JPH04280340A - Information supply system - Google Patents

Abstract

PURPOSE:To effectively use limited resources and to continue the supply of information to the other low-order layer when a release request is generated while information from the low-order layer is supplied. CONSTITUTION:Counter groups 11, 21a and 21b, whose number corresponds to the number of self information (m), (n) and (k) are provided for information centers 10, 20a and 20b. The information centers 10, 20a and 20b respectively reset the counter groups 11, 21a and 21b to a value '0' at the start time of a system, increases the counter of information concerned by one whenever the supply of information to the low-order layer is started and the counter of information concerned is decreased by one when the supply of information is completed and released. When the low-order layer releases the supply of information, the information centers 10, 20a and 20b continue the supply of information when the count value is not '0', and stops the accumulation of information when the count value is '0'. Then, the centers issue the release request of the supply of information to high-order information centers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information supply system that individually supplies information such as music and moving images to each user terminal in response to requests from a large number of user terminals.

0002

2. Description of the Related Art In recent years, systems have been developed in which information such as music and videos is distributed and stored in several information centers, and the information centers supply information in response to requests from user terminals. Conventionally, in this type of information supply system, a group of information that is requested most frequently is stored in the lowest layer information center, and a group of information that is requested least frequently is stored in the top layer information center and communicated with each information center. The user terminals are arranged in a tree-like multi-layer structure, and the probability that each information center becomes incapable of processing is averaged out to significantly reduce the total information capacity of all the information centers.

FIG. 6 is a block diagram showing a conventional information supply system, and FIGS. 7 and 8 are flowcharts for explaining the start and stop operations of information supply in the information supply system of FIG. 6, respectively. As shown in FIG. 6, this system includes an upper layer information center 1 at the top layer, lower layer information centers 2a and 2b at the middle layer as a whole system, and user terminals 3a to 3d at the lowest layer as a whole system. is composed of multiple tree-like layers. In FIG. 7, when an information reproduction request is issued from the lowest layer, for example, the user terminal 3d, to the lower layer information center 2b (step S1).
If the requested information does not exist in the lower layer information center 2b (step S2), the lower layer information center 2b requests the information from the upper layer information center 1 and stores the information from the upper layer information center 1. Start (step S3). Then, playback of the stored information is started and supplied to the lowest layer user terminal 3d (step S4), and this playback start processing is ended (step S5).

Here, as shown in FIG. 8, while the lower layer information center 2b is accumulating information from the upper layer information center 1, the user terminal 3d that requested the information cancels the request. When the lower layer information center 2b issues a cancellation request (step S6), the lower layer information center 2b stops supplying information (step S7), and also stops storing information and cancels the information supply to the upper layer information center 1. By issuing the request (step S8), limited resources are used effectively. In this case, the lower layer information center 2b generally requests the upper layer information center 1 to cancel information supply when the user terminal 3d issues the cancellation request.

Furthermore, while the lower layer information center 2b is storing information from the upper layer information center 1, if another user terminal 3c requests the information, the lower layer information center 2b transfers the stored information to that user. It is supplied to the terminal 3c.

[0006]

[Problems to be Solved by the Invention] However, in the conventional information supply system described above, when the lower layer information center 2b requests the upper layer information center 1 to cancel the information supply, when one user terminal 3d issues a cancellation request. I will do it, so
While the lower layer information center 2b is accumulating information from the upper layer information center 1, if another user terminal 3d issues a release request, the lower layer information center 2b will send the information to the upper layer information center 1. There is a problem in that the supply of information to the user terminal 3c that has issued the request for cancellation of supply and subsequently requested it is stopped.

As shown in FIG. 8, even if one user terminal 3d issues a cancellation request, the lower layer information center 2b
Although the above-mentioned problem can be solved by configuring the upper layer information center 1 not to request cancellation of information supply to the upper layer information center 1, there is a problem that limited resources cannot be used effectively.

Therefore, the present invention makes it possible to effectively utilize limited resources, and to continue supplying information to other lower layers when a release request occurs during information supply from a lower layer. The purpose is to provide an information supply system.

[0009]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, when a user terminal requests information that has not been stored, a lower layer information center receives information from an upper layer information center and provides information to the user. If a release request is received from a user terminal during supply, it is determined whether the information is being supplied to another user terminal, and if the information is not being supplied, a release request is issued to the upper information center. do. That is, according to the present invention, a plurality of user terminals placed in the lowest layer receive information, and information groups for which information requests from the user terminals occur with a relatively high frequency are accumulated, and each of the information groups is A lower layer information center that supplies information in response to an information request from the user terminal, and information that stores a group of information for which information requests from the user terminal occur relatively infrequently and that is not stored in advance in the lower layer information center. When the user terminal requests the lower layer information center, the information is supplied to the lower layer information center, and when a cancellation request to stop the information supply is received from the lower layer information center, the information is supplied. and an upper layer information center that stops the information, and the lower layer information center receives information from the upper layer information center and supplies it to the user terminal when the user terminal requests unstored information. , when a release request is received from the user terminal during supply, it is determined whether the information is being supplied to another user terminal, and if the information is not being supplied, a release request is issued to the upper information center. An information supply system having a release means is provided.

0010

[Operation] Since the present invention has the above configuration, when the user terminal requests unstored information, the lower layer information center receives information from the upper layer information center, supplies it to the user terminal, and supplies the information to the user terminal. When a cancellation request is received from a user terminal during the process, it is determined whether the information is being supplied to another user terminal, and if the information is being supplied, the cancellation request is not issued to the upper information center. Therefore, limited resources can be used effectively, and when a cancellation request occurs during information supply from a lower layer, it is possible to continue supplying information to other lower layers.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an information supply system according to the present invention.

In FIG. 1, this system includes an upper layer information center 10 at the top layer, lower layer information centers 20a and 20b at the middle layer as a whole system, and user terminals 30a to 30a on the lowest layer as a whole system. 30d is composed of multiple tree-like layers. The upper layer information center 10 stores information groups with relatively low request frequency (number of information m), and the lower layer information centers 20a and 20b store information groups with relatively high request frequency (number of information n and k, respectively). ) are stored.

[0013] The lower layer information centers 20a and 20b respectively provide lower user terminals (30a, 30b) and (30c).
, 30d), if the information exists (step S12), the information is supplied; on the other hand, if the information does not exist, the request is made to the upper layer information center 10, While accumulating information from the upper layer information center 10, the lower layer user terminals (30a, 3
0b), (30c, 30d).

Further, the upper layer information center 10 is indicated by the broken line φ in the diagram.
As shown in , by connecting to the upper layer center 10 of another system or an even higher information center,
, 20b generates a request for information supply, if the information exists, the information is supplied; on the other hand, if the information does not exist, a request is made to the upper layer information center 10 of another system, While accumulating information from the upper layer information center 10 etc., the lower layer information center 20a, 20
It is also possible to supply b.

Each of the information centers 10, 20a, and 20b has counter groups 11 (counters 111 to 11p) (p=m+
α), 21a (counters 21a1 to 21aq) (q=n
+α), 21b (counters 21b1 to 21br) (r=
k+α) is provided. Information center 10, 20a,
20b are these counters 111 to 11p, respectively.
21a1 to 21aq and 21b1 to 21br are reset to the count value "0" when the system is started up, and each time the upper layer starts supplying information to the lower layer, the information counter is incremented by one, and the information The counter of the information is decremented by one when the supply is completed and when it is released. The information centers 10, 20a, and 20b each continue to supply information when the count value is not "0" when the information supply is canceled by the lower layer, and accumulate information when the count value is "0". and issues a request to cancel information supply to the upper layer information center.

Next, the specific operation of the above embodiment will be explained with reference to FIGS. 2 and 3. For example, user terminal 30d
An information reproduction request is generated (step S11), and if the requested information i (i=1 to r) does not exist in the lower layer information center 20b (step S12), the lower layer information center 20b upper layer information center 1
0 and starts accumulating information from the upper layer information center 10 (step S13). Next, the counter 20bi of the information i of the counter groups 20b1 to 20br is set to 1.
(step S14), starts supplying to the lower layer user terminal 30d (step S15), and ends this playback start process (step S1).
6). Note that in step S12, the user terminal 30d
If the requested information i (i=1 to k) exists in the lower layer information center 20b, the process jumps to step S14.

Here, when another user terminal 30c requests the information i, the information center 20b supplies the stored information i to the user terminal 30c, and also increases the counter 20bi of the information i by one. Increment.

As shown in FIG. 3, for example, when the user terminal 30d issues a cancellation request to cancel the request for information i (step S21), the information center 20b supplies information to the user terminal 30d. is released (step S22), and the counter 20bi of information i is decremented by one (step S23). Then, it is determined whether the information i is being stored from the upper layer information center 10 (step S24), and if it is not being stored, the process is terminated (step S25), and if it is being stored, the information i is counted. It is determined whether the value is "0" (step S26). If the count value is not "0", the process ends (step S27), and therefore the supply of information i to other user terminals 30c is continued.

Furthermore, when this user terminal 30c issues a cancellation request to cancel the request for information i (step S21), the information center 20b cancels the information supply to the user terminal 30d (step S2).
2) Also, the counter 20bi of information i is decremented by one (step S23). Then, it is determined whether the information i is being stored from the upper layer information center 10 (step S
24) If the information is not being stored, the process is ended (step S25), and if the information is being stored, it is determined whether the count value of the information i is "0" (step S26). If the count value is "0", the storage of information i is stopped (step S28), and a request to cancel information supply is issued to the upper layer information center 10 (step S29). In this way, when information i is supplied to a plurality of user terminals 30c and 30d, an information supply cancellation request is issued to the upper layer information center 10 only by the cancellation request of the last user terminal 30c ( Step S29).

Therefore, according to the above embodiment, the information centers 10, 20a, and 20b each have counters 111 to 11 whose number corresponds to at least their own information numbers m, n, and k.
p, 21a1-21aq, 21b1-21br,
Each time the supply of information to the lower layer starts, the counter for the information is incremented by one, and when the supply of information is completed or canceled, the counter for the information is decremented by one, and the count value becomes "0". If not, the information supply to the lower layer is continued, so limited resources can be used effectively.In addition, if a cancellation request occurs while information is being supplied from a lower layer, information to other lower layers is Supply can be continued.

In the above embodiment, the counter of the information is incremented by one every time the supply of information to the lower layer is started, and the counter of the information is incremented by one when the supply of information is completed and when the supply of information is canceled. Although the configuration is configured such that the count is decremented by one, it may alternatively be configured such that the count is incremented when the accumulation of information is started, and the count is decremented when the accumulation of information is finished or stopped. In this case, when each information center 10, 20a, 20b receives a request to cancel information supply from a lower layer while storing information supplied from an upper layer information center, it refers to the value of the counter for that information. , if the count value is "1", information storage is stopped and a request to cancel information supply is issued to the upper layer information center.

As another embodiment, as shown in FIGS. 4 and 5, each information center 10, 2
A flag bit group F is provided in 0a and 20b to indicate supply information i (i = 1 to p, q, r) and its supply destination j (j = 1 to s), and it is determined whether the information is being supplied or not. It may also be determined. The second embodiment will be described below with reference to FIGS. 4 and 5.

First, in FIG. 4, an information reproduction request is generated by the user terminal 30d, for example (step S31).
), if the requested information i (i=1 to r) does not exist in the lower layer information center 20b (step S32),
The lower layer information center 20b requests the information i from the upper layer information center 10 and starts accumulating the information from the upper layer information center 10 (step S33). Next, a flag bit corresponding to the information i and the user terminal 30d is set (step S34), and supply to the lower layer user terminal 30d (terminal j) is started (step S34).
35), this supply start process is ended (step S36).
). Note that the information i requested by the user terminal 30d in step S32 is stored in the lower layer information center 20b.
If it exists, the process jumps to step S34.

Here, when another user terminal 30c requests the information i, the information center 20b supplies the stored information i to the user terminal 30c, and also sends the information i and the user terminal 30c to the information i. Set the corresponding flag.

As shown in FIG. 5, for example, when the user terminal 30d issues a cancellation request to cancel the request for information i (step S41), the information center 20b supplies information to the user terminal 30d. (step S42), and also resets the information i and the flag corresponding to the user terminal 30d (step S43). Then, it is determined whether the information i is being stored from the upper layer information center 10 (step S44), and if it is not being stored, a request to cancel the information supply is issued to the upper layer information center 10, and the process ends. (Step S47), and if the information is being stored, it is determined whether all the flags of information i are "0" (Step S45). If all the flags are "0", the accumulation of information i is stopped and the upper layer information center 10
(Step S4)
6) End this process (step S47). On the other hand, if all the flags are not "0", this process is ended (step S47), and therefore information supply to other user terminals 30c is continued.

Therefore, in this embodiment as well, limited resources can be used effectively, and when a release request occurs while information is being supplied from a lower layer, information supply to other lower layers can be stopped. can be continued.

[0027]

As explained above, according to the present invention, when the user terminal requests unstored information, the lower layer information center receives information from the upper layer information center and transmits the information to the user terminal. If a cancellation request is received from a user terminal while the information is being supplied, it is determined whether the information is being supplied to another user terminal, and if the information is being supplied, a cancellation request is not issued to the upper layer information center. . Therefore, limited resources can be used effectively, and when a cancellation request occurs during information supply from a lower layer, it is possible to continue supplying information to other lower layers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of an information supply system according to the present invention.

FIG. 2 is a flowchart for explaining an information supply start operation of the lower layer information center in FIG. 1;

FIG. 3 is a flowchart for explaining an operation of stopping information supply by the lower layer information center in FIG. 1;

FIG. 4 is a flowchart for explaining the operation of starting the information supply of the lower layer information center in the second embodiment of the information supply system according to the present invention.

FIG. 5 is a flowchart for explaining the operation of stopping the information supply of the lower layer information center in the second embodiment of the information supply system according to the present invention.

FIG. 6 is a block diagram showing a conventional information supply system.

FIG. 7 is a flowchart for explaining the operation of starting information supply by the lower layer information center in FIG. 6;

FIG. 8 is a flowchart for explaining an operation of stopping information supply by the lower layer information center in FIG. 6;

[Explanation of symbols]

10 Upper layer information centers 20a, 20b Lower layer information centers 30a-30d User terminals 11, 21a, 21b Counter groups 111-11p, 21a1-21aq, 21b1-21
br, 21bi Counter F Flag bit group

Claims (3)

[Claims] Claim 1: A plurality of user terminals arranged at the lowest layer to receive information, and a group of information for which information requests from the user terminals occur with a relatively high frequency are accumulated, and each piece of information in this information group is A lower layer information center supplies information in response to an information request from the user terminal, and a group of information for which information requests from the user terminal occur relatively infrequently is stored, and information not stored in the lower layer information center is provided to the user. When a terminal requests the lower layer information center, the information is supplied to the lower layer information center, and when a cancellation request for stopping the information supply is received from the lower layer information center, the information supply is stopped. and an upper layer information center, and when the user terminal requests unstored information, the lower layer information center receives information from the upper layer information center and supplies it to the user terminal. supply release means for determining whether the information is being supplied to another user terminal when a release request is received from the user terminal, and issuing a release request to the upper level information center if the information is not being provided. information supply system. 2. The supply release means of the lower layer information center has a counter for counting the number of the user terminals to which information is being supplied, and the value of this counter indicates whether the information is transmitted to other user terminals. 2. The information supply system according to claim 1, wherein the information supply system determines whether or not the information is currently being supplied. 3. Supply canceling means of the lower layer information center receives information from the upper layer information center, stores it, supplies it to the user terminal, sets the information being stored as a flag, and sets the information being stored as a flag. 2. The information supply system according to claim 1, wherein it is determined whether the information is being supplied to other user terminals based on the state.