JPS63155838A - Control system for store and forward exchange network - Google Patents

Abstract

PURPOSE:To effectively utilize network resources by constituting the titled system so that when a retransmission of a transmission data is request from a receiving terminal equipment, a receiving side store and forward exchange equipment requests the retransmission to a transmitting side store and forward exchange equipment, if it is not held. CONSTITUTION:This facsimile transmission network consists of sub-networks SNTa, SNTb, and a communication line LN for connecting them. The subnetwork SNTa consists of a public telephone transmission circuit network PSTNa, (n) pieces of facsimile equipments FXa1-FXak connected to said network, and a store and forward exchange equipment SAFa, and the subnetwork SNTb is also constituted in the same way. A transmitting side store and forward exchange equipment holds a transmission data from a transmitting terminal equipment for a prescribed period, and the receiving side also holds the transmission data in the same way. When a retransmission of the transmission data is requested from the receiving terminal equipment, a receiving side store and forward exchange equipment requests a retransmission of its transmission data to the corresponding transmitting side store and forward exchange equipment, when it is not held.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a control method for a store-and-forward network.

[Prior art] For example, when a data transmission network is established using a line network such as a public telephone line, rather than operating each data terminal device independently, a center with larger functions than the data terminal device is used. It is better to install a central station device (for example, a store-and-forward device) and use the functions of this central station device in each data terminal device, because each data terminal device can be used with a smaller function, so the data transmission network When viewed as a whole, it is economically advantageous.

Furthermore, such a center station device is provided at each remote location, and each center station device provides services for the area of the remote location.

By interconnecting these center station devices through a line network such as a digital high-speed line network, a large-scale network can be efficiently constructed.

Now, when using such a network to perform broadcast transmission in which the same message (data) is transmitted to multiple destinations, for example, the center station equipment (hereinafter referred to as the sending side) to which the data terminal equipment on the sending side connects The transmission data is transmitted from the center station device (hereinafter referred to as the center station device) to the center station device connected to each destination (hereinafter referred to as the receiving center station device), and is temporarily stored in the receiving center station device.

The accumulated transmission data is then transmitted from the receiving center station device to each destination data terminal device.

By the way, in order to cope with the need to receive received data again at the destination data terminal device, the receiving center station device conventionally retains the data received from the sending center station device for a certain period of time. That's what I was doing.

However, in this conventional method, the same message (
Since the transmitted data (transmitted data) is held in a plurality of receiving center station devices for a long period of time, the resources of the entire network (memory capacity in this case) are not used effectively.

[Objective] The present invention was made in order to eliminate the disadvantages of the prior art, and an object thereof is to provide a control method for a store-and-forward network that can effectively utilize network resources.

[Configuration] In order to achieve this object, the present invention retains transmitted data from a transmitting terminal device in a transmitting storage and forwarding device to which the transmitting terminal device connects for a predetermined transmitting side retention period, and at the same time, when the receiving terminal device The storage and forwarding device on the receiving side retains the transmitted data for a predetermined retention period on the receiving side, and the storage and forwarding device on the receiving side,
When a receiving terminal device requests retransmission of transmission data, if the requested transmission data is not held, the corresponding transmitting storage and forwarding device is requested to retransmit the transmission data.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a facsimile transmission network according to an embodiment of the present invention.

In the figure, this facsimile transmission network includes two subnetworks 5NTa and 5NTb and a communication port 11 that interconnects these subnetworks 5NTa and 5NTb.
It is composed of LN. This communication line LN is constituted by, for example, a high-speed digital line network or a dedicated line.

The subnetwork 5NTa is the public telephone network PSTN.
a, facsimile machines FXa L to FXak connected to the public telephone line PSTNa, and a storage and forwarding apparatus 5AFa connected to the public telephone line 1!1PsTNa through a plurality of lines.

The subnetwork 5NTb is the public telephone network PSTN.
b, m facsimile devices FXbx to FXbm connected to the public telephone network PSTNb, and a storage/exchange bag [5AFb] connected to the public telephone network PSTNb by a plurality of lines.

And these subnetworks 5NTa, 5NTb
The storage and forwarding devices 5AFa and 5AFb constituting the storage and forwarding device 5AFa and 5AFb are interconnected by a communication line LN, and data transmission between these storage and forwarding devices 5AFa and 5AFb is realized via this communication line LN.

Here, the sub-networks 5NTa and 5NTt> may be configured at remote locations within the same country, or may be configured in different countries. In addition, in the case of the former,
The public telephone lines m PSTNa and PSTNb are configured by, for example, connecting one public telephone line network in the same country in a closed area.

FIG. 2 shows an example of the storage/forwarding device 5AFa. In addition.

The other storage/forwarding device 5AFb also has a similar configuration.

In the figure, a system control unit 1 controls the entire storage and forwarding device 1sAFa, and also includes a communication control unit CCU that controls data transmission to and from the storage and forwarding bag [5AFb] via a communication line LN, and , facsimile communication control units FCU 1 to FCUi for exchanging data with facsimile machines [FXat-FXak] via i lines connected to the public telephone network PSTNa.
is controlled appropriately.

The magnetic storage device 2 is a facsimile device Fxa1 to FXak.
It is for storing various information such as transmission information and transmission condition information received from the storage and forwarding device 5AFb, and a magnetic disk device 2a for recording/reproducing data on a magnetic disk. It consists of a magnetic disk control device 2b for controlling data input/output and the like. In addition, the operation display section 3 is operated by this storage/exchange device 5AFa.
It consists of an input device such as a keyboard and a display device such as a screen display device necessary for operating the computer.

This storage/exchange bag @5AFa is capable of retransmitting, re-receiving, and checking the contents of the image information stored in the magnetic storage device 2.
Various functions such as changing and canceling the destination can be realized, and the function to edit image information as appropriate is also provided.

Note that the operation display section 3 is used during this image editing.

Further, the storage and forwarding device 5AFa is connected to another storage and forwarding device 5A.
The data received from Fb is held in the magnetic storage device 2 for a predetermined reception side holding period, and the storage and forwarding device 5AFb
The data sent to is held in the magnetic storage device 2 for a predetermined sending side holding period. In this case, the receiving side retention period is set to a shorter period than the transmitting side retention period.

FIG. 3 shows an example of the facsimile machine FXaz.

In addition, other facsimile machines FXaz to FXaL
FXbx to FXbm are similarly configured.

The facsimile machine FXa1 is connected to the public telephone line PSTN.
a, a well-known facsimile terminal device FX for transmitting and receiving image information, and an operation terminal device O5 for transmitting and receiving data requesting various services to the storage and forwarding device 5AFa.
It consists of

Therefore, by operating the operating terminal device DS, the operator can request the storage/exchange device 5AFa to retransmit, rereceive, confirm the contents, change the destination, cancel, etc. the image information.

With the above configuration, the store and forward devices 5AFa and 5AFb provide store and forward services to the facsimile machines forming the subnetworks 5NTa and 5NTb, respectively.

Furthermore, when there is a request to transmit data to a facsimile machine belonging to a different subnetwork, the storage and forwarding device of the subnetwork to which the destination facsimile machine belongs transmits the transmission data to the target facsimile machine via the communication port fiLN. Request a relay as follows. Also,
Multiple destinations can be specified for the same subnetwork.

For example, when facsimile machine FXa1 of subnetwork 5NTa broadcasts transmission to all other facsimile machines FX2 to FXh of the same subnetwork 5NTa, facsimile machine FXI transmits data to storage and forwarding device 5.
The image information is transmitted to the storage/exchange device 5AFa while requesting AFa to perform broadcast transmission and specifying the destination at that time. However, in this case, when specifying the destination, for example, "
By setting in advance specific destination information that will alert all other facsimile devices in the same subnetwork, it is only necessary to notify the storage and forwarding device 11sAFa of the destination information. Further, this destination information can also be input from the operation terminal device DS.

As a result, the storage/exchange device 5AFa temporarily stores the specified destination and image information in the magnetic storage device 2, calls one destination, and when a connection is established, transmits the image information to that destination, and then transmits the image information to all the destinations. Repeatedly performs broadcast transmission to the specified destination. Furthermore, it is also possible to specify the time at which the storage/forwarding device 5AFa starts broadcast transmission. and,
The image information transmitted in this way is held in the magnetic storage device 2 only for the sending side holding period.

Further, for example, when the facsimile device FXax of the subnetwork 5NTa transmits image information to the facsimile device FXb1 of the subnetwork 5NTb, the facsimile device [FXax sends data that indicates the subnetwork 5NTb as destination information, and
The image information is transmitted to the storage and forwarding device 5AFa while continuously specifying the telephone number of the facsimile machine FXb1 on the public telephone network PSTNb in b.

As a result, the storage and forwarding device 5AFa temporarily stores the destination information and image information in the magnetic storage device 3, and first stores the destination information and image information in the communication line LN.
By storage and forwarding device 5A of subnetwork 5NTb
Fb and requests the storage/forwarding device 5AFb to perform relay transmission with the telephone number of the facsimile machine FXb1 in the public telephone network PSTNb specified as the relay destination information, and transmits the stored image information. do.

Thereby, the storage/exchange device 1sAFb temporarily stores the designated destination and image information in the magnetic storage device 3, calls the facsimile device FXb1, and transmits the image information stored at that time.

In this way, data transmission between different sub-networks is achieved. In addition, in this case, the storage and exchange device 5A
Fa holds the transmitted data only during the transmitting side holding period, and the storage and forwarding device 5AFb holds the transmitted data only during the receiving side holding period.

When image information is transmitted between different subnetworks in this way, the received image information includes the file number in the storage and forwarding device of the subnetwork to which the receiving facsimile device belongs, and the file number of the sending facsimile device. Two types of file numbers, that is, the file number of the storage and forwarding device of the subnetwork to which it belongs, and identification information of the storage and forwarding device to which the sending facsimile device belongs are added.

Also, during one broadcast transmission, for example, "Facsimile device FXa1.FXaz of subnetwork 5NTa, facsimile device FXb<m- of subnetwork 5NTb"
Multiple destinations across different subnetworks can also be specified, such as x>+FXbmJ. At that time, destination information related to the subnetworks 5NTa and 5NTb and image information to be transmitted are accumulated in the storage and forwarding devices WSAFa and 5AFb of the subnetworks 5NTa and 5NTb, respectively.
The image information is broadcasted to the destination specified by TatSNTb.

Here, if the facsimile device that sent the data belongs to the subnetwork 5NTa, the storage and forwarding device 5NTa holds the transmitted data for the sending side retention period, and the storage and forwarding device 5NTb holds the transmitted data for the receiving side retention period. Hold. Furthermore, if the facsimile device that sent the data belongs to the subnetwork 5NTb, the storage and forwarding device 5NTa holds the transmitted data for the receiving side retention period, and the storage and forwarding device! 5NTb holds the transmitted data only for the sending side holding period.

In this way, data is transmitted between the subnetworks 5NTa and 5NTb via the communication line LN, and the network as a whole functions as one network.

Now, the image information is transmitted from the facsimile machine FXa1 to the facsimile machine FXbx, and the facsimile machine FXbx
Consider a case where bl requests the storage and forwarding device SAi to re-receive image information. In addition, when making this re-reception request,
Specify the image information that you want to re-receive using the two file numbers attached to the received image information, and add the identification information of the storage and forwarding device to which the sending facsimile machine belongs to the sending storage and forwarding device. There is. Also, the file number of the storage and forwarding device in the subnetwork to which you belong is placed first, the file number of the storage and forwarding device in the subnetwork to which the sending facsimile device belongs is placed second, and The storage/forwarding device 1isAFb is configured to be able to distinguish between two file numbers.

As a result, as shown in FIG. 4, the storage/forwarding device 5AFb first performs the message (image information ) is retained (
Judgment 401).

At that time, if the receiving side retention period has not passed since receiving the message for which re-reception was requested and the message is retained (result of judgment 401 is YES), the facsimile machine FXb1 that requested re-reception is sent to Send the message (process 402
). Furthermore, before retransmitting the message, the facsimile device FXb1 is notified that the message can be retransmitted.

As a result, immediately before re-receiving the message, a message indicating that the message can be re-received is displayed on the operation terminal device DS of the facsimile group [FXbx].

Further, if the receiving side retention period has passed and the message requested for re-reception is not held (the result of judgment 401 is No), the storage and forwarding device 5AFb transmits the message to the transmitting side storage and forwarding device 5.
AFa is asked whether it is possible to re-receive the message by specifying the file number of the storage and forwarding device 5AFa (processing 4).
03).

As a result, the storage/forwarding device 5AFa notifies identification information indicating whether or not it holds the specified message, and if it holds the message, it resends the message ( (described later).

Therefore, it is determined whether the message can be re-received based on the result of the inquiry (process 404), and when the result of judgment 404 is NO, the facsimile machine FXbz is notified that the message cannot be re-transmitted (process 405). )
. As a result, the operation terminal device DS of the facsimile machine FXb1 displays that the message cannot be re-received.

Further, when the result of the judgment 404 is YES, the message subsequently transmitted from the storage/forwarding device 5AFa is transmitted to the facsimile group [FXbl (process 406).

In process 406, as in process 402, before retransmitting the message, the facsimile device FXb1 is notified that the message can be retransmitted.

The storage and forwarding device on the receiving side (in this case, the storage and forwarding device!5
When one inquiry is made by the process 408 executed by AFb), the storage and exchange bag @ (in this case, storage and exchange bag f!! S A Fa ) on the sending side executes the process shown in FIG.

That is, first, based on the file number notified from the storage and forwarding device on the receiving side, it is checked whether the message (image information) requested to be re-received is held (determination 501).
.

At that time, if the sender's retention period has not passed since sending the message for which re-reception was requested and the message is retained (result of judgment 501 is YES), the receiver's accumulated information indicates that the message can be resent. After notifying the exchange device (processing 502
), transmits the message to the storage and forwarding device (process 50
3).

In addition, if the transmitting side retention period has passed and the message requested for retransmission is not retained (the result of judgment 501 is No), the storage and forwarding device on the receiving side is notified that the message cannot be retransmitted (processing 542). ).

In this way, the message (
If the storage and forwarding device on the receiving side holds the message when a request is made to re-receive the message (image information).

The message will be resent immediately.

Furthermore, if the storage and forwarding device on the receiving side does not hold it, the storage and forwarding device on the sending side is queried whether the designated message can be retransmitted.

Then, if the sending storage and forwarding device is capable of retransmission,
The designated message is retransmitted from the storage and forwarding device on the sending side to the storage and forwarding device on the receiving side, and further transmitted to the facsimile device that requested re-reception.

If the message cannot be re-received, the operator of the facsimile machine on the receiving side.

All that is required is to request the operator of the sending facsimile machine to resend the message.

By the way, the receiving side storage period is set as the period during which the storage and forwarding device on the receiving side holds image information (telegram; transmission data), and the period is set as the period during which the storage and forwarding device on the sending side holds the image information. The transmission side retention period is determined to be a period in which the number of messages in the entire network is reduced and the serviceability of the network for data terminal devices (facsimile devices) is not deteriorated. At this time,
While actually operating the network, you can change these retention periods as appropriate to find the most suitable period.

In the above-described embodiments, a facsimile machine is used as the terminal device, but the present invention can also be applied to cases where other terminal devices are used.

Further, in the above-described embodiment, one network is formed by two sub-networks, but the number of sub-networks is not limited thereto. Additionally, if the storage and forwarding device on the receiving side can specify the file number added by the storage and forwarding device on the sending side from the file number added by itself, it is possible to specify only one file number when re-receiving. can.

Furthermore, the configuration of the storage and forwarding device is not limited to that described above.

[Effects] As explained above, according to the present invention, the transmission data from the transmitting terminal device is held in the transmitting storage and forwarding device connected to the transmitting terminal device for a predetermined transmitting side retention period, and the receiving terminal device is connected to the transmitting side storage and forwarding device. The storage and forwarding device on the receiving side retains the transmitted data for a predetermined retention period on the receiving side, and the storage and forwarding device on the receiving side,
When a receiving terminal device requests retransmission of transmitted data, if the requested transmitted data is not held, the corresponding transmitting storage and forwarding device is requested to retransmit the transmitted data, so network resources can be effectively used. Get the advantage of being available.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a facsimile transmission network according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of a storage and forwarding device, FIG. 3 is a block diagram showing an example of a facsimile device, and FIG. 5 is a flowchart showing an example of processing by the storage and forwarding device on the receiving side, and FIG. 5 is a flowchart showing an example of processing at the storage and forwarding device on the transmitting side. LN...Communication line. 5NTa, 5NTb...subnetwork, 5AFa
, 5AFb...Storage and forwarding device. PSTNa, PSTNb...Public telephone network, FXa
t-FXat+FXbt-FXbm@@Facsimile device, 1...System control unit, 2...Magnetic storage device. 3...Operation display unit, CCU...Communication control unit. FCUI to FCUi...Facsimile communication control unit. FX...Facsimile terminal device, DS...Operation terminal device. Agent Patent Attorney Crest 1) Makoto ′・,−1′ Figure 2

Claims (2)

[Claims] (1) In a control method for a store-and-forward network that is equipped with a plurality of store-and-forward devices that provide store-and-forward services to multiple terminal devices scattered in a predetermined area, and in which these store-and-forward devices are interconnected through a line network. , the transmitting storage and forwarding device to which the transmitting terminal device connects retains the transmitted data from the transmitting terminal device for a predetermined transmitting side retention period, and the receiving storage and forwarding device to which the receiving terminal device connects The transmission data is retained for a predetermined retention period on the reception side, and when the transmission data retransmission is requested from the terminal device on the reception side, the storage and forwarding device on the reception side responds when the requested transmission data is not retained. 1. A control method for a store-and-forward network, characterized by requesting a transmitting-side store-and-forward device to retransmit transmitted data. (2) A control method for a store-and-forward network according to claim 1, wherein the holding period on the receiving side is set to be shorter than the holding period on the transmitting side.