JPS63153939A - Data communication system - Google Patents

Abstract

PURPOSE:To perform the multiple address of data economically without necessitating a large amount of page memories, by sending multiple address data to plural opponents by every buffer. CONSTITUTION:A data A1 to be sent first is transmitted for three times continuously to every reception terminal of 302-304. A number to distinct each of three reception terminals 302-304 is attached on each data A1, therefore, it is possible to distinct the data of the reception terminal even when it is sent continuously by a racket network 301. Furthermore, a transmission terminal 300 registers in advance that the opponents are the reception terminals 302-304 as a pre-procedure. Since it is recognized immediately which line out of lines lines 307-309 should be selected at a time when the packet network 301 receives each data A1, the data A1-A3 are sent in order to the opponents 302-304.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a data communication system using a packet switching network.

[Conventional example]

Traditionally, broadcast facsimile machines (facsimile machines that have the ability to deliver the same document to multiple recipients in one operation) temporarily store documents to be sent in memory and then connect the contents to each recipient. It was a sequential broadcast in which the information was sent in sequence. Therefore, documents to be delivered must be stored (a large amount of memory (page memory) is required, and each time all the stored documents are sent, the recipients are connected to each other (sequential broadcasting is performed, and the delivery is not complete). It was not a broadcast in any sense.

Furthermore, even when a packet multiplexing service is used, it is common to accumulate data in a page memory and then simultaneously transmit it to a plurality of parties using a plurality of LCNs, which requires a page memory.

FIG. 3 is a diagram showing an example of conventional normal transmission.

CR indicates a call request (transmission request), and the called side (receiving side)
When the connection is OK, a CC (connection complete) signal is sent back to the calling party, and the connection at the network layer 100 is completed.

Next, control is transferred to the upper transport layer 101.
When a CR is issued and a confirmation signal TCA is received, a transport layer connection is established, and transmission and reception of data including a control signal/image signal in a TDT signal begins.

The session layer 102 sends C3S including 8 o'clock information, etc., and receives the response R35P and enters the activated state. Next, the document layer 103 sends TDT/C3UI/CDUI to negotiate the facsimile function, and receives a response TDT/R3UI/RDCLP from the receiving side.
receive. As a result, the sending side sends the negotiation results of facsimile functions such as paper size to TDT/C3UI/CD.
S is sent to the receiving side. This doesn't require a response. Only then is the image data sent as TDT/C3UI/CDUI every 1 packet, and continues until one page's worth of data is sent.

To indicate that one page has been transmitted, TDT/C3
UI/CDPB is sent and the acknowledgment is T
Returned as DT/R, SUI/RDPBP.

This is repeated for each document to be sent. When all documents have been sent, TDT/C3UI/CDE indicating the end of the document is sent, and in response, TDT/C3UI/CDE is sent.
Document layer 1 receives DT/RSUI/RDEP
The transmission and reception of 03 is completed. Afterwards, TDT/
After sending C3E and receiving TDT/R3EP in response, session layer 102 is terminated.

Furthermore, in order to terminate the network layer 100 connected by the SR, a CQ is transmitted, and upon receiving a CF in response, the network layer 100 is released, and the completion of the series of documents is completed. In the case of broadcasting in the case of transmission to one destination as described above, the process from CR transmission to CF reception is repeated for each of a plurality of destinations. Therefore, the same image data (TDT/C8U summer/CDUI of document layer 103) for each destination
) is sent repeatedly, requiring a large amount of memory to store all image data.

FIG. 4 shows this in the form of a sequence diagram. At 200, the network layer is connected, at 201 a pre-procedure for image data transmission is performed, at 202 the image data is repeatedly sent page by page, at 203 a post-procedure is performed, and at 20
Step 4 opens the network layer, Step 205 determines whether all the distribution has been sent to the destination, and if not, step 2
It returns to 00 and starts transmitting to the next destination, and when all transmissions are completed, the broadcast operation ends.

〔the purpose〕

SUMMARY OF THE INVENTION It is an object of the present invention to provide a data communication system that eliminates the drawbacks of the above-mentioned conventional example and that does not require a large amount of page memory and can economically broadcast data.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described.

FIG. 1 shows a sequence diagram of broadcast transmission, and corresponds to FIG. 4 of the conventional example.

Note that packet multiplexing (LCM) in a packet switching network is
) will be briefly explained using Fig. 3. Packet multiplexing is physically one line (corresponds to one line number).
By applying the principle of time division, multiple separate pieces of information are transmitted, and then reassembled on the receiving side. The sending side 300 broadcast the message.

305 and is connected to the packet switching network 301 through one line 306. Here, it is assumed that aOO is routed to three locations: 302, 303, and 304. Since 300 has three LCNs, data Al to be sent first is transmitted three times in succession for each LCM. However, each AI data has three LCs.
A number is attached to distinguish between the LCNs 301 and 301, so that it is possible to determine which LCN the data belongs to even if the data is sent consecutively. Furthermore, 300 registers in advance that each LCN is the other party 302, 303, and 304 as a pre-procedure, and when 301 receives each data AI, the line 3
You can immediately know which one of 07.308.309 to choose. In this way, the first A1 data is sent to line 3 in the order it was sent.
07.308.309 to the other party 302.303.
304 respectively. Similarly, A2. The data in A3 will also be sequentially sent to the other party. This is the principle of broadcast transmission using packet multiplexing.

Next, FIG. 2 shows a sequence diagram. This corresponds to the conventional example shown in FIG. First, LCNI is started from the initial state 400 and the network layer 406 is connected. Next, LCM2 is activated and network layer 2,407 is connected. Similarly, LCNn is activated and network layer n, 401 is connected.

The steps up to this point are the pre-procedures for registering and connecting the other party for each LCN. Then there is the transport layer.

408 transport layer 2, 409 and transport layer 3, 402 are connected to complete the terminal-to-terminal connection. Then, the transmission of image data begins, but as mentioned above, the same data can be sent to multiple parties in a time-sharing manner, so first send several packets of image data, which is generally held in the software, using 410. When it is confirmed by the packet procedure that this has been received by the other party, the process moves to 411 and the data in the same buffer is sent to the next party. After confirming that the same message has been received, the process moves to the next step 403.

When the image data held in the buffer has been sent to all destinations in this way, the buffer of the previous transmission data is released and the next image data starts to be transmitted from 410.

Do this again for the next opponent.

In this way, after filling the transmission data buffer one by one and sending all the data, each process processes 412, 413, and 405 to release the network layer, and when all destinations are released, the broadcast ends. .

In this way, a large amount of page memory is not required, and each buffer of transmission data can be sent to a plurality of destinations, making it possible to perform transmission and reception similar to the original broadcasting. Of course, if an error occurs in a certain party during the process, only that LCN is disconnected and excluded from the broadcast in order to avoid the inconvenience of not being able to release the transmission buffer forever and putting other parties on hold. This is a method commonly used during normal sequential broadcasting, and there is no problem with it. In addition, we predicted that it would take time to exchange packets and that the buffer would overflow because it would not match the image loading speed.
Instead of using a scanner at a constant speed, a step motor may be used to read the next line after all LCNs have been confirmed.

Although the above-mentioned embodiment has been explained using a facsimile machine as an example, the present invention can be applied to any data communication device connected to a packet switching network, such as Teletex, Videotex, etc.

〔effect〕

As explained above, according to the present invention, data can be broadcast economically without requiring a large amount of page memory.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of packet multiplexing of this embodiment, Fig. 2 is a diagram showing a sequence diagram of this embodiment, Fig. 3 is a diagram showing a conventional transmission example, and Fig. 4 is a diagram for broadcasting. FIG. 2 is a diagram showing a sequence diagram of FIG. 300 is a sending terminal, 306, 307.308.309 are lines, 301 is a packet network, 302, 303.304 is a receiving terminal, 406.40
7,401 is a network layer l, 2°n.

Claims (1)

[Claims] 1) Data communication: Execute the network layer, transport layer, and document layer of the protocol layer of the data communication procedure independently for each communication destination via the packet communication network for each LCN, and broadcast and receive these layers. A data communication method characterized by communicating in correspondence with each other party at the time.