JP2646386B2 - ISDN terminal communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an integrated services digital network (ISDN).
etwork).

[Related Art] In recent years, the construction of ISDN has been promoted in each country, and commercial services have been started in Japan in April 1988 with some functions.

As one of the connection modes of the terminal device to the ISDN, there is a method of arranging a network terminating device on a subscriber line from the ISDN and connecting various terminal devices to a home bus drawn from the network terminating device.

In this case, the home bus corresponds to a basic interface of ISDN, and this basic interface has one D channel for transmitting a call control message and two B channels for transmitting information.

For example, an ordinary terminal device such as a telephone or a facsimile device uses one of two B channels for information transmission during communication to perform a call or data transmission. On the other hand, since it is possible to simultaneously use two B channels, conventionally, one terminal device transmits data to one destination using two B channels and simultaneously transmits data to another destination. A terminal device that performs dual processing such as receiving data from the beginning has been proposed.

[Problems to be Solved by the Invention] However, conventionally, in the case of a normal terminal device not having the dual processing function, another incoming call is not accepted during execution of one communication, and the dual processing is not performed. In the case of the terminal device having the above, other incoming calls were not accepted during the execution of the two simultaneous communications.

For this reason, there is a problem that even if an emergency call is received from another party during normal communication, the terminal device cannot perform the emergency communication.

The present invention solves the above problem, and during normal communication execution,
ISDN that can receive emergency calls and perform emergency communication
It is an object of the present invention to provide a terminal communication method.

[Means for Solving the Problems] For this purpose, the present invention relates to a terminal device that communicates using one of the B channels, which is an information channel, wherein the called side performs communication using one of the B channels During the execution, if a call setup message to which the identification information indicating the emergency communication is added and the call is received and the call is received, the call execution procedure for the communication in progress is executed, and the call setup procedure is performed in response to the incoming call. Performing the emergency communication while executing the procedure for releasing the call for the emergency communication, and then performing the procedure for resuming the interrupted call,
The suspended communication is resumed.

Further, in a terminal device having a function of simultaneously executing a plurality of communications using all information channels, the calling side first sends a call setup message requesting communication on the information channel to initiate a call. However, if the call setup message is not transmitted to the called party because the called party is using all of the information channels, a call setup message requesting packet communication using a signaling channel is then sent to the called party. While re-calling with the identification information indicating the emergency communication added, in this case, the called party, in the call control message indicating that the call cannot be received,
In addition to responding by adding identification information indicating that emergency communication can be accepted, a call interrupting procedure of one ongoing communication is executed to release one information channel, and the calling side receives the above-mentioned signal from the called side. Upon receiving the call control message and detecting the identification information indicating that the emergency communication can be accepted, the first call setup message is sent again to make a call, so that emergency communication between the calling side and the called side terminal is performed. Is to run.

[Operation] This allows the called terminal device to receive an urgent call and perform emergency communication during normal communication.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a system configuration diagram of a communication system using ISDN according to one embodiment of the present invention. In the figure, the terminal device TE _A ~TE _D is a facsimile apparatus installed in the customer premises, respectively, are connected to the network terminating device NT by home bus. Each of the network terminating devices NT is connected to the ISDN via a subscriber line.

In the present embodiment, it is assumed that the terminal device TE _A does not have a dual function of simultaneously executing image transmission and image reception, and the terminal device TE _B has a dual function. Note that either the terminal device TE _C or the terminal device TE _D may be used.

Each facsimile device installed as a terminal apparatus TE _A ~TE _D are the same configuration, shows the block diagram in Figure 2. In the figure, a scanner 1 reads a document image to extract image information, and a plotter 2 records the image information on a recording sheet. The encoding / decoding unit 3 performs encoding for compressing image information data and decoding for returning to original data. The image memory 4 stores image information to be transmitted and received image information as needed.

The ISDN interface circuit 5 has an I interface layer 1 function corresponding to the CCITT I series recommendation, and is connected to an ISDN network terminating device via a home bus. The ISDN control unit 6 has layer 2 and layer 3 functions, and manages information transferred to and from the network using the layer 1 functions. The communication control unit 7 transmits image information according to a predetermined transmission control procedure. In this embodiment, the data link for transmitting image information may be temporarily disconnected during communication in order to respond to an incoming call of emergency communication. At this time, the transmission of the image information is restarted by the above-described transmission control procedure when the data link is restarted, without causing a protocol error.

The ISDN interface circuit 5, the ISDN control unit 6, and the communication control unit 7 exchange signals on the D channel, which is a signal channel, via the local bus 8, and communicate on the B channel, which is an information channel, via the local bus 9. Is exchanging information.

The operation display unit 10 includes a display, operation keys, and the like, and displays the status of the apparatus and operation guidance, and allows the operator to perform various operations. The system control unit 11
It is composed of a microcomputer system and controls each of the above units.

The system bus 12 includes the above components and a local bus.
8 and 9 are connected, and transfer predetermined data between them.

With the above configuration, for example, as shown in FIG.
It is assumed that normal communication is being performed between the terminal devices TE _A and TE _B. Next, a case where an emergency call is made from terminal device TE _D to terminal device TE _{A at} this time will be described.

In this case, the terminal equipment TE _D, the operator allows the operation display section 10, the terminal equipment TE with the configuration indicating that emergency call
The ISDN number of _A is input, and a predetermined calling operation is performed as shown in FIG. 4 (process 101). Accordingly, by starting the terminal equipment TE _D is first call setup message "SETUP"
Is sent to ISDN (hereinafter abbreviated as network) (process 102).

As shown in FIG. 5 (a), the call setup message “SETUP” of this embodiment includes a common part common to various call control messages of the user / network interface layer 3 and an individual part different in content depending on each message. It is composed of
The common part includes a “protocol identifier”, a “call number”, and a “message type”, and the “message type” indicates that the call setup message is “SETUP”.

The individual unit is composed of “transmission capability”, “channel identifier”, “destination number”, “higher layer compatibility information”, and “user / user information”. Here, circuit switching is designated by "transmission capability", B channel is designated by "channel identifier", and "user
In the “user information”, predetermined emergency ID information for identifying that the communication is emergency communication is set.

The network receives this call setup message "SETUP",
While this message is sent to the terminal device TE _A on the called side, a call setting acceptance message “CALLPROC” is returned to the calling side.

On the other hand, the terminal device TE _A is now, as shown in FIG. 6,
Running normal communication and the terminal device TE _C (step 201).
Here, when the call setup message “SETUP” is received from the network (process 202), the “user / user information” of the message is checked (process 203). If "user / user information" is added and the emergency ID information is set in the information (Y in step 204), after transmitting a call message "ALERT" (step 205), the terminal device It sends a message "SUSP" interrupted to suspend communication with the TE _C (process 206).

The network receives the suspension message "SUSP" and, if suspension is possible, returns a suspension confirmation message "SUSP _A CK, while an information notification message" HC indicating that the call was suspended ".
TIFY "and sends to the terminal TE _C. Then, while suspending the call between TE _A and TE _C, the B channel used for communication is suspended.

Upon receiving the interruption confirmation message “SUSPACK” (Y in step 207), the terminal device TE _A sends a response message “CONN” (step 208).

Network sends back a response message "CONN" while sending the terminal equipment TE _D, an acknowledgment message "CONNACK" to the terminal TE _A.

The terminal device TE _A transmits the response confirmation message “CONN AC
Receiving a K "(Y of process 209), also, the terminal apparatus TE _D is
Upon receiving the response message “CONN” (FIG. 4, process 10)
3 "CONN"), thereby, both to perform the emergency communication (Figure 4 and processing 104, FIG. 6, process 210) When the emergency communication is finished, the terminal apparatus TE _D is
A disconnection message “DISC” is sent to execute a predetermined disconnection procedure. That is, the network sends its disconnect message "DISC"
One to be sent to the terminal TE _A, and returns a release message "REL" to the terminal apparatus TE _D. Then, the terminal apparatus TE _D sends a release complete message "REL COM".

Further, the terminal device TE _A sends a release message “REL” and receives a release completion message “REL COM” (FIG. 4, process 105, FIG. 6, process 211).

Thus, emergency communication between the terminal device TE _D and the terminal device TE _A is completed.

Thereafter, the terminal device TE _A sends a suspended call resume message “RES” to resume the suspended normal communication (process 212). Network is resumed if, while returning the restart confirmation message "RES ACK", the terminal device TE _C,
The information notification message "NOTIFY" indicating that resume the call is sent to the terminal TE _C.

Terminal TE _A receives the resume confirmation message "RES ACK" (Y of process 213), resumes normal communication with the terminal device TE _C (process 214).

By the way, when the terminal device TE _A receives the call setup message “SETUP” during the normal communication, and the “user / user information” has no emergency communication ID (N in process 204),
Sends the release completion message "REL COMP" so that incoming calls will not be accepted.

As described above, the calling side that performs emergency communication sets an emergency communication ID in the “user / user information” of the call setup message “SETUP” and makes a call. Then, the terminal without the function of performing the dual processing, during the normal communication,
When an incoming call for the emergency communication is received, the call in communication is temporarily interrupted to execute the emergency communication.

Next, for example, as shown in FIG.
_B assumes that normal communication is being performed between each of the terminal device TE _A and the terminal device TE _C , and in this case, an emergency call is made from the terminal device TE _D to the terminal device TE _B. Will be described.

In this case, the terminal device TE _D is set the message "SETUP"
Is sent to the terminal device TE _B (FIG. 4, process 1).
02) Since the other party is already using two B-channels, the release complete message "REL COM
P "is returned.

In the release completion message “REL COMP”, as shown in FIG. 5 (b), the reason why the call setting is not accepted is indicated by “reason display” which is additional information.

Terminal TE _D is, ( "REL COMP" process 103) when receiving the release completion message "REL COMP", reading the reasons (processing 106). And the other party already has two B's
If it is indicated that communication is being performed using the channel (Y in process 107), then a call setup message “SETUP” designating packet communication using the D channel is transmitted (process 108). That is, the packet is specified by the “transmission capability” of the call setup message “SETUP” shown in FIG. 5A, and the D channel is specified by the “channel identifier”. Note that the emergency ID for “user / user information” is set in the same manner.

Terminal TE _B, as shown in FIG. 8, this case, 2
The normal communication is executed using the three B channels (process 301), but the call setup message “SETUP” of the packet by the D channel is transmitted from the network to the terminal device TE _B.

When receiving the call setup message “SETUP” here (Y in process 302), the terminal device TE _B “user / user information”
The presence / absence and its contents are checked (process 303). When the emergency ID is set as the information (Y in step 304), as shown in FIG.
A release completion message "REL COMP" in which the same emergency reception ID as described above is added to "user information" is transmitted (process 305).
Next, as in the case where the terminal device TE _A executes the terminal device TE _C in FIG. 3, a predetermined temporary interruption procedure of one communication, in this example, communication with the terminal device TE _A is executed (process 30).
6).

On the other hand, the terminal device TE _D, the release completion message "REL
When "COMP" is received (FIG. 4, Y in process 109), the "user / user information" of the message is checked (process 110). If the emergency reception ID is set (Y in step 111), a predetermined time is passed (step 11).
2), call setup message "SETUP" as in process 102
Is sent to the terminal device TE _B (process 113).

Here, when the terminal device TE _B has not completed at least one of the two communications, the release completion message “REL
COMP "will be answered.

In this case (N in process 114), the call is re-established after a predetermined time (to process 113). Thus, the same call is repeated until the other party answers.

On the other hand, after the terminal device TE _B can receive a call, the terminal device T B
From E _D, the call setup message "SETUP" is sent,
Network, while sending the call setup message "SETUP" to the terminal apparatus TE _B, returns a call proceeding message "CALL PROC".

Upon receiving the call setup message “SETUP” (Y in process 307), the terminal device TE _B sends out a call message “ALERT” and then a response TE “CONN”. Network, while delivering the message to the terminal device TE _D, sends back an acknowledgment message "CONN" to the terminal apparatus TE _B.

Thus, Y of the terminal device TE _B and the terminal device TE _D and executes a predetermined call setup procedure (FIG. 4 process 114, FIG. 8 for 30
8) Next, predetermined emergency communication is performed between the two via the B channel (FIG. 4, process 104, FIG. 8, process 309).

When the emergency communication ends, the terminal device TE _D, as executed in the terminal apparatus TE _A in FIG. 3, performing a predetermined cutting instructions in emergency communications to the terminal apparatus TE _A (Figure 4 -
Process 105, FIG. 8 and process 310) Thereafter, the terminal device TE _B executes the interrupted normal communication restarting procedure as the terminal device TE _A executed to the terminal device TE _C in FIG. (Process 311), normal communication is resumed (Process 312).

By the way, in the process 103 in FIG. 4, when the "reason display" of the release completion message "REL COMP" is not in use of two B channels, for example, there is no designated destination number (N in step 107), the transmission operation is stopped. Also, when there is no emergency ID in [user / user information] of the release message “REL” (process 111
N), since it is considered that the other terminal does not have the emergency communication reception function of the present embodiment, the calling operation is similarly stopped.

As described above, when a call is made to a terminal having a function of performing dual processing on two B channels and communication is being performed, a call is again made using a call setup message "SETUP" in a D channel packet. On the other hand, the called side notifies the calling side of the acceptance of the emergency communication by the "user / user information" of the release completion message "REL COMP", and disconnects one of the communications. After that, the calling side calls again as usual and executes emergency communication.

In the above-described embodiment, there is a case where the terminal device sends a message for interrupting the normal communication to execute the emergency communication and the interrupt confirmation message is not returned from the network, and the terminal device cannot be interrupted. In this case, a procedure for disconnecting the normal communication may be executed to shift to the emergency communication.

Also, a password set by the operator together with the emergency ID is set in the "user / user information" of the call setup message "SETUP" so that only specific terminal devices can perform such emergency communication. Is also good.

Further, in the present embodiment, the case where the basic interface has one D channel and two B channels has been described, but it is obvious that the present invention can be similarly applied to other cases such as the primary group speed interface. .

Further, it goes without saying that the present invention is not limited to facsimile apparatuses, but can be widely applied to telephones and other various data terminal apparatuses.

[Effects of the Invention] As described above, according to the present invention, in a terminal device using one of the information channels, the called side performs a call to which identification information indicating emergency communication is added during execution of communication. When a setting message is received and an incoming call is received, the procedure for temporarily interrupting the ongoing communication is executed, and a predetermined response procedure is executed for the incoming call to perform emergency communication. Since the call resuming procedure is performed, an emergency call can be accepted and emergency communication can be performed during normal communication.

In a terminal device capable of simultaneously using a plurality of information channels, the calling side, when the called side is using all the information channels, makes a call with a call setup message requesting packet communication using a signaling channel. ,
The receiving side adds the identification information indicating the emergency communication to the message, and upon receiving the emergency communication information by the call, the called side disconnects one communication and accepts the next normal call from the calling side. As a result, the emergency communication can be performed during the normal communication in the same manner as described above.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ISDN communication system according to an embodiment of the present invention, FIG. 2 is a block diagram of a facsimile apparatus which is a terminal device of the communication system, and FIG. 3 uses one information channel. FIG. 4 is a sequence diagram of a communication procedure showing a case where a communicating terminal device performs emergency communication with another terminal device during communication, FIG. 4 is an operation flowchart showing a calling side process, and FIGS. FIG. 6 is an explanatory diagram showing information of a call control message, FIG. 6 is an operation flowchart showing a receiving side process in the above communication, and FIG. FIG. 8 is a sequence diagram of a communication procedure showing an emergency communication, and FIG. 8 is an operation flowchart showing a receiving side process in the communication. DESCRIPTION OF SYMBOLS 1 ... Scanner 2 ... Plotter 3 ... Encoding / decoding part 4 ... Image memory 5 ... ISDN interface circuit 6 ... ISDN control part 7 ... Communication control part 10 Operation display unit, 11 ...... system control unit, TE _A ~TE _D ...... terminal, NT ...... network unit.

Claims (2)

(57) [Claims] 1. An ISDN terminal communication system wherein each communicating terminal device is connected to an ISDN by a user network interface having a signal channel and a plurality of information channels, and communicates using one of the information channels. The terminal device on the receiving side receives a call setup message to which identification information indicating emergency communication is added during execution of communication using one of the information channels and receives the call. While performing the temporary suspension procedure for the call and performing the emergency communication by performing the call setting procedure in response to the incoming call, while performing the emergency communication call release procedure, the An ISDN terminal communication method characterized by executing a restart procedure to restart the interrupted communication. 2. Each terminal device for communication is connected to ISDN by a user network interface having a signal channel and a plurality of information channels, and a called party simultaneously executes a plurality of communications using all of the information channels. In the ISDN terminal communication system that has the function of performing the above, when the calling side sends out a call setup message requesting communication on the information channel and makes a call, the called side is using all of the information channels. Therefore, if the call setup message is not transmitted to the called party, the call setup message requesting packet communication using the signal channel is re-added with identification information indicating emergency communication, and the call is re-established. When the call side receives a call setup message requesting the packet communication while using all of the information channels, the caller immediately receives a call control message indicating that the call cannot be connected. While responding by adding identification information indicating that the call is acceptable, the calling party executes a suspending procedure for one ongoing communication call to release one of the information channels, while the calling party receives a call from the called party. Upon receiving the call control message and detecting the identification information indicating that the emergency communication can be accepted, a call setting message requesting communication on the information channel is sent again to make a call, thereby making a call with the calling side. ISDN characterized by executing emergency communication between terminals on the side
Terminal communication method.