JPH03297268A - Transmission control system for isdn terminal equipment - Google Patents

Abstract

PURPOSE:To designate an opposite terminal equipment whose subaddress is not cleared by adding function identification information representing a desired transmission function to a useruser information element of a call setting message. CONSTITUTION:A caller terminal equipment informs output information information to designate a function of a plotter 6 in use to a called terminal equipment as a user-user information element for a call setting message. The called terminal equipment upon the receipt of the call setting message checks whether or not the content of a designation function of the user-user information element added to the message is coincident with a function of the plotter 6 of its own terminal equipment stored in a parameter memory 3 and replies the call when they are coincident. Thus, even when a subaddress of an opposite terminal equipment is not cleared, the operator of the caller terminal equipment makes data transmission with the called terminal equipment provided with a desired function and the convenience of operation of the equipment is considerably improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a transmission control method for ISDN terminal equipment.

[Prior Art] The basic interface specifications for ISDN multiplex three channels, two information channels and one signal channel, into one interface, and if the connection with ISDN is made into a passive bus format, one Up to eight terminal devices can be connected to one basic interface.

In addition, when multiple terminal devices are connected to the same basic interface, the originating terminal cannot specify the desired terminal device just by specifying the ISDN number, so By setting a subaddress and using this subaddress, the originating terminal can specify the target terminal device.

[Problems to be Solved by the Invention] However, with this method, if the subaddress of the other party's terminal is not known, there is a risk that the originating terminal will not be able to specify the desired other party's terminal. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transmission control method for an SDN terminal device that can specify an appropriate partner terminal even if the subaddress of the partner terminal is not known. There is.

[Means for Solving the Problems] The present invention is provided with a storage means for storing function identification information for identifying the functions equipped in the own terminal, and the originating terminal includes a desired user information element in a call setting message. The terminating terminal adds function identification information representing the transmission function of the call setup message, and when the received call setup message includes a user-to-user information element, the function identification information added to the user-to-user information element is stored in the storage means. The incoming call is answered when the function identification information matches the stored function identification information.

[Effects] Therefore, since the originating terminal can specify the destination terminal by specifying the desired device function, etc., desired data transmission can be performed even if the subaddress is not known.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a facsimile machine according to an embodiment of the present invention. This facsimile machine uses ISDN as a transmission line and has a group 3 facsimile function, a group 4 facsimile function, and a telephone call function.

In the figure, a control unit 1 executes operation control processing of the facsimile machine, group 3 facsimile transmission procedure processing, group 4 facsimile transmission procedure processing of the upper layer, and call procedure processing, and a system memory 2 , stores a processing program executed by the control unit 1 and various data necessary for executing the processing program, and constitutes a work area of the control unit 1.

The parameter memory 3 is for storing various information specific to this facsimile machine, such as the device functions of the plotter described later, and is a battery-backed SR.
It consists of a non-volatile semiconductor memory device such as AM (static random access memory) in which data can be written.

The clock circuit 4 is for obtaining current time information,
The scanner 5 is for reading the original image at the resolution set in the Group 4 facsimile device,
The plotter 6 records and outputs images at the resolution set in the group 4 facsimile device. As the plotter 6, a thermal recording type plotter using thermal recording paper or a laser beam printer type plotter using plain paper as the recording paper is used.

The operation display section 7 is used to operate the facsimile machine, and includes various operation keys and various display devices such as a liquid crystal display for displaying guidance information to the operator.

The encoding/decoding unit 8 encodes and compresses the image signal using a predetermined encoding method, and also decodes the encoded and compressed image information into the original image signal, and performs pixel density conversion. The unit 9 is for converting the pixel densities of the images of the scanner 5 and the plotter 6 and the pixel densities of the image that can be transmitted by the destination terminal device, when the pixel densities of the images are different.

The image storage device 10 is for storing various information such as a transmitted image signal, transmitted image information, received image information, and received image signal.

The ISDN interface circuit 11 is for physically connecting to the ISDN, and is for layer 1 signal control section 12.
is equipped with an ISDN layer 1 signal processing function and a function of integrating/separating a D channel (signal channel) signal and two B channel (information channel) signals.

The D channel transmission control unit 13 uses the D channel to
It is used to perform transmission control processing such as call control processing performed with the DN, and C0DEC14 is used to perform signal conversion processing between analog signals and digital data to transmit analog signals using the ISDN B channel. It is.

The B channel transmission control unit 15 controls the ISDN B channel (
This is for performing transmission control processing of layers 2, 3, 4, and 5 of the group 4 facsimile transmission control processing using the information channel).

The group 3 facsimile modem 16 is for realizing the group 3 facsimile modem function, and has a low-speed modem function (V,
21 modem) and a high-speed modem function (V, 29 modem, V, 27ter modem) mainly for exchanging image information.

The switch 17 is used to switch and connect the CODEC 14 to either the group 3 facsimile modem 16, the handset 18 for calling, or the speaker 19 for outputting a ring tone or the like.

Control unit 1, system memory 2, parameter memory 3, clock circuit 4. Scanner 5, plotter 6, operation display section 7, encoding/decoding section 8, pixel density conversion section 9, image storage device 10
, layer 1 signal control section 12, D channel transmission control section 13
, C0DEC 14, B channel transmission control section 15, group 3 facsimile modem 18, and switching device 17,
It is connected to an internal bus 20, and exchange of various information between these elements is mainly done through this internal bus 20.
It is done through. Further, a hook signal FS representing the hook state of the handset 18 is applied to the control section 1 via the internal bus 20.

Figure 2 shows that a terminal device connected to ISDN
An example of a call control procedure in circuit switching mode performed with a DN is shown.

That is, the originating terminal first sets circuit switching mode as the transfer mode and sends a call setup message 5ETUP specifying the destination terminal to the ISDN to request call setup with the destination terminal, and the ISDN A call setup message 5ETUP is sent to the received terminal, and the call is made. Further, the ISDN sends a call setup acceptance message CALLPROC to the originating terminal to notify the call setup status.

When the destination terminal detects an incoming call, it sends a paging message ALE to the ISDN if it is ready to receive the call.
RT is continuously sent at predetermined intervals, and the SDN sends a paging message ALERT to the calling terminal to notify that it has started calling the called terminal.

When the destination terminal responds to the incoming call, it sends a response message C0NN to I
The ISDN sends a response message C0NN to the calling terminal to notify that the called terminal has accepted the call.

In addition, ISDN sends a response confirmation message C0N to the destination terminal.
A NACK is sent to confirm the response of the destination terminal, and at that point, an information channel (B channel) for data transmission is established between the originating terminal and the destination terminal.

Thereby, data transmission between the originating terminal and the destination terminal using the information channel is executed according to the transmission control procedure set in the transmission function of each terminal.

When the data transmission is finished, the originating terminal sends a disconnection message DISC to the ISDN to request release of the information channel, and the ISDN sends a disconnection message DISC to the destination terminal to notify that the information channel has been restored.

As a result, when the destination terminal responds to the ISDN with a release message REL notifying completion of channel disconnection, the ISDN sends a release message REL to the originating terminal. When the channel release is completed, the originating terminal sends a release completion message R.
Send EL-COMP to ISDN and notify that,
Thereby, ISDN sends a release completion message REL-C.
By sending the OMP to the destination terminal, the information channel is released, and the information channel set between the originating terminal and the destination terminal is completely released.

In this way, an information channel is set up between the originating terminal and the destination terminal, data transmission is performed, and when the data transmission is completed, the information channel is released.

In addition, each message for ISDN call setup is
As shown in Figure 3(a), a protocol identifier identifies the protocol specifications (format, sequence, etc.) that define a layer 3 call control message, and identifies which call the message is related to. message type to identify the content of each message, essential information elements that are always added to each message, and additional information elements that are added to each message as necessary.

Note that the required information elements are 0.
One or more additional information elements are set, and zero, one, or more additional information elements are arranged depending on the situation.

The call setup message 5ETUP, as shown in FIG. ”, “Higher Layer Consistency”, and “
It has information elements such as "User/User".

An outline of these information elements will be explained below.

The "transmission capability" information element indicates whether the content of the information to be transmitted is voice, unrestricted digital information, restricted digital information, or 3.1KH.
Information transfer ability indicating whether it is z audio, 7KHz audio, or video, transfer mode indicating whether the switching function used is circuit switching or packet switching, and information transfer rate indicating the speed of information transfer. , information representing the information transfer format, ゛, and information representing the user information protocol.

The "calling number" information element indicates the ISDN number of the calling terminal, and the "terminating number" information element indicates the ISDN number of the called terminal.

The "lower layer compatibility" information element is used to check the possibility of communication with a partner terminal, and its basic content is the same as the "transmission capability" information element.

Furthermore, this "lower layer compatibility" information element includes more detailed content.

The "higher layer compatibility" information element is used to check the compatibility with the partner terminal, for example, group 2
/Group 3 facsimile, Group 4 facsimile,
Displays which terminal function the terminal has, such as mixed mode, teletex, videotex, telex, or message handling system.

The "User-User" information element is used to convey information between users, and the contents of this "User-User" information element are transparently transferred to the other user without being interpreted by the ISDN. communicated.

In this example, as the "user-user" information element,
Output identification information for specifying the function of the plotter 6 to be used is notified to the destination terminal in a signal format as shown in FIG.

This output identification information includes an output selection identifier SID for identifying this output identification information itself, a specification function SF for specifying whether the function of the plotter 6 is thermal recording paper or plain paper, and a specified It consists of a specification class SC for specifying the manner of response to terminals equipped with functions other than the above functions.

Here, the designated class SC is either information indicating that a terminal device not equipped with the specified function cannot receive a call, or information indicating that a terminal device not equipped with the specified function can receive a call after a certain period of time. is set.

FIG. 5 shows an example of the processing of the called terminal when it receives the call setup message 5ETUP.

First, the contents of the "Transfer Capability" information element, "Low Layer Compatibility" information element, and "High Layer Compatibility" information element of the call setup message 5ETUP are checked to see if it is possible to communicate with the calling terminal. (Judgment 101), Judgment 101
When the result is YES, a "user-user" information element is added and the output selection identifier SI is added to the content.
It is checked whether D is included (decision 102).

When the result of judgment 102 is YES, the specified function S
It is checked whether the contents of F match the function of the plotter 6 of the own terminal stored in the parameter memory 3 (determination 103).

When the result of judgment 103 is NO, the specified class S
C is checked to see if a terminal that does not have the specified function can respond (decision 104).

When the result of determination 104 is YES, the process waits until a predetermined time has elapsed (process 105), and then starts a call setting procedure with the ISDN (process 106).

On the other hand, when the result of judgment 102 is NO, it means that the output paper has not been selected, and when the result of judgment 103 is YES, it means that the output paper is equipped with the recording function specified by the originating terminal. Therefore, the process moves to immediate process 106 to execute the call setting procedure, and then executes the facsimile transmission procedure (group 3 facsimile function or group 4 facsimile function) with the originating terminal to transmit image information (process 107). When the image information transmission is completed, a call release procedure is executed with the ISDN (process 108), and a series of incoming call processing is completed.

Also, if the originating terminal and the transmission function do not match, it is determined in step 101.
If the result of the call setting message 5ETUP is NO, or if the specified class SC specifies "no response" and the result of the judgment 104 is NO, the call setup message 5ETUP is ignored (process 109) and this process ends. .

With the above configuration, as shown in FIG. 6, the facsimile machine FXa connects two facsimile machines 1FXb, 1FXb, and 1FXb connected to the same S/T point (basic interface connection point).
A case will be described in which a call is made to either one of FXc. Here, the facsimile machine FXb is equipped with a plotter 6 that records images on plain paper, and the facsimile machine FXc is equipped with a plotter 6 of a thermal recording type.

The operator of facsimile machine 1FXa must
IS of facsimile machine FXb, FXc as DN number
If you specify the DN number and specify plain paper as the recording paper,
The facsimile device FXa adds a "user-user" information element to the call setting message 5ETUP sent to the ISDN, in which output selection information with plain paper set as the content of the designated function SF is set.

Note that if there is no particular designation, information indicating that a response is not possible is set as the designated class SC.

As a result, facsimile devices FXb and FXc are
From the DN, the same "user-user" as in the call setup message 5ETLIP sent from the facsimile machine tFXa
Call setup message 5ETUP with attached information element
receive.

At this time, the facsimile machine FXb that has analyzed the contents of the "user-user" information element immediately sends a response message C0NN to the ISDN in order to respond to the incoming call, and
Since this is a case where the facsimile machine FXc cannot respond, it ignores the received call setup message 5ETUP and does not perform the subsequent call setup procedure.

As a result, the facsimile machine FXa can perform the desired functions,
In this case, the facsimile machine FXb having the function of recording an image on plain paper can be appropriately called, and the transmission operation desired by the operator can be performed.

In addition, facsimile f! ! The eFXa operator
When response enabled is set as the content of the specified class SC during a call operation, the facsimile device [FXc sends a response message C0NN to the ISDN at a certain time delay than the facsimile device 1FXb, but in this case, the ISDN A call control operation is performed for the facsimile device FXb that responded with the response message C0NN first, and a release completion message RE is performed for the facsimile device FXc that responded with the response message C0NN later.
Send L-GOMP to release the call.

In this way, in this embodiment, even if the subaddress of the destination terminal is not known, data transmission can be performed with a destination terminal equipped with the functions desired by the operator of the originating terminal, which is very convenient.

In the above-described embodiment, the present invention is applied to the recording function of a facsimile machine, but the present invention can be similarly applied to specifying other functions.

Further, in the above embodiment, the present invention is applied to a facsimile machine, but the present invention can also be applied to other terminal devices.
The invention can be applied in a similar manner.

[Effects of the Invention] As explained above, according to the present invention, even if the sub-address of the destination terminal is not known, it is possible to connect to a destination terminal equipped with the functions desired by the operator of the originating terminal. The effect is that the usability is greatly improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a facsimile machine according to an embodiment of the present invention, FIG. 2 is a time chart showing an example of a call setting procedure executed with an ISDN, and FIG. (b) is a schematic diagram illustrating an example of the information elements of a call setup message. Figure 4 is a schematic diagram illustrating an example of output selection information. Figure 5 is a schematic diagram illustrating an example of the output selection information. Flowchart showing an example of processing at the time of detection, FIG. 6 is a schematic diagram for explaining the operation of the embodiment. ■...Control unit, 2...System memory, 3...Parameter memory.

Claims (1)

[Claims] The originating terminal is equipped with a storage means for storing function identification information for identifying the functions equipped on its own terminal, and the originating terminal adds the function identification information representing the desired transmission function to the user-user information element of the call setup message, and When the received call setup message includes a user-user information element and the function identification information added to the user-user information element matches the function identification information stored in the storage means, the terminal A transmission control method for an ISDN terminal device characterized by responding to incoming calls.