JP3215484B2 - Control method for ISDN terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling an ISDN terminal device having a group 3 facsimile transmission function and a call function, using an ISDN as a transmission line, and a method of using an ISDN as a transmission line. The present invention relates to a method for controlling an ISDN terminal device having a transmission function.

[0002]

2. Description of the Related Art In an ISDN, data transmission is possible by connecting a group 3 facsimile apparatus in the same manner as a public telephone line, and when the wiring on the subscriber side is a passive bus type, the same subscriber number is used. A plurality of terminal devices having different terminal characteristics can be connected to the basic interface (ISDN number).

In addition, ISDN defines a multiple subscriber number service in which a plurality of subscriber numbers can be set for the same basic interface. For each subscriber number, a user can arbitrarily select different types of services. A terminal device can be connected.

[0004] Thus, for example, a group 3 facsimile apparatus and a telephone apparatus can be connected to the same basic interface and used independently. In this way, the user can arbitrarily set the usage status of the terminal on the subscriber line, so that the degree of freedom when using ISDN is very high.

[0005]

However, conventionally,
The following inconveniences have occurred.

For example, when a group 3 facsimile apparatus is connected to a public telephone line, a call operation is performed manually, a meeting is made with an operator of a partner terminal, and an image information transmission operation is started by manual operation. Image information transmission by a so-called manual transmission procedure is possible.

On the other hand, the following situation occurs in ISDN.

As described above, in ISDN, a plurality of types of terminal devices can be connected to a basic interface having the same subscriber number. Therefore, in a call setup procedure performed between the ISDN and the terminal device, It is stipulated that a terminal function is specified when a call is made.

[0009] As a display of this terminal function, for example, a "communication capability" information element and a "higher layer consistency"
There are information elements, and these information elements are included in the call setup message that the calling terminal sends to the ISDN at the time of calling.

[0010] The "transmission capability" information element indicates whether the content of information to be transmitted is voice, unrestricted digital information, restricted digital information, 3.1KHz audio, 7KHz audio, or video. It consists of information that expresses the ability. The "higher layer compatibility" information element is used for checking the compatibility with the partner terminal. For example, telephone, group 2 / group 3 facsimile, group 4 facsimile, mixed mode, teletex, video Tex, Telex,
Displays which terminal function is provided from among terminal functions such as audio-visual and a message handling system.

Here, considering the manual transmission procedure described above, in order to make a call using the telephone function first,
The terminal device sets the data representing the voice in the “communication capability” information element and sends a call setup message in which the data representing the telephone is set in the “higher layer compatibility” information element to the ISDN, and issues the other terminal. Call.

[0012] For this reason, if the group 3 facsimile apparatus on the receiving side does not have a call function, it cannot answer this call and cannot perform the image information transmission operation intended by the user on the calling side. Things happen.

When a telephone device other than the group 3 facsimile device is connected to the called subscriber's line, a telephone function is set as a terminal function in this call, so that a response is made. This is a telephone device, which causes a problem that a call cannot be connected to a group 3 facsimile device.

Incidentally, ISDN has an inter-network connection function with a public telephone line network. Therefore, a telephone device or a group 3 facsimile device connected to the ISDN and a telephone device connected to the public telephone line network are provided. Data transmission is possible between the device and a group 3 facsimile device.

On the other hand, depending on the ISDN, the setting of the “transmission capability” information element is limited to “voice” in the inter-network connection function with the public telephone line network.

When such an ISDN is interposed between the calling terminal and the called terminal, the calling terminal adds "3.1 KHz audio" to the "transmission capability" information element in the same manner as a normal call. If set, this call is rejected, causing a disadvantage that the intended image information transmission operation cannot be performed.

The present invention has been made in view of such circumstances, and has as its object to provide a control method for an ISDN terminal device capable of performing an image information transmission operation according to a manual transmission procedure. Also, in the inter-network connection function with the public telephone line network, even if an ISDN that limits the setting of the “transmission capability” information element to “voice” is interposed,
It is another object of the present invention to provide a control method for an ISDN terminal device capable of performing an appropriate image information transmission operation.

[0018]

SUMMARY OF THE INVENTION The present invention relates to a method for controlling an ISDN terminal device using an ISDN as a transmission path and having a group 3 facsimile transmission function.
ISDN number for Group 3 facsimile and I for telephone
A storage means for storing an SDN number; when an incoming call is detected, data representing "voice" is set in a "transmission capability" information element of the received call setup message;
The "Destination number" information element contains an I for group 3 facsimile.
If the SDN number is set and the ISDN number for the group 3 facsimile stored in the storage means does not match the ISDN number for the telephone, it is determined that the call is for the group 3 facsimile transmission function. A group 3 facsimile transmission operation is performed.

[0019] Also, an ISDN having a group 3 facsimile transmission function while using ISDN as a transmission path.
In the control method of the N terminal device, at the time of group 3 facsimile communication, a call is transmitted by transmitting a call setting message in which data indicating "3.1 KHz audio" is set in a "transmission capability" information element to a designated destination. When
When the called destination rejects the incoming call in response to the predetermined call setting message, the contents of the "reason indication" information element included in the call setting message received from the called destination are examined, and the incoming call rejection is performed. If the reason is that the call can be re-established, a call setup message in which the data indicating "voice" is set in the "transmission capability" information element is transmitted to the designated destination and the call is made again. It was made. In addition, the call setting message sent at the time of the re-calling includes:
Do not add the “Higher layer compatibility” information element.

[0020]

[0021]

[0022]

Therefore, at the time of manual transmission operation, data representing "3.1 KHz audio" is set in the "transmission capability" information element, and "group 2 / group 3 facsimile" is set in the "higher layer consistency" information element. Is transmitted, a group 3 facsimile apparatus connected to the designated subscriber's line can be appropriately called. When an incoming call is detected, the value of the “communication capability” information element is set to “voice”.
In this case, if it can be determined that the facsimile function is designated, the incoming call is answered by the facsimile function. Therefore, even if the call is made by the manual transmission operation, an appropriate incoming call response can be made. In addition, when an incoming call is rejected when a call is made using the value of the information element at the time of a normal call, the setting of the “transmission capability” information element is limited to “voice”.
Since recall operation is performed assuming that N intervenes,
The probability that the call connection with the partner terminal can be properly performed is improved, and the communication possibility is improved.

[0023]

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

FIG. 1 shows a group 3 facsimile apparatus according to an embodiment of the present invention. This group 3 facsimile apparatus uses ISDN as a transmission path and also has a call function.

In FIG. 1, a system control unit 1 executes an operation control process of the facsimile apparatus, a group 3 facsimile transmission procedure process, and a call procedure process. It stores a processing program to be executed and various data necessary for executing the processing program, and configures a work area of the system control unit 1.

The parameter memory 3 stores various kinds of information unique to the facsimile machine.
It is composed of a rewritable nonvolatile semiconductor storage device such as a battery-backed SRAM (static random access memory).

The scanner 4 is for reading a document image at the resolution set in the group 3 facsimile apparatus, and the plotter 5 is for recording and outputting the image at the resolution set in the group 3 facsimile apparatus. is there.

The operation display unit 6 is used to operate the facsimile machine, and includes various operation keys and
It comprises various display devices such as a liquid crystal display for displaying guidance information and the like to the operator.

The encoding / decoding unit 7 encodes and compresses the image signal by a predetermined encoding method, and decodes the encoded and compressed image information into the original image signal. The image processing unit 8 performs a pixel density conversion process, a scaling process, and the like. The image storage device 9 includes a transmission image signal,
This is for storing various information such as transmission image information, reception image information, and reception image signal.

The tone generating circuit 10 generates various tone signals such as a ringing tone, and the tone signals are applied to a speaker 11. Therefore, an audio signal corresponding to the tone signal output from tone generation circuit 10 is output from speaker 11.

[0031] The ISDN interface circuit 12
Physically connected to DN and ISDN Layer 1
And a function of integrating / separating a signal of D channel (signal channel) and a signal of B channel (information channel).

The D-channel transmission control unit 13 is for performing transmission control processing such as call control processing performed with ISDN using the D channel.
This is for performing an analog signal / digital data signal conversion process for transmitting an analog signal using the DN B channel.

The group 3 facsimile modem 15 is for realizing a group 3 facsimile modem function, and a low-speed modem function (V.21 modem) for exchanging transmission procedure signals, and mainly for transmitting image information. High-speed modem function for exchange (V.29 modem, V.29 modem)
27 ter modem).

The switching circuit 16 connects the analog signal connection terminal of the CODEC 14 to the group 3 facsimile modem 15,
Alternatively, it is for switching connection to one of the handsets 17 for talking.

System control unit 1, system memory 2, parameter memory 3, scanner 4, plotter 5, operation display unit 6, encoding / decoding unit 7, image processing unit 8, image storage device 9, tone generation circuit 10, D Channel transmission control unit 13,
CODEC 14, Group 3 facsimile modem 15,
The switching circuit 16 is connected to a system bus 18, and various types of information are exchanged between these elements mainly through the system bus 18. A hook signal HS indicating a hook state of the handset 17 is applied to the system control unit 1 via the system bus 18.

FIG. 2 shows an example of a call control procedure in a circuit switching mode performed by a terminal device connected to ISDN with ISDN.

That is, the calling terminal first sets the circuit switching mode as the transfer mode, and sends a call setup message SETUP designating the destination terminal to the destination to the ISDN to request a call setup with the destination terminal. Sends a call setup message SETUP to the designated destination terminal to make a call. Further, the ISDN sends a call setting acceptance message CALL_PROC for notifying the call setting status to the calling terminal.

Upon detecting an incoming call, the called terminal sends a call message ALERT to ISDN when the own terminal is ready to receive a call, and the ISDN sends a call message ALERT to the calling terminal to call the called terminal. Notify that it has started.

When the called terminal responds to the incoming call, it sends a response message CONN to the ISDN, and the ISDN sends a response message CONN to the calling terminal to notify that the called terminal has accepted the call.

The ISDN sends a response confirmation message CONN_ACK to the destination terminal to confirm the response of the destination terminal, and at that time, an information channel (B channel) for data transmission between the calling terminal and the destination terminal. Is established.

Thus, data transmission using the information channel is performed between the originating terminal and the destination terminal according to the transmission control procedure set for the transmission function of each terminal.

When the data transmission is completed, the originating terminal sends a disconnection message DISC to the ISDN to request the release of the information channel.
An EL is sent to the calling terminal to notify the recovery of the information channel. On the other hand, the ISDN sends the disconnect message DI
An SC is transmitted to request the release of the information channel, and the destination terminal sends a release message REL to the ISDN to notify the restoration of the information channel.

As a result, the originating terminal sends a release completion message REL_COMP for notifying the completion of channel disconnection to IS
In response to the DN, the information channel between the calling terminal and the ISDN is released. At the same time, the ISDN sends a release completion message REL_COMP to the destination terminal,
The information channel between N and the terminating terminal is released. Thereby, the information channel set between the calling terminal and the called terminal is completely released.

Thus, an information channel is set between the calling terminal and the called terminal, data transmission is performed, and when the data transmission is completed, the information channel is released.

As shown in FIG. 3A, each message for ISDN call setting is a protocol specification (format, format,
Protocol identifier)
A call number to identify which call the message is involved in, a message type to identify the content of each message, mandatory information elements that are always added to each message, and each message And additional information elements that are added as needed. Note that 0, 1, or a plurality of essential information elements are set according to the message type, and 0, 1, or a plurality of additional information elements are arranged according to the situation.

The call setup message SETUP has "communication capability" as an essential information element, as shown in FIG.
The additional information elements include, for example, "calling number",
It has information elements such as "destination number", "destination sub-address", "lower layer compatibility", "higher layer compatibility", and "user / user".

The release completion message REL_COM
P has, for example, "reason display" as an essential information element, and has information elements such as "display" and "user / user" as additional information elements.

The outline of these information elements will be described.

The “transmission capability” information element indicates whether the content of information to be transmitted is voice, unrestricted digital information, restricted digital information, 3.1 kHz audio, 7 kHz audio, or video. Capability, transfer mode indicating whether the switching function used is circuit switching or packet switching, information transfer speed indicating information transfer speed, information indicating information transfer mode, information indicating user information protocol, etc. Consists of

The “calling number” information element is the ISDN of the calling terminal.
A number is shown, and a “calling subaddress” information element shows a subaddress set in the calling terminal. The “destination number” information element indicates the ISDN number of the destination terminal,
The “destination subaddress” information element indicates a subaddress set in the destination terminal. The contents of the sub-address can be arbitrarily defined by the user.

[0051] The "lower layer consistency" information element is to be used for a communication possibility check with the partner terminal.
The basic content is the same as the "communication capability" information element. Further, the "lower layer consistency" information element includes more detailed contents.

The "higher layer compatibility" information element is used for checking the compatibility with the partner terminal, and includes, for example, telephone, group 2 / group 3 facsimile, group 4 facsimile, mixed mode, teletex,
Displays which terminal function is provided among terminal functions such as Videotex, Telex, Audio-Visual, and Message Handling System.

The "user / user" information element is used for transmitting information between users, and the content of the "user / user" information element is transmitted transparently without being interpreted by ISDN. It is transmitted to the other user.

The “reason indication” information element is a message including the information element (in this case, the release completion message REL_
(COMP) is generated, and diagnostic information indicating the reason for the error that occurred during the call setup procedure and the like is notified.

The "display" information element is for displaying various display information from the ISDN to the user.

With the above configuration, when in the standby state, the system control unit 1 performs the operation as shown in FIG.

That is, it is monitored whether a document has been set on the scanner 4, whether the handset 17 has gone off-hook, whether an incoming call has been detected, or whether another function has been selected by the user (judgments 101, 102, 103, 104). N
O loop), judgment is made when a document is set on the scanner 4 10
If the result of step 1 is YES, the switching circuit 16
After connecting the EC 14 to the group 3 facsimile modem 15, a facsimile transmission process (process 105) is executed,
When the off-hook is detected and the result of the judgment 102 is YES, the switch circuit 16 connects the CODEC 14 to the handset 17 and then executes a call process (process 106).
When the result of the judgment 103 that the incoming call is detected becomes YES, the incoming call processing (process 107) is executed, and when the user selects any function and the result of the judgment 104 becomes YES, the user responds to the selected function. Execute the process (process 108)
Upon completion of each process, the process returns to the standby state.

FIGS. 5 and 6 show an example of facsimile transmission processing (processing 105).

The system control unit 1 determines whether the user operates a start key (not shown) of the operation display unit 6, the user picks up the handset 17 and goes off-hook, or performs another operation such as inputting a number. Is monitored (NO loop of determinations 201, 202, and 203).

When the user performs another operation such as inputting a number and the result of determination 203 becomes YES, the input process (process 204) of the selected operation is executed and the input data is stored.

When the start key is turned on and the result of the judgment 201 becomes YES, it means that a normal automatic calling operation has been performed, and the "transmission capability" information element of the call setting message SETUP contains "3.1 KHz". In addition to setting data representing "audio", data representing "group 2 / group 3 facsimile" is set in the "higher layer compatibility" information element (process 205), and the call setup message SETUP is sent to ISDN. Call the designated destination (process 206).

Next, a predetermined call setting procedure is executed (step 207), and when an information channel is established with the partner terminal (step 208), a predetermined group 3 facsimile transmission procedure is executed using the information channel. Then, the transmission image information is transmitted to the partner terminal (step 209).

When the group 3 facsimile transmission procedure using the information channel is completed (process 210), a predetermined call disconnection recovery operation is performed (process 211), and a series of transmission operations is completed.

When the user is off-hook in the call waiting state and the result of determination 202 is YES, in this case, the user performs a group 3 facsimile transmission operation after talking with the user of the partner terminal. Since the transmission operation has been started, the switching circuit 16
After the EC 14 is connected to the handset 17, the user inputs a number (step 212).

When the number input is completed, data indicating “3.1 KHz audio” is set in the “transmission capability” information element of the call setup message SETUP, and
Data indicating “Group 2 / Group 3 facsimile” is set in the “Higher layer compatibility” information element (process 213), and the call setup message SETUP is sent to ISDN.
To send the designated destination (process 21).
4).

Next, a predetermined call setting procedure is executed (process 215), and when an information channel is established with the partner terminal (process 216), a call is made between the user of the own terminal and the user of the partner terminal. It is. In this state, it is monitored whether the start key is turned on, an on-hook is detected, or a disconnection message DISC is received (decisions 217, 21).
8,219 NO loop).

When the start key is turned on and the result of determination 217 is YES, a predetermined group 3 facsimile transmission procedure is executed using the information channel, and the transmission image information is transmitted to the partner terminal (step 220). .

When the group 3 facsimile transmission procedure using the information channel is completed (process 221), a predetermined call disconnection recovery operation is performed (process 222), and a series of transmission operations is completed.

Further, the on-hook is detected and the judgment 218 is made.
When the result of step (3) is YES, a disconnection message DISC is transmitted (step 223), a release message REL is received (step 224), and a release completion message REL_COMP is received.
Is sent (process 225), and the series of operations is terminated.

When the disconnection message DISC is detected and the result of decision 219 is YES, a release message REL is sent out (process 226), and a release completion message REL_COMP is received (process 227), and a series of operations is performed. finish.

As described above, in this embodiment, even when the manual transmission operation is started, the data indicating "3.1 KHz audio" is set in the "transmission capability" information element, and the "higher layer consistency" is set. A call setup message SETUP in which data representing "group 2 / group 3 facsimile" is set in the information element is transmitted to call the other terminal, so that if the other terminal has the group 3 facsimile function, an incoming call response is made. And can communicate.

FIG. 7 shows an example of the call process (process 106).

First, the user inputs a number (step 301), and when the number input is completed, a call setting message S
The data indicating "voice" is set in the "communication capability" information element of ETUP, and the data indicating "telephone" is set in the "higher layer compatibility" information element (process 3).
02), the call setting message SETUP is sent to ISDN, and a designated destination is called (process 303).

Next, a predetermined call setting procedure is executed (process 304), and when an information channel is established with the partner terminal (process 305), a call is made between the user of the own terminal and the user of the partner terminal. It is. In this state, it is monitored whether an on-hook is detected or a disconnection message DISC is received (NO loop of determinations 306 and 307).

Further, the on-hook is detected, and the decision 306 is made.
Is YES, the disconnection message DISC is transmitted (process 308), the release message REL is received (process 309), and the release completion message REL_COMP is received.
Is sent (process 310), and a series of operations is terminated.

When the disconnection message DISC is detected and the result of decision 307 is YES, a release message REL is sent out (process 311), and a release completion message REL_COMP is received (process 312). finish.

FIGS. 8 and 9 show an incoming call process (process 10).
7) shows an example.

The system control unit 1 sends the call setting message S
The ETUP information element is analyzed (process 401), and data representing "voice" is set in the "communication capability" information element, and data representing "telephone" is set in the "higher layer compatibility" information element. Check (judgment 40
2) If the result of determination 402 is NO, data representing “3.1 KHz audio” is set in the “transmission capability” information element, and “group 2 / group 3” is set in the “higher layer compatibility” information element. A check is made to see if data representing "facsimile" has been set (decision 40).
3). If the result of determination 404 is NO, the incoming call is ignored because the calling terminal and the terminal capability are different (process 4).
04).

When the result of the judgment 402 becomes YES, since the call for the telephone function is received at this time, the switching circuit 1
6, after the CODEC 14 is connected to the handset 17, the generation of a ringing tone is started from the tone generation circuit 10 (process 405), a call message ALERT is transmitted (process 406), and the process waits until the user goes off-hook (decision 40).
7 NO loop).

When the user picks up handset 17 and detects an off-hook, and the result of decision 407 is YES,
A response message CONN is sent out (process 408), the generation of the ringing tone from the tone generation circuit 10 ends, and a response confirmation message CONN_ACK is received (process 41).
0).

As a result, an information channel is established, and a call is made between users using the information channel. In this state,
It waits until an off-hook is detected or a disconnection message DISC is received (NO loop of determinations 411 and 412).

When off-hook is detected and the result of determination 411 is YES, a disconnection message DISC is sent (process 413), a release message REL is received (process 414), and a release completion message REL_COMP is sent (process 413). 415), a series of operations ends.

When the disconnection message DISC is detected and the result of decision 412 is YES, a release message REL is sent out (process 416), and a release completion message REL_COMP is received (process 417). finish.

When the result of the judgment 403 is YES, the call for the group 3 facsimile function is received. Therefore, after the switching circuit 16 connects the CODEC 14 to the group 3 facsimile modem 15, a predetermined call setting procedure is executed ( In process 418), when an information channel is established with the partner terminal (process 419), a predetermined group 3 facsimile transmission procedure is executed using the information channel, and image information is received (process 420).

When the group 3 facsimile transmission procedure using the information channel is completed (process 421), a predetermined call disconnection recovery operation is performed (process 413), and a series of transmission operations is completed.

In this way, when there is an incoming call by the telephone function, predetermined call processing is performed, and when there is an incoming call by the group 3 facsimile function, the image is processed by the group 3 facsimile transmission procedure. An information receiving operation is performed.

FIG. 10 shows a group 3 facsimile apparatus according to another embodiment of the present invention. This group 3 facsimile machine uses ISDN as a transmission line,
Only Group 3 facsimile transmission function is provided. In the figure, the same parts as those in FIG. 1 and corresponding parts are denoted by the same reference numerals.

In the figure, the system control section 1 executes the operation control processing of the facsimile apparatus and the group 3 facsimile transmission procedure processing. The analog signal side connection end of the CODEC 14 is connected to the group 3 facsimile modem 15.

In this embodiment, the subscriber line to which this group 3 facsimile apparatus is connected can cope with a case where a plurality of subscriber numbers are set.
As shown in FIG. 11, a facsimile ISDN number set for the group 3 facsimile transmission function and a telephone ISDN number set for the telephone function are stored in the parameter memory 3. These ISDN numbers are registered when the user operates and inputs the operation display unit 6. However, when only the facsimile ISDN number is registered, the same ISDN number is also registered in the telephone ISDN number.

Although the group 3 facsimile apparatus is not provided with a call function (telephone function), if the home wiring to which the group 3 facsimile apparatus is connected is of a passive bus type, it is connected to the same passive bus. A telephone terminal may be connected, and in such a case, a plurality of subscriber numbers may be set.

FIG. 12 exemplifies a calling operation executed by this group 3 facsimile apparatus.

When a call operation is performed, the system control unit 1 sets data representing “3.1 KHz audio” in the “transmission capability” information element of the call setup message SETUP, and sets the “higher layer compatibility” information. Data indicating "group 2 / group 3 facsimile" is set in the element (process 501), the call setup message SETUP is sent to ISDN, and a designated destination is called (process 502).

Next, a message is received until a response message CONN or a release completion message REL_COMP is received (process 503, judgment 504, 505).
NO loop), when the partner terminal responds normally, the response message CONN is received, and the result of decision 504 is YE
When it becomes S, an information channel is established with the partner terminal (process 506).

Then, a predetermined group 3 facsimile transmission procedure is executed using the information channel, the transmission image information is transmitted to the partner terminal (step 507), and the group 3 facsimile transmission procedure using the information channel is completed (processing 507). 508), execute a predetermined call disconnection recovery operation (process 5).
09), a series of transmission operations ends.

When the call with the partner terminal is rejected, a release completion message REL_COMP is received, and a decision 505 is made.
If the result is YES, the contents of the "reason display" information element is examined to determine whether the rejection reason is a recallable one (decision 510). Here, the content of the "reason display" information element that can be recalled depends on the ISDN function (service) to which the called terminal is connected.

When the content of the "reason display" information element is a content that can be recalled, and the result of determination 510 is YES, the retransmission call process in the transmission capability change mode is activated (processing 51)
1) End a series of operations. If the content of the "reason display" information element is a content that cannot be recalled, and the result of determination 510 is NO, the process ends with an error (step 51).
2) End a series of operations. In this case,
The contents of the “reason display” information element may be displayed on the operation display unit 6 to draw the user's attention.

FIG. 13 shows an example of the transmission capability change mode recall process.

In this case, data representing "voice" is set in the "transmission capability" information element of the call setup message SETUP (process 601), and the call setup message SETUP without adding the "higher layer compatibility" information element is sent to ISDN. The call is transmitted and the designated destination is called (process 602).

Next, message reception is performed until the response message CONN or the release completion message REL_COMP is received (processing 603, determination 604, 605).
NO loop), when the partner terminal responds normally, the response message CONN is received, and the result of decision 604 is YE
When it becomes S, an information channel is established with the partner terminal (step 606).

Then, a predetermined group 3 facsimile transmission procedure is executed using the information channel, the transmission image information is transmitted to the partner terminal (step 607), and the group 3 facsimile transmission procedure using the information channel is completed (processing 607). 608), execute a predetermined call disconnection recovery operation (process 6).
09), a series of transmission operations ends.

When the call with the partner terminal is rejected, a release completion message REL_COMP is received, and a decision 605 is made.
When the result of step (1) is YES, the process ends in an error (process 610), and the series of operations ends.

As described above, if the incoming call is rejected at the time of the first call, and if the reason for the incoming call rejection is that the call can be re-established, the “voice transmission capability” information element of the call setup message SETUP contains “voice transmission capability”. And set the data that represents
Since the call is re-established by sending the call setup message SETUP without adding the "higher layer compatibility" information element, ISDN which limits the setting of the "transmission capability" information element to "voice" between the called terminal and In the case of intervening, at the time of recall, a response from the called terminal can be expected, and an appropriate image information transmission operation can be performed.

FIG. 14 shows an operation example when a call is received.

First, the information element of the call setup message SETUP is analyzed (determination 701), and it is checked whether or not data indicating “voice” is set in the “transmission capability” information element (determination 702).

When the result of decision 702 is YES,
It is checked whether the value of the "destination number" information element matches the ISDN number for facsimile (decision 703). Judgment 7
When the result of step 03 is NO, the call is to the telephone terminal and the call is ignored (step 704).

If the result of decision 703 is YES, it is checked whether the facsimile ISDN number and the telephone ISDN number match (decision 705), and if they match and the result of decision 705 is YES, This is a case where a plurality of subscriber numbers are not set, and processing 70
4 and ignore this incoming call.

If the result of decision 705 is NO,
When a plurality of subscriber numbers are set, it can be considered that the calling terminal has originated a call for the group 3 facsimile transmission function. Is established (operation 706),
A predetermined group 3 facsimile transmission procedure is executed using the information channel, and image information is received from the partner terminal (step 707).

When the group 3 facsimile transmission procedure using the information channel is completed (process 708), a predetermined call disconnection recovery operation is executed (process 709), and a series of transmission operations is completed.

If the data indicating “voice” is not set in the “transmission capability” information element,
If the result of step 2 is NO, data representing "3.1 KHz audio" is set in the "transmission capability" information element and "group 2 / group 3 facsimile" is represented in the "high layer compatibility" information element. It is checked whether data has been set (decision 710). Judgment 71
When the result of 0 is NO, since the calling terminal and the terminal capability are different, the process shifts to step 704 to ignore the incoming call.

If the result of decision 710 is YES, the process moves to step 706 and the subsequent steps are executed.
A group 3 facsimile transmission operation is performed with the partner terminal to receive image information.

As described above, in the present embodiment, when it is determined that the other terminal has requested the group 3 facsimile transmission function at the time of detecting the incoming call, the incoming call is answered and the group 3 facsimile reception operation is performed. Because
The communication possibility increases, and the usability of the group 3 facsimile terminal device improves.

[0112]

As described above, according to the present invention,
At the time of manual transmission operation, data representing "3.1 KHz audio" is set in the "transmission capability" information element, and data representing "group 2 / group 3 facsimile" is set in the "higher layer consistency" information element. Since the call setting message is transmitted, the group 3 facsimile connected to the designated subscriber's line can be appropriately called. Also, when an incoming call is detected, even if the value of the "transmission capability" information element is "voice", if it can be determined that the facsimile function has been designated, the incoming call is answered by the facsimile function, so the call is sent by manual transmission operation. In this case, an appropriate incoming call response is possible. When an incoming call is rejected when a call is made using the value of the information element at the time of a normal call, an ISDN that limits the setting of the “transmission capability” information element to “voice” is interposed. Since the re-call operation is performed assuming the case, the probability that the call connection with the partner terminal can be appropriately performed is improved, and the effect that the communication possibility is improved is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a group 3 facsimile apparatus according to one embodiment of the present invention.

FIG. 2 is a time chart showing an example of a call control procedure performed between an ISDN and a terminal device.

FIG. 3 is a schematic diagram showing an example of a signal format of a call setup signal and information elements of a call setup message.

FIG. 4 is a flowchart showing a processing example of the apparatus of FIG. 1 in a standby state.

FIG. 5 is a flowchart illustrating a part of an example of a facsimile transmission process.

FIG. 6 is a flowchart showing another part of the example of the facsimile transmission process.

FIG. 7 is a flowchart illustrating an example of a call process.

FIG. 8 is a flowchart illustrating a part of an example of a facsimile reception process.

FIG. 9 is a flowchart illustrating another example of the facsimile reception process.

FIG. 10 is a block diagram showing a group 3 facsimile apparatus according to another embodiment of the present invention.

FIG. 11 is a schematic diagram showing an example of information stored in a parameter memory.

FIG. 12 is a flowchart showing a processing example at the time of calling by the apparatus of FIG. 10;

FIG. 13 is a flowchart illustrating an example of a transmission capability change mode recall process.

FIG. 14 is a flowchart showing a processing example at the time of an incoming call of the apparatus of FIG. 10;

Claims (3)

(57) [Claims] An ISDN having an ISDN as a transmission path and having a group 3 facsimile transmission function.
In the method of controlling a terminal device, an ISDN number for group 3 facsimile and an IDN for telephone
A storage means for storing an SDN number; when an incoming call is detected, data representing "voice" is set in a "transmission capability" information element of the received call setup message;
The "Destination number" information element contains an I for group 3 facsimile.
If the SDN number is set and the ISDN number for the group 3 facsimile stored in the storage means does not match the ISDN number for the telephone, it is determined that the call is for the group 3 facsimile transmission function. Performing a group 3 facsimile transmission operation on the ISDN terminal device. 2. An ISDN having an ISDN as a transmission path and having a group 3 facsimile transmission function.
In the terminal device control method, at the time of group 3 facsimile communication, a call is transmitted to a designated destination by transmitting a call setting message in which data indicating "3.1 KHz audio" is set in a "transmission capability" information element. When the called destination rejects the call in response to the predetermined call setting message, the contents of the "reason indication" information element included in the call setting message received from the called destination are examined, and the If the reason for the rejection is a recallable one,
A method for controlling an ISDN terminal device, comprising transmitting a call setup message in which data representing "voice" is set in a "transmission capability" information element and calling again. 3. The control method for an ISDN terminal device according to claim 2, wherein a “high layer compatibility” information element is not added to the call setup message sent at the time of the re-calling.