JP3470585B2 - Broadcast connection data distribution system and distribution server, and recording medium recording broadcast connection distribution program - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a registration process of a large number of terminals during connection establishment when data is distributed to a large number of user terminals in a data distribution service utilizing a communication network such as news distribution and electronic publishing. Broadcast connection distribution system that enables many terminals to receive distribution services at any time by
Temu, and a data distribution server, as well as a recording medium for recording a broadcast-type connection delivery program.

[0002]

2. Description of the Related Art As transmission data of a data distribution service, for example, text data files of news articles,
It includes image data files or files that summarize several news items. 2. Description of the Related Art Conventionally, as a data distribution management method, as shown in FIG. 2, each of the terminals 1, 2, and 3 notifies a data distribution server of a request for data distribution in advance, and the server administrator selects a terminal desiring distribution. The distribution list is collected, the distribution list file is input to the server, and the distribution list of the server (list of distribution destination terminals) has been established at this point. After that, the distribution list was used to manage the data distribution when the connection was established when the data communication was started. That is, in FIG. 2, since the terminals 1 and 2 have previously notified the server side of the distribution request, the server administrator collects the distribution requests, and the terminals 1 and 2 are recorded in the distribution list of the server. I had confirmed this as a terminal. The terminal 3 issued a distribution request after the distribution list was confirmed. Service
Terminal to the connection establishment request by the broadcast of the scan 1, 2, 3
Sends an establishment response to the server to the connection.
However, although the server receives the responses from the terminals 1 and 2,
Since the terminal 3 is not registered in the distribution list, it is ignored even if a connection response arrives. After that, the data is transmitted from the server to the terminals 1 and 2. Since the data transmission is also performed by the broadcast, the terminal 3 also receives the data. The terminals 1, 2, and 3 return a data transmission response including information regarding data that needs to be retransmitted to the server. The server receives the responses from the terminals 1 and 2, but ignores them because they are not described in the response distribution list from the terminal 3. The server retransmits the necessary data to the terminals 1 and 2. Necessary data is not retransmitted to the terminal 3.
When all the necessary data are delivered to the terminals 1 and 2, the server sends a connection release request to the terminals 1, 2 and 3. In the terminal 3, the transmission response is ignored by the server, and thus the necessary data is not retransmitted and ends. FIG. 2 shows a case where a connection establishment request and a release request are broadcast by multicast communication. As described above, in data transmission, the server manages transmission and retransmission for the terminals 1 and 2, but does not manage transmission and retransmission for the terminal 3.

FIG. 4 is a block diagram of a conventional data distribution server. The communication control unit 401 sends data and requests,
Upon receiving the response, the transmission management unit 402 performs packet transmission processing such as connection establishment request, data transmission, retransmission, connection release request, etc., especially confirmation of data distribution to terminals recorded in the distribution list, data Communication processing such as resending is performed. The response management unit 403 also passes the information included in the received response to the transmission management unit 402. The distribution list storage unit 404 stores a distribution list aggregated by the server administrator or another application program, and delivers it to the transmission management unit 402 before the step of the connection establishment process. Examples of multicast documents include Deering, S, E, and Multicast.
Routing in Interworks and
Extended LANs, ACM Trans
actions on Computer System
ms, No. 8, 1990. And Kumar, V, MBone Interactive
e Multimedia on the Inter
net, New Riders Publish
g, Indianapolis, Indiana, 19
96. Chapter 1. In addition, as a reference of a connection management method for managing transmission and retransmission, S is
hiroshita, T, et all, Perfor
ranceevaluation of reliab
le multicast transport pro
tocol for large-scale del
Ivery, Proc. IFIP Fifth Int
l. Worksshop onProtocols fo
r High-Speed Networks (PfH
SN'96), Oct. 1996. There is.

[0004]

In the conventional connection distribution system using the method based on the prior distribution list, as the processing flow of the server, (1) distribution list pre-aggregation 201, (2) connection establishment processing 202, ( 3) The data transmission management process 203, which is a three-step process step, is performed, and the distribution list is fixed before the connection establishment process 202. The reason why the three-stage processing is performed is that the high-speed distribution list generation cannot be performed simultaneously in step 202 of the connection establishment processing. As described above, according to the conventional method, since the distribution list is generated and confirmed before the connection is established, the server cannot manage the data transmission to the terminal that desires the distribution after the confirmation of the distribution list. It was
In broadcast-type data distribution, which distributes and manages information to an unspecified number of terminals such as broadcasting, it is necessary to manage information distribution to the terminals that wish to distribute at the start of data distribution, but distribution before the step of connection establishment processing. With the conventional method of determining the terminal, it was not possible to realize the data delivery management that immediately responded to the desire of the terminal. Especially, we couldn't process the distribution list of many terminals at high speed.
The distribution list was created when there was enough time before the connection was established. An object of the present invention, to solve such a conventional problem, in connection establishment process at the start of data transmission, the terminal wishing to data delivery time to time, data distribution broadcasting capable of receiving the service It is to provide a connection distribution system, a distribution server, and a program recording medium thereof.

[0005]

In order to achieve the above object, in the broadcast type connection management method of the present invention, at the step of the connection establishment process at the time of starting data transmission, the process of consolidating the terminals of the delivery destination is also performed, By determining the delivery destination terminal immediately before the transmission, the terminal desiring the data delivery can receive the data delivery service at any time. In particular, in order to be able to deal with the case where the number of distribution destination terminals is large, the processing of consolidating the distribution destination terminals in the step of connection establishment processing is performed at high speed.
That is, the data distribution server of the present invention is provided with a distribution list generation unit that sequentially stores the terminal information of the connection establishment response of the terminal and fixes the distribution list when the connection is established. The distribution list generator has a function to check the duplication of the information about the terminals already received during connection establishment and the information about the terminals included in the newly received response, and additionally store the terminal information only when there is no duplication. It is provided by the data structure of a binary tree. At the step of connection establishment processing, distribution list generation processing is performed by comparing the terminal names based on this binary tree. That is, when the connection establishment response is received, the terminal information included in the response is received, the duplication of the terminal name is checked by the data structure of the binary tree, and if the duplication does not occur, the terminal information is additionally stored. It is repeated during the connection establishment period of the connection establishment response reception process, and the distribution list is fixed at the end of the connection establishment period. Thereafter, data transmission management processing such as data transmission and retransmission based on a transmission response is performed in the step of data transmission management processing based on the distribution list. As described above, the data structure of the binary tree allows the distribution list generation process of a large number of terminals to be realized at high speed while establishing the connection, using only the processing amount of the depth of the tree.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration diagram of the entire data distribution system to which the present invention is applied. In FIG. 1, a data distribution server 101 distributes data such as news and digital magazines to a large number of terminals 1031 to 1034 via a network 102. Further, the server 101 requests each terminal to connect before data distribution (connection establishment request).
105 is transmitted. From these servers 101 to terminals 10
Broadcast communication such as multicast is used for communication to 31 to 1034. Also, each terminal 1031 to 1034
Returns a response 106, which is a delivery confirmation, to the server 101.

FIG. 3 is a communication sequence chart of the connection management method of the present invention. As shown in FIG. 3, the communication process of the server is mainly composed of (1) step 301 of connection establishment process and (2) step 302 of data transmission management process. In step 301 of the connection establishing process, the server determines each terminal 1, 2, 3
A connection establishment request is broadcast to. Each terminal 1, 2, 3
Returns a connection establishment response, and the server generates a distribution list of the terminals 1, 2, 3 that perform data distribution based on each of these responses. At the end of step 301 of this connection confirmation process, the distribution list is fixed. In FIG. 3, the terminals 1, 2, and 3 return the connection establishment response,
The terminals 1, 2 and 3 are determined as terminals to be recorded in the distribution list. In the next step 302 of server data transmission management, data transmission management such as data transmission, reception of a response to the data transmission, and retransmission is performed for the terminals 1, 2, and 3 in the distribution list. The server receives the responses from all the terminals 1, 2, and 3 registered in the distribution list, and retransmits the necessary data to the terminals 1, 2, and 3. After the data distribution is completed, the connection release request is transmitted to the terminals 1, 2, 3 and the communication is completed. As described above, according to the method of the present invention, when the connection establishment response is received, the information regarding the terminal included in the response is received, the distribution list generating unit checks the duplication, and additionally stores the information when the duplication does not occur. The process of receiving the connection establishment response is repeated during the connection establishment period, and the distribution list is fixed when the connection establishment period ends. In the step of data transmission management processing based on this distribution list, data transmission management processing such as data transmission and retransmission based on a transmission response is performed. In this way, data transmission becomes possible based on the terminal's distribution request immediately before data transmission, so that the terminal can receive the data distribution service at any time.

FIG. 5 is a block diagram of a data distribution server showing an embodiment of the present invention. As is clear from FIG. 5,
A distribution list generation unit 505 is newly provided to generate a distribution list from the information included in the connection establishment response when the connection is established. This distribution list generation unit 505
A distribution list that is a list of information (terminal name, address, additional information) of distribution destination terminals is generated during connection establishment, and when the connection establishment is completed, the distribution list is finalized and passed to the distribution list storage unit 504. As will be described later, the distribution list generation unit 505 stores terminal information in a binary tree data structure (see FIG. 10 described later).
In the data structure of the branch tree, a duplication check is performed between the terminal information already received during the establishment of the connection and the information about the terminal included in the newly received response. The structure has a function to store additional data. The other processing units perform packet transmission processing such as connection establishment request, data transmission, retransmission, and connection release request with the communication control unit 501 that transmits data and requests and receives responses, as in the conventional case. A transmission management unit 502, a response processing unit 503 for sending information included in the connection establishment response to the distribution list generation unit 505, and a response processing unit 503 for passing a response to the received data transmission to the transmission management unit 502,
The distribution list storage unit 504 stores the distribution list and transfers the distribution list to the transmission management unit 502 at the start of data transmission. The transmission management unit 502 performs communication processing such as confirmation of data distribution to terminals recorded in the distribution list and data retransmission, and the transmission management unit 502 records the number of connection establishments and the number of repetitions. It has the function of a counter.

FIG. 6 is a block configuration diagram of the distribution list generation unit in FIG. 5, and FIG. 7 is a diagram showing an example of the distribution list used in the present invention. Distribution list generation unit 505
Is a distribution list temporary memory 601 and a list processing unit 60.
2 and a response information memory 603. The distribution list temporary memory 601 stores a distribution list as shown in FIG. 7 during connection establishment. As in the example of FIG. 7, in the distribution list, a terminal name, a terminal address, and additional information are recorded for each terminal in each line. The additional information is any information that the terminal wants to transmit to the server (here,
c1, c2, ... Cn) are described. In FIG.
When receiving the connection establishment response packet, the distribution list generation unit 505 performs the following processing. That is, the list processing unit 602 receives the terminal information (terminal address, terminal name, additional information) of the connection establishment response packet from the response processing unit 503, and receives this from the response information memory 60.
Store in 3. Next, the list processing unit 602 checks whether or not the terminal name and terminal address of the response information memory 603 and the terminal name and terminal address of the distribution list stored in the distribution list temporary memory 601 are duplicated. . If they overlap, the terminal information in the response information memory 603 is discarded. On the other hand, if they do not overlap, the terminal information in the response information memory 603 is added to the distribution list in the distribution list temporary memory 601. Then, the response information memory 603
Discard the terminal information of. When the connection establishment period ends, the distribution list in the distribution list temporary memory 601 is confirmed, and the distribution list is sent to the distribution list storage unit 504.

FIG. 8 is a configuration diagram of a connection establishment response packet used in the present invention. As shown in FIG. 8, the connection establishment response packet includes a server address 801, a terminal address 802, a terminal name 803, and additional information 804. Terminal address 802, terminal name 8
03 and additional information 804 are terminal information. After the communication control unit 501 receives the packet and passes it to the response management unit 503, the response management unit 503 transfers the terminal information to the distribution list generation unit 5.
Send to 05.

FIG. 9 is a flow chart of the connection management operation in the server of the present invention. The processing in the server of the connection establishing method of the present invention will be described with reference to FIG. First, the number of repetitions of connection establishment is set and the repetition counter is set to 0 (initialization) (step S0). This allows the connection establishment procedure to be executed multiple times in consideration of the loss of the connection establishment request packet and the connection establishment response packet in the network. The number of repetitions and the repetition counter are set in the transmission management unit 502. Next, it waits for a connection establishment request response (W0). When the end is designated by W0 (step S10), the process ends.
In W0, when data distribution is requested by the transmission management unit 502 according to a distribution schedule or an instruction from the outside (data distribution request is generated), a connection establishment request packet is multicast to the terminal group (step S1). At the stage of W0, when a plurality of data distribution requests are generated during the connection generation processing and the data transmission management processing, one of them becomes valid,
Other requests are waiting. Next, the transmission management unit 502
Then, a timer for waiting for a connection establishment response packet is set (step S2). At this point, a connection establishment response is awaited (W1). Next, the response management unit 503 receives the connection establishment response packet and sends the terminal information to the distribution list generation unit 505 (step S3).

Next, the distribution list generation unit 505 checks whether or not the terminal information of the distribution list in the distribution list temporary memory 601 and the terminal information received in step S3 overlap (step S4). The distribution list search process is
This is performed by searching a binary tree described later. When there is duplication, the received terminal information is discarded. On the other hand, step S
When there is no overlap in 4, the terminal information is added to the binary tree of the distribution list (step S5). Next, when the timer for the establishment response waiting set in step S2 does not time out, the connection establishment response waiting W1 occurs, and the response receiving process (S3, S4, S5) is repeated (step S
6). When the time-out occurs in step S6, the repeat counter is incremented by 1 and it is confirmed whether or not the number of times of connection establishment has been reached (step S7). If the number of repetitions has not been reached, the distribution list in the distribution list temporary memory 601 is confirmed and sent to the distribution list storage unit 504 (step S8). Next, the distribution list storage unit 504 sends the distribution list to the transmission management unit 502 and requests the start of data transmission (step S).
9). Steps S8 and S9 are performed as a series of processes, and the transmission management unit 502 performs data transmission management processes of data transmission, response reception, data retransmission, and connection release using the distribution list determined immediately before data transmission. After the data transmission management process is completed, the process waits for a connection establishment request (W0). If there is a data delivery request that has been waiting in the previous W0 state, or if one or more data delivery requests have occurred during the connection generation processing and data transmission management processing, The request is temporarily waiting, and one of them becomes valid at the stage of W0, and the request S1 for establishing a connection is made. W
When there are multiple data distribution requests with 0, other requests continue to wait. Hereafter, step S1 for designating the end
The process of W0 and steps S1 to S9 is repeated until it becomes 0.

FIG. 10 is an explanatory diagram of the binary tree data structure of the distribution list of the present invention. Figure 10 (a) shows the turn
10B shows the processing before arrival, and FIG. 10B shows the processing after the arrival of satur. Further, FIG. 10C shows the configuration of each node. The process of the distribution list generation unit 505 needs to be performed at the time of establishing a connection, which is a communication process, and high speed is required. For high-speed processing, the distribution list is stored in the distribution list temporary memory 601 with the binary tree data structure shown in FIG. Since the duplication check is realized by the search process of the binary tree, it can be performed at high speed. Also, addition of terminal information is easy. As a reference of the data structure of the binary tree, for example, "Data structure and program learned in C", Chapter 5, binary tree, pp159-202, Leendert
It is written by Ammeraal, translated by Hironori Koyama, Ohmsha. FIG. 10 shows a configuration example of a binary tree for checking the duplication of terminal names. As shown in FIG.
Each node is composed of a data storage area, a left pointer and a right pointer. A small node is located at the position of the left pointer by comparing the character strings in the alphabet of the terminal name in the data area, and a large node is located at the right pointer. The terminal name of the new node is checked by tracing the pointer in the direction of the alphabet of the terminal name from the root node toward the leaf node, and if there is no duplication,
It is added as a leaf node. A leaf node is an empty node with left and right pointers.

In FIG. 10, the terminal names markury, su
n, venus, earth, luna, mars, j
An example is shown in which the responses from the terminals including the "upiter" and "saturn" arrive in this order. Last satu
When rn arrives, mark, earl, l
Since the right pointer of the luna was empty after tracing the nodes of una, it was determined that there was no duplication of the terminal names, and a new node of the saturn was generated as a leaf node at the position of the right pointer. Although each node has been described as an example including only the terminal name, the address of the terminal and the additional information are also attached, and the address of the terminal may be used for checking the redundancy. In this way, by using the binary tree, it is only necessary to search the depth of the binary tree, it is not necessary to search all existing nodes, and it is possible to quickly check the duplication of terminal names and add new terminal information. It is possible and suitable for handling responses from multiple terminals during connection establishment. Note that, in the past, instead of the binary tree as described above, a configuration in which nodes for storing information are arranged in series is used, and a sequential search is used for checking redundancy and adding a new node. Therefore, the processing speed is slow and it is not suitable for processing a large number of responses during connection establishment. In the present invention, since the delivery destination terminal can be determined during connection establishment, even if data delivery requests are successively issued, data can be delivered to a desired terminal at the time of delivery start, which is extremely efficient. is there.

By converting the operation steps shown in FIG. 9 into a program and storing the converted program in a recording medium such as a CD ROM, the recording medium can be carried to any server of the data distribution system and executed by the CPU. If so, the broadcast type connection management method of the present invention can be realized.

[0016]

As described above, according to the present invention,
By using the binary tree data structure, the distribution list of the distribution destination terminals can be generated at high speed when the connection is established immediately before the data transmission, so that many user terminals can participate in the data distribution service at any time. Becomes
As a result, in the broadcast-type data distribution service for unspecified terminals, advanced communication processing including response processing and retransmission management can be provided immediately according to the wishes of the terminals, and there are many thousands of distribution destination terminals. Even in such a case, the distribution list of the distribution destination terminal can be generated at high speed, and the server manager or another application program does not have to perform the aggregation processing for data distribution, which is extremely efficient.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an entire data distribution system to which the present invention is applied.

FIG. 2 is a sequence chart of a communication method using a conventional advance distribution list.

FIG. 3 is a nonce chart of the connection management method of the present invention.

FIG. 4 is a diagram showing a configuration example of a conventional data distribution server.

FIG. 5 is a configuration diagram of a data distribution server showing an embodiment of the present invention.

6 is a block configuration diagram of a distribution list generation unit in FIG.

FIG. 7 is a diagram showing an example of a distribution list handled in FIGS. 5 and 6;

FIG. 8 is a configuration diagram of a connection establishment response packet used in the present invention.

FIG. 9 is a flowchart of a connection management operation in the server according to the present invention.

FIG. 10 is an explanatory diagram of a binary tree data structure of a distribution list used in the present invention.

[Explanation of symbols]

101 ... Data distribution server, 102 ... Network, 1
031 to 1034 ... Terminal, 501 ... Communication control unit, 502
... transmission management unit, 503 ... response management unit, 504 ... distribution list storage unit, 505 ... distribution list generation unit, 601 ... distribution list temporary memory, 602 ... list processing unit, 603 ... response information memory, 801 ... server address, 802 ... Terminal address, 803 ... Terminal name, 804 ... Additional information.

Continuation of front page (56) Reference JP-A-5-48631 (JP, A) INTERNET DRAFT, dr aft-shiroshita-rmt p-spec-00. txt C MAGAZINE, SoftBank Corp., Vol. 5, No. 4, pp. 102-109 IEICE Technical Report SSE 95-196 IPSJ Transactions, Vol. 39, No. 6, 2009-2019 Page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04L 12/56 H04L 29/08 H04L 12/18

Claims (5)

(57) [Claims] 1. In a broadcast-type connection data distribution system for distributing data from a server to a large number of terminals via a network, a connection establishment request response waiting state is set after a connection establishment repetition count is set and a repetition counter is initialized. A means for generating, a means for transmitting a connection establishment request packet to each terminal of the terminal group according to a data distribution instruction, and a terminal information included in the received connection establishment response packet when the connection establishment response packet is received from each terminal. , A means to compare and collate with the terminal information of the distribution list already generated and check if there is no duplication of the terminal information, and if there is duplication, discard the received terminal information and eliminate the duplication And a means for adding the received terminal information to the distribution list, Once confirmed, a means for requesting the start of data transmission, and if one or more terminals request data distribution after the distribution list is confirmed, the request is temporarily held and the above connection establishment request response wait state is entered. And a means for validating at least one of them at the point of time. 2. The broadcast type connection data distribution system according to claim 1, wherein the means for checking whether or not the terminal information is duplicated comprises:
Node comprising data storage area and the left pointer and the right pointer using the data structure of the binary tree which is connected from the root node to the leaf node, the redundancy of the terminal information Ji E Tsu <br/> click, duplicate A broadcast-type connection data distribution system, wherein the terminal information is added to the data structure of the binary tree when there is no such information. 3. A data distribution server that distributes data to a large number of terminals via a network, and a communication control unit that transmits data and requests and receives responses, and a connection establishment request, data transmission, retransmission, and connection release. A transmission management unit for transmitting a packet including a request, a response processing unit for transmitting information included in a connection establishment response from each terminal received by the communication control unit to generate a distribution list, and a distribution list. A duplication check of a distribution list storage unit that stores the distribution list to the transmission management unit at the start of data transmission, information about a terminal already received during connection establishment, and information about a terminal included in a newly received response is performed. And a distribution list generation unit that additionally stores the terminal information as a distribution list when there is no duplication. Data distribution server to. 4. The data distribution server according to claim 3, wherein the distribution list generation unit stores a distribution list temporary memory for storing a distribution list obtained in the connection establishment process, and terminal information of a connection establishment response packet. When the response information memory and the terminal information of the connection establishment response packet are received, they are stored in the response information memory, and then stored in the distribution list temporary memory and the terminal name and terminal address stored in the response information memory. The distribution list device name,
Check whether it is the same as the terminal address,
And a list processing unit that sequentially adds terminal information when they do not overlap each other. 5. A recording medium in which a program for broadcast-type connection data distribution for distributing data from a data distribution server to a large number of terminals via a network is recorded, wherein a computer of the data distribution server sets a number of times of connection establishment repetitions. After setting and initializing the repeat counter, means for generating a connection establishment request response wait state, means for transmitting a connection establishment request packet to each terminal of the terminal group by a data distribution instruction, connection establishment response packet from each terminal Upon reception, a means for comparing and collating the terminal information included in the received connection establishment response packet with the terminal information of the distribution list that has already been generated to check whether or not there is duplication of the terminal information, duplication. When the received terminal information is discarded when there is no duplication Means for adding the received terminal information to the distribution list, means for requesting start of data transmission when the distribution list is confirmed, and data distribution request from one or more terminals after the distribution list is confirmed, A computer-readable recording medium in which a broadcast connection data distribution program is recorded, which makes a request temporary and functions as a means for validating at least one of the connection establishment request response waiting states.