JPH0532938B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention temporarily stores facsimile image signals in a storage device configured with a memory such as a magnetic disk device, and then transmits the facsimile image signals to another facsimile terminal via a relay line. This invention relates to a facsimile image signal exchange system for transmission.

[Technical background of the invention]

Conventionally, when transmitting a facsimile image signal from a facsimile terminal to another facsimile terminal, the image signal from the facsimile terminal at the sending end is temporarily stored in a storage device such as a memory, and then transmitted to the other facsimile terminal when the relay line is idle. A store-and-forward method for transmitting information is known.

FIG. 1 is a diagram showing an example of a facsimile image signal exchange system using such a storage and forwarding method.
A and 3B are connected via a relay line 4, and a plurality of facsimile terminals 5 are connected to each storage station 3A and 3B, and the facsimile image signal output from the sending side facsimile terminal 5 is sent to the exchange 1
is temporarily stored in the storage device 2 of the storage station 3A, and then transmitted to the receiving side exchange 1 via the exchange 1 and the relay line 4 when the receiving facsimile terminal 5 or the relay line 4 becomes idle. , and is further transmitted to the facsimile terminal 5 on the receiving side via the exchange 1.

According to such a store-and-forward method, the trunk line 4
It has the advantage of being able to smooth out peak loads and improving line usage efficiency.

[Problems with background technology]

However, if the storage device 2 in each storage station 3A, 3B has a failure in its storage function, it becomes impossible to transmit the facsimile image signal as described above, and only real-time transmission via the exchange 1 is possible. This has the disadvantage that the advantages of the store-and-forward method are lost.

In this case, it is conceivable to prepare a spare storage device 2, but this is not preferable because the economic burden increases when the frequency of use and storage capacity are taken into consideration.

[Purpose of the invention]

The present invention solves the above drawbacks and provides a facsimile image signal exchange system that can transmit facsimile image signals with a relatively inexpensive configuration without sacrificing the advantages of the storage and exchange system even when a failure occurs in the storage device at each storage station. There is a particular thing.

[Summary of the invention]

The present invention connects a plurality of storage stations via a central station having the same configuration as these storage stations, and when a failure occurs in a storage station on the transmitting side or the receiving side and the storage function, the facsimile image signal of the storage station in which the failure occurs is transmitted. The above objective is achieved by having the central office handle the accumulation of data on behalf of the central office.

[Embodiments of the invention]

FIG. 2 is a system configuration diagram showing an embodiment of the present invention, in which six storage stations 3A to 3F are connected in a star shape through a central station 6 consisting of an exchange 1 and a storage device 2. , shows a configuration for transmitting facsimile image signals between storage stations 3A to 3F.

FIG. 3 is a diagram showing the configuration of the storage stations 3A, 3B and the central station 6 in FIG. 2 in more detail. 2, and one or more facsimile terminals 5 are connected to the exchange 1. In addition, the central 6 is composed of an exchange 1 and a storage device 2 like each storage station,
It is coupled to storage stations 3A and 3B via a relay line 4.

In such a configuration, the operation when the storage functions of the storage stations 3A and 3B are all normal will be explained using the sequence diagram shown in FIG.

First, assuming that the storage station 3A is on the sending side and the storage station 3B is on the receiving side, an operation is performed to call the storage station 3A from the facsimile terminal 5 on the sending side. Then, in response to this call, a response signal is sent back from the storage station 3A to the sending facsimile terminal 5. Therefore, when the sending facsimile terminal 5 transmits the dial number of the storage device 2 of the storage station 3A, in response, the storage device 2 sends back a response signal via the exchange 1 indicating that storage is possible. As a result, the sending facsimile terminal 5 transmits the facsimile image signal to the storage station 3A. As a result,
The facsimile image signal is stored in the storage device 2 of the storage station 3A.

When the facsimile image signal is stored in the storage station 3A, the storage station 3A calls the central station 6, transmits the dial number of the storage device 2 of the central station 6, and establishes a line connection with the central station 6. At this time, the central station 6 receives this dial number and sends it to the receiving storage station 3B.
When a call is made and a response signal is returned from the storage station 3B, this response signal is returned as is to the transmitting storage station 3A. This means that the receiving storage station 3B is operating normally, so
The transmitting storage station 3A transmits the dial number of the storage device 2 of the receiving storage station 3B, and on the condition that a subsequent response signal is returned, the already stored facsimile image signal is sent to the receiving storage station 3B. to be transmitted. As a result, the facsimile image signal stored in the storage station 3A is transmitted to and stored in the storage device 2 of the receiving storage station 3B.

When the facsimile image signal is stored in the receiving side storage station 3B, the storage station 3B calls the receiving side facsimile terminal 5 and sends a dial number to establish a mutual line connection, and then the facsimile image signal is stored in its own station. The facsimile image signal is transmitted to the receiving facsimile terminal 5.

Through such operations, the facsimile image signal is transmitted from the sending facsimile terminal 5 to the receiving facsimile terminal 5.

Therefore, under normal conditions, the central station 6 is the storage station 3.
This means that only the exchange operation between A and 3B is performed.

Next, the operation when a failure occurs in the storage function of the storage station 3A will be described with reference to the sequence diagram shown in FIG.

In this case, even if the sending facsimile terminal 5 sends the dial number of the storage device 2 of the storage station 3A, a response signal is not returned, so the sending facsimile terminal 5 determines that a failure has occurred in the storage station 3A. and calls the storage device 2 of the central station 6,
and send the dial number. Then, when the response signal is returned, a facsimile image signal is transmitted and stored in the storage device 2 of the central office 6.

The facsimile image signal stored in the central station 6 is then transmitted to and stored in the receiving storage station 3B by the line connection operation of the central station 6, and further transmitted to the receiving facsimile terminal 5 via this storage station 3B. Ru.

That is, when a failure occurs in the storage station 3A, the sending facsimile terminal 5 transmits the dial number of the storage device 2 of the central station 6, and the central station 6 stores and receives the facsimile image signal of the facsimile terminal 5 on its behalf. It is transmitted to the side storage station 3B.

Next, the operation when a failure occurs in the storage function of the storage station 3B will be explained with reference to the sequence diagram shown in FIG.

In this case, the transmitting side storage station 3A calls the central station 6, and the central station 6 further calls the receiving side storage station 3B and sends a dial number.
An attempt is made to establish a line connection between the storage stations 3A and 3B, but since a normal response signal is not received from the storage station 3B, the sending storage station 3A determines that there is a failure in the receiving storage station 3B. The dial number of the storage device 2 of the central office 6 is transmitted. Then, at the stage when the response signal has been changed, the already stored facsimile image signal is transmitted and stored on behalf of the storage device 2 of the central office.

Thereafter, the central station 6 that performed the storage on behalf of the user calls the receiving facsimile terminal 5 via the exchange 1 of the receiving storage station 3B, establishes a line connection, and transmits the already stored facsimile image signal to the receiving facsimile terminal 5. do.

That is, if a failure occurs in the storage function of the receiving storage station 3B, the central station 6 stores the facsimile image signal from the transmitting storage station 3A on behalf of the central station 6, and then transmits the facsimile image signal via the exchange 1 of the receiving storage station 3B. and directly transmits it to the receiving facsimile terminal.

Incidentally, whether or not the central station 6 is allowed to store facsimile image signals on behalf of the central station 6 depends entirely on the response from the partner storage station. However, the response signal may not be detected due to a momentary line interruption or equipment malfunction. In such a case, even though the storage station is normal, the central station will store the image signal on behalf of the central station, which is undesirable in terms of system operation. Therefore, the storage device 2 of the central station 6 is configured to collect information regarding the storage functions of all storage stations at any time and detect the presence or absence of a failure, and reject requests for substitution from stations that have not obtained this failure information. I'm starting to do that.

This eliminates unnecessary storage on behalf of the central station 6, and prevents a drop in transmission efficiency.

〔Effect of the invention〕

As explained above, the present invention connects a plurality of storage stations through a central station having the same configuration as these storage stations, and when a failure occurs in the storage function of a storage station on the transmitting or receiving side, the failure occurs in the storage station. Since the central station is responsible for storing facsimile image signals, even if a failure occurs in the storage station, facsimile image signals can be transmitted without sacrificing the advantages of the store-and-forward method, improving system reliability. can do. In addition, since the central station is shared by each storage station, the configuration can be made cheaper than when a spare storage device is installed at each storage station. If a function is provided to monitor the system, it can be used to manage the entire system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional facsimile image signal exchange system, FIG. 2 is a system configuration diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing details of the main parts of FIG. 4 to 6 are sequence diagrams for explaining the operation. 1...Switching machine, 2...Storage device, 3A to 3F...
...Storage station, 4...Relay line, 5...Facsimile terminal, 6...Central station.

Claims (1)

[Scope of Claims] 1. A system having a plurality of storage stations each consisting of an exchange and a storage device, in which facsimile image signals temporarily stored in the storage devices are stored in the other storage station via a relay line connecting the storage stations. In a facsimile image signal storage/exchange method for transmitting facsimile image signals to a device, the plurality of storage stations are connected via a central station having the same configuration as these storage stations, and if a failure occurs in the storage function of the storage station on the transmitting or receiving side, the failure occurs. A facsimile image signal storage and exchange system characterized in that the facsimile image signals of the generating and storage stations are stored by the central station and the facsimile image signals are transmitted between the storage stations. 2. A patent claim characterized in that when a failure occurs in a storage station on the transmitting side, a facsimile terminal connected to the storage station calls a storage device to a central station and causes the storage device of the central station to store facsimile image signals on its behalf. The facsimile image signal storage and exchange method described in item 1. 3. Claim 1, characterized in that when a failure occurs in the storage station on the receiving side, the storage station on the transmitting side calls the storage device in the central station and causes the central station to store the facsimile image signal in the storage device on behalf of the central station. The facsimile image signal storage and exchange method described in . 4. The central station has a means for monitoring the storage function of each storage station, and does not perform storage of facsimile image signals if the storage function of the corresponding storage station is normal when requesting storage of facsimile image signals. A facsimile image signal storage and exchange system according to claim 1.