JP2001306435A - Data transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmission system capable of effectively utilizing the transmission band of a communication line. SOLUTION: In the data transmission system, a contents server 6 sends contents data specified by a reservation request from a DTE 1 to a communication line 4 or 5 in order to store the data in a DCE 3 connected to the DTE 1. Limit time in which the contents data should be stored in the DCE 3 is specified in the reservation request. The server 6 manages the limit time specified by the reservation request, performs schedule processing and determines the transmission timing of the contents data guaranteeing the limit time and as an optimum communication line, the 1st communication line 4 or the 2nd communication line 5, on the basis of both of the managed limit time and prescribed communication information. Furthermore, the server 6 sends the contents data to the optimum communication line 4 or 5 in accordance with the determined transmission timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a data transmission system, and more particularly, to a server which transmits data designated by a reservation request of a data terminal device to a line terminal connected to the data terminal device. Data transmission system.

[0002]

2. Description of the Related Art Many data transmission systems as described above have been proposed. Hereinafter, a data transmission system disclosed in Japanese Patent Application Laid-Open No. H08-140081 will be described as an example. In the data transmission system, an information providing apparatus (hereinafter, referred to as a server) and an information storage apparatus installed by each user as an information providing destination are connected via a network. The server accepts the reservation request from each user, suspends the transmission of the data until the delivery time of the data determined by a predetermined method, and confirms that another user who wants to transmit the same data appears. stand by. When the delivery time comes, the server sends out data to be transmitted to the user on the communication line. The information storage device of each requesting user stores the data transmitted via the communication line. As described above, in the conventional data transmission system, the server only needs to transmit data to the information storage device by the delivery time, so that the server can select a time period during which the communication line is free and transmit the data. it can. As a result, the communication line can be effectively used.

[0003]

By the way, communication lines have different characteristics depending on their types. For example, in the case of a wired public line represented by ISDN, if the same data is transmitted to many users at the same time, the transmission bandwidth of many communication paths is consumed for the data transmission. Not suitable. on the other hand,
A satellite line is suitable for multicasting, unlike a wired public line, because a common transmission band can be used when transmitting the same data to many users. However, in the conventional data transmission system, the data is transmitted to the same communication line regardless of whether the data is transmitted to a single destination or to a large number of destinations. There was a problem. For example, consider a case in which a data transmission system accommodates a wired public line as a communication line. In such cases,
Even when the number of destination users is large and it is better to multicast the data, the server must transmit the data over a wired public line, and as a result, the transmission bandwidth of the public line becomes Wasted.

Another problem is that, in a conventional data transmission system, when a user tries to download large data such as moving image data, the user must pay a considerable communication cost. There was a problem.

[0005] Therefore, an object of the present invention is to provide a data transmission system capable of effectively utilizing a transmission band of a communication line and enabling a user to download data from a server at low cost.

[0006]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, according to a first invention, a content data designated by a reservation request of a data terminal device is connected to the data terminal device. A data transmission system transmitted by a server to one of a plurality of communication lines for storing in a line termination device, wherein the reservation request further includes:
The time limit that the content data specified by the data terminal device must be stored in the line termination device is specified, and either the server or the communication line sets the time limit specified by the reservation request from the data terminal device. Based on both the time limit management unit to manage, the time limit managed by the time limit management unit, and the predetermined communication information,
A transmission unit that determines a transmission timing of the content data that guarantees the time limit, and a scheduling unit that determines an optimal transmission line from among the plurality of communication lines. And a data transmission unit for transmitting content data.

A second invention is according to the first invention, wherein the predetermined communication information is at least the size of the content data designated by the reservation request, or the data terminal device to which the content data is transmitted. Including the number of

According to the first and second aspects of the invention, the scheduling unit determines the transmission timing of the content data that guarantees the time limit specified by the reservation request and the optimum communication line. Here, since the processing of the scheduling unit is based on communication information represented by the size of the content data and the number of transmission destinations, a communication line suitable for each property is determined. As a result, the transmission band of each communication line can be used effectively.

A third invention is according to the first invention, and the line terminating device operates by receiving power supply from any one of the communication lines. According to the third aspect, since the line terminating apparatus can always operate, the server can transmit the content data regardless of the state of the data communication terminal (typically, power on / off, busy state). It can be sent to a communication line.

A fourth invention is according to the first invention, wherein the line terminator includes a content storage unit for storing content data transmitted via an optimal communication line in an internal storage area. And a data transmission unit that reads content data specified by a read request from the data terminal device from the content storage unit and transmits the content data to the data terminal device.

According to the fourth invention, the data terminal device comprises:
Since the content data is obtained not from the server but from the line terminating device, the user does not need to access the server when the communication line is busy or when the communication line is expensive. As a result, content data can be obtained at low cost.

A fifth invention is according to the fourth invention, wherein the data transmitting unit further reads the content data specified by the read request, and further reads the content data not specified by the read request. Is read, and the plurality of content data are combined and transmitted to the data terminal device. According to the fifth aspect, the data transmission unit can additionally transmit content data not specified in the read request to the data terminal device. An advertisement represented by content data that has not been requested to be read can be added and transmitted to the data terminal device.

A sixth invention is according to the fourth invention, wherein the line terminating device transmits a storage completion notification indicating that the received content data has been stored in the storage area to the data terminal device. According to the sixth aspect, since the line termination device can transmit the storage completion notification to the data communication terminal, the user of the data terminal device can confirm that the content data desired by the user is stored in the line termination device. You can know.

A seventh invention is according to the sixth invention, and the storage completion notification is transmitted by an HTML (HyperText Markup Lang).
uage) format. An eighth invention is according to the sixth invention, and the storage completion notification is an electronic mail.

According to the seventh and eighth aspects of the present invention, the data terminal device can refer to the storage completion notification by using the WWW browser and the e-mail software which are widely used, and the content data desired by the user can be obtained. Is stored in the line termination device.

A ninth invention is according to the sixth invention, wherein the line termination device can transmit a storage completion notification in a plurality of formats, and the storage completion notification transmitted to the data terminal device is Is set by the user of the data terminal device. According to the ninth aspect, since the storage completion notification is transmitted in a user's favorite method, the usability is further improved.

A tenth invention is according to the fourth invention, wherein at least one of the plurality of communication lines accommodates an area management device for managing a storage area of a line termination device, The area management device responds to the request from the server,
An area securing instruction for instructing the line termination device to secure a storage area for content data is transmitted.

According to the tenth aspect, before transmitting the content data, the recording area of the line terminal is reserved for the content data. Therefore, the line termination device does not fall into a state where there is no recording area for storing the received content data.

An eleventh invention is according to the fourth invention, wherein the line terminating device performs a cache process to determine whether or not the frequently requested content data requested by the data terminal device has been updated. Query the server, the server
In response to the inquiry from the line termination device, the updated content data is transmitted to the line termination device, and the line termination device stores the content data received from the server in the content storage unit.

According to the eleventh aspect, the line terminal can autonomously acquire the latest content data. Therefore, when the user requests the latest content data, the data terminal device may obtain the content data not from the server but from the line termination device. Thus, the user can quickly refer to the latest content data.

A twelfth invention is according to the eleventh invention, wherein the line terminating device makes an inquiry to the server in the cache processing when the communication traffic of the communication line is low. According to the twelfth aspect, the communication traffic of the communication line can be smoothed with respect to time, whereby the transmission band of the communication line can be effectively used.

A thirteenth invention is according to the eleventh invention, wherein the recording area of the content storage unit is divided into a plurality of partial recording areas, and the line termination device obtains the information using a reservation request. The content data and the content data obtained by the cache processing are stored in different partial recording areas in the content storage unit. According to the thirteenth aspect, the partial recording area for the content data acquired by using the reservation request is reserved. As a result, it is possible to prevent the storage area of the content data acquired by using the reservation request from becoming insufficient due to the storage of the content data acquired by the cache processing.

A fourteenth invention is according to the fourth invention, and includes a plurality of line terminators. One of the line terminators is stored in a content storage unit of another line terminator. Get existing content data. According to the fourteenth aspect, the line terminating device obtains content data from another line terminating device, so that it is possible to prevent access from being concentrated on the server.

A fifteenth invention is according to the first invention, wherein a protocol for functioning as a mail server is mounted on the line termination device, and the line termination device transmits and receives electronic mail. Do. According to the fifteenth aspect, when the user requests acquisition of the e-mail, the data terminal device may acquire the e-mail not from the server but from the line terminal. This allows the user to read the e-mail quickly.

A sixteenth invention is according to the fifteenth invention, wherein the line terminating device sends an electronic mail to the communication line when the communication traffic of the communication line is low. First
According to the sixth aspect, the communication traffic of the communication line can be smoothed with respect to time, whereby the transmission band of the communication line can be effectively used.

A seventeenth invention is according to the sixteenth invention, wherein the electronic mail is given a priority indicating its importance. The timing of sending the electronic mail to the communication line is changed. According to the seventeenth aspect, according to the priority,
Since e-mail is sent to the communication line, the line termination device can send low-priority e-mail when communication traffic on the communication line is low, and immediately send high-priority e-mail to the communication line. Becomes

According to an eighteenth aspect, in order to store content data designated by a reservation request from a data communication terminal in a line termination device connected to the data terminal device, the content data is stored in one of a plurality of communication lines. A data transmission method sent by a server, wherein a reservation request further specifies a time limit at which content data specified by the server itself must be stored in a line termination device. Is based on both the management step for managing the time limit specified in the reservation request of the data terminal device and the time limit managed in the management step, and the predetermined communication information. The server comprises a transmission timing and a scheduling step of deciding an optimum one from among a plurality of communication lines. According to the transmission timing determined by-menu ring step, the optimal communication line, and a data transmission step of transmitting the content data.

A nineteenth invention is a data transmission system in which a server sends out content data specified by a reservation request from a data terminal device to a communication line in order to transmit the content data to the data terminal device. In addition,
A reservation status data creation unit for creating reservation status data indicating download conditions for each content data based on a received reservation request, wherein a download condition of the content data designated by the data terminal device is specified; A data transmission unit that transmits the reservation status data created by the creation unit to the data terminal device, whereby a request for a reservation from the data terminal device that wants to receive the same content data under the same download condition is collected. A DL condition management unit that manages content data and download conditions specified by a reservation request from a data terminal device, and a content data guarantee that guarantees the download conditions based on the download conditions managed by the DL condition management unit. Scheduling to determine transmission timing When, according to the transmission timing determined by the scheduling unit further includes a data sending unit for sending the contents data to the communication line.

A twentieth invention is according to the nineteenth invention, wherein the download condition is a time limit at which the content data designated by the data terminal device must be stored in the line terminal device.

According to the nineteenth and twentieth aspects, the server transmits the reservation status data to the data terminal device, and receives a reservation request from the data terminal device that desires to receive the same content data under the same download condition. Therefore, it is possible to multicast the content data, that is, to simultaneously transmit the content data to a plurality of data terminal devices, thereby efficiently using the transmission band of the communication line.

A twenty-first invention is according to the twentieth invention, and receives a reservation request from the data terminal device and requests the number of data terminal devices wishing to receive the same content data by the same time limit. Further includes a reception processing unit that determines a cost required for transmitting the content data in accordance with. According to the twenty-first aspect, since different costs are set according to the number of data terminal devices that desire to receive the same content data by the same time limit, the user can obtain the content data at a low cost. Becomes possible.

A twenty-second invention is according to the twenty-first invention, wherein the reception processing unit further specifies a time limit not indicated in the reservation status data in the reservation request from the data terminal device. Then, the cost required for transmitting the content data specified by the reservation request is determined according to the grace time from the current time to the time limit. 22nd
According to the invention, different costs are set according to the grace time, so that the user can acquire the content data at low cost.

The twenty-third invention is according to the nineteenth invention, wherein the download condition is a cost required for transmitting the content data designated by the data terminal device by the reservation request, and the download request from the data terminal device. Accept
According to the number of data terminal devices requesting the same content data, the data transmission device further includes a reception processing unit that determines a cost required for transmitting the content data. When the value falls below the specified value, the content data designated by the reservation request is transmitted to the communication line. According to the twenty-third invention,
The user can acquire the content data at his desired cost.

A twenty-fourth invention is according to the nineteenth invention, wherein the download condition is the number of data terminal devices requesting the same content data. A reception processing unit that determines a cost required for transmitting the content data in accordance with the number of data terminal devices that desire to receive the content data, wherein the data transmission unit is configured to transmit the number of reservation requests received by the reception processing unit; Is larger than a predetermined value, the content data specified by the reservation request is transmitted to the communication line. According to the twenty-fourth aspect, different costs are set according to the number of data terminal devices, so that the user can acquire the content data at low cost.

A twenty-fifth invention is a method in which the server sends out the content data designated by the reservation request from the data terminal device to the communication line and transmits the content data to the data terminal device. Further, a download condition of the content data specified by the data terminal device is specified, and a reservation status data generating step of generating reservation status data indicating download conditions for each content data based on the received reservation request; A data transmitting step of transmitting the reservation status data generated in the status data generating step to the data terminal device, whereby a reservation request from the data terminal device wishing to receive the same content data under the same download condition is provided. Is recruited and the content specified by the reservation request from the data terminal device A DL condition management step of managing data and download conditions, a scheduling step of determining transmission timing of content data that guarantees the download conditions based on the download conditions managed in the DL condition management step, and a scheduling step. A data transmission step of transmitting content data to the communication line according to the determined transmission timing.

According to a twenty-sixth aspect, in order to store a content data set designated by a reservation request from a data terminal device in a line termination device connected to the data terminal device, the content data set is connected to one of a plurality of communication lines. A data transmission system transmitted by a server, wherein the content data set includes a plurality of different content data, and the reservation request further stores the content data set designated by the data terminal device in the line termination device. A time limit that must be set is specified, and either the server or the communication line manages the time limit specified by the reservation request from the data terminal device and the time limit manager. Data that guarantees the time limit based on both the time limit and the predetermined communication information. And a scheduling unit for determining a transmission timing of the packet and an optimal one from among the plurality of communication lines. The server transmits the content data set to the optimal communication line in accordance with the transmission timing determined by the scheduling unit. And a line termination device connected to a plurality of communication lines, and, from a content data set received from an optimal communication line, only content data that matches a predetermined selection condition. Read it out and send it to the data terminal device.

A twenty-seventh invention is according to the twenty-sixth invention, wherein the line terminating device is connected to a plurality of communication lines and stores a content data set received from an optimum communication line. And a data transmission unit that reads only content data that meets a predetermined selection condition from the content storage unit in response to a read request from the data terminal device, and transmits the content data to the data terminal device. According to the twenty-sixth and twenty-seventh aspects, unnecessary content data is not transmitted from the line termination device to the data terminal device.

A twenty-eighth invention is according to the twenty-seventh invention, wherein each piece of content data included in the content data set is added with attribute information indicating its own attribute. A selection condition list storing unit that stores a selection condition list describing a selection condition based on an attribute of the content data to be transmitted to the terminal device; wherein the data transmission unit includes a selection condition list stored in the selection condition list storage , The content data is read from the content storage unit and transmitted to the data terminal device.

According to the twenty-eighth aspect, the selection condition based on the attribute information of each content data is set, so that content data having an unnecessary attribute is not transmitted from the line termination device to the data terminal device.

A twenty-ninth invention is according to the twenty-eighth invention, and the selection condition list is created based on a keyword input to the data terminal device by the user. According to the twenty-ninth aspect, it becomes possible to transmit only the user-preferred content data to the data terminal device.

[0041] A thirtieth invention is according to the twenty-seventh invention, wherein the line terminator is provided at a predetermined timing.
The information processing apparatus further includes a data deletion unit that deletes the content data set stored in the content storage unit.

A thirty-first invention is according to the twenty-seventh invention, wherein the data deletion section has a recordable capacity capable of storing the content data set in the content storage section smaller than a predetermined reference recordable capacity. Delete the content data set when it becomes

A thirty-second invention is according to the twenty-seventh invention, wherein each content data set is added with deletion timing information serving as a basis for deleting itself, and the data deletion unit The content data set is deleted according to the deletion timing information added to the content data set.

According to the thirty-third to thirty-second inventions, the content data set is automatically deleted by the line terminal, so that it is possible to prevent the recording area of the content storage unit from running out.

A thirty-third invention is according to the twenty-sixth invention, wherein the line terminator is connected to a plurality of communication lines, and is determined in advance from a content data set received on an optimum communication line. A content storage unit that stores only the content data that meets the selected selection condition, and a data transmission that reads the content data stored in the content storage unit in response to a read request from the data terminal device and transmits the content data to the data terminal device And parts.

According to a thirty-fourth aspect, in order to store a content data set specified by a reservation request from a data terminal device in a line termination device connected to the data terminal device, the content data set is connected to one of a plurality of communication lines. A data transmission method transmitted by a server, wherein the content data set includes a plurality of different content data, and the reservation request further includes the content data set designated by the data terminal device stored in the line termination device. A time limit that must be set is specified, and either the server or the communication line manages the time limit specified by the reservation request from the data terminal device and the time limit management step. Content that guarantees the time limit based on both the time limit and the specified communication information. And the transmission timing of the data set,
A scheduling step of determining an optimal one from among the plurality of communication lines, and the server according to the transmission timing determined in the scheduling step,
A data transmission step of transmitting a content data set to an optimal communication line, wherein the line terminating device is connected to a plurality of communication lines, and a predetermined one is set from a content data set received on the optimal communication line. Only the content data is read and transmitted to the data terminal device.

[0047]

FIG. 1 is a diagram showing an overall configuration of a data transmission system according to a first embodiment of the present invention.
In FIG. 1, a data transmission system includes several data terminal devices (hereinafter referred to as DTE (Data Terminal Equipment)).
1), a wired or wireless transmission line 2, and a circuit terminating device (hereinafter referred to as DCE (Data Circuit terminating Equipm
ent)), a first communication line 4 and a second communication line 5 as an example of a plurality of communication lines in the claims.
And a content server (hereinafter simply referred to as a server) 6
And

The DTE 1 is a device operated by a user such as a personal computer,
The content data CD (see FIG. 4) downloaded from is output to give the content represented by the content data CD to the user. DTE 1 is transmitted by transmission path 2
The DCE 3 is connected so that bidirectional data communication can be performed.

The DCE 3 has at least one switch 41.
(Described later), and performs bidirectional data communication with the server 6 through the first communication line 4. Also, D
The CE 3 is preferably supplied with electric power through the first wired communication line 4, so that it can operate constantly. Further, the DCE 3 includes a receiving antenna 53
(Described later), and receives data from the server 6 through the second communication line 5. DCE3 is shown in FIG.
As shown in (1), a processing unit 31, a user interface 32, a line interface 33, a receiving unit 34, and a content storage unit 35 are provided.

The above DTE 1 and DCE 3 are installed on the user side (typically, the user's house) as shown in FIG. FIG. 1 shows only one user's equipment (DTE1 and DCE3) for convenience.
The data transmission system accommodates a large number of user devices. Further, a unique identification information ID _USER is assigned to each user's device in advance to identify the user. In the present embodiment, the illustrated DTE1 and DCE3
The combination of, as the identification information ID _USER, and alpha ₁ is assigned.

The first communication line 4 is a wired public line, in which several exchanges 41 are accommodated. The plural exchanges 41 are connected by a communication path represented by an optical fiber, a twisted pair, or a coaxial cable. The first communication line 4 is suitable for transmitting different content data CDs to a large number of DTEs 1 because each exchange 41 performs routing. However, server 6
However, if the same content data CD is simultaneously distributed to many DTEs 1 using the first communication line 4, the transmission bandwidth of many communication paths is consumed for transmission of the content data CD. , The first communication line 4 is not suitable for multicasting.

In the present embodiment, the second communication line 5 includes a transmitting antenna 51, an artificial satellite 52, and a receiving antenna 53.
Consists of satellite links including Unlike the first communication line 4, the second communication line 5 is suitable for multicasting because the same transmission band can be used when transmitting the same content data CD to many DTEs 1. But,
Since the transmission band of the second communication line 5 is shared by all DTEs 1, the second communication line 5 has a large number of DTEs.
1 is not suitable for transmitting different content data CD. This is because, when different content data CDs are sent out on the second communication line 5, the transmission band becomes short immediately. The DCE 3, the first communication line 4 and the second communication line 5 constitute a data transmission network 7 as shown in FIG.

The server 6 is installed on the side of the information provider that provides each user with the content data CD, and has in advance identification information ID _SERVER for uniquely identifying itself. The server 6 is connected to at least one exchange 41 and performs bidirectional data communication with the DCE 3 via the first communication line 4. Further, the server 6 is connected to the transmission antenna 51, and transmits data to the DTE 1 through the second communication line 5. As shown in FIG. 3, the server 6 includes a processing unit 61, a line interface 62, a transmission unit 63, and a content storage unit 64.
, A transmission destination list storage unit 65 and a charging list storage unit 66
, A transmission cost list storage section 67 and a transmission initial cost list storage section 68.

As shown in FIG.
Stores some content data CD. Each
Content data CD contains moving image data, still image data, sound
Voice data, graphic data or character data, or this
It is composed of a combination of two or more of these. Also,
Each content data CD has an identification information ID_CDAnd the day
Tasize I_DSIs added. Identification information ID_CDIs a con
The storage location where the content data CD is stored (that is,
(Recording area in the content storage unit 64 of the server 6)
Is uniquely specified in the data transmission system. Data
Is I_DSIndicates the size of the content data CD. Book
In the embodiment, as shown in FIG.
_AAnd CD_BIs stored. Also, content
Data CD _AContains the identification information ID_CDAs β₁,and
Data size I_DSAs γ₁Is added and the content
Data CD_BContains the identification information ID_CDAs β_Two, Data
Is I_DSAs γ_TwoIs added.

The transmission destination list storage section 65 includes
Time limit management unit and DL condition management unit
Destination list L_DESTIs stored. Destination list L
_DESTRepresents some unit records U as shown in FIG.
R₁(The illustration shows three unit records UR₁₁~ UR₁₃From)
Be composed. Each unit record UR₁Is the target
The download condition of the Tenz data CD is specified.
More specifically, the download condition number (hereinafter, DL article
(Referred to as case number) N_DL, Identification information ID_CD, Time limit LT,
Transmission cost TC, at least one identification information ID_USER,
And communication line flag F_CIRIt is a combination of DL article
Item number N_DLIs the unit record UR₁Number that uniquely identifies
No. Next, the identification information ID_CD, Time limit LT and
Identification information ID _USERWill be described. Destination list L
_DESTIn the identification information ID_CDUser wants to send
The content data CD to be specified is specified. Also, time limit
LT is specified by the user and requested by the user.
The content data CD is the content storage unit 3 of the DCE 3
5 indicates the time that must be stored. Identification
Report ID_USERIs the destination list L_DESTIn particular,
Indicates the destination of the content data CD. Also, transmission cost
The TC transmits the content data CD from the server 6 to the DCE3.
Indicates the amount to be charged to the user when transmitted to the user. Ma
Communication line flag F _CIRIs the content
Indicates the communication line used to transmit the data CD. In this embodiment
Is the communication line flag F_CIRIf the value of is 1, the first
Indicates the communication line 4, and if it is 0, the second communication line
Suppose line 5 is shown.

FIG. 5 shows three simple examples as specific examples.
Place record UR₁₁~ UR₁₃List L consisting of_DEST
It is shown. Unit record UR₁₁Contains the identification information I
D_CDAs β₁, As the time limit LT
8:00 and α_Two~ Α ₅₀₀A total of 499
Different identification information ID_USERIs described. α_Two~
α₅₀₀Is assigned to another user's device not shown in FIG.
Identification information ID_{US ER}It is. Note that α₁Is the unit
Record UR₁₁Is not described. Therefore,
Content Data CD_ABy 18:00 on February 17,
Identification information ID_USER499 DCE3s specified by
Sent to. Further, the unit record UR ₁₁To send
450 yen is described as the cost TC. Accordingly
Content data to be transmitted to the above 499 units
CD_AIs currently 450 yen. Unit record UR₁₂And
And UR₁₃Is the unit record UR described above.₁₁Has the same meaning as
The description is omitted. In the example of FIG.
Identification information ID_CDIs β_TwoIs a unit record UR₁Is shown
This is not a content data CD_BSend
Indicates that no user wants to be
You.

The charging list storage unit 66 stores the charging list L
Store _PAY . In the charging list L _PAY , as shown in FIG. 6, charging information I _{PAY for} each identification information ID _USER is described. The billing information I _PAY indicates the total amount of the transmission costs TC of all the content data CDs acquired within a predetermined period by the user specified by the same set of identification information ID _USER . In the present embodiment, for the sake of simplicity, the charging information I
_{The PAY} is described as only the total amount of the transmission cost TC, but other fees that the user must pay to the information provider (such as the copyright fee of the content data CD) may be added to the total amount. . Further, in FIG. 6, as a specific example, the identification information ID _USER is alpha ₁ charge information I _PAY
A charging list L _PAY including (a total amount of 1500 yen) is shown. Note that the charge information I _PAY other than alpha _1, for convenience, not shown and described.

The transmission cost list storage 67 stores a transmission cost list _LTC . In the transmission cost list _LTC , as shown in FIG. 7, the transmission cost TC required for transmitting the content data CD is described for each transmission user number N _USER . In the present embodiment, the numbers of transmission users N _{USER1 to} N _USER5 are prepared as the number of transmission users N _USER , and the number of transmission users N _USER1 ranges from 1 to 19. Transmission expense TC ₁ transmission number of users N _USER1 is defined as 550 yen. Other transmission user number N _USER2 to N _{US ER5} also shows a range of as illustrated, the transmission expense TC ₂ to Tc ₅ corresponding to each is set to the price of as illustrated.

The initial transmission cost list storage section 68 stores an initial transmission cost list L _ITC in order to determine the initial value of the transmission cost TC. As shown in FIG. 8, the initial transmission cost list L _ITC describes the initial transmission cost ITC required for transmitting the content data CD for each grace time TM. The grace period TM, essentially, a reservation request RS _TR from the time the server 6 receives a time until the specified time limit LT by the reservation request RS _TR. In this embodiment, the grace time TM is the grace time T
M _{1 to} TM ₅ are prepared, and the grace time TM ₁ is 0
Up to 12 hours. The transmission initial cost ITC ₁ grace time TM ₁ is defined as 550 yen. Other window time TM ₂ to Tm ₅ is also a time range as illustrated, it transmits the initial cost ITC ₂ ~IT corresponding to each
C ₅ is set to the price of as illustrated.

Hereinafter, the data transmission system having the above configuration will be described.
Until the DTE 1 acquires the content data CD
The communication procedure of FIG.
This will be described with reference to FIG. First, in FIG.
Responds to a request from DTE1 (not shown)
Destination list L_DESTBased on the reservation status data D
_RSIs created (step ST1). Step ST1 is
It corresponds to the reservation status data creation unit in the claim,
The detailed processing procedure is shown in FIG. FIG.
And the processing unit 61 of the server 6
_DEST(See FIG. 5) each unit record UR₁From, DL article
Item number N_DLRetrieves time limit LT and transmission cost TC
(Step ST110). Next, the processing unit 61
Is the required number of download condition lists (hereinafter, DL
L)_DL(Step ST12)
0). Each DL condition list L_DLIs the retrieved DL condition
Number N _DL, Time limit LT, and transmission cost TC
Of the target content data CD
Specify load conditions.

[0061] In the next step ST120, the processing unit 61 generates a reservation status data D _RS (step ST
130). Reservation status data D _RS, as shown in FIG. 12, in DTE1 side is data to show the DL condition list L _DL content data CD. Also, if the user
When specifying the L condition number N _DL, so DTE1 can create a reservation request RS _TR described below, reservation status data D _RS is created. This allows the user to easily specify the DL condition list _LDL that meets his / her condition.
Furthermore, since there may be no DL condition list L _DL that meets the user's conditions, the reservation status data D _RS contains
By operating E1, the content data CD and the time limit LT can be designated. Thus, the process of step ST1 ends.

Now, the processing unit 61 is shown in FIG.
Unit record UR₁₁~ UR₁₃Based on the reservation status
Data D_RSSuppose that Under this assumption,
About situation data D_RSWhen DTE1 performs display processing on
As shown in FIG. 12, three DL condition lists L_DL1~ L
_DL3Is displayed on the screen of DTE1. DL condition list
L_DL1Is the content data CD_AAnd there
Is 18:00 on February 17 as time limit LT, and
In addition, 450 yen is described as the transmission cost TC. Other D
L condition list L_DL2And L_DL3Contains the DL condition list
L_DL1The description is omitted because the same information is described.
I do. In the example of FIG. 5, the identification information ID _CDIs β_TwoIn
Unit record UR₁There is no reservation status data D_RS
Is the content data CD_BDL condition list L for_DLTo
Not included.

The above-mentioned reservation status data D _RS is transferred from the processing unit 61 to the line interface 62, and further, the first communication line 4
After undergoing a conversion process for converting to a format suitable for the first communication line, as shown in FIG. At this time,
The line interface 62 corresponds to a data transmitting unit in the claims. The reservation status data _DRS is transmitted to the first communication line 4
And received by the line interface 33 of the DCE 3 via some of the exchanges 41. Reservation status data D
_{The RS} is transferred to the user interface 32 via the processing unit 31 after being subjected to a conversion process for returning to the original format by the line interface 33. The user interface 32 receives the reservation status data D
After performing a conversion process for converting the _RS into a format suitable for the transmission path 2, the _RS is transmitted to the transmission path 2. Reservation status data D
_{The RS} is transmitted on the transmission path 2 and received by the DTE 1 (sequence SQ1).

DTE1 is the reservation status data D_RSTo receive
In response, a reservation request is created (step ST2). This
, The DTE1 receives the reservation status data D_RSFrom
After returning to the format, output processing is performed, and DL condition list
L_DLIs displayed (see FIG. 12). By this
The user refers to the reservation status of each content data CD.
The time limit LT that matches your download conditions.
DL list L including transmission cost TC_DLLooking for
Can be. Users can match their download requirements
If found, the DL condition number N_DLSpecify
You. In response to this designation, DTE 1
Reservation request RS shown_TRCreate FIG. 13 (a)
And reservation request RS_TRUser wants to download
For reserving transmission of content data CD
And at least the identification information ID _TRAnd identification information ID
_SERVERAnd identification information ID_USERAnd DL condition number N_DLAnd
Including. Identification information ID_TRMeans that the signal is a reservation request RS_TRso
Identify something. Identification information ID_SERVERIs a reservation request
RS_TR(That is, the server 6) is specified. Identification
Report ID_USERIs the reservation request RS_TRSource (that is, DTE
Specify 1). DL condition number N_DLIs the user's finger
Server 6, so that the server 6
The content data CD that the user wants to acquire, and the time limit L
T and its transmission cost TC can be specified.
You.

[0065] On the other hand, the user, if there is no DL condition list L _DL to suit their own terms, by operating the DTE1, to specify the content data CD and the time limit LT he or she wants to get. In response to this designation, DTE1
To create a reservation request RS _TR shown in (b). FIG. 13 (b)
Of the reservation request RS _TR of FIG.
Instead of the DL condition number _NDL , the identification information ID _CD of the content data CD that the user wants to acquire and the time limit LT
Is set.

The above reservation request RS_TRIs based on DTE1
After being converted into a format suitable for the transmission path 2, the sequence shown in FIG.
As shown in FIG.
Received by the user interface 32 of FIG.
It is. Further, the reservation request RS _TRIs the user interface
Received a conversion process to convert to the original format in step 32
Then, via the processing unit 31, the line interface 3
3 is transferred. The line interface 33 is reserved for reception.
Request RS_TRInto a format suitable for the first communication line 4
After performing the conversion process, the data is transmitted to the first communication line 4.
You. Reservation request RS _TRTransmitted over the first communication line 4
To the line interface 62 of the server 6 (see FIG. 3).
(Sequence SQ2). Line interface
The chair 62 receives the reception reservation request RS_TRTo return to the original format
Of the processing unit 61 after the conversion processing of FIG.
(Not shown).

The processing unit 61 has its identification information ID _TR
By checking the reservation request RS _TR on the memory.
Is stored. Further, the processing unit 6
1, receives the reservation request RS _TR, transmittable time limit LT the designated content data CD to DTE1 to determine whether it is set (step ST3). FIG. 14 shows the detailed processing procedure of step ST3. FIG.
In 4, the processing unit 61 sets the reception reservation request RS _TR
It is determined whether or not the time limit LT in the above indicates a past time (step ST31). Processing in the case of a past time will be described later. On the other hand, if it is not a past time, the processing unit 61 creates an area reserve request RS _ER shown in FIG. 13 (c) (step ST32). FIG.
(C), the region allocation request RS _ER is a signal for requesting the securing of a recording area of the content storage unit 35 (see FIG. 2), at least the identification information ID _RER, the identification information ID _USER, Data size _IDS . Identification information ID _RER identifies that the area reserve request RS _ER. The identification information ID _USER is a DCE for which a recording area should be secured.
Shows a 3 are the same as those set in the received reservation request RS _TR. The data size I _DS is the reception reservation request RS
The size of the content data CD specified by the _TR , which is obtained as follows. That is, the processing unit 61 analyzes the reception reservation request _RSTR, and
In the case of the format 3 (a), the identification information ID is obtained from the transmission destination list L _DEST (see FIG. 5) based on the DL condition number N _DL .
Get a _CD . On the other hand, the reception reservation request RS _TR is
In the case of the format (b), the identification information ID _CD is obtained therefrom. The processing unit 61 uses the identification information ID _CD acquired in this way, from the content storage unit 64, acquires the data size I _DS of the content data CD in question. The processing unit 61 creates an area reservation request RS _ER from the identification information ID _ER , the identification information ID _USER and the data size I _DS obtained as described above.

The area reservation request RS _ER is sent to the processing unit 61
Is transmitted to the line interface 62, and then transmitted to the control channel of the first communication line 4, as shown by a sequence SQ3 in FIG. Here, the control channel is
It is prepared in advance for controlling devices (exchanger 41 and DCE 3) in the first communication line 4. As in the reservation status data D _RS, the data that is ultimately received by the DTE1 is transmitted to the data channel of the first communication line 4. The area reservation request _RSER is received by a predetermined exchange 41 via some exchanges 41. The predetermined exchange 41 is typically installed near the DCE 3.

The predetermined exchange 41 receives the reception area securing request R
S_ERIn response to the area reservation instruction IS _ERCreate (Step
ST4). Area reservation instruction IS_ERIs recorded in DCE3
This is a signal for instructing to secure an area.
Also, as shown in FIG._IERWhen,
Reception area reservation request RS_ERSame identification information ID as that of_USER
And data size I_DSAnd Identification information ID
_IERIs the area reservation instruction IS_ERIs specified. Work
Generated area reservation instruction IS_ERIs the control of the first communication line 4.
Through a control channel, DCE3,
More specifically, to the line interface 33 (see FIG. 2)
Is transmitted (sequence SQ4). Step S
At T4, the predetermined exchange 41 determines that
Work as area manager.

The line interface 33 secures a reception area.
Instruction IS_ERAfter performing the conversion process (described above), the processing unit
To the server 31. The processing unit 31 issues an area securing instruction
IS _ERIn response to the receipt of
Data size I_DSThe recording area for the minutes
(Step ST5). Succeed in securing it
And the processing unit 31_RDCreate
Acknowledgment AS_RDIs a signal indicating that the area was successfully allocated.
At least, as shown in FIG.
Identification information ID for specifying the signal_RDAnd its source
Information ID for identifying_USERAnd the recipient
ID of server 6_SERVERAnd Positive acknowledgment
AS_RDIs a line interface from the processing unit 31.
33, as shown by the sequence SQ5 in FIG.
It is sent to the control channel of the first communication line 4. That
Later, a positive response AS_RDThrough the first communication line 4
Server 6 via a line interface 62 (see FIG. 3).
(Sequence SQ5). In addition, secure the recording area
Will be described later.

After performing the conversion process (described above) on the reception acknowledgment AS _RD , the line interface 62
Transfer to 1. The processing unit 61 creates a reception completion notification AS _RR in response to the reception of the acknowledgment AS _RD (step ST6). The reception completion notification AS _RR is the reservation request RS _TR
13 is a signal indicating that the reception of
As shown in (f), at least the identification information ID _RR ,
It includes an identification information ID _USER and an identification information ID _SERVER . The identification information ID _RR specifies that it is a reception completion notification AS _RR . The identification information ID _USER specifies the destination (that is, DTE1) of the reception completion notification AS _RR . Identification information ID _SERVER
Specifies the transmission source of the reception completion notification AS _RR (that is, the server 6). Also reception completion notice AS _RR above, after undergoing a conversion process by the line interface 62 similar to the reservation status data D _RS, is sent to the first communication line 4 (sequence SQ6). Thereafter, the reception completion notification AS _RR is processed by the DCE 3 in the same manner as the reservation status data D _RS , then transmitted on the transmission path 2 and received by the DTE 1.

DTE 1 performs reception completion output processing in response to reception of the reception completion notification AS _RR (step ST).
7). More specifically, the DTE 1 displays on the screen a message indicating that the reservation request RS _TR transmitted in step ST2 has been normally processed by the server 6 in steps ST3 and ST6, and notifies the user.

Although not shown in FIG. 9, if the processing in step ST3 or ST6 cannot be completed normally for some reason, the processing unit 61
Create a failure notification. The failure notification is sent to the reception reservation request RS _TR by the processing unit 61 in step ST31.
Is created when it is determined that the time limit LT in the above indicates a past time (FIG. 14; step ST33).
Also, in step ST5, if the storage area allocation fails, the DCE 3 creates a negative response and
To the server 6 by the same procedure as S _RD. Even when the above negative response is received, a failure notification is created. The failure notification is, like the reception completion notification AS _RR , the first communication line 4,
The signal is received by the DTE 1 via the DCE 3 and the transmission path 2. In response to the reception of the failure notification, the DTE 1 displays on the screen a message indicating that the reservation request RS _TR transmitted this time cannot be normally processed by the server 6 in step ST3 or ST6, Notify the user.

In the above description of the sequences SQ1 to SQ6, all the downlink signals, that is, the reservation status data D
_Although the first communication line 4 has been used for transmitting the _RS , the region reservation request RS _ER , the region reservation instruction IS _ER and the reception completion notification AS _RR , the second communication line 54 may be used. However, since each downlink signal is not multicasted, it is preferable that each downlink signal is transmitted through the first communication line 4.

Now, after the processing of step ST7, the DTE
Communication procedure until 1 acquires content data CD
Will be described with reference to the sequence chart of FIG.
In FIG. 10, the processing unit 61 includes a reservation request receiving process.
(Step ST8). Step ST8 is a request
Section, and the detailed processing procedure is shown in FIG.
As shown in FIG. In FIG. 15, first, the processing unit 6
1 is a reception reservation request RS _TRTo DL condition number N_DLIs there
It is determined whether or not it is (step ST81). DL condition number N
_DLIf there is (see FIG. 13A), the processing unit 61
Is the destination list L_DESTFrom the DL condition number N_DLBut
Matching unit record UR₁Out of the memory
(Step ST82). Next, the processing unit 61
Is the reception reservation request RS_TRTo identification information ID_USERThe note
UR on unit record₁After adding to the unit record
Code UR₁ID information within_USERTotal (that is,
Number of users who have reserved transmission of the content data CD
N_USER) Is counted (step ST83).

Next, the processing unit 61 extracts the transmission cost TC corresponding to the counted total number N _USER from the transmission cost list L _TC (see FIG. 7) (step ST84). Here, in order to avoid confusion, in the following, step ST8 will be described.
The transmission expense TC described in the unit record UR ₁ taken out by 2, referred to as current transmission expense TC. On the other hand, the transmission expense TC obtained from the transmission expense list L _TC at step ST 84, referred to as the new transmission expense TC.

Next, the processing unit 61 compares the current transmission cost TC with the new transmission cost TC (step ST85). If the current transmission cost TC is equal to or less than the new transmission cost TC, the processing unit 61 performs no processing and proceeds to step ST.
87, but if not, step ST
Execute 86. That is, if the new transmission cost TC is lower than the current transmission cost TC, the processing unit 61 selects the new transmission cost TC assuming that there is an advantage to the user,
Writing a transmission expense TC to unit record UR ₁ on the memory (step ST86), then step ST8
Go to 7. In step ST87, the processing unit 6
1 stores the unit record UR ₁ on the memory in the destination list storage unit 65 and updates the destination list L _DEST .
When step ST87 ends, the processing unit 61 ends the processing in FIG.

Here, the unit record UR₁Update process
A specific example of (steps ST82 to ST86) will be described.
Now, it is assumed that the execution of step ST81 has been started.
Reservation request RS_TRHas DL condition number N_DLAs one
Is the identification information ID_USERAs α ₁Is set
You. Further, in step ST82, the unit record shown in FIG.
Code UR₁₁Is taken out. Under these assumptions,
After the execution of step ST83, as shown in FIG.
, The unit record UR₁₁Has α₁Has been added, for a total of 5
00 identification information IDs_USERIs described. I
Therefore, in step ST84, as the new transmission cost TC
400 yen is taken out. Therefore, in step ST86
After the execution, as shown in FIG.
₁₁, 400 yen is written as the transmission cost TC.

[0079] Further, in the execution start time of step ST81, the unit record UR _11, rather than 499,
There are ten identification information ID _USER , and the unit record U
Transmission expense TC for R ₁₁ are assumed to be 550 yen. When other conditions are the same as described above, even if one of the identification information ID alpha ₁ is a _USER is newly added to the unit record UR _11, the new transmission expense TC (i.e. acquired in step ST 84, 550 Yen) is equal to the current transmission cost TC (ie, 550 yen). In other words, under the above assumptions, the unit record UR _11, only alpha ₁ is added. As described above, in the reservation request receiving process, as the number of users who want to transmit under the same conditions (time limit LT, content data CD) increases, the transmission cost TC increases.
Is updated to be lower.

Also, in step ST81 of FIG.
And DL condition number N_DLIs not set (FIG. 13
(B)), the processing unit 61 is a new unit record.
De UR ₁To create a new unit record UR₁
DL condition number N unique to_DLAfter assigning
RS seeking_TRFrom the identification information ID_CD, Identification information ID_USERAnd
And the time limit LT is acquired (step ST88). Next
In step ST89, the processing unit 61
The difference between the time limit LT and the current time, that is, the grace time TM
Is calculated. Thereafter, the processing unit 61 sets the initial transmission cost.
List L_TC(See FIG. 8), the calculated grace time TM
Initial transmission cost ITC corresponding to the new unit record
UR₁As the transmission cost TC to be written to
Step ST89). As a result, we have all the necessary information
Therefore, the processing unit 61 sets the DL condition number N
_DL, Identification information ID_CD, Time limit LT, transmission cost TC and
And identification information ID_USERInto a new unit record
Code UR₁Is created (step ST810). That
Thereafter, the processing unit 61 executes the created unit record UR₁
Is stored in the destination list storage unit 65, and the destination list L
_DESTIs updated (step ST811). Step ST
When 87 is completed, the processing unit 61 executes the processing in FIG.
finish.

[0081] Here, a specific example of a newly added processing unit record UR ₁ (step ST88~ST811). Suppose now that the execution of step ST81 is started,
At that time, the destination list L _DEST is in the state of FIG. It is also assumed that β ₁ is set as the identification information ID _CD , α ₁ is set as the identification information ID _USER , and 2:00:00 on February 15 is set as the time limit LT in the current reception reservation request RS _TR. . The current time is 2/14 on February 14.
0:00. Under this assumption, the grace time TM is 24
Since it is time, in step ST89, 480 yen is taken out as the transmission initial cost ITC. Therefore, at the end of step ST811, the destination list L _DEST contains a new unit record UR as shown in FIG.
₁₄ will be added.

In the above-described new addition processing, the reception reservation request R
The more temporal latitude by the time limit LT, which is set to S _TR, that is, the longer the delay time TM, the initial value of the transmission expense TC is set lower. If the grace time TM is long, it is expected that a reservation request RS _{TR of the} same condition from another user will arrive at the server 6, and the same content data CD
Is transmitted to a plurality of users at the same time, so that the transmission cost TC is set low as described above.

Further, as shown in FIG. 10, the processing unit 61 of the server 6 performs scheduling for determining the transmission timing of the content data CD (step ST9). The scheduling will be described as being performed after updating the transmission destination list L _DEST (step ST8) for convenience. However, the scheduling may be performed every predetermined time. Step ST
Reference numeral 9 corresponds to the scheduling unit in the claims, and the detailed processing procedure is shown in FIG. In FIG. 17, the processing unit 61 determines from the transmission destination list L _DEST (see FIG. 5) that the time limit LT−the current time <the reference time RT
Selecting a first condition is satisfied unit record UR ₁ that (step ST 91). Here, the reference time RT is the time limit LT described in the unit record UR _1, the time to ensure that the server 6 is completed transmits the content data CD into DCE3, a time margin to a predetermined The sum is determined in advance in consideration of parameters represented by the transmission band of the first communication line 4 and the transmission band of the second communication line 5. In the following description, the first to satisfy unit record UR _1, referred to as the first set.

Next, the processing unit 61 determines whether to use the first communication line 4 or the second communication line 5 for each unit record UR ₁ included in the first set (see FIG. 1). Step ST92). FIG. 18 shows the detailed processing procedure of step ST92. In FIG. 18, the processing unit 61 converts the unit record U to be processed from the first set.
The R ₁ 1 single selects (step ST921). Then, the processing unit 61, the number of users N _USER in unit record UR ₁ to be processed is determined whether it exceeds the reference value V _REF1 (step ST922). The reference value V _REF1 is
A threshold for the user who wants to download the content data CD in terms of unit record UR ₁ is determined to very high transmission bandwidth, etc. of both the first communication line 4 and the second communication line 5 Is predetermined in consideration of the parameters

As described above, the second communication line 5 (satellite line) is suitable for multicasting, and when the number of transmitting users is extremely large, it is better to use the second communication line 5 for the content data CD. Can be sent cheaply. In view of the above, the processing unit 61 determines the number of users N
_USER is if it exceeds the reference value V _REF1, using the second communication line 5, it determines to transmit the content data CD specified in DCE3 by the processing target unit record UR _1. For example, assuming now that the reference value V _REF1 is 19, the transmission unit 61 sets the communication line flag F _CIR having a value of 0 to the unit record U as shown in FIG.
Set to R ₁ (step ST923).

On the other hand, the processing unit 61 performs step ST
In 922, when the number of users N _USER does not exceed the reference value V _REF1, the user number N _{US ER} processing target unit record UR ₁ determines whether exceeds the reference value V _REF2 (step ST924). Reference value V _REF2 is a threshold for determining that the user is less likely to want to download the content data CD under the conditions of the process target unit record UR _1, first communication line 4 and the second communication line In consideration of the parameters such as the transmission bandwidths of the first and second transmission lines, at least a value smaller than the reference value V _REF1 is selected in advance.

As described above, the first communication line 4 (public line) is not suitable for multicasting, and when transmitting the same data to a small number of DTEs 1 (ie, users), the first communication line 4 is One communication line 4 can transmit cheaper. In view of the above, when the number of users N _USER does not exceed the reference value V _REF2 , the processing unit 61 uses the first communication line 4 to transmit the content data CD specified by the unit record UR ₁ to be processed.
Is transmitted to each user, and a communication line flag F _CIR having a value of ₁ is set in the processing target unit record UR ₁ as illustrated in FIG. 19B (step ST).
925).

On the other hand, the processing unit 61 performs step ST
In 924, when the number of users N _USER exceeds the reference value V _REF2 , the data size I _DS of the content data CD transmitted according to the processing target unit record UR ₁ is acquired from the content storage unit 64, and the data size I _DS is obtained. _DS
Is _larger than reference size V _REF3 (step ST926). The reference size V _REF3 is a threshold for judging that the size of the content data CD transmitted under the condition of the processing target unit record UR ₁ is large, and the first communication line 4 and the second communication line 5 Are determined in advance in consideration of parameters such as both transmission bands.

In the first communication line 4, the transmission band for transmitting the content data CD is the second transmission band.
Can be larger than that of the communication line.
In view of the above, even when the number of users N _USER exceeds the reference value V _REF2 , the processing unit 61 performs step ST9.
Data size I _DS at 26 when it is determined to exceed the standard size V _REF3 executes step ST 925. In the opposite case, the processing unit 61 performs step ST
923 is executed.

When one of steps ST923 and ST925 is completed, that is, when the communication line flag F _CIR is set, the processing unit 61 proceeds to step ST92.
Execute 7. In other words, the processing unit 61, the unit unit UR ₁ unselected determines whether there as a process target (step ST927). Processing unit 61, when determining that there is a unit record UR ₁ unselected, returning to step ST921, unit record U of the unselected
For any of R _1, it performs the same processing as described above. On the other hand, the processing unit 61 outputs the unselected unit record UR ₁
If it is determined that there is no data, the process of FIG. 18 ends.

[0091] The process in FIG. 18, for each unit record UR ₁ included in the first set, or use a first communication line 4, either by using the second communication line 5 is determined. However, as described above, the second communication line 5 (satellite line)
When trying to send different data to many users, the transmission band quickly runs out. Therefore,
In step ST92, a number of unit record UR _1, 0
When the communication line flag F _CIR having the value of
Waiting for transmission of the content data CD occurs, and as a result, the content data CD may not be stored in the DCE 3 by the time limit LT. In order to avoid such a situation, the processing unit 61 performs step ST9.
In 2 of the next, for all of the unit record UR ₁ that is included in the first set, limit the content data CD time LT
By this time, it is determined whether transmission to DCE3 can be completed (step ST93). Processing of step ST93, when the value of 1 as the communication line flag F _CIR is set each unit record UR _1, based on the current time, whereby the size I of the content data CD to be identified
_Since the transmission completion time of the content data CD can be roughly estimated from the _DS and the transmission band of the first communication line 4, the transmission time is calculated by comparing the calculated transmission completion time with the time limit LT. For each unit record UR ₁ in which the communication line flag F _CIR having a value of 0 is set, the size I _{DS of the} content data CD and the current time are used as a reference,
Since the transmission completion time of the content data CD can be known from the transmission band of the second communication line 5, the calculation is performed by comparing the calculated transmission completion time with the time limit LT. When the processing unit 61 determines that transmission of all the content data CDs can be completed by the time limit LT by the above processing, the processing in FIG. 17 ends.

On the other hand, the processing unit 61
Content CD cannot be sent before the time limit LT.
In the case of the rejection, each unit record UR₁Communication suitability for each
V_CRIs obtained (step ST94). The following explanation
Then, the content data CD can be transmitted by the time limit LT.
Unit record UR determined to be unsuccessful₁Cannot be sent
Place record UR₁Called. Communication suitability V_CRIs one
Unit record UR₁Content data C specified by
D to the first communication line 4 determined in step ST92.
Or it is suitable to transmit using the second communication line 5
It is an index indicating whether or not there is. Communication suitability V_CRIs the first
The second communication line 5 and the second communication line 5 use different methods.
Can be Therefore, hereinafter, the first communication line 4
Communication suitability V_CRIs the communication suitability V_CR1Called the second
Of communication suitability V for communication line 5_CRIs the communication suitability V
_CR2Called. The communication unit 61 has a unit record UR
₁Communication line flag F having a value of 1_CIRIs set
If the identification information ID _USERNumber of users N_USERIs small
The size I of the content data CD_DSIs bigger
Grace time from the current time to the time limit LT
The higher the TM, the higher the communication suitability V_CR1Calculate
You. Further, the communication unit 61 includes a unit record UR.₁To
Communication line flag F_CIRIf 0 is set as
Is the number of users N_USERIs larger, the content day
TA CD size I_DSIs smaller, the current time
The longer the grace time TM from the start to the time limit LT, the higher
Value communication suitability V_CR2Is calculated.

After step ST94, the processing unit 6
1, from the transmission impossible unit record UR _1, selects the unit record UR ₁ closest time limit LT from the current time as a reference unit record UR ₁ (step ST
95). Further, the processing unit 61 selects _one that satisfies the second condition from those that do not belong to the untransmittable unit record UR1 in the _first set, as a candidate unit record UR.
_It is selected as ₁ (step ST96). The second condition is a condition that the time limit LT is closer to the current time, the same communication line flag F _CIR is set, and the communication suitability V _CR is lower than the reference unit record UR ₁ .

Next, the processing unit 61 converts the content data CD specified by the candidate unit record UR ₁ into another communication line (that is, a flag F _CIR which is not currently set).
In by transmitting a communication line) specified, the content data CD that is identified by the reference unit record UR ₁ determines whether the transmission completion to the time limit LT (step ST97). The process of step ST97 will be specifically described. The transmission time required to transmit the content data CD specified by the candidate unit record UR ₁ from the server 6 to the DCE 3 is determined by the size I _DS of the content data CD and the transmission band of the first communication line 4 or the second It can be calculated from the transmission band of the communication line 5. Therefore, the transmission completion time ET of the reference unit record UR ₁ is
It can be obtained from the transmission time estimated in step ST93 based on the current time. Further, from the transmission completion time ET of the reference unit record UR _1, Subtracting transmission time calculated for the candidate unit record UR _1, and transmits the content data CD identified by the candidate unit record UR ₁ in a different communication line in case, the content data CD that is identified by the reference unit record UR ₁ is DCE3
Can be roughly estimated. Processing unit 61, a new transmission completion time ET obtained by the approximation is, as early than the limit time LT of the reference unit record UR _1, as can be guaranteed time limit LT of the reference unit record UR _1, candidate unit record U
The current value of the communication line flag F _CIR of R ₁ is changed to another value (step ST98). On the other hand, the processing unit 61
The new transmission completion time, if there is no earlier than the time limit LT reference unit record UR _1, to change the current value of the communication line flag F _CIR of the reference unit record UR ₁ itself to another value (step ST99 ). When step ST98 or ST99 described above ends, the processing unit 61 returns to step ST93 and repeats the above-described processing.

Here, the above steps ST94 to ST99
Will be schematically described with reference to FIG. Step
If it is determined that the transmission cannot be completed by
Same communication line flag F_CIRUnit record UR with_1i, U
R_1j, UR_1k, UR_1l, UR _1mHave the following relationship:
And That is, five unit records UR_1i~ UR _1m
Is the time limit LT as shown on the time axis t in FIG.
_i~ LT_mAnd have Further, the unit record UR_1i
~ UR_1mCompleted transmission of content data CD specified by
Time ET_i~ ET_mAre also shown on the time axis t. this
In such a situation, the transmission completion time ET_kAnd ET_lBut,
Time limit LT_kAnd LT_lUnit later
Record UR_1kAnd UR_1lIs non-sendable unit record
UR₁Is selected as Further, FIG.
Place record UR_1i~ UR_1mCommunication suitability V_CRi~ V_CRm
Are also shown.

In the above situation, in step ST95,
The unit record UR _1k is selected as the reference unit record UR ₁ , and in step ST96, the candidate unit record U
The unit record UR _1j is selected as R ₁ . Then, in step ST97, if the content data CD of the unit record _1j is transmitted through another communication line, it is determined whether or not the time limit LT _k of the reference unit record UR _1k can be guaranteed. ST98
In FIG. 20B, as shown in FIG.
The communication line flag F _CIR is changed to another value so that the content data CD of R _1j can be transmitted to another communication line.

Now, refer to FIG. 10 again. The processing unit 61 of the server 6 transmits the content data CD,
In order to charge the user, a data transmission / charging process is performed (step ST10). The data transmission / charging process is described as being performed after the scheduling (step ST9) for the sake of convenience, but may be performed at predetermined intervals in addition to this. Step ST10 corresponds to the data transmitting section in the claims, and the detailed processing procedure is shown in FIG. In FIG. 21, first, the processing unit 61 sets a unit record UR ₁ (hereinafter, a transmission target unit record) in which the communication flag F _CIR is set and the limit time LT closest to the current time is set from the destination list L _DEST. UR ₁ hereinafter) selecting (step ST 101). Then, the processing unit 61 from the content storage unit 64, adds the same as the identification information ID _CD transmission target unit record UR ₁ content data C
D is taken out (step ST102). Further, the processing unit 61 retrieves the identification information ID _USER transmission target unit record UR ₁ (step ST 103).

Next, the processing unit 61 is configured as shown in FIG.
Is created (step ST10).
4). In FIG. 13G, the transmission data TD includes an identification information ID _TD , an identification information ID _CD, and an identification information ID _TD.
USER , identification information ID _SERVER , and content data CD
And The identification information ID _TD specifies the transmission data TD. Identification information ID _CD are those set in the transmission target unit record UR _1. Identification information ID
_USER is destination of the transmission data TD, i.e. those which are set in the transmission target unit record UR _1. The identification information ID _SERVER specifies the source of the transmission data TD (that is, the server 6). The content data CD is stored in step S
It was taken out at T102.

[0099] When step ST104 is completed, the processing unit 61 checks the value assigned to the transmission target unit record UR ₁ communication line flag F _CIR (step ST105). Then, if the communication line flag F _CIR is 1, the processing unit 61 transfers the transmission data TD created in step ST104 to the line interface 62 (see FIG. 3). And the line interface 62
After performing a conversion process on the received transmission data TD,
As shown in a sequence SQ7 of FIG. 11, transmission data TD in a format suitable for the first communication line 4 is transmitted to the first communication line 4 (step ST106).

On the other hand, if the communication line flag F _CIR is 0 in step ST 105, the created transmission data TD is transferred to the transmission unit 63, further converted there, and then converted into the second communication line 5. (Step ST107). The transmission data TD transmitted to the second communication line 5 is not shown for convenience.

Steps ST106 and ST107
When the shift is completed, the processing unit 61 executes the billing process.
Do. More specifically, the processing unit 61
By accessing the data storage unit 66 (see FIG. 6),
Place record UR₁ID information set to_USERand
Billing information I_PAYIs a charge list L_PAYTake out from
(Step ST108). And the processing unit 61
Is the extracted billing information I_PAYTo each of the
Unit record UR₁Is added to the transmission cost TC (step
ST109), whereby the billing information I_PAYUpdate
You. Thereafter, the processing unit 61 sets the charge list storage unit 6
6 and the updated billing information I _PAYAnd identification
Information ID_USERIs the charging list L_PAYRegister to (Step
ST1010). As a result, the content sent this time
The transmission cost TC of the data CD is charged.

[0102] After the completion of step ST1010, the processing unit 61, the transmission target unit record UR ₁ of this time, remove from the destination list L _DEST (step ST101
1), then determine whether the transmission target unit record UR ₁ unselected absence (step ST1012), if, returns to the step ST 101, the same processing is repeated. On the other hand, if there is no transmission target unit record UR ₁ unselected, the processing unit 61 ends the step ST10.

The above transmission data TD is obtained in step ST1.
06 and transmitted to the first communication line 4 via several exchanges 41, the line interface 33 of the DCE3.
Is received by The line interface 33 transfers the transmission data TD in a format suitable for the first communication line 4 to the processing unit 31 after returning to the original format. The processing unit 31 performs a data storage process in response to the reception of the transmission data TD (step ST11). Step ST11
Is shown in FIG. In FIG. 22, the processing unit 31 includes at least the identification information ID _CD and the content data C in the received transmission data TD.
D is stored in a predetermined recording area in the content storage unit 35 (step ST111). Here, the predetermined recording area is the one secured in step ST5.

[0104] Next, the processing unit 31 creates a storage completion notice AS _CD (step ST 112). The storage completion notice AS _CD, is data for notifying that stores transmission request content data CD by reservation request RS _TR is completed. Here, the storage completion notification AS _CD is typically data in HTML (Hyper Text Markup Language) format or e-mail. In order to create data in the HTML format, the DCE 3 needs to have a function as a WWW server. In addition, to create an e-mail, the DCE 3 needs to function as a mail server. If the DCE 3 can create the storage completion notification AS _CD in both the HTML format and the e-mail method, the DCE 3 stores the storage completion notification AS _CD by a user operation or by a default method. Whether or not the completion notification AS _CD is transmitted needs to be set.

[0105] In the next step ST 112, the processing unit 31, the power supply of the DTE1 is determined on or not (step ST113), if turned on, the storage completion notice AS _CD created, the user interface 32 Forward. The user interface 32 receives the storage completion notification AS
After performing a conversion process for converting the _CD into a format suitable for the transmission path 2, the _CD is transmitted to the transmission path 2 (step ST11).
4). The storage completion notification AS _CD is transmitted on the transmission path 2,
Received by DTE1 (sequence SQ8).

Incidentally, the transmission data TD is transmitted not only on the first communication line 4 but also on the second communication line 5 when step ST107 is executed. More specifically, the server 6 sets a predetermined multicast address to the DC to receive the current transmission data TD.
Notify E3. Thereafter, the server 6 transmits the transmission data TD
The transmission data TD in which the multicast address is set is created as the identification information ID _USER of (see FIG. 13G). The transmission data TD is received from the transmission unit 63 of the server 6 via the transmission antenna 51, the artificial satellite 52, and the reception antenna 53 only by the reception unit 34 of the DCE 3 to which the multicast address has been notified. The receiving unit 34 returns the transmission data TD in a format suitable for the second communication line 5 to the original format, and then transfers it to the processing unit 31. In this case as well, the processing unit 31 performs the same data storage processing as described above in response to the reception of the transmission data TD. However, when the transmission data TD is transmitted to the second communication line 5, it reaches all the DCEs 3 accommodated in the data transmission system.
Only the processing unit 31 having the notified multicast address performs the data storing process on the transmission data TD, and the other units having the identification information ID _USER need to be discarded.

In response to receiving the storage completion notification AS _CD , the DTE 1 displays a message indicating that the requested content data CD has been stored to the server 6 (step S).
T12). As a result, the user recognizes that the content data CD has arrived at the DCE 3, and can refer to the content data CD thereafter. The user operates the DTE 1 at his or her convenience to specify the content data CD to be referred to this time. In response to this designation, DTE1 sends read request R
An _SRO is created (step ST13). Read request R
S _RO is the content data CD specified by the user.
Is read from the content storage unit 35 so that the DCE3
Is a signal to request.

The above read request RS _RO is converted into a format suitable for the transmission line 2 by the DTE 1, and then sent out to the transmission line 2 as shown in a sequence SQ9 of FIG.
It is received by the user interface 32 of the CE 3 (see FIG. 2), and is transferred to the processing unit 31 after being returned to the original format. The processing unit 31 reads the content data CD specified this time from the content storage unit 35 in response to the reception of the read request RS _RO and transfers the content data CD to the user interface 32. The user interface 32 receives the content data CD
Is converted into a format suitable for the transmission line 2, and then, as shown in a sequence SQ10 of FIG.
Transmit to DTE1 (step ST14). DTE1
After returning the received content data CD to the original format, the content data CD is output (step ST15), whereby the content represented by the content data CD is output to the user.

[0109] Incidentally, in step ST113 of FIG. 22, the processing unit 31 when the power of the DTE1 is determined to be OFF, the power supply until turned on, to hold the storage completion notice AS _CD created (step ST1
15). Then, when the processing unit 61 detects that the power is turned on, the storage completion notification A similar to the above is received.
The S _CD, via the user interface 32 and the transmission path 2, and transmits to the DTE 1. Hereinafter, DTE1 and DC
During E3, the processing of steps ST12 to ST15 is performed.

As described above, in the data transmission system according to the first embodiment, the server 6 is connected to one of the first communication line 4 unsuitable for multicast and the second communication line 5 suitable for it. The transmission data TD can be transmitted. Under this condition, the server 6 performs step S
By performing T9, based on both the state of the first communication line 4 and the second communication line 5, the number of users N _USER , the communication information including the data size I _DS , and the time limit LT, the transmission data TD Select a communication line suitable for transmission. Therefore, the server 6 transmits the same content data C
When transmitting D to many users, basically, the second
Can be selected, so that data can be distributed to the user at a lower cost. Conversely, even if viewed from the user side, the content data CD can be produced at lower cost.
Will be able to get. As described above, according to the first embodiment, it is possible to provide a data transmission system capable of delivering data with higher cost performance than a conventional data transmission system.

By the way, Japanese Patent Application Laid-Open No. 10-41976 discloses a method of selecting one communication line from a plurality of communication lines connecting a plurality of terminals according to the size of transmission data. . Accordingly, a data transmission system disclosed in Japanese Patent Application Laid-Open No. H08-140081 (hereinafter referred to as a conventional data transmission system) cited in the section of the prior art,
There is a possibility that the difference between the combination with the communication line selection method and the data transmission system according to the first embodiment will be discussed. However, in the combination of the conventional data transmission system and the communication line selection method, first, after a data transmission time is determined, a communication path for transmitting the data is selected. In such control, a situation in which the second data having a very large number of destinations must be transmitted while the first data having a small number of destinations (the number of users) is being transmitted through a communication line suitable for multicasting. In such a case, a communication line suitable for the multicast cannot be used, so that another communication line must be used for transmitting the second data. In other words, the second data is transmitted on a communication line relatively unsuitable for multicasting, so that a plurality of communication lines are not effectively used.

However, the data transmission of the first embodiment
The transmission system performs scheduling (step ST9).
, Each unit record UR that satisfies the first condition₁Against
Based on both the time limit LT and the above communication information.
The transmission timing of the transmission data TD and its transmission
Determine the communication line to be used. Specifically, the steps
According to ST921 to ST926, each unit record UR₁
For each transmission user number N _USERAnd transmission data size I_DS
Communication line used for data transmission is temporarily determined based on the
Is done. With such a tentative decision alone, the first and
And the same situation as the second data, that is,
Was originally multicast because of the data
Data that cannot be multicast
Therefore, the data transmission system has a communication suitability V_CR
Use to change the provisionally determined communication line to another communication line
(See steps ST94 to ST99).
Thereby, the first communication line 4 and the second communication line
5 is used effectively, that is, to smooth communication traffic
Time limit L specified by each user.
T can be guaranteed.

Further, according to the first embodiment, the server 6
Provides the user with the reservation status and download conditions of each content data CD using the reservation status data _DRS , and recruits users who wish to transmit the content data CD under the same download conditions. If the user finds a download condition that meets his wishes, the DTE 1 sends the reservation request RS including the DL condition number N _DL
Create and send a _TR . In response to receiving the reservation request RS _TR, the server 6 updates the unit record UR _1. At this time, as the number of users having the same download condition increases, the server determines that the transmission cost TC of the content data CD is higher.
As it is cheaper, to update the unit record UR _1. In this way, the user, by which joining to the reservation request RS _TR users who wish to transmit the content data CD previously can acquire the content data CD at a lower cost.

Further, even if the user cannot find a download condition that meets his / her wish, the more the time limit LT is set in the future, the lower the transmission cost TC of the server 6 becomes. to create a set unit record UR _1. This also allows the user to acquire the content data CD at a lower price.

In the first embodiment described above, the down
Explanation will be given by taking the time limit LT as an example of the load condition.
did. However, the download condition is transmission cost TC
And the number of sending users N_USERIt may be. The former place
In this case, step S in the scheduling process of FIG.
At T91, a unit record UR satisfying the first condition
₁The transmission cost TC set for each is predetermined.
After selecting a value below the specified value,
Step ST92 and subsequent steps are performed. In the latter case,
In step ST91 of FIG. 17, the first condition is satisfied.
Unit record UR₁As the transmission set for each
Number of trusted users N_USERIs greater than or equal to a predetermined value
Is selected, the processing after step ST92 is performed.
It is.

Further, in the first embodiment described above, the processing unit
The knit 61 has a reservation request RS shown in FIG._TRReceiving
In the case of receiving, the steps ST88 to ST811 of FIG.
Execute, new unit record UR₁Create and send
Destination list L_DESTDescribed as being added to. However
The unit record UR newly created is not limited to this. ₁
Unit record U that satisfies the following third condition
R₁Is the destination list L _DESTAlready exists in
Unit record UR₁May be performed. Third
Record UR that satisfies the condition₁Is a new unit
Code UR₁Time limit LT and transmission cost TC
And has a faster time limit LT,
Credit cost TC is set, and the same content
This specifies the data CD. In this case,
In the integration process, a new unit record UR₁Identification information
Report ID_USERIs a unit record UR that satisfies the third condition.₁
And the transmission cost TC is also updated.
The above integration process starts from the time limit LT set by the user.
As soon as the content data CD is stored in DCE3
Does not require disadvantages for the user, but rather
Users can download content data CDs cheaper
There is a merit in that it can be cut.

Further, when a plurality of unit records UR ₁ for the same content data CD exist in the transmission destination list L _DEST , the processing unit 61 may perform the following processing. In other words, the processing unit 61, the unit record UR ₁ closer time limit LT is the current time, even when the transmission expense TC is set cheaper than the other unit record UR _1, similar to the above integration processing You may do.

In the first embodiment, the DCE
3 responds to the read request RS _RO from DTE1,
It has been described only that the content data CD is transmitted to the DTE1. However, the processing unit 31 may delete the content data CD from the content storage unit 35 immediately after transmission or after a predetermined time has elapsed. Further, even if the read request RS _RO from the DTE 1 has not been transmitted, the processing unit 31 stores the content data CD in the content storage unit 35, and after a predetermined time elapses, stores the content data CD in the content storage unit 35. May be deleted. The deletion timing of the content data CD as described above is specified by the server 6 by adding it to the transmission data TD or registered in the DCE 3 in advance.

In the first embodiment, FIG.
The storage completion notification AS _CD has been transmitted to the DTE 1 by the DCE 3 as shown in the sequence SQ 8 of FIG.
After the transmission of the transmission data TD, a similar storage completion notification AS _CD
May be transmitted to DTE1. Further, in the first embodiment, the reservation status data D _RS has been transmitted to the DTE 1 via the DCE 3 as shown in a sequence SQ 1 of FIG. However, the present invention is not limited to this, and the user operates the DTE that is not connected to the DCE 3 to transmit the reservation status data D _RS
Refers to the, it may transmit a reservation request RS _TR from the DTE. However, even in this case, since the content data CD is stored in DCE3, the reservation request RS _TR, it is necessary to identify information ID _USER of DCE3 is set.

Further, in the first embodiment, the server 6
The description has been given as including the transmission destination list storage unit 65, the charging list storage unit 66, the transmission cost list storage unit 67, and the transmission initial cost list storage unit 68. However, the present invention is not limited to this, and the server merely performs creation and transmission of the reservation status data _DRS and transmission of the content data CD.
Other processing may be performed by another device accommodated in the data transmission network 7 or another server connected to the data transmission network 7.

Further, DCE3 is not only DTE1, but also
A telephone and / or facsimile may be configured to be connectable. In this case, the DCE 3 refers to information such as a service class added to telephone voice data and / or facsimile character data transmitted through the first communication line 4 or the like, and transmits the transmission data TD or the reservation data TD. preferentially over status data D _RS, distributes sound data and / or character data requires real time to the telephone and / or fax.

[0122] In the first embodiment, the processing unit 61, for each unit unit UR _1, as the transmission timing, the time limit LT is in the order closer to the current time, thereby when transmitting the specified content data CD explained. However, not limited thereto, the processing unit 61 as a transmission timing, each unit unit UR ₁ may determine the transmission time of the content data CD to be specified. However, even in this case, a transmission time at which the time limit LT can be guaranteed is determined.

Further, in the first embodiment, from the viewpoint of simplifying the description, each content data CD has the identification information ID.
It has been described that the content is stored in the content storage unit 64 with the _CD and the data size _IDS added. But,
The present invention is not limited to this. Only the content data CD is stored in the content storage unit 64, and when the processing unit 61 creates the transmission data TD, the unique identification information ID _CD
May be assigned to it and added.

In the first embodiment, one content data CD is transmitted from DCE 3 to DTE 1. However, the present invention is not limited to this.
3, in combination with the content data CD is designated, and another content data CD that is not specified by the read request RS _RO by the read request RS _RO, DT
It may be transmitted to E1. By combining and transmitting such a plurality of content data CDs, the following applications are possible. For example, DTE1 is a read request RS for content data CD representing a movie that the user wants to watch.
Assume that _RO is sent to DCE3. In response to the read request RS _RO , the DCE 3 combines and transmits the content data CD of the movie requested by the user and the content data CD representing the advertisement not requested by the user to the DTE 1, whereby the DTE 1 is transmitted.
Can display both movies and advertisements on their screens.

In the first embodiment, the content data CD includes moving image data, still image data, audio data,
Graphic data or character data, or two of them
It has been described as one or more combinations. However, the present invention is not limited to this, and a program for changing contents (characters and the like) represented by itself may be added to the content data CD. This allows the DTE 1 to change the contents (characters and the like) to be displayed on its own screen based on the instructions of the program. More specifically, the program is described so as to display the alphabet “A” in the first time zone, and “B” in the second time zone different from the first time zone. It is assumed to be written so as to display an alphabet. Under this assumption,
The DTE 1 executes the program and displays “A” in the first time zone and “B” in the second time zone.

As another example, it is assumed that DTE 1 transmits to DCE 3 a read request RS _RO for content data CD representing a WEB page (home page) that the user wants to browse. The DCE 3 combines the content data CD of the WEB page requested by the user with the content data CD representing the banner advertisement (or the link information to the advertisement) not requested by the user, and performs DT.
E1 so that DTE1 can display both the web page and the banner ad (link to the ad) on its screen. As a result, the information provider can obtain advertising revenue.

In the first embodiment, DTE1 is
The case where the pay content data CD is obtained via the DCE 3 has been described. However, the data transmission system also accommodates a server storing free content data. The server for such free content data does not particularly need to perform scheduling and charging as in the first embodiment, and simply transmits the free content data requested by the DTE1 to the DTE1 via the DCE3. Good. In this case, DCE3 is D
The frequency at which TE1 requests the same free content data is calculated. Furthermore, when the communication traffic of the first communication line 4 is low, the DCE 3 inquires whether free content data, which is frequently requested, has been updated in the server. The server, in response to such a query,
If the content data has been updated, the latest content data is transmitted to DCE3. DCE3
Stores the received latest content data in the content storage unit 35. Thus, DCE3 becomes DTE1
A cache process for acquiring new free content data may be performed autonomously irrespective of the transmission request. D
The TE1 is basically turned on and off by the user, whereas the DCE3 is always on, so that the DCE3 can spontaneously perform the above cache processing.

In the above cache processing, DC
There are the following methods for E3 to know that the communication traffic is low. First, the DCE 3 inquires the exchange 41 of the first communication line 4 about the current traffic,
There is a method of determining whether the current traffic is lower than a predetermined reference value. Also, the first communication line 4
One switch 41 notifies the DCE 3 of the current traffic, and the DCE 3 may determine whether the notified traffic is lower than the reference value. Other,
In general, it is well known that communication traffic of the first communication line 4 falls from midnight to dawn.
As a third method, the time included in the time period is D
The timer is preset in CE3, and the D
When the time set in the timer comes, the CE 3 performs a cache process.

Further, when the cache processing is performed, it is preferable that the recording area of the content storage unit 35 be divided into a plurality of partial recording areas. Further, one partial recording area is allocated to store paid content data CD, and another partial recording area is allocated to store free content data acquired by the DCE 3 by the cache processing. As a result, it is possible to prevent the recording area for storing the paid content data CD from being lost due to the cache processing.

When receiving a transmission request from DTE 1, DCE 3 determines whether or not the content data specified by the transmission request is stored in the other partial recording area. When the content data is stored in another partial recording area, the DCE 3 reads out the content data without accessing the server, and
Send to E1. With the above cache processing,
Since the DTE 1 can obtain the content data already stored in the DCE 3 before transmitting the transmission request, the user can quickly obtain the desired content data. In addition, since the cache processing is performed when the communication traffic is low, the communication traffic of the first communication line 4 can be smoothed with respect to time, and the transmission efficiency of the first communication line 4 can be reduced. It is possible to increase.

In the first embodiment, DCE3 is
It has been described that the pay content data CD is acquired from the server 6. However, the DCE 3 may perform a sharing process for sharing the free content data with another DCE 3. In order to realize the sharing of the content data, the DCE 3 (the data acquisition side) determines whether or not another DCE 3 has the content data that the DCE 3 wants to acquire (especially, the content data having a high request frequency described in the cache processing). Inquire about The other DCE 3 (data transmission side) responds to the inquiry by
E3 determines whether or not the content data to be acquired is stored therein, and if so, transmits it to DCE3 on the data acquisition side.

As another method for realizing the content data sharing process, there is the following method. That is, the server manages information indicating a list of content data held by each DCE 3 accommodated in the data transmission system, and transmits the list information to the DCE 3 on the data acquisition side. Thereby, the DCE 3 on the data acquisition side can know the DCE 3 (data transmission side) having the content data that it wants to acquire, and performs data communication with the DCE 3 on the data transmission side to acquire the content data. I do.

By sharing the content data described above, access to the server can be prevented from being concentrated, and the DCE 3 can obtain content data from the DCE 3 installed in the vicinity. Content data can be obtained quickly.

The DCE 3 requests to store the content data CD in another DCE 3 when the recording area of its own content storage unit 35 is insufficient or when it is desired to obtain the content data from the server. As a result, the other content storage unit 35 stores the D on the data acquisition side.
The content data for CE3 is stored. The DCE 3 on the data acquisition side, when there is room in its own recording area,
Data communication with another DCE 3 is performed to acquire target content data.

The above DCE3 has SMTP (Simplified
e Mail Transfer Protocol) and POP (Post Office
Protocol), and the DCE 3 may function as a mail server. Even when DCE3 functions as a mail server, regarding the delivery of e-mail,
As described above, it is preferably performed when the communication traffic of the first communication line 4 is low. However, for emails with a higher priority,
It is preferable that the DCE 3 distributes immediately regardless of the level of communication traffic. In addition, since the DCE 3 is always activated as described above, it is possible to always receive an e-mail. In this case, the DTE 1 executes the e-mail program and performs an operation for accessing the DCE 3 and acquiring the e-mail when the user performs an operation for receiving the e-mail. Thus, DT
E1 receives an e-mail from the DCE 3 installed in its vicinity without passing through the first communication line 4, so that the user can quickly read the e-mail.

Further, a program for realizing a firewall may be mounted on the DCE 3 described above.
The firewall can prevent malicious external users from entering the DCE3 and DTE1. More specifically, the DCE 3 internally stores a list of transmission sources, transmission destinations, and reception destinations permitted to transmit and receive data, and transmits data from transmission sources and transmission destinations not described in the list. Discard all incoming data. Furthermore, the DCE 3 discards all data to be transmitted to destinations not described in the list. As a result, the DTE 1 does not need to receive a so-called spam e-mail. In addition, by protecting the list with a password, it is possible to set so that the DTE 1 does not receive content data including sexual expression or violence when a child is operating the DTE 1. Furthermore, D
The CE 3 detects illegal data represented by a virus from the data transmitted and received by the line interface 33, and discards the illegal data or all transmitted and received data including the illegal data. This can prevent DTE1 from being infected with a virus.

Further, in the first embodiment, DCE3 is
In the description, the content data CD itself is transmitted to the DTE 1 in response to the read request RS _RO from the DTE 1. However, the DCE3 is not limited to this.
When functioning as a W server, a URL (Uniform Resource Locator) is allocated to the received content data CD and stored in the content storage unit 35. Furthermore, D
The CE 3 creates an HTML file in which the assigned URL and a brief description of each content data CD are described. This allows the user to use not only the DTE 1 connected to the DCE 3 via the transmission line 2 but also other devices (a personal computer,
It is also possible to refer to the favorite content data CD by using a mobile phone or an information portable terminal. In addition, the DCE 3 creates an e-mail in which the assigned URL and a brief description of each content data CD are described, and transmits the e-mail using an e-mail address designated in advance. In this case, the user sends the DCE 3
It is possible to refer to the content data CD that the user likes using not only the DTE 1 connected to the device but also other devices (a personal computer, a mobile phone, and a personal digital assistant) equipped with e-mail software. Also,
Whether to create an HTML file or an e-mail for each content data CD may be changed according to a user setting.

Next, a data transmission system according to a second embodiment of the present invention will be described. The basic configuration of the data transmission system according to the second embodiment is as shown in FIG. 1, and therefore, in the following description, the components corresponding to the configuration in FIG. To simplify.
In the following, in the data transmission system of the second embodiment, differences from those of the first embodiment will be described in detail.

First, the server 6 will be described. The server 6 has a configuration similar to that of FIG. However, the content storage unit 64 stores not the content data CD but FIG.
As shown in FIG. 3A, the difference is that several content data sets CDS are stored. FIG.
In (a), each content data set CDS includes:
Including the identification information ID _CDS, the data size I _DSS, a combination of several attribute information I _AT and the content data CD. The identification information ID _CDS uniquely specifies the storage location where the content data set CDS is stored (that is, the recording area in the content storage unit 64 of the server 6) in the data transmission system. Data size I
_DSS indicates the size of the content data set CDS. Attribute information _IAT is the same set of content data CD
Indicates the attribute of Since the content data CD is the same as that of the first embodiment, the description is omitted. Note that the content data set CDS is, as in the first embodiment,
Although the identification information ID _CD and the data size I _DS for each content data CD may be included, they are not essential in the second embodiment, so that illustration and description thereof are omitted.

Next, a specific example of the content data set CDS will be described. In the present embodiment, the content storage unit 6
4 includes the content data sets CDS ₁ and CDS
₂ is stored. The content data set CDS ₁
In this embodiment, it is assumed that the advertisement is prepared for advertisement of a store or a company. The content data set CDS _1, includes content data CD ₁₁ ~CD _1p of p number (p is a natural number of 1 or more) representing different contents of the advertisement to each other. The content data CD _11, the attribute information I _AT11 constituting the same set are added. Other content data CD ₁₂
Also ~CD _1p, like the content data CD _11, the attribute information I _AT12 ~I _AT1p constituting the same set are added.

Attribute information I_AT11Is the content data CD
₁₁The attribute information is information indicating the attribute of FIG.
As shown in (b), category information I_CA11, Name information I
_SP11, Product information I_GD11And Sell Price Information I_PR11Consists of
Category information I_CA11Is the same set of content data C
D₁₁Information indicating the category to which the advertisement represented by
It is. For example, category information I_CA11Is the type of advertiser
Is shown. Also, name information I_SP11Is the advertiser ’s store or
Indicates the name of the company. Product Information I_GD11Is the product to be advertised
Or indicate a service. Sell Price Information I_PR11Is advertised
Indicates the price of the product or service. In this embodiment,
Is attribute information I_AT11Is an attribute of advertising
It has been described as indicating the species, name, product, and price. Only
However, the present invention is not limited to these four types._AT11
Contains information indicating the number of items in stock
Good. Other attribute information I_AT12~ I_AT1pAlso, attribute information I
_AT11Similarly, the category information I_CA11~ I_CA1p, Name information
I_SP11~ I_SP1p, Product information I _GD11~ I_GD1pAnd selling price information
Report I_PR11~ I_PR1pConsists of

Next, the content data set CDS
_TwoAre prepared for news in this embodiment,
Q pieces of news (q is one or more)
Natural number) content data CD_{twenty one}~ CD_2qIf you include
Set. Content data CD_{twenty one}Have the same set
Attribute information I_AT21Is added. Other content data C
D _{twenty two}~ CD_2qAlso, content data CD_{twenty one}alike,
The same set of attribute information I _AT22~ I_AT2qIs added.
Attribute information I_AT21~ I_AT2qIs the content data CD _{twenty one}~
CD_2qInformation indicating the attributes of
As shown in FIG. 23 (c), the same set of content data
CD_{twenty one}~ CD_2qThe category to which the content represented by
Category information I indicating_CA21~ I_CA2qConsists of For example,
Category information I_CA21~ I_CA2qIs related to entertainment, economic,
A smaller news category represented by sports
Show Lee.

Next, the DCE 3 will be described. DCE
3 is a sorting condition list storage 36 as shown in FIG.
And a storage destination list storage unit 37, which is different from that of the first embodiment (see FIG. 2). The selection condition list storage unit 36 and the storage destination list storage unit 37 store the selection condition list _LSC and the storage destination list _LST (both will be described later).

Hereinafter, a communication procedure until the DTE 1 acquires the content data CD in the data transmission system having the above configuration will be described with reference to the sequence charts of FIGS. 25 and 26. First, the steps and the sequence of FIG. 25 are different from those of FIG.
1 and ST22 in that a sequence SQ21 is further provided. Other than that, there are some differences, but they are basically the same. Therefore, in FIG.
The same step numbers and sequence numbers are assigned to those corresponding to the steps and sequences described above, and the description thereof will be limited to differences. Also, the steps and sequence of FIG. 26 are different from those of FIG.
T11 and ST14 correspond to steps ST11 'and ST11.
14 in that the step ST23 is replaced with a step ST23. Otherwise, it is basically the same. Therefore, in FIG. 26, the same steps and sequences as those in FIG. 10 are denoted by the same step numbers and sequence numbers, and description thereof will be limited to differences.

First, in FIG. 25, the DTE 1 performs a selection condition setting request process in accordance with the operation of the user (step ST21). More specifically, the DTE 1
(A) As shown in FIG.
Display _SC on its own screen. The user operates the DTE 1 to input some keywords W _KEY to the selection condition input form IF _SC . Here, the keyword W _KEY means an attribute of the content data CD required by the user. For example, the user, advertising of food-related, if you want to select only those that include the lowest price is, the selection condition input form IF _FC, enter the keyword W _KEY to the intention of that effect. In response to the input of the keyword W _KEY , the DTE 1 creates a selection condition setting request RS _SCS . The selection condition setting request RS _SCS is a signal for requesting the DCE 3 to set a selection condition SC for causing the DTE 1 to output only the user-desired content data CD. At least, the identification information ID _SCS is input. And a keyword W _KEY . The identification information ID _SCS specifies that the signal is a selection condition setting request RS _SCS . As a result, the DCE 3 can grasp the content data CD that the user likes.

The above selection condition setting request RS_SCSIs DT
After being converted into a format suitable for the transmission line 2 by E1, FIG.
As shown in the sequence SQ21 of FIG.
The user interface 32 of the DCE 3 (see FIG. 2)
Received). Further, the selection condition setting request RS
_SCSIs converted to the original format by the user interface 32.
After receiving the conversion processing for
Received. The processing unit 31 has its identification information ID
_SCSCheck that the received signal is
Fixed request RS_SCSRecognizing that
Is performed (step ST22). Details of step ST22
FIG. 28 shows a simple processing procedure. In FIG.
Processing unit 31 receives the reception selection condition setting request RS_SCSFrom
Keyword W _KEYIs taken out (step ST221).
Next, the processing unit 31 outputs the retrieved keyword W
_KEYSelection condition number N unique to_SCAssign (step
ST222). Thereafter, the processing unit 31 determines the sorting condition.
Access the list storage unit 36 and select the current sorting condition number.
N_SCAnd keyword W_KEYThe combination of the cases
Sorting condition list L_SCAdd to (step
ST223). As a result, the sorting condition list storage unit 36
Is the selection condition number N as shown in FIG._SCEvery
Selection condition list L in which selection conditions SC are described_SCIs created
As a result, the DCE3 has the user-specified
The selected sorting condition SC is set.

When the above selection conditions have been set, the same communication and processing as in the first embodiment, that is, step S
T1 to ST10 and sequences SQ1 to SQ7 (FIG.
And FIG. 10) are performed in the data transmission system. It should be noted here that in the first embodiment, in steps ST1 to ST10, processing is performed in units of content data CD, but in the second embodiment, processing is performed not in units of content data CD, but in units of content data CD. The point is that processing is performed for each data set CDS. Therefore, to briefly explain, DTE1 is the reservation request RS
_{The TR} requests the server 6 to transmit the content data set CDS. Further, the server 6 performs scheduling and data transmission / charging processing for the requested content data set CDS. Therefore, the transmission data T transmitted in the sequence SQ7 of the second embodiment
D is the identification information ID when compared with that of FIG.
Instead of the _CD and the content data CD, the identification information I
It differs in that it includes _DCS and content data set CDS.

As described in the first embodiment, the transmission data TD is transmitted to the most suitable communication line (the first communication line 4 or the second communication line 5). Below,
For convenience, the description is continued on the assumption that the optimal communication line is the first communication line 4. Transmission data T on the first communication line 4
D is transferred to the processing unit 31 after being received by the line interface 33 of the DCE 3 via some exchanges 41. The processing unit 31 transmits the transmission data T
In response to the reception of D, data storage processing is performed (step ST11 '). FIG. 29 shows the detailed processing procedure of step ST11. FIG. 29 is different from FIG. 22 in that step ST111 is different from steps ST111 ′ and ST1.
It differs in that it replaces 12 '. Therefore, in FIG. 29, steps corresponding to those in FIG. 22 are denoted by the same step numbers, and description thereof is omitted. In FIG. 29, the processing unit 31 stores at least the content data set CDS in the received transmission data TD in a predetermined recording area in the content storage unit 35 (step ST111 ′). Here, the predetermined recording area is the one secured in step ST5.

[0149] Next, the processing unit 31 performs update processing of the storage destination list L _ST (step ST 112 '). More specifically, the identification information ID _CDS of the current content data set CDS, the address information I _ADD specifying the recording area where it is stored, and the date and time information I _ADD where it is stored
_DT (that is, the current date and time) is combined and added to the storage destination list _LST . Therefore, the storage destination list _LST includes
As shown in FIG. 30, address information I _ADD and date and time information I _DT are described for each content data set CDS stored in the content storage unit 35. Further, the storage destination list L _ST, space for writing recordable capacity C _REC showing the capacity to record the current data are prepared in advance in the content storage unit 35, the processing unit 31, after storing the current data Recordable capacity C in
To record the _REC in the storage destination list L _ST. Step S above
When T112 'ends, the processing unit 31 performs the processing of step ST112 and subsequent steps, and executes the storage completion notification AS _CD
Is transmitted to DTE1 (sequence SQ8).

After the end of step ST12, since the storage capacity C _REC of the content storage section 35 has decreased, the processing unit 31 performs a data deletion process (step S12).
T23). Step ST23 corresponds to the data deleting unit in the claims, and the detailed processing procedure is as shown in FIG.
Is shown in In Figure 31, the processing unit 31 obtains the current recordable capacity C _REC from the storage destination list L _ST (step ST231). Next, the processing unit 31
Is the current recordable capacity C _REC, is compared with the reference recording capacity C _REF predetermined, the reference recordable capacity C _REF is equal to or less than the recordable capacity C _REC (Step ST232).

The processing unit 31 has a reference recordable capacity C
_REFIs the current recordable capacity C_RECDetermined not to be
In this case, the recording area of the content storage unit 35 is still insufficient.
And store a new content data set CDS
Is determined, and the step ST23 ends without any processing. one
On the other hand, the processing unit 31 has a reference recordable capacity C_REFIs present
Current recordable capacity C_RECIf it is determined that:
The recording area of the contents storage unit 35 is becoming smaller.
Therefore, the process proceeds to Step ST233. Processing unit 3
1 is a storage destination list L_STOf the oldest storage date and time
Date and time information I shown _DTAnd the same set of addresses
Information I_ADDIs obtained (step ST233).

[0152] Next, the processing unit 31 from the recording area indicated by the obtained address information I _ADD, delete the content data set CDS to (erased) (step ST23
4). Further, the processing unit 31 stores the storage destination list L _ST
Is updated (step ST235). To be more specific, the processing unit 31, time information I _DT and the address information I _ADD and obtained in step ST233, it deletes the identification information ID _CDS in the same set with them from the storage destination list L _ST, further, The recordable capacity C _REC is updated to the value after deleting the content data set CDS.
When step ST235 is completed, the processing unit 31
Returns to step ST231. That is, the processing unit 31 _proceeds to step ST2 until the recordable capacity C _REC of the content storage unit 35 exceeds the reference recordable capacity C _REF.
The processing of 31 to ST235 is repeated. Thus, the content storage unit 35 always has at least a recording area for the reference recordable capacity C _REF .

Now, the DTE 1 sends the storage completion notification A
In response to receiving the S _CD, executes step ST12.
After step ST12, the user performs an operation necessary for reading the content data set CDS from the DCE3 on the DTE1 at his own convenience. In response to this operation, the DTE 1 creates a read request RS _RO (step ST13). In the present embodiment, the read request RS _RO is a signal for requesting the DCE 3 to read the content data set CDS specified by the user from the content storage unit 35.

The above read request RS _RO is transmitted from DTE1 to DCE3 as shown in sequence SQ9. The processing unit 31 of the DCE 3 transmits the read request R
In response to the reception of S _RO , the data transmission process of step ST14 'is performed. Step ST14 'corresponds to the data transmitting section in claim 22, and its detailed description is shown in FIG. First, the processing unit 31 acquires all the sorting conditions SC from the sorting condition list L _SC (see FIG. 27B) (step ST141 ′). Next, the processing unit 31 accesses the content storage unit 35, and sets the content data set C specified by the user.
From the DS, the content data CD that matches the obtained sorting condition SC is selectively read (step ST14).
2 '). Next, the processing unit 31 transmits the read content data CD to the DTE 1 via the user interface 32 and the transmission path 2 (step ST1).
43 '). DTE1 is the received content data CD
(Step ST15), whereby the contents represented by the content data CD are provided to the user.

In the above second embodiment, the user
Sorting condition that indicates the condition of the content data CD that you want
SC (see FIG. 27B) is set to DCE3. now,
The DCE3 has five sorting rules as shown in FIG.
It is assumed that the case SC is set. Further, the server 6
Reservation request RS_TRIn response to a plurality of content data C
D, the content data set CDS containing
It transmits to DCE3 at the timing determined by the ring. D
CE3 converts the received content data set CDS
Then, it is stored in the content storage unit 35. Now, as shown in FIG.
Content Data Set CDS₁And CDS_TwoBut
It is assumed that the content is stored in the content storage unit 35. In FIG.
As shown, the content data set CDS₁Identifies
Information ID _CDS1And its data size I_DSS1And four
Content Data CD₁₁~ CD₁₄Contains. further,
Content data CD₁₁Has a category called food-related
Category information I indicating_CA11With the XX supermarket
Name information I indicating the name _SP11And a product called radish
Product Information I_GD11And the product price I of 100 yen_{PR 11}When
Is added. Other content data CD₁₂~ CD
₁₄As shown in FIG._AT12(Category information
I_CA12, Name information I_SP12, Product information I_GD12, And goods
Price I_PR12) -I_AT14(Category information I_CA14, Name information
I_SP14, Product information I_GD14, And product price I_PR14Pair of
Alignment) is added. Also, the content data set
CDS_TwoIs the identification information ID_CDS2And its data size I
_DSS2And three content data CDs_{twenty one}~ CD_{twenty three}Including
In. Furthermore, the content data CD_{twenty one}The entertainment show
Category information I indicating the category of staff_CA21Is added
ing. Furthermore, the content data CD_{twenty two}And CD_{twenty three}
Contains category information I indicating a category of economic relations.
_CA22Information I indicating sports and sports relations_CA23With
Be added.

Under the above assumption, when the processing unit 31 performs the data transmission process (step ST14 ') according to the selection condition SC (see FIG. 27B), the content data CD ₁₁ , CD ₂₂ and CD ₂₃ shown in FIG. 34 are obtained. Is selected and transmitted from the user interface 32 to the DTE 1. In the example of FIG. 34, the content data CD ₁₁ , CD ₂₂
And each piece of information accompanying the CD ₂₃ is transmitted, but is essentially composed of the content data CD ₁₁ , CD ₂₂ and CD.
Only ₂₃ needs to be sent. According to the second embodiment described above, the user can set the selection condition SC in the DCE3, so that it is possible to efficiently refer only to the content data CD desired by the user.

In the second embodiment, the advertisement is
Content data CD to represent₁₁~ CD _1pAnd its attribute information
Report I_AT11~ I_AT1pWas set. However,
Notification attributes (product price and inventory status) and ad content
Content data set CDS₁But
After being transmitted to DCE3, some content data C
D₁And / or attribute information I_AT1Does not fit the current situation
In some cases. The server 6 for dealing with such a point
Is the content data CD₁And / or attribute information I
_AT1Information that is a signal to update the latest
Create a request and send it to DCE3. The information change request is
Identification information ID_CD1And the latest content data CD₁You
And / or attribute information I_AT1including. DCE3 is information
In response to receiving the change request, the identification information I of the information change request
D_CD1Using old content data CD₁and/
Or attribute information I_AT1Specify the recording area of the
Recording area, and delete the latest content.
Data CD₁And / or attribute information I_AT1Newly
The content is stored in the content storage unit 35. By the above processing,
Content Data Set CDS₁Don't send the whole thing
And some of the content data CDs₁And / or
Attribute information I_AT1It is possible to change only this
The first communication line 4 and the second communication line 5
Can be used effectively. What
In addition, the above information change request, at the time of scheduling,
The transmission timing should be such that the data is transmitted to DCE3 as soon as possible.
Preferably, the ringing is determined.

In the second embodiment, the DTE
1 is a content data set C including various news
When you get the DS _2, first, the reservation request RS _TR server 6
Was sent to. However, the content data set CD
For the S _2, the push technology, may be transmitted to the DTE 1. More specifically, the user of the DTE1, relative to the content creator data set CDS ₂ (e.g., newspaper), the content data set C
To subscribe to the distribution services of DS _2. In such a case, the creator side server, the server 6, the content data set CDS _2, and requests to send the DCE3 subscribers. At this time, the creator side server, the server 6 notifies the identification of the subscriber information ID _USER, the time limit LT and content data set CDS _2. Server 6
Is the notified subscriber identification information ID _{US ER} , time limit L
Use the T and content data set CDS ₂ generates transmission data TD.

In the second embodiment, when the recordable capacity C _REC of the content storage unit 35 becomes small,
The old content data set CDS has been deleted (see step ST23). However, the deletion timing of the content data set CDS is not limited to this, and the following two timings may be used. First, information indicating the expiration date of each advertisement is added to each content data set CDS. The DCE 3 deletes the content data set CDS when the expiration date added to each content data set CDS expires. Next, information indicating the creation date and time of each advertisement is added to each content data set CDS. The DCE 3 deletes the content data set CDS at a timing when a certain period has elapsed from the creation date and time added to each content data set CDS. The information indicating the expiration date and the creation date and time correspond to the deletion timing information in the claims.

In the second embodiment, the DCE
3 matches the selection condition SC when transmitting to DTE1
Only the content data CD from the content storage unit 35
It has been described that data is read and transmitted. However, only this
Instead, the processing unit 31 sets the content data set C
When receiving the DS, the content data that matches the selection condition SC
Data CD only and select it and retrieve it.
5 may be stored. Further, the processing unit 31
Discard the content data CD that does not match the different condition SC
You. In this case, the processing unit 31 reads from the DTE1.
Extrusion request RS _ROIn response to the
Reads the content data CD from the content storage unit 35
Then, it transmits to DTE1. This allows the user to
You can get only the content data CD you want
And unnecessary content data CDs
The recording area is not stored in the
Can be used.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a data transmission system according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a line termination device (DCE) 3 shown in FIG.

FIG. 3 is a block diagram showing a configuration of a content server 6 shown in FIG.

FIG. 4 is a diagram showing a structure of content data CD stored in a content storage unit 64 shown in FIG.

FIG. 5 is a schematic diagram of a destination list L _DEST stored in a destination list storage unit 65 shown in FIG. 3;

FIG. 6 is a schematic diagram of a charging list L _PAY stored in a charging list storage unit 66 shown in FIG. 3;

7 is a schematic diagram of the transmission expense list L _TC stored in transmission expense list storage unit 67 shown in FIG.

FIG. 8 shows an example of the transmission initial cost list storage unit 68 shown in FIG.
Initial cost list L to be sent _ITCFIG.

FIG. 9 is a first half of a sequence chart showing a communication procedure in the data transmission system shown in FIG. 1;

FIG. 10 is a latter half of a sequence chart showing a communication procedure in the data transmission system shown in FIG. 1;

FIG. 11 is a flowchart showing a detailed processing procedure of step ST1 shown in FIG. 9;

FIG. 12 is a diagram for explaining the contents of reservation status data _DRS shown in FIG. 9;

FIG. 13 is a diagram for explaining the structure of each data and signal shown in both FIGS. 9 and 10;

FIG. 14 is a flowchart showing a detailed processing procedure of step ST13 shown in FIG.

FIG. 15 is a flowchart showing a detailed processing procedure of step ST8 shown in FIG.

16 is a diagram showing a unit record UR ₁ is updated or newly created at step ST8 shown in FIG. 15.

FIG. 17 is a flowchart showing a detailed processing procedure of step ST9 shown in FIG. 10;

FIG. 18 is a flowchart showing a detailed processing procedure of step ST92 shown in FIG.

FIG. 19 is a view for explaining a communication line flag F _CIR set by the processing of FIG. 18;

20 is a diagram for schematically explaining the processing of steps ST94 to ST99 in FIG. 17;

FIG. 21 is a flowchart showing a detailed processing procedure of step ST10 shown in FIG.

FIG. 22 is a flowchart showing a detailed processing procedure of step ST11 shown in FIG.

FIG. 23 is a diagram for describing a content data set CDS in the second embodiment.

FIG. 24 is a block diagram showing a configuration of a DCE 3 according to the second embodiment.

FIG. 25 is a first half of a sequence chart showing a communication procedure in the data transmission system of the second embodiment.

FIG. 26 is a sequence chart showing a communication procedure in the data transmission system of the second embodiment.

FIG. 27 is a diagram for explaining a selection condition list L _SC stored in the selection condition list storage unit 36 shown in FIG. 24.

FIG. 28 is a flowchart showing a detailed processing procedure of step ST22 shown in FIG.

FIG. 29 is a flowchart showing a detailed processing procedure of step ST11 ′ shown in FIG.

30 is a diagram showing a storage destination list L _ST stored in the storage destination list storage unit 37 shown in FIG. 24.

FIG. 31 is a flowchart showing a detailed processing procedure of step ST23 shown in FIG. 26;

FIG. 32 is a flowchart showing a detailed processing procedure of step ST14 ′ shown in FIG. 26.

FIG. 33 is a diagram showing a specific example of a content data set CDS stored in the content storage unit 35 shown in FIG.

FIG. 34 is a diagram showing a specific example of content data CD transmitted from the user interface 32 shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Data terminal device (DTE) 3 ... Line termination device (DCE) 31 ... Processing unit 32 ... User interface 33 ... Line interface 34 ... Receiving unit 35 ... Content storage part 4 ... 1st communication line 41 ... Switching device 5 ... Second communication line 6 ... Content server 61 ... Processing unit 62 ... Line interface 63 ... Transmission unit 64 ... Content storage unit 65 ... Destination list storage unit 66 ... Charging list storage unit 67 ... Transmission cost list storage unit 68 ... Transmission initial cost storage

Claims (34)

[Claims] 1. A data transmitted by a server to one of a plurality of communication lines in order to store content data specified by a reservation request of a data terminal device in a line termination device connected to the data terminal device. In the transmission system, the reservation request further specifies a time limit at which the content data specified by the data terminal device must be stored in the line terminating device, and the server or the communication line Either, a time limit management unit that manages a time limit specified by a reservation request from the data terminal device, a time limit managed by the time limit management unit, and both predetermined communication information as a basis. A transmission timing of the content data for guaranteeing the time limit and a schedule for determining an optimum one from among the plurality of communication lines. A-ring portion, wherein the server, according to the transmission timing determined by the scheduling unit, the optimal communication line, a data transmitting unit for transmitting the content data, the data transmission system. 2. The data according to claim 1, wherein the predetermined communication information includes at least a size of the content data specified by the reservation request or a number of data terminal devices to which the content data is transmitted. Transmission system. 3. The data transmission system according to claim 1, wherein the line termination device operates by receiving power supply from any of the communication lines. 4. The line termination device, wherein a content storage unit for storing content data transmitted via the optimal communication line in an internal storage area, and a read request from the data terminal device. The data transmission system according to claim 1, further comprising: a data transmission unit that reads out the content data from the content storage unit and transmits the content data to the data terminal device. 5. The data transmitting unit further reads the content data specified by the read request,
The data transmission system according to claim 4, further comprising: reading content data not specified by the read request; combining the plurality of content data; and transmitting the combined content data to the data terminal device. 6. The data transmission system according to claim 4, wherein the line termination device transmits a storage completion notification indicating that received content data has been stored in the storage area to the data terminal device. 7. The storage completion notification is sent in HTML (Hyper T
The data transmission system according to claim 6, wherein the data transmission system is in ext Markup Language (ext Markup Language) format. 8. The data transmission system according to claim 6, wherein the storage completion notification is an electronic mail. 9. The line termination device can transmit the storage completion notification in a plurality of types of formats, and the storage completion notification transmitted to the data terminal device is set by a user of the data terminal device. The data transmission system according to claim 6, wherein: 10. An area management device that manages a storage area of the line termination device is accommodated in at least one of the plurality of communication lines, and the area management device responds to a request from the server. 5. The data transmission system according to claim 4, wherein in response to the request, the line terminal transmits an area securing instruction for instructing securing of a storage area for the content data. 11. The line terminating device performs a cache process and inquires of the server whether or not content data requested frequently by the data terminal device has been updated. 5. The data according to claim 4, wherein in response to an inquiry from the server, the updated content data is transmitted to the line termination device, and the line termination device stores the content data received from the server in a content storage unit. Transmission system. 12. The data transmission system according to claim 11, wherein said line terminating device makes an inquiry to a server in said cache processing when communication traffic of said communication line is low. 13. The recording area of the content storage unit,
The line termination device is configured to store the content data obtained by using the reservation request and the content data obtained by the cache processing in the partial storage areas different from each other in the content storage unit. The data transmission system according to claim 11, wherein the data transmission system stores the data. 14. The apparatus according to claim 4, further comprising a plurality of said line terminating devices, wherein one of the line terminating devices acquires content data stored in a content storage section of another line terminating device. Data transmission system. 15. The data transmission system according to claim 1, wherein a protocol for functioning as a mail server is mounted on the line terminal, and the line terminal transmits and receives electronic mail. 16. The data transmission system according to claim 15, wherein said line termination device sends said electronic mail to said communication line when communication traffic of said communication line is low. 17. The electronic mail is given a priority indicating its importance, and the line terminating device sends the electronic mail to the communication line according to the priority of each of the electronic mails. 17. The data transmission system according to claim 16, wherein 18. A server sends out content data specified by a reservation request from a data communication terminal to any one of a plurality of communication lines in order to store the content data in a line terminal connected to the data terminal device. In the data transmission method, the reservation request further specifies a time limit at which content data specified by itself must be stored in the line terminating device, and the server or the communication line A management step of managing a time limit specified in a reservation request of the data terminal device; and a content that guarantees the time limit based on both the time limit managed in the management step and predetermined communication information. A data transmission timing; and a scheduling step of determining an optimum one from among the plurality of communication lines. The server according to the transmission timing determined by the scheduling step, the optimal communication line, and a data transmission step of transmitting the content data, the data transmission method. 19. A data transmission system in which a server sends out content data specified by a reservation request from a data terminal device to a communication line in order to transmit the content data to the data terminal device. Further, a download condition of the content data specified by the data terminal device is specified, and a reservation status data creating unit that creates reservation status data indicating download conditions for each content data based on the received reservation request; A data transmission unit that transmits the reservation status data created by the reservation status data creation unit to the data terminal device, whereby the reservation from the data terminal device that desires to receive the same content data under the same download condition is provided. Request for a request, and the content specified by the reservation request from the data terminal device. DL to manage Tsudeta and download conditions
A condition management unit, a scheduling unit that determines the transmission timing of the content data based on the download condition managed by the DL condition management unit, and that determines the transmission timing of the content data. A data transmission system, further comprising: a data transmission unit that transmits content data to the communication line. 20. The data transmission system according to claim 19, wherein the download condition is a time limit at which content data specified by the data terminal device must be stored in the line terminal device. 21. Receiving a reservation request from the data terminal device and, according to the number of data terminal devices wishing to receive the same content data by the same time limit, reduce the cost required for transmitting the content data. The data transmission system according to claim 20, further comprising a reception processing unit for determining. 22. If the reservation request from the data terminal device specifies a time limit not indicated in the reservation status data, the reception processing unit may further perform processing from the current time to the time limit. 22. The data transmission system according to claim 21, wherein a cost required for transmitting the content data specified by the reservation request is determined according to the grace time. 23. The download condition is a cost required for the data terminal device to transmit the content data designated by the reservation request, and is a data requesting the same content data by receiving the reservation request from the data terminal device. According to the number of terminal devices, further comprising a reception processing unit that determines a cost required for transmitting the content data, the data transmission unit is configured to reduce the cost determined by the reception processing unit to a predetermined value or less. 20. The data transmission system according to claim 19, wherein when it has become, the content data specified by the reservation request is transmitted to the communication line. 24. The download condition is the number of data terminal devices requesting the same content data, the number of data terminal devices receiving a reservation request from the data terminal device and desiring to receive the same content data. Further comprising: a reception processing unit that determines a cost required for transmitting the content data, wherein the number of reservation requests received by the reception processing unit is equal to or greater than a predetermined value. 20. The data transmission system according to claim 19, wherein in such a case, the content data specified by the reservation request is transmitted to the communication line. 25. A method in which a server sends content data designated by a reservation request from a data terminal device to a communication line and transmits the content data to the data terminal device, wherein the reservation request further comprises: A reservation condition data creating step of creating reservation condition data indicating download conditions for each content data based on a received reservation request, wherein the download condition of the content data designated by the data terminal device is specified; A data transmission step of transmitting the reservation status data created in the data creation step to the data terminal device, whereby a reservation request from the data terminal device that desires to receive the same content data under the same download condition is provided. The computer designated by the reservation request from the data terminal device. DL to manage Ntsudeta and download conditions
A condition management step; a scheduling step of determining a transmission timing of the content data, which guarantees the download condition based on the download condition managed in the DL condition management step; and a transmission timing determined in the scheduling step, A data transmission step of transmitting content data to the communication line. 26. A server for transmitting a content data set designated by a reservation request from a data terminal device to one of a plurality of communication lines in order to store the content data set in a line termination device connected to the data terminal device. The content data set includes a plurality of different content data, and the reservation request further includes a content data set designated by the data terminal device stored in the line termination device. A time limit that must be set, and either the server or the communication line manages a time limit specified by a reservation request from the data terminal device; and the time limit. The time limit is retained based on both the time limit managed by the management unit and the predetermined communication information. A scheduling unit that determines a transmission timing of a content data set to be transmitted and an optimal one from among the plurality of communication lines, and wherein the server determines an optimal communication line according to the transmission timing determined by the scheduling unit. A data transmitting unit for transmitting a content data set, wherein the line terminating device is connected to the plurality of communication lines, and a predetermined selection is performed from the content data set received from the optimal communication line. A data transmission system that reads out only content data that meets a condition and transmits the content data to the data terminal device. 27. The line termination device, which is connected to the plurality of communication lines, stores a content data set received from the optimum communication line, and receives a read request from the data terminal device. 27. A data transmission unit which reads only content data which meets a predetermined selection condition from the content storage unit in response, and transmits the content data to the data terminal device.
2. A data transmission system according to claim 1. 28. Each of the content data included in the content data set is added with attribute information indicating an attribute of the content data set, and the line terminating device sets an attribute of the content data to be transmitted to the data terminal device. Further comprising a selection condition list storage unit for storing a selection condition list in which the selection conditions based on the selection condition are described, wherein the data transmission unit stores the content from the content storage unit according to the selection condition list stored in the selection condition list storage unit. 28. The data transmission system according to claim 27, wherein data is read and transmitted to said data terminal device. 29. The data transmission system according to claim 28, wherein the selection condition list is created based on a keyword input to the data terminal device by a user. 30. The data transmission system according to claim 27, wherein the line termination device further includes a data deletion unit that deletes a content data set stored in the content storage unit at a predetermined timing. 31. The data deletion unit deletes a content data set when a recordable capacity capable of storing a content data set in the content storage unit becomes smaller than a predetermined reference recordable capacity.
The data transmission system according to claim 30. 32. Each of the content data sets includes:
31. The data deletion unit according to claim 30, wherein deletion timing information serving as a basis for deleting itself is added, and the data deletion unit deletes the content data set according to the deletion timing information added to each content data set. Data transmission system. 33. The line terminating device is connected to the plurality of communication lines, and stores only content data that matches a predetermined selection condition from a content data set received on the optimal communication line. 27. A content storage unit that reads content data stored in the content storage unit in response to a read request from the data terminal device, and transmits the content data to the data terminal device. 2. A data transmission system according to claim 1. 34. A server for transmitting a content data set designated by a reservation request from a data terminal device to one of a plurality of communication lines in order to store the content data set in a line termination device connected to the data terminal device. The content data set includes a plurality of different content data, and the reservation request further stores the content data set specified by the data terminal device in the line termination device. A time limit that is required to be specified, and either the server or the communication line manages a time limit specified by a reservation request from the data terminal device; and the time limit. The restriction is based on both the time limit managed in the management step and the predetermined communication information. And the transmission timing of the content data set to ensure the time,
Determine an optimal one from among the plurality of communication lines,
A data transmission step of transmitting a content data set to an optimal communication line in accordance with the transmission timing determined in the scheduling step, wherein the line terminating device comprises a plurality of communication lines. A data transmission system that is connected to the data communication apparatus and reads only predetermined content data from a content data set received on the optimal communication line and transmits the content data to the data terminal device.