management information recording disk 118, and reads information from these disks.
The command input unit 116 receives an operation command input from the administrator of the server 110.

  FIG. 3 shows a configuration example of the terminal 230. The terminal 230 includes a CPU 231, ROM 232, RAM 233, nonvolatile storage medium 234, NIM 235, write / read unit 236, command input unit 237, decoder 238, and video / audio output unit 239.

The CPU 231 executes or controls processing performed on the terminal 230. The CPU 231 executes or controls various processes by loading the program into the RAM 233 and executing the loaded program.
The ROM 232 stores a program for executing or controlling processing performed in the terminal 230 and settings that are necessary for starting the terminal 230 and that do not need to be changed.
The RAM 233 temporarily holds programs and data executed by the CPU 231.
The non-volatile storage medium 234 stores the downloaded content, and stores information that is referred to when downloading the content or reproducing the content. For example, the nonvolatile storage medium 234 is configured by a hard disk, a memory card, or the like.

  The NIM 235 is an interface for connecting to the network 150.

The writing / reading unit 236 writes information to the nonvolatile storage medium 234 and reads information from the nonvolatile storage medium 234.
The command input unit 237 receives an operation command input from the user of the terminal 230.
The decoder 238 decodes the content information CD such as a moving image or music and generates an audio signal or a video signal.
The video / audio output unit 239 outputs audio and video corresponding to the audio signal and video signal generated by the decoder 238, and also outputs an image corresponding to the image information sent from the CPU 231.

FIG. 4 shows functional blocks of the server 110 and the terminal 230.
The server 110 includes an authentication unit 120, a content transmission processing unit 121, a transmission monitoring unit 122, a restart information notification unit 123, a restart authentication unit 124, a transmission restart processing unit 125, a content storage unit 126, a temporary storage unit 127, and a user management information storage. Part 128.

The authentication unit 120, the content transmission processing unit 121, the transmission monitoring unit 122, the resumption information notification unit 123, the resumption authentication unit 124, and the transmission resumption processing unit 125 are loaded by the CPU 111 into the RAM 113 and executed. The content storage unit 126 is a function realized by the writing / reading unit 115 and the content information recording disk 117, and the temporary storage unit 127 is a function realized by the RAM 113. .
The user management information storage unit 128 is a function realized by the writing / reading unit 115 and the user management information recording disk 118.

The content storage unit 126 records content information CD of a plurality of contents.
The temporary storage unit 127 temporarily stores various information generated during the operation of the server 110.
The user management information storage unit 128 records authentication information VR and resumption information SD.

  The authentication unit 120 determines whether or not to accept the start request for the download start request (connection request) QCC from the terminal 230, and if so, outputs an authentication success notification SI. For this authentication, authentication information VR stored in the user management information storage unit 128 is used. The authentication information VR includes user identification information UID for identifying the user of the terminal 230, and password information PAD indicating the password of the user.

  The content transmission processing unit 121 divides the content information into a plurality of packets (transmission packets) SP in accordance with the authentication success notification SI output from the authentication unit 120 and transmits the divided content information. Prior to transmission of content information, the content transmission processing unit 121 also performs content selection processing, and billing processing when the selected content is paid content.

The content transmission processing unit 121 also outputs a transmission monitoring instruction WC and a resume information notification instruction RC prior to transmission of content information.
The transmission monitoring instruction WC includes download identification information DID for identifying a download to be started (start is determined) and information UID for identifying a user who performs the download.
The resume information notification instruction RC includes download identification information DID for identifying a download to be started.

  The transmission monitoring unit 122 monitors whether or not the connection between the server 110 and the terminal 230 is maintained, that is, monitors whether or not packet transmission / reception is performed. This monitoring is performed based on the transmission monitoring instruction WC.

  The restart information notifying unit 123 notifies the terminal 230 of the restart information SD when starting to download each content. The notification of the resume information SD is performed according to the resume information notification instruction RC.

  The resume information SD includes download identification information DID for identifying the download to be started, content identification information CID for identifying the content to be downloaded, and subsequent resume when the download is interrupted. The reconnection address RBD used for designating the server 110 from the terminal 230 is included.

  In response to a restart request from the terminal 230 after the download is interrupted, the resuming authentication unit 124 determines whether to permit resuming of the download, and if so, resumes sending a notification RSI indicating that the authentication has been successful. Tell part 125.

  The transmission restart processing unit 125 restarts the download on the condition that the authentication is successful in the restart authentication unit 124. That is, the continuation of the interrupted content information is transmitted to the terminal.

  The terminal 230 includes a download start processing unit 240, a download processing unit 241, a download monitoring unit 242, a resume information processing unit 243, a download resume unit 244, a progress information adding unit 245, a display unit 246, a content storage unit 247, and a management information storage. Unit 248, temporary storage unit 249, and input unit 250.

  The download start processing unit 240, the download processing unit 241, the download monitoring unit 242, the resume information processing unit 243, the download resume unit 244, and the progress information addition unit 245 load the program stored in the ROM 232 or the like into the RAM 233 by the CPU 231. The display unit 246 is a function realized by the video / audio output unit 239, and both the content storage unit 247 and the management information storage unit 248 are the writing / reading unit 236. And the temporary storage unit 249 is a function realized by the RAM 233, and the input unit 250 is a function realized by the command input unit 237.

The content storage unit 247 stores the downloaded content.
The management information storage unit 248 stores information referred to when content is downloaded or content is reproduced, for example, reconnection information RAD described later.

The temporary storage unit 249 temporarily stores various information generated in the operation of the terminal.
The input unit 250 receives an operation command input from the user of the terminal 230. This operation command includes a connection instruction (download start instruction) CC, a download cancel instruction CC, and a reconnection instruction (download resumption instruction) RDC2 for the server.

  The download start processing unit 240 transmits a connection request QCC to the server 110 in response to the connection instruction CC for the server received via the input unit 250, or allows the user to input information necessary for authentication in the server 110, 110.

  The download processing unit 241 performs a process of downloading content information transmitted from the server 110, that is, a process of storing the content information in the content storage unit 247.

The download monitoring unit 242 monitors whether the connection between the server 110 and the terminal 230 is maintained.
For example, the download monitoring unit 242 monitors the processing in the download processing unit 241, and after the download processing unit 241 receives the transmission packet SP storing the content information CD, the content information is within a predetermined time. If another transmission packet SP storing a CD is not received, it is determined that the communication line has been disconnected.

  If the download monitoring unit 242 determines that the communication line has been disconnected, the download monitoring unit 242 gives a line disconnection notification NDI to the progress information adding unit 245.

  When the download monitoring unit 242 receives a download cancel instruction CAC from the input unit 250, the download monitoring unit 242 transmits a cancel request CAD to the server 110 and gives a cancel notification CAI to the resume information processing unit 243 and the progress information adding unit 245.

  When the terminal 230 is turned off, for example, when the terminal 230 is an in-vehicle terminal and the engine of the mounted vehicle is turned off, the cancellation similar to the cancel instruction CAC from the input unit 250 is performed. It is desirable that an instruction is automatically given to the download monitoring unit 242.

  Further, when the communication line is disconnected and the communication line is reconnected (connection is restored), the download monitoring unit 242 gives the download resuming instruction RDC1 that instructs the download resuming processing unit 244 to resume downloading. .

  The restart information processing unit 243 generates and updates information necessary for restart after downloading is interrupted. That is, the reconnection address RBD is extracted from the resume information SD transmitted from the server 110 and stored in the temporary storage unit 249, or the reconnection information RAD generated or updated by the progress information adding unit 245 is stored. Or stored in the management information storage unit 248.

  The download resuming unit 244 performs a process (download resuming process) for resuming after the download is interrupted. This resumption process is performed when a download resumption instruction RDC1 is received from the download monitoring unit 242 or when a download resumption instruction RDC2 is received from the input unit 250. When resuming the download, the download resuming unit 244 designates the reconnection information RAD and connects to the server 110 (uses the reconnection information RAD to designate the server 110 and the download to be resumed), thereby resuming the download. A request is made and the progress information GD is notified to the server 110.

  The progress information adding unit 245 generates progress information GD indicating the degree of download progress, for example, information indicating the size of the downloaded data, and stores it in the reconnection address RBD (included in the resumption information SD transmitted from the server 110). By adding, the reconnection information RAD is generated, or the reconnection information RAD is updated by updating the progress information GD included in the previously generated reconnection information RAD. The reconnection information RAD generated or updated is stored in the management information storage unit 248.

  The display unit 246 is used for displaying a video of the downloaded content and a guidance screen for operating the terminal 230, particularly a guidance screen for prompting input of user identification information, a password, and the like.

FIG. 5 shows a transmission process in which the server 110 transmits the content information CD.
FIG. 5 shows processing when the user of the terminal 230 purchases content, downloads the content information CD of the purchased content from the server 110, and saves the content information CD in the content storage unit 247.

  In the following, it is assumed that the terminal 230 is mounted on a mobile object, for example, an automobile, and the terminal 230 moves, and therefore cannot be continuously connected to the same AP 151, and the connection and disconnection of the communication line are frequently repeated. is doing. In addition, when the user turns off the engine of the automobile, the terminal 230 mounted on the automobile may be turned off, so that the time from the interruption of the download to the resumption such as the parking time becomes longer. However, it is assumed that the resumption of download can be automatically started without a complicated operation.

  First, the authentication unit 120 and the content transmission processing unit 121 of the server 110 perform a download start process including a user authentication process and a process for selecting a content to be purchased (S10). The processing in step S10 will be described later with reference to FIG.

  When the download start process is completed in step S10, before sending the content information CD, the resume information notifying unit 123 transmits the resume information SD including the reconnection address RBD to the terminal 230 (S11). As will be described later, the reconnection address RBD is used when restarting after the download is interrupted. As will be described in detail below, in the present embodiment, information indicating the downloaded data size is added to the reconnection address RBD as download progress information, which is used for reconnection after the download is interrupted.

  The reconnection address RBD is different from the connection address used for designating the server 110 at the start of downloading in step S10. When the server 110 receives the reconnection address RBD, It can be recognized that the user of the terminal 230 does not request a new content download but requests a restart of the download after the interruption.

  After step S11, the process proceeds to step S12, and the transmission monitoring unit 122 determines whether the download is canceled by the user of the terminal 230. Whether or not the cancellation has been made can be determined by whether or not the server 110 has received a cancellation request CAD from the terminal 230.

When the download is canceled (Yes in step S12), the transmission monitoring unit 122 transmits the information ZT (c) indicating the transmitted data size stored in the temporary storage unit 127 for storage. Data size information ZT (h) is stored in the user management information storage unit 128 (step S13), and the download process is terminated.
Note that “c” and “h” in parentheses attached to the reference symbol “ZT” are used to indicate the difference between the storage units stored, and when there is no need to distinguish between them, or generalization It is not attached when explaining. The same applies to other symbols.

  Thus, only when the download is canceled (Yes in step S12) or when the confirmation response RP is not returned from the terminal 230 (No in step S15 described later) as described later, the user management information storage is performed. Since the transmitted data size ZT (h) is written or rewritten (updated) to the unit 128, the data size ZT (h) need not be frequently rewritten, and the system load at the time of writing and rewriting Can be reduced.

  Next, when the download is continued without being canceled (No in step S12), the content transmission processing unit 121 transmits the content information CD to the terminal 230 (step S14).

  Since the communication line may be disconnected during the transmission of the content information CD, the transmission monitoring unit 122 monitors whether or not the connection with the terminal 230 is continued (step S15). This monitoring is performed, for example, based on whether or not an acknowledgment (response packet) RP is received within a predetermined time since the transmission packet SP storing the content information is transmitted.

  When the transmission monitoring unit 122 determines that the connection is not continued (No in step S15), the transmission monitoring unit 122 proceeds to step S13.

  On the other hand, when the transmission monitoring unit 122 determines that the connection is continued (Yes in step S15), the transmission monitoring unit 122 transmits the transmitted data every time it receives a response packet RP from the terminal 230. The size ZT is calculated, and the transmitted data size ZT (c) included in the update information RD stored in the temporary storage unit 127 is updated (S16).

  Then, the transmission monitoring unit 122 determines whether or not the content information CD has been transmitted to the end (S17). If the content information CD has not been transmitted to the end (No in step S17), the process returns to step S12. If the content information CD has been transmitted to the end (Yes in step S17), the process proceeds to step S18.

  In step S18, the transmission monitoring unit 122 performs processing for invalidating the reconnection address RBD transmitted in step S11. In the process for invalidation, for example, the download identification information DID included in the reconnection address RBD is deleted from the user management information storage unit 128.

FIG. 6 shows a download process in which the terminal 230 downloads the content information CD.
First, the download start processing unit 240 and the download processing unit 241 access the server 110 to start a session, and perform a download start process including a user authentication process and a content selection process to be purchased (S20). The process in step S20 will be described later with reference to FIG.

When the download start process ends and communication (session) is established, the restart information processing unit 243 receives restart information SD including the reconnection address RBD specified when reconnecting after interrupting the download from the server 110. (S21).
The restart information processing unit 243 acquires the reconnection address RBD from the restart information SD (transmitted from the server 110 in the process of step S11 of FIG. 5) and stores the reconnection address RBD in the temporary storage unit 249.

  Next, the download monitoring unit 242 determines whether or not the user intentionally cancels the download (S22). Whether or not the user intentionally cancels the download can be determined by whether or not the download monitoring unit 242 has received a download cancel instruction CAC from the input unit 250.

  When the user intentionally cancels the download (Yes in step S22), the progress information adding unit 245 acquires the data size of the content information CDm stored in the content storage unit 247 and acquires the acquired data size. ZD (m) is added to the reconnection address RBD stored in the temporary storage unit 249 to generate reconnection information RAD, and the restart information processing unit 243 stores the reconnection information RAD as management information. The data is stored in the unit 248 (S30).

  Then, the download monitoring unit 242 performs processing for terminating the session established in step S20, and disconnects the communication line (S31).

  On the other hand, if the user intentionally continues the download without canceling the download (No in step S22), the process proceeds to step S23, and the transmission packet SP from the server 110 (transmitted from the server 110 in step S14 in FIG. 5). It is determined whether or not it has been received. If not received (No in step S23), the process proceeds to step S25.

If received (Yes in step S23), a reception process is performed (S24). In this reception process, the data included in the received transmission packet SP and successfully received is stored in the content storage unit 247, and the response packet RP is transmitted to the server 110. In the response packet RP, information indicating the size of the data received so far (accumulated value of the amount of data transmitted in the transmission packet SP for the download of the content and received normally) is “transmitted data size” ZT ". If there is a “missing” in a plurality of bytes included in the transmission packet SP from the server 110, the “immediately before the missing” is set as “transmitted data size ZT”. The response packet RP from the terminal 230 is used by the server 110 for the determination in step S15 in FIG. 5, and is processed in step S16.
After step S24, the process proceeds to step S25.

In step S25, the download monitoring unit 242 determines whether the communication line is disconnected. For example, the download monitoring unit 242 determines that the communication line is disconnected when the packet SP from the server 110 is not received for a predetermined time.
For example, when a trouble occurs such as when the terminal 230 is out of the service area of the wireless network during download or when the terminal 230 enters a tunnel, the communication line is disconnected.

  If the download monitoring unit 242 determines that the communication line is not disconnected (No in step S25), the download monitoring unit 242 proceeds to step S26, and determines that the communication line is disconnected (Yes in step S25). The process proceeds to step S27.

  In step S26, the download monitoring unit 242 determines whether or not the content information CD has been received to the end. If it is determined that the content information CD has been received to the end (Yes in step S26), the process proceeds to step S31. If it is determined that it has not (No in step S26), the process proceeds to step S22.

In step S27, the progress information adding unit 245 generates reconnection information RAD based on the reconnection address RBD stored in the temporary storage unit 249.
That is, the progress information adding unit 245 acquires the data size of the content information CDm stored in the content storage unit 247, and reconnects the acquired data size ZD (m) stored in the temporary storage unit 249. The reconnection information RAD is generated by adding to the management address RBD, and the generated reconnection information RAD is stored in the management information storage unit 248.

  Thereafter, the download monitoring unit 242 waits for the connection of the communication line to be restored (S28). Here, as a case where the communication line is connected, for example, when the terminal 230 enters the communication area of any AP 151 (the reception intensity of the beacon signal from any AP 151 is equal to or higher than a predetermined threshold value). If there is).

  If the communication line is connected (Yes in step S28), the download resuming unit 244 performs reconnection download processing for resuming download (S29). The processing in step S29 will be described later with reference to FIG.

FIG. 7 shows processing when the terminal 230 downloads the content information CD from the server 110.
Here, the download start processing performed in step S10 of FIG. 5 and step S20 of FIG. 6 corresponds to the processing performed by each device in steps S40 to S48.

  First, a session is started when the terminal 230 makes a connection request to the server 110 via the network 150 (S40). For example, the terminal 230 designates a predetermined connection address (URL) and makes a connection request to the server 110 (designates the server 110 with the connection address (URL) and makes a connection request).

The authentication unit 120 of the server 110 requests the terminal 230 to transmit user identification information UID (S41). This request is made by displaying a guidance screen. The same applies to the following steps S43, S45 and S47.
The download start processing unit 240 receives an input of the user identification information UID from the user via the input unit 250, and sends the input user identification information UID to the server 110 as a response (S42).

Next, the authentication unit 120 of the server 110 requests the terminal 230 to transmit a password (S43).
The terminal 230 receives a password input from the user via the input unit 250, and transmits password information PAD indicating the input password to the server 110 as a response (S44).

  The authentication unit 120 of the server 110 refers to the authentication information VR stored in the user management information storage unit 128, and the combination of the user identification information UID received in step S42 and the password information PAD received in step S44 is obtained. When it is determined that it is correct, the content transmission processing unit 121 of the server 110 sends a content selection request to the terminal 230 (S45).

  The terminal 230 receives selection of content to be downloaded from the user via the input unit 250, and sends content identification information CID indicating the selected content to the server 110 as a response (S46). By step S46, the user of the terminal 230 can select the content to purchase.

If the content selected in step S46 is paid content, the content transmission processing unit 121 of the server 110 notifies the terminal 230 of charging (S47).
The download processing unit 241 of the terminal 230 receives an input as to whether or not to accept the charge from the user via the input unit 250, and receives information indicating that the charge is accepted or information indicating that the charge is not accepted as a response. It transmits to the server 110 (S48). When the user of the terminal 230 agrees to charge, the user acquires the right to download the content information CD of the selected content.

Here, the content transmission processing unit 121 notifies the transmission monitoring unit 122 of download identification information DID for identifying the download to be started.
The transmission monitoring unit 122 stores the notified download identification information DID in the user management information storage unit 128.

If the content information CD is large-capacity data, it takes a long time to download. Therefore, until the download is completed, the communication line is disconnected without intention of the user, or the user intentionally downloads it. May be canceled.
Therefore, immediately after the user of the terminal 230 acquires the download right, the restart information notifying unit 123 of the server 110 transmits the restart information SD including the reconnection address RBD to the terminal 230 (S49).
In the terminal 230 that has received the resume information SD, the resume information processing unit 243 extracts the reconnection address RBD from the resume information SD and stores it in the temporary storage unit 249.

  After notifying the reconnection address RBD, the content transmission processing unit 121 of the server 110 reads the content information CD of the content selected in step S46 from the content storage unit 126 one packet at a time, and sequentially transmits it to the terminal 230. (S50).

Upon receiving the content information CD to the end, the terminal 230 returns a content information download completion notification to the server 110 (S51).
In the server 110 that has received such notification, the authentication unit 120 ends the session (S52).

  FIG. 8 shows processing (reconnection transmission processing) in which the server 110 continues transmission of the content information CD upon reconnection. FIG. 8 shows processing at the server 110 when the terminal 230 reconnects to the server 110 and transmission continues after the download of the content information CD is interrupted. In FIG. 8, the same steps as those in FIG. 5 are denoted by the same reference numerals as those in FIG.

First, when the terminal 230 reconnects to the server 110 by specifying the reconnection information RAD including the downloaded data size ZD (m) (information indicating) as described later, the resuming authentication unit 124 performs the resuming authentication. (S60).
For example, first, the restart authentication unit 124 does not store the download identification information DID notified by the reconnection information RAD (download identification information DID included in the reconnection information RAD) in the user management information storage unit 128. In this case, it is assumed that the authentication has failed.
Further, when the download identification information DID notified by the reconnection information RAD is stored in the user management information storage unit 128 (matches the stored one), the restart authentication unit 124 The transmitted data size ZT (h) corresponding to the download identification information DID is acquired from the user management information storage unit 128. Then, the resuming authentication unit 124 determines the difference between the acquired transmitted data size ZT (h) and the downloaded data size ZD (m) notified by the reconnection information RAD within a predetermined threshold range. If it is within (the absolute value of the difference value is less than or equal to the threshold value), it is assumed that the authentication has succeeded, and if the difference value exceeds the range of the threshold value, the authentication has failed. This threshold value is, for example, the maximum data amount that can be transmitted in one packet.

  As described above, the resuming authentication unit 124 uses the download identification information DID and the downloaded data size ZD (m) transmitted from the terminal 230 as the download identification information DID and the transmitted data size ZT stored in the server 110. By comparing with (h), it is possible to determine whether the request is an illegal download request with a small number of steps, the authentication process can be simplified, and the password for authentication can also be input from the terminal 230. It can be omitted. For this reason, the present invention can omit the download start process with a large number of steps as shown in FIG. 7, so that the download can be restarted in a short time, and the content can be downloaded efficiently. Can do.

If the restart authentication is successful (Yes in step S60), the process proceeds to step S12. If the restart authentication fails (No in step S60), the process proceeds to step S18.
If the resuming authentication is not successful (failed) (No in step S60), the transmission monitoring unit 122 regards it as an unauthorized download request and does not resume the transmission of the content information CD. The reconnection information RAD is invalidated.

  If the resuming authentication is successful in step S60, the transmission monitoring unit 122 determines whether the download is canceled by an operation by the user of the terminal 230 (S12).

If canceled by the user's operation (Yes in step S12), the transmission monitoring unit 122 deletes the transmitted data size ZT (h, old) stored in the user management information storage unit 128, Instead, the new transmitted data size ZT (c) stored in the temporary storage unit 127 is stored in the user management information storage unit 128 as the transmitted transmitted data size information ZT (h, new). (Step S61) and the download process is terminated.
Note that “old” and “new” in parentheses attached to the symbol “ZT” are for distinguishing between the information before update and the information after update. It is not attached when it is explained in the form. The same applies to other symbols.
Here, the transmitted data size after the download is interrupted is the sum of the data size transmitted before the download is interrupted and the size of data transmitted after the interrupt.

Next, when the download is continued without being canceled (No in step S12), the content transmission processing unit 121 transmits the content information CD to the terminal 230 (step S62).
Here, the content transmission processing unit 121 transmits the content information CD from the data position calculated based on the data size notified by the reconnection information RAD specified in step S60. The information indicating the “data position” indicates to which part in the content information CD stored in the content storage unit 126 has been downloaded, or from which part transmission should be started next.

Since the communication line may be disconnected during the transmission of the content information CD, the transmission monitoring unit 122 monitors whether or not the connection with the terminal 230 is continued (step S15).
If it is determined that the connection with the terminal 230 is not continued (No in Step S15), the transmission monitoring unit 122 proceeds to Step S61 described above.
On the other hand, if it is determined that the connection with the terminal 230 is continued (Yes in step S15), the transmission monitoring unit 122 transmits the transmitted data size ZT every time the response packet RP is received from the terminal 230. And the transmitted data size ZT (c) included in the update information RD stored in the temporary storage unit 127 is updated (S63).
The “transmitted data size” after the download is interrupted is the sum of the data size transmitted before the download is interrupted and the data size transmitted after the interrupt.

  The transmission monitoring unit 122 determines whether the content information CD has been transmitted to the end (S17). If the content information CD has not been transmitted to the end (No in step S17), the process returns to step S12. If the content information CD has been transmitted to the end (Yes in step S17), the process proceeds to step S18.

  In step S18, the transmission monitoring unit 122 performs processing for invalidating the reconnection address RBD (step S11 in FIG. 5) transmitted to the terminal 230.

FIG. 9 shows a process in which the terminal 230 continues to download the content information CD after reconnection (reconnection download process).
FIG. 9 shows processing at the terminal 230 when the terminal 230 reconnects to the server 110 after the download of the content information CD is interrupted to continue the download. Here, the processing of the flowchart of FIG. 9 is performed when the disconnected communication line is reconnected as shown in step S29 of FIG. 6 or when the user of the terminal 230 receives a download restart instruction via the input unit 250. It starts when the RDC2 is input. 9, the same steps as those in FIG. 6 are denoted by the same reference numerals as those in FIG.

First, the download resuming unit 244 specifies the reconnection information RAD stored in the temporary storage unit 249 or the management information storage unit 248 and connects to the server 110 (S70). In other words, the server 110 is connected to the server 110 by transmitting a packet including the server 110 as the connection destination and the reconnection information RAD specifying the download to be resumed.
The reconnection information RAD includes information ZD (m) indicating the downloaded data size stored in the management information storage unit 248.
In step S60 of FIG. 8 described above, this information ZD (m) is used for authentication.

  Next, the download monitoring unit 242 determines whether or not the user intentionally cancels the download (S22).

When the user intentionally cancels the download (Yes in step S22), the progress information adding unit 245 updates the reconnection information RAD stored in the temporary storage unit 249, and then restarts the information processing unit 243. However, the updated reconnection information RAD is stored in the management information storage unit 248 (S71).
For example, the progress information adding unit 245 acquires the data size ZD (m) of the content information CDm stored in the content storage unit 247, and the acquired data size ZD (m) is stored in the temporary storage unit 249. The reconnection information RAD (new) after updating is obtained by replacing the data size ZD (m, old) added to the reconnection information RAD (old).
Then, the download monitoring unit 242 performs processing for terminating the session established in step S70, and disconnects the communication line (S31).

  On the other hand, when the user intentionally continues the download without canceling the download (No in step S22), the process proceeds to step S23, and it is determined whether or not the transmission packet SP from the server 110 has been received. If not received (No in step S23), the process proceeds to step S25.

  If received (Yes in step S23), a reception process is performed (S24), and after step S24, the process proceeds to step S25.

  If it is determined in step S25 that the communication line is not disconnected, the process proceeds to step S26. If it is determined in step S25 that the communication line is disconnected (Yes in step S25), the process proceeds to step S72. move on.

  If it is determined in step S26 that it has been received to the end, the process proceeds to step S31. If it is determined that it has not been received to the end, the process proceeds to step S22.

In step S72, the progress information adding unit 245 updates the reconnection information RAD stored in the temporary storage unit 249.
That is, the progress information adding unit 245 acquires the data size of the content information CDm stored in the content storage unit 247, and the acquired data size ZD (m, new) is stored in the temporary storage unit 249. By replacing the data size ZD (m, old) added to the reconnection information RAD (old), the reconnection information RAD (new) is updated and stored in the management information storage unit 248.

  Thereafter, when the connection of the communication line is recovered (Yes in S28), the download monitoring unit 242 returns to Step S70.

  FIG. 10 shows a process in which the terminal 230 continues to download the content information CD from the server 110 after reconnection.

First, the download resuming unit 244 of the terminal 230 makes a download resumption request by specifying the reconnection information RAD and connecting to the server 110 (S80).
The restart authentication unit 124 of the server 110 performs reconnection authentication using the download identification information DID and the data size ZD (m) notified by the reconnection information RAD, and if the authentication is successful, a content transmission processing unit 121 resumes the transmission of the content information CD from the data position calculated based on the data size notified by the reconnection information RAD (position following the download before interruption) (S81).

  Upon receiving the content information CD to the end, the terminal 230 returns a content information download completion notification to the server 110 (S82). In the server 110 that has received such a notification, the authentication unit 120 ends the session (S83).

  In the example described above, when the download is interrupted, the data size that has been transmitted so far is stored in the server 110, and is used by the terminal 230 to specify the server 110 when restarting after the download is interrupted. The downloaded data size is added to the reconnection address and notified to the server 110. The server 110 compares the notified downloaded data size with the transmitted data size held in the server 110. Based on the comparison result, it is determined whether or not resumption is permitted. However, instead of the data size, authentication may be performed using information indicating the data position in the content information corresponding to the data size. good. The data position corresponding to the data size can be said to be equivalent to the data size, and in any case is progress information indicating the degree of download progress.

A TCP packet can be used as a packet for transmission / reception between the server 110 and the terminal 230. Furthermore, information using CGI (Common Gateway Interface) can be used as the reconnection information RAD.
Hereinafter, a case will be described in which information indicating a data position is used for authentication when resuming download, a TCP packet is used as a packet for transmission / reception, and information using CGI is used as reconnection information RAD.

FIG. 11 is a schematic diagram of the TCP packet TP. The TCP packet TP includes a “data” area DAR for storing data to be transmitted and a TCP header TH.
The TCP header TH includes an “SRC PORT” field (also referred to as “source port number” field) TH1, a “DEST PORT” field (also referred to as “source port number” field) TH2, and a “SEQ” field (“transmission sequence”). TH3, "ACK" field (also referred to as "response confirmation number" field) TH4, "HLEN" field (also referred to as "header length" field) TH5, "Reserved" field TH6, "Code Bit" field (Also referred to as “code bit” field) TH7, “Window” field (also referred to as “window” field) TH8, “Checksum” field (also referred to as “checksum” field) TH9, “Urgent Point” er ”field (also referred to as“ urgent pointer ”field) TH10 and“ Option ”field (also referred to as“ option ”field) TH11.

The “SRC PORT” field TH1 stores a transmission source port number for identifying an application that is a transmission source of the TCP packet TP.
The “DEST PORT” field TH2 stores a destination port number prepared by an application that is a transmission destination (destination) of the TCP packet TP.
The “transmission sequence number” field TH3 stores a sequence number SEQ indicating the head position of data (a portion to be transmitted in the packet) stored and transmitted in the “data” area DAR.
The sequence number SEQ is set to an initial value SEQ (I) corresponding to the start position of the content information CD stored in the content storage unit 126 of the server 110 (the start position when transmitting with the first transmission packet). It has a value obtained by adding the number of bytes of data stored in the “data” area DAR and transmitted so far.
The “response confirmation number” field TH4 stores a response confirmation number ACK indicating the data position (byte position) of the received data. The response confirmation number ACK is a value obtained by adding the data size (number of bytes) of the data received in each transmission packet SP to the sequence number SEQ of the received data. Indicates the start position of. Also, if there is a “missing” in the middle, add up to the number of bytes before “missing”. The server 110 subtracts the initial value SEQ (I) corresponding to the head position of the content information CD (the head position when transmitting with the first transmission packet) from the response confirmation number ACK, so that the downloaded information has already been downloaded. The data size can be recognized.
The “HLEN” field TH5 stores a header length indicating the size of the TCP header TH.
The “Reserved” field TH6 is a reserved area and is not used in the present invention, and therefore stores all values of “0”.
The “Code Bit” field TH7 stores six types of flag values for control. This includes a flag indicating whether the packet is used as the transmission packet SP or the response packet RP.
The “Window” field TH8 stores information indicating the window size on the receiving side.
The “Checksum” field TH9 stores inspection data for inspecting an error in the TCP packet TP.
The “Urgent Pointer” field TH10 stores a value indicating how much of the data is urgent data when the URG flag indicating urgent data is on.
The “Option” field TH11 is used for setting various characteristics in the TCP connection, and stores, for example, the maximum segment size (MSS) and the like.

  Note that when the response packet RP is composed of TCP packets, the response packet RP may be composed only of the header TH in FIG.

FIG. 12 is a schematic diagram illustrating an example of reconnection information RAD when CGI is used. The reconnection information RAD is
“Server name / CGI path / CGI name? 1st parameter & 2nd parameter”
Is generated in the form
The server name is the server name of the server 110.
The CGI path is a path to a CGI execution program or script in the server 110.
The CGI name is a file name of the CGI execution program or script of the server 110.
A plurality of parameters to be passed to the CGI execution program or script indicated by the CGI name can be specified. Here, download identification information DID is stored as the first parameter, and information (data position information) DP indicating the download restart position of the content information CD in the content storage unit 126 of the server 110 is stored as the second parameter. .

  Of the reconnection information RAD shown in FIG. 12, the reconnection address RBD is configured up to the first parameter DID. That is, the reconnection address RBD is a part of the reconnection address RAD, and the reconnection information RAD is generated by adding the data position information DP to the reconnection address RBD. For this reason, the reconnection information RAD may also be referred to as a reconnection address. In order to distinguish between them, the reconnection address RBD may be referred to as “pre-complementation reconnection address”, and the reconnection information RAD may be referred to as “post-complementation reconnection information”.

  The process in the case of using the reconnection information RAD using the TCP packet and the CGI is generally the same as the process described above with reference to FIG. However, it is necessary to read “data size” as “data position”. Also, the following points are different.

  The reconnection address RBD used in step S10 is composed of the portion up to the first parameter DID in the reconnection information RAD shown in FIG. 12, and the content transmission processing unit 121 is about to start. Download identification information DID for identifying the download is generated and notified to the transmission monitoring unit 122, and the transmission monitoring unit 122 stores the notified download identification information DID in the user management information storage unit 128.

In step S15, whether or not the connection with the terminal 230 is continued is determined as follows.
When communication is performed so that there is no omission in the content information CD using TCP, when the server 110 transmits a TCP packet storing a certain amount of data, a confirmation response from the terminal 230 that has received such a TCP packet. The response packet RP is returned as the response packet RP. The response confirmation number ACK of the response packet RP can be used to confirm which transmission packet SP is the response, and by using the response confirmation number ACK included in the response packet RP. The server 110 can recognize the rear end position of normally received data or the head position of data to be transmitted next.

In step S16, the data position is updated instead of updating the data size.
In this case, the transmission monitoring unit 122 treats the response confirmation number ACK included in the response packet RP as representing the data position, and transmits the transmitted data position DPc included in the update information RD stored in the temporary storage unit 127. Is updated (S16).
For example, the response confirmation number ACK is treated as indicating the head position of the data to be transmitted next, and the value indicating the last position of the transmitted data (by subtracting “1” from the response confirmation number ACK). ).

  In step S30, the progress information adding unit 245 acquires the data size of the content information CDm stored in the content storage unit 247, and generates the data position information DP based on the acquired data size (that is, the data size). Is added to the initial value SEQ (I) of the sequence number to generate the data position information DP and add it to the reconnection address RBD stored in the temporary storage unit 249 to generate the reconnection information RAD Then, the restart information processing unit 243 stores the reconnection information RAD in the management information storage unit 248 (S30).

  When the reconnection information RAD is generated in step S27, the progress information adding unit 245 acquires the data size of the content information CDm stored in the content storage unit 247, and acquires the acquired data size ZD (m ) To generate the relocation information RAD by generating the data position information DP (m) based on the data and adding it to the reconnection address RBD stored in the temporary storage unit 249. The RAD is stored in the management information storage unit 248.

  In step S49 of FIG. 7, the restart information notification unit 123 generates a reconnection address RBD using CGI, and transmits the restart information SD including the generated reconnection address RBD to the terminal 230. The reconnection address RBD is generated by adding the download identification information DID included in the restart information notification instruction RC from the content transmission processing unit 121 to a predetermined part of “server name / CGI path / CGI name?”. This is done.

  In step S60, the terminal 230 designates the reconnection information RAD including the download identification information DID and the data location information DP (m) and reconnects to the server 110, and the restart authentication unit 124 notifies the reconnection information RAD. Data position information DP (h) corresponding to the download identification information DID after confirming that the downloaded identification information DID is stored in the user management information storage unit 128 (matches the stored one). Is obtained from the user management information storage unit 128, and the difference between the acquired data position information DP (h) and the data position information DP (m) notified by the reconnection information RAD is a predetermined threshold range. Is within (the absolute value of the difference value is less than or equal to the threshold value), it is assumed that the authentication has succeeded, and the difference value exceeds the range of the threshold value. , It is assumed that the authentication has failed. This threshold value is, for example, the maximum data amount that can be transmitted in one packet.

  When the reconnection information RAD uses CGI, when the terminal 230 connects to the server 110 by specifying the reconnection information RAD shown in FIG. 12, the server 110 executes the program dlcont for restarting the download. The resuming authentication unit 124 and the content transmission processing unit 125 realized by the executed program dlcont have download identification information DID indicated by dlid = xx... X and data position information indicated by pos = yy. Get DP.

  In step S61, the transmission monitoring unit 122 deletes the data position information DP (h, old) stored in the user management information storage unit 128, and instead, new data stored in the temporary storage unit 127 is obtained. The position information DP (c) is stored as data position information DP (h, new) for storage (step S61), and the download process is terminated.

  In step S62, the content transmission processing unit 121 starts the content from the data position represented by the data position information DP (m) notified by the reconnection information RAD specified in step S60 (with the data position as the head position). An information CD is transmitted.

  In step S <b> 63, every time the transmission monitoring unit 122 receives the response packet RP from the terminal 230, the transmission monitoring unit 122 acquires the response confirmation number ACK as the data location information DP, and updates the update information RD stored in the temporary storage unit 127. The included data position information DP (c) is updated.

  When updating the reconnection information RAD stored in the temporary storage unit 249 in step S71 of FIG. 9, the progress information adding unit 245 uses the data size ZD () of the content information CDm stored in the content storage unit 247. m), data position information DP (m) is generated based on the acquired data size ZD (m), and added to the reconnection information RAD (old) stored in the temporary storage unit 249. By replacing the existing data position information DP (m, old), updated reconnection information RAD (new) is obtained.

  Similarly, when the progress information adding unit 245 updates the reconnection information RAD stored in the temporary storage unit 249 in step S72, the data size ZD (m) of the content information CDm stored in the content storage unit 247 is similarly determined. The data position information DP is generated based on the acquired data size ZD (m), and is added to the reconnection information RAD (old) stored in the temporary storage unit 249. By replacing with (m, old), the updated reconnection information RAD (new) is stored in the management information storage unit 248.

  In step S80 of FIG. 10, when the resuming authentication unit 124 of the server 110 performs resuming authentication using the download identification information DID and the data location information ZD (m) notified by the reconnection information RAD, and the authentication is successful. The content transmission processing unit 121 resumes the transmission of the content information CD from the data position notified by the reconnection information RAD (S81).

  As described above, in the present invention, when resuming the download, the information indicating the data size or the data position is authenticated using the progress information indicating the progress of the download. That is, step S70 in FIG. 9 is a process for specifying the server 110 by the reconnection address and notifying the progress information in general terms, and step S60 in FIG. 8 includes authentication using the progress information. 5, step S13 in FIG. 5 and step S61 in FIG. 8 include processing for storing progress information in the server 110 (transmission side), and are therefore also referred to as a transmission side progress information storage step. Step 72 includes a process of generating or updating the reconnection information RAD using the progress information at the terminal 230 (receiving side).

  As described above, according to the present embodiment, when restarting the interrupted download, since the terminal 230 can additionally download only the data following the already downloaded data, the interrupt is repeated during the download. Even when the connection time between them is short, the download of the content information can be completed. Further, when restarting the interrupted download, the server 110 uses the progress information such as the data size or the data position in the middle of the download for authentication. Even if the RBD is illegally obtained, the content information CD cannot be easily downloaded. Therefore, despite the simple authentication, the security can be enhanced and unauthorized access can be eliminated.

  Although the case where the TCP protocol is used for downloading the content information CD has been described with reference to FIG. 11, the present invention is not limited to such a protocol. For example, the server 110 and the terminal 230 can use a Real-time Transport Protocol (RTP) protocol for downloading content information. In this case, the server 110 and the terminal 230 transmit an RTCP (Real-Time Transport Control Protocol) packet. Since information such as the number of bytes, the number of transmitted packets, and the number of lost packets is included, the server 110 can recognize whether the data transmission has succeeded or failed based on these information, and can use these information as progress information. it can.

  Referring to FIG. 12, resumption information notifying unit 123 of server 110 reconnects using “CGI” at “server name / CGI path / CGI name? First parameter (download identification information DID)”. In the above description, the resumption information SD including the reconnection address RBD is generated and transmitted to the terminal 230. However, the information generated by the resumption information notification unit 123 is It is not limited to information. For example, the resumption information notifying unit 123 generates the reconnection information RAD by “server name / CGI path / CGI name? First parameter (download identification information DID) & second parameter (data position)”. May be. When doing so, the restart information notifying unit 123 may store an initial value (for example, “0”) in the “second parameter (data position)” portion.

  Furthermore, although the case where the address using CGI is used as the reconnection address has been described with reference to FIG. 12, the present invention is not limited to this. For example, the reconnection address is formed by a URL that does not use CGI, and after the terminal 230 connects to the server 110 by specifying this reconnection address, the download identification information DID and the downloaded data size are transmitted to the server 110. You may make it notify progress information GD, such as information showing ZD or data position DP.

Embodiment 2. FIG.
In the first embodiment, the transmission monitoring unit 122 displays the progress information GT (h) stored in the user management information storage unit 128, for example, the transmitted data size ZT (h) or the data position DP (h). The rewriting timing is the time when the terminal 230 cancels the download or the time when the response packet RP from the terminal 230 is not returned to the server 110, but the present invention is not limited to this. For example, the transmission monitoring unit 122, when receiving the response packet RP from the terminal 230 (that is, every time it receives), progress information GT (h) stored in the user management information storage unit 128, for example, transmitted The data size ZT (h) or the data position DP (h) may be rewritten.
In this way, the server 110 can always obtain the latest information without having to wait for a download cancel or a download interruption timeout.

Embodiment 3 FIG.
In the above-described first embodiment, the restart authentication unit 124 of the server 110 performs the progress (for example, the progress degree represented by the progress information GD (m) included in the reconnection information RAD as the restart authentication when restarting the download (for example, The degree of progress represented by the downloaded data size ZD (m) or data position DP (m) and the progress information GT (h) stored in the server 110 (for example, the transmitted data size ZT (h) or If the difference value with respect to the data position DP (h)) is larger than a preset threshold value, it is determined that the download request is illegal, but in addition to such a determination or instead of such a determination. More than the degree of progress represented by the progress information GT (t) stored in the server 110 (for example, the transmitted data size ZT (h) or data position DP (h)) If the degree of progress represented by the progress information GD (m) included in the connection information RAD (for example, the downloaded data size ZD (m) or the data position DP (m)) is large, an illegal download request Judgment can also be made so that downloads are not resumed.
When the resuming authentication unit 124 of the server 110 determines that the download request is illegal, the restart identification unit 124 deletes the download identification information DID included in the reconnection information RAD used in the download request from the user management information storage unit 128. Thereafter, such reconnection information RAD can be designated so that the terminal 230 cannot connect to the server 110.
As a result, the server 110 can detect that the content information CD is broken due to the presence of extra data in the data downloaded by the terminal 230, and can reject an unauthorized download request.

Embodiment 4 FIG.
The server 110 and the terminal 230 may set a timeout time (hereinafter referred to as a restart timeout time) for resuming the download. In an environment where connection to the network 150 is not continuous (when connection to and disconnection from the network 150 is repeated) as in the case where the terminal 230 is a vehicle-mounted terminal, the download is resumed after the download is interrupted. It takes very little time (eg, more than a day) to be done. For this reason, the server 110 and the terminal 230 can set the restart timeout time in a predetermined time, for example, in units of days such as one day.
The start time for measuring the timeout time is preferably when, for example, it is determined that the download is interrupted in step S12 or S15 of FIG. 5 or FIG.
When such a restart timeout period has elapsed, in the server 110, for example, the transmission monitoring unit 122 uses the download identification information DID included in the reconnection information RAD for which the timeout period has elapsed as the user management information. You may make it erase from the memory | storage part 128. FIG. In the terminal 230, for example, the restart information processing unit 243 may delete the reconnection information RAD for which the timeout time has elapsed from the management information storage unit 248 and the temporary storage unit 249.
The restart timeout period is determined by, for example, the transmission monitoring unit 122 of the server 110 or the restart information processing unit 243 of the terminal 230 according to the type of the terminal 230 to be used, the network connection status, and the number of users using the download service. Also good. When there are many users, it is desirable to set the restart timeout time to be short.
By doing so, it is not necessary to store old data (download identification information DID) in the server 110 for a long period of time, so that the data storage area can be reduced.

Embodiment 5 FIG.
In the first embodiment, the server 110 uses the progress information stored in the response packet RP from the terminal 230 (representing the degree of progress such as the downloaded data size or the corresponding data position) and the content information CD. The progress information GTh stored in the user management information storage unit 128 of the server 110 is the progress included in the last received response packet RP. Information. On the other hand, the terminal 230 receives the size of the data received and stored in the content storage unit 247 from the content storage unit 247 and sets it as the downloaded data size ZD, which is calculated based on the data size or this Information indicating the data position is notified to the server 110 at the time of reconnection as progress information GD.

If the communication line is disconnected before sending the confirmation response RP even though the terminal 230 has received the data and stored it in the content storage unit 247, the terminal 230 has received the data normally. Therefore, the information reflecting the size of the data normally received before disconnection is not transmitted to the server 110, and the server 110 uses the progress information stored in the response packet RP received last before disconnection of the communication line as the user management information. It is held in the storage unit 128. As a result, the progress indicated by the progress information degree GD notified from the terminal 230 at the time of reconnection, the progress indicated by the progress information GT held in the user management information storage unit 128 of the server 110, (If the degree of progress is the data size or the data position, it may be the maximum number of bytes that can be transmitted in one packet).

In the fifth embodiment, considering such a case, the progress information stored in the response packet RP last transmitted to the server 110 before the download is interrupted is held in the terminal 230, for example, in the management information storage unit 248. When the terminal 230 requests reconnection, the terminal 230 (not the progress information GD (m) indicating the degree of progress such as the size of the data stored in the content storage unit 247 or the data position corresponding thereto) The progress information GD (n) held in the management information storage unit 248 is notified to the server 110.
The progress information GD (n) is generated in the same manner as the progress information GD (m), but is distinguished because the generation timing is different.

  By doing so, the progress information GD (n) notified by the reconnection information at the time of reconnection (if the last response packet RP before the interruption is correctly received by the server 110), The progress information GT (h) stored in the user management information storage unit 128 of the server 110 should represent the same degree of progress. Therefore, the restart authentication unit 124 of the server 110 stores in the user management information storage unit 128. The progress information GT (h) that has been sent and the progress information GD (n) notified from the terminal 230 are compared, and whether or not they match (whether or not their difference is equal to or less than a predetermined threshold value). No), resumption authentication can be performed. For this reason, unauthorized access can be more reliably eliminated.

  As a result of such processing, the terminal 230 determines the degree of progress (downloaded data size ZD (n) or data location DP (n) represented by the progress information GD (n) notified to the server 110 for authentication. n)), the actual progress (the size ZD (m) of the data stored in the content storage unit 247 or the data position DP (m) corresponding thereto may be larger. Minutes are deleted or ignored, and the same data is transmitted again after downloading is resumed.

  DESCRIPTION OF SYMBOLS 100: Content communication system, 110: Content transmission apparatus (server), 111: CPU, 112: ROM, 113: RAM, 114: NIM, 115: Write / read part, 116: Command input part, 117: Content information recording 118: User management information recording disk, 120: Authentication section, 121: Content transmission processing section, 122: Transmission monitoring section, 123: Resumption information notification section, 124: Resumption authentication section, 125: Transmission resumption processing section, 126: Content storage unit 127: Temporary storage unit 128: User management information storage unit 230: Content download device (terminal) 231: CPU, 232: ROM, 233: RAM, 234: Non-volatile storage medium, 235: NIM, 236: writing / reading unit, 237: command 238: Decoder, 239: Video / audio output unit, 240: Download start processing unit, 241: Download processing unit, 242: Download monitoring unit, 243: Resumption information processing unit, 244: Download resumption unit, 245 : Progress information addition unit, 246: display unit, 247: content storage unit, 248: management information storage unit, 249: temporary storage unit, 250: input unit, 150: network, 151: AP.

Claims (24)

A communication method performed by a content communication system having a content transmission device and a content download device that downloads content information from the content transmission device via a network,
A content transmission processing step of dividing the content information into a plurality of transmission packets and transmitting the content information to the content download device for downloading by the content download device;
An address notification step in which the content transmission device notifies the content download device of a reconnection address used for designating the content transmission device when restarting after the download is interrupted;
A transmission side progress information storage step in which the content transmission device stores progress information indicating the degree of progress of the download in a user management information storage unit;
After the download is interrupted, the content download device is connected to the content transmission device using the reconnection address, and progress information indicating the degree of download progress generated by the content download device is transmitted to the content transmission device. A reconnect step to notify,
The content transmission apparatus compares the progress information stored in the user management information storage unit with the progress information notified from the content download apparatus, and whether or not the comparison result satisfies a predetermined condition A re-authentication step to determine
In the resuming authentication step, on the condition that the result of the comparison is determined to satisfy the predetermined condition, the content transmission device transmits the continuation of the content information on which the download has been interrupted to the content download device. And a transmission resumption processing step for transmitting the communication method.   The communication method according to claim 1, wherein the degree of progress represented by the progress information is a downloaded data size or a data position in content information corresponding to the data size. The transmitting side progress information storing step includes:
The content transmission device transmits the content information to the content download device, and indicates the size of the data that has been confirmed to be received by the content download device or the information indicating the data position in the content information corresponding to the size. The communication method according to claim 2, wherein information is stored in a user management information storage unit. The content download device includes:
A response that is received as a transmission packet from the content transmission device and stores the information indicating the data position in the content information corresponding to the size of the data stored in the internal content storage unit as the progress information The communication method according to claim 3, wherein the packet is transmitted to the content transmission device. In the restart authentication step, as a determination as to whether or not the predetermined condition is satisfied,
A difference value between the degree of progress represented by the progress information stored in the content transmission apparatus and the degree of progress represented by the progress information notified from the content download apparatus by the content transmission apparatus is: The communication method according to any one of claims 1 to 4, wherein it is determined whether or not the value is within a predetermined threshold range. 3. The communication method according to claim 1, wherein the content transmission device performs a process of storing the progress information in the user management information storage unit when it is determined that the download is interrupted. The content transmission device determines that the download of the content information is interrupted when an acknowledgment from the content download device is not received after a predetermined time. Communication method. The content download device includes:
The progress information stored in the last response packet before interruption of the download is held in the management information storage unit,
In the reconnection step, the progress information held is notified to the content transmission device;
The communication method according to claim 4, wherein the content transmission device sets the predetermined threshold value to 0 in the restart authentication step. The content transmitting device is
A download identification information storage step of storing download identification information for identifying the downloaded download in the user management information storage unit;
In the reconnection step, the content download device notifies the content transmission device of download identification information of the interrupted download,
The content transmission device includes:
In the restart authentication step, determine whether the download identification information notified in the reconnection step is stored in the user management information storage unit;
The content transmission processing unit of the content transmission device, when the comparison result satisfies the predetermined condition and the download identification information notified in the reconnection step is stored in the user management information storage unit The communication method according to any one of claims 1 to 8, wherein the continuation of the content information is transmitted. The content transmission device deletes download identification information of the interrupted download from the user management information storage unit when a predetermined time-out period elapses after the download is interrupted. The communication method according to claim 9. In the restart authentication step, as a determination as to whether or not the predetermined condition is satisfied,
Whether or not the content transmission device has a degree of progress represented by the progress information stored in the content transmission device equal to or greater than a degree of progress represented by the progress information notified from the content download device. The communication method according to claim 1, wherein the determination is performed. A content transmission device that transmits content information to a content download device via a network,
A content transmission processing unit that divides the content information into a plurality of transmission packets for transmission to the content download device for downloading by the content download device;
A resumption information notifying unit for notifying the content download device of a reconnection address used for designating the content transmission device at the time of resumption after interruption of the download;
A user management information storage unit;
A transmission monitoring unit for storing progress information indicating the degree of progress of the download in the user management information storage unit;
When the content download device is connected to the content transmission device using the reconnection address after the download is interrupted, and notifies the progress information indicating the degree of progress of download generated by the content download device, A restart authentication unit that compares the progress information stored in the user management information storage unit with the progress information notified by the content download device, and determines whether the comparison result satisfies a predetermined condition; ,
The resumption authentication unit transmits, to the content download device, the continuation of the content information on which the download has been interrupted to the content transmission processing unit on the condition that the comparison result has determined that the predetermined condition is satisfied. A content transmission apparatus comprising: a transmission resumption processing unit.   The content transmitting apparatus according to claim 12, wherein the degree of progress represented by the progress information is a downloaded data size or a data position in the content information corresponding to the data size. The transmission monitoring unit
The content transmission device transmits the content information to the content download device, and indicates the size of the data that has been confirmed to be received by the content download device or the information indicating the data position in the content information corresponding to the size. The content transmission apparatus according to claim 13, wherein the content transmission apparatus is stored as information in a user management information storage unit. The resumption authentication unit determines whether or not the predetermined condition is satisfied, the degree of progress represented by the progress information stored in the user management information storage unit, and the progress notified by the content download device The content transmission according to any one of claims 12 to 14, wherein a determination is made as to whether or not a difference value from the degree of progress represented by the information is within a predetermined threshold range. apparatus. The content transmission apparatus according to claim 12 or 13, wherein the transmission monitoring unit stores the progress information in the user management information storage unit when it is determined that the download is interrupted. The transmission monitoring unit determines that the download of the content information is interrupted when a confirmation response from the content download device is not received after a predetermined time. Content transmission device. The transmission monitoring unit stores download identification information for identifying the started download in the user management information storage unit,
When the content download device notifies the content transmission device of download identification information of the suspended download for resuming the download, the resuming authentication unit is configured so that the download identification information notified from the content download device is: It is determined whether or not stored in the user management information storage unit,
When the comparison result satisfies the predetermined condition and the download identification information notified from the content download device is stored in the user management information storage unit, the content transmission processing unit The content transmission device according to any one of claims 12 to 17, wherein the continuation is transmitted. The resuming authentication unit deletes the download identification information of the suspended download from the user management information storage unit when a predetermined time-out period elapses after the download of the content information is suspended. The content transmission apparatus according to claim 18. The restart authentication unit determines whether or not the predetermined condition is satisfied,
Determining whether or not the degree of progress represented by the progress information stored in the user management information storage unit is greater than or equal to the degree of progress represented by the progress information notified from the content download device; The content transmission apparatus according to claim 12 or 13, A content download device that downloads content information transmitted from a content transmission device via a network,
A content storage unit;
A download processing unit that receives content information transmitted by dividing into a plurality of transmission packets from the content transmission device, and stores the content information in the content storage unit;
A resumption information processing unit that receives the reconnection address when the reconnection address used for designating the content transmission device at the time of resumption after interruption of the download is transmitted from the content transmission device; ,
Download resume unit for connecting to the content transmission device using the reconnection address and notifying the content transmission device of progress information indicating the progress of the download when resuming the content information download after interruption When,
It has been determined that the comparison result between the progress information indicating the degree of progress of the download stored in the content transmission device and the progress information notified from the content download device to the content transmission device satisfies a predetermined condition. And a download processing unit for receiving a continuation of the content information whose download has been interrupted from the content transmission device.   The content download apparatus according to claim 21, wherein the degree of progress represented by the progress information is a downloaded data size or a data position in the content information corresponding to the data size. A response that is received as a transmission packet from the content transmission device and stores the information indicating the data position in the content information corresponding to the size of the data stored in the internal content storage unit as the progress information The content download device according to claim 21 or 22, further comprising a download monitoring unit that transmits a packet to the content transmission device. The management information storage unit holds the progress information stored in the last response packet before the download is interrupted,
When resuming after the download is interrupted, the progress information held is notified to the content transmission device,
The content download device according to claim 23, wherein the notified progress information is used for authentication in the content transmission device.

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