JP3351118B2 - Data transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device such as a video server for transmitting data such as a video signal in response to a request from a terminal.

[0002]

2. Description of the Related Art In recent years, with the advancement of broadcasting services such as CATV, aircraft, and hotels, so-called video-on-demand services (hereinafter referred to as "on-demand services"), which provide programs according to the needs of individual users instead of unilateral broadcasting. , VOD) has begun. In order to realize VOD, it is necessary to prepare and accumulate many programs and transmit data such as video signals in response to a request from a terminal. An ideal system requires the same number of channels as the terminal. In urban CATV where the number of terminals reaches tens of thousands, such a system is not practical, and a limited VOD channel (hereinafter abbreviated as VOD channel) is provided and services are provided within that range. It is common to do. In other words, if all the VOD channels are used, the state is the same as when the telephone is busy, and the VOD
Viewers who want to receive the service will have to wait until the channel becomes available. When such a service is put to practical use, there is a demand for a system that can obtain the highest possible viewer satisfaction within a limited range of resources such as channels.

[0003] A conventional data transmission device will be described below. FIG. 5 is a block diagram of a conventional data transmission device.

The receiving means 501 receives a data request from a terminal, and generates request source information such as the address of the terminal that has requested data and a data read request. The destination setting means 502 generates destination information such as a destination address of data based on the request source information. Storage means 50
Reference numeral 4 includes a tape, an optical disk, a hard disk, and the like, and stores data such as video signals. Reading means 503
Reads out necessary information from the storage means in accordance with the read request and outputs it to the sending means 505 as sending data. The sending means 505 sends out sending data to the terminal specified in the sending destination information.

[0005]

However, in the above-mentioned conventional configuration, the use of the transmitted data is limited to the terminal that has requested the data, so that another terminal, for example, the same data is requested with a slight time difference. Terminal
Since the same control procedure is repeated to transmit data, other terminals are sent until the data transmission to the previous terminal is completed.
There is a problem that the data is not transmitted and the channel use efficiency is deteriorated.

[0006] The present invention solves the above-mentioned conventional problems, and improves the efficiency of use of channels and the like without impairing performance such as response time to a request from a terminal, thereby realizing higher user satisfaction. A data transmission device is provided.

[0007]

According to a first aspect of the present invention, there is provided a data transmitting apparatus for storing data, receiving a data request from a terminal,
Receiving means for generating a read request, request source information including at least the address of the terminal which has issued the data request, reading data from the storage means in accordance with the read request, transmitting the data as transmission data, and transmitting at least transmission preparation completion information Reading means for generating a preparation completion notification; destination setting for determining a valid terminal that has received a request before completion of transmission preparation from the transmission preparation completion notification and request source information, and generating destination information including at least the address of the valid terminal Means,
Transmission means for transmitting transmission data to an effective terminal according to the transmission destination information.

[0008] A data transmitting apparatus according to a second aspect of the present invention is a storage means for storing data, a data request received from a terminal, a read request, and a request including at least an address of the terminal which issued the data request. Receiving means for generating source information, reading means for reading data from the storage means in accordance with the read request, and sending the data as transmission data, reading completion time for estimating the data transmission preparation completion time from the request source information, and generating a transmission preparation completion prediction Prediction means; destination setting means for estimating a valid terminal that has received a request before the transmission preparation completion time from transmission preparation completion prediction and request source information, and generating destination information including at least the address of the valid terminal; Transmission means for transmitting transmission data to an effective terminal according to the information.

A data transmitting apparatus according to a third aspect of the present invention includes a storage unit for storing data, a data request from a terminal, a read request, and a request including at least an address of the terminal that issued the data request. Receiving means for generating original information, reading means for reading data from the storage means in accordance with the read request and sending it out as transmission data, and generating a transmission preparation completion notification including at least transmission preparation completion information, and request source information per unit time And the density determination means for generating a density reduction notification when the value falls below a predetermined value, and the data transmission preparation is completed from the transmission preparation completion notification, the request source information and the density reduction notification. And determines the valid terminal that has received the request before the time of occurrence of the density reduction notification, and generates transmission destination information including at least the address of the valid terminal. And the destination setting unit that, in accordance with the destination information, and a sending means for sending the transmission data data to terminals that need, has a configuration that.

[0010]

According to the first aspect of the present invention, with the above-described configuration,
The data to be transmitted in response to a request from one terminal is also transmitted to another terminal that has requested the same data during the period until the preparation for transmission is completed.

Further, according to the second aspect of the present invention, with the above-described configuration, data to be transmitted in response to a request from one terminal is requested to have the same data by a time when it is predicted that transmission preparation is completed. It will also be sent to another terminal that has been.

Further, according to the third aspect of the present invention, with the above-described configuration, data to be transmitted in response to a request from one terminal can be transmitted up to a predetermined frequency of a terminal requesting the same data. During the falling period, the same data is transmitted to another terminal that has requested the same data.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a data transmitting apparatus according to the first embodiment of the present invention. In FIG. 1, 101 is a receiving unit, 102 is a destination setting unit, 103 is a reading unit, 104 is a storage unit, and 105 is a sending unit.

The operation of the data transmission apparatus of the present embodiment configured as described above will be described below. Figure
In step 1, the accepting unit 101 accepts a "data request" from many connected terminals, requests the reading unit 103 to read the requested data by a "read request", and an address of the terminal that has requested the data. The “request source information” including the above information is sent to the destination setting unit 102. The reading means 103 reads the data from the storage means 104 based on the "read request" and sends the data or the head of the data to the sending means 105 as "transmission data", and also completes the preparation for reading the data or the head of the data. Judgment is made and a “delivery preparation completion notification” is sent to the destination setting means 102. Destination setting means 102
Determines one or more destinations of “transmission data” from the “request source information” and the “transmission preparation completion notification”, and sends the destination to the transmission unit 105 as “transmission destination information”. The sending means 105 sends data to the terminal according to the "destination information".

FIG. 4 is a timing chart showing the operation of the data transmission device according to the first embodiment of the present invention. In this example, for two data, X and Y, a total of seven terminals, A
-There is a request from G, the requests from five of the terminal AEs are valid, processed as two sets of data transmission by the effect of the present invention, the requests from the remaining two terminals are processed as separate requests Have been. That is, the reading means 103 starts reading the data X in response to the request from the terminal A which is received at the first time. Also, at time, there is a request for data Y from terminal B, and reading means 103 prepares in parallel. Then, 3
Requests for data X from the terminals C, D, and F, respectively,
First, the request for the data Y from the two terminals E and G occurs at the respective times or times. Terminals C and D request data X
The data X is transmitted to the terminals A, C, and D all at once at the time when the preparation for the transmission is completed, since the reception was previously received. Similarly, at the time, the data Y
Are sent to terminals B and E all at once. On the other hand, the request for the data X from the terminal F is accepted at or after the time, so that it is processed as another data request and transmitted using another channel. The same applies to the request for data Y from terminal G.

As described above, according to the present embodiment, the data X request from the terminal A can be shared with the requests from the terminals C and D without causing side effects such as delay in transmission. And three channels can be provided on one channel.

FIG. 2 is a block diagram showing a configuration of a data transmission device according to a second embodiment of the present invention. In FIG. 2, reference numeral 202 denotes a transmission destination setting unit, 203 denotes a reading unit, and 206 denotes a reading notification prediction unit.
01, 104, and 105) are similar to the configuration of FIG. Figure 2
Therefore, the reading means 203 does not generate the “transmission preparation completion notification”,
The read notification prediction means 206 predicts the completion of the data transmission preparation based on the "request source information" from the reception means 101, and generates "transmission preparation completion prediction". The transmission destination setting means 202 starts a process equivalent to the “transmission preparation completion notification” in the embodiment of the first invention with this “transmission preparation completion prediction”. Subsequent operations are the same as those of the first embodiment. According to the embodiment of the second invention, in addition to the effects of the embodiment of the first invention, a communication amount with the reading means can be reduced, and a system which can estimate the time required for reading statistically, This is effective for a system in which the reduction in the amount of communication between means is effective for cost reduction.

FIG. 3 is a block diagram showing a configuration of a data transmission device according to a third embodiment of the present invention. In FIG. 3, reference numeral 302 denotes a transmission destination setting unit, 307 denotes a density determination unit, and other components (101, 103, 104, 105)
Is similar to the configuration of FIG. In FIG. 3, the density determination means
Reference numeral 307 measures the number of data requests per unit time, that is, the reception density, and generates a “density reduction notification” when the value falls below a predetermined value. Destination setting means 302
Is a “sending preparation completion notification” similar to that of the first embodiment.
When both of the notification of “density decrease notification” of the present embodiment are received, it is determined that the reception is completed, and one or more destinations of “transmission data” are determined as in the first embodiment of the present invention. Then, the information is sent to the sending means 105 as “destination information”. According to the third embodiment of the present invention, in addition to the effects of the first embodiment of the present invention, while there is a frequent request for the same data, the reception of the request is extended so that the response time of a movie or the like is increased to some extent. Can afford more effective use of one channel.

[0020]

As described above, according to the first aspect of the present invention, data transmitted in response to a request from one terminal is
The same data can be transmitted to another terminal that has requested the same data until the transmission preparation is completed, without causing side effects such as transmission delay, and can be transmitted to multiple terminals using one channel. Service can be realized.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the communication amount of the reading means can be reduced, and the time required for reading statistically can be estimated. It is possible to realize, at a lower cost, a system that can be used and a system in which the reduction in the amount of communication between means is effective for cost reduction.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, the reception of requests is extended while requests for the same data are frequently made,
If you can afford some response time, such as a movie,
More effective utilization of one channel can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data transmission device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a data transmission device according to a second embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of a data transmission device according to a third embodiment of the present invention;

FIG. 4 is an operation timing chart of the data transmission device according to the first embodiment of the present invention;

FIG. 5 is a block diagram showing a configuration of a data transmission device in a conventional example.

[Explanation of symbols]

 101, 501 Reception means 102, 202, 302, 502 Destination setting means 103, 203, 503 Reading means 104, 504 Storage means 105, 505 Transmission means 206 Read notification prediction means 307 Density determination means

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shotaro Tanaka 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (56) References JP-A-8-23531 (JP, A) JP-A-7-321572 (JP, A) JP-A-8-18945 (JP, A) JP-A-8-32601 (JP, A) Special table Hei 9-510327 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 29/00 H04N 7/00 H04L 12/00

Claims (1)

(57) [Claims] 1. A storage unit for storing data, a receiving unit for receiving a data request from a terminal, and generating a read request and request source information including at least an address of a terminal that has issued the data request. Reading means for reading data from the storage means in accordance with the read request, transmitting the data as transmission data, and generating a transmission preparation completion notification including at least transmission preparation completion information; and the request source per unit time. Density determination means for measuring the number of information, and generating a density reduction notification when the value falls below a predetermined value; data from the transmission preparation completion notification, the request source information and the density reduction notification; Destinations that have completed preparation for sending data and that have received a request before the time of occurrence of the density reduction notification, and that generate destination information including at least the address of the valid terminal. A constant section, in accordance with the delivery destination information, de - said delivery de the terminals that need data - de and a sending means for sending the data - data sending device.